Curriculum Vitaes

Hisashi Mizutani

  (水谷 尚)

Profile Information

Affiliation
Nippon Veterinary and Life Science University

J-GLOBAL ID
201601012964432815
researchmap Member ID
B000258755

Education

 2

Papers

 45
  • Rena Sato, Saku Koyama, Miya Yasukawa, Takuma Inoue, Tomochika Matsumura, Asuka Kanazawa, Yukari Nozue, Yuriko Wada, Itaru Yoshimura, Yujiro Hagita, Hisashi Mizutani, Tsuyoshi Tajima, Tadaharu Ajito, Ryotaro Miura
    Animals : an open access journal from MDPI, 12(23), Dec 2, 2022  
    The objectives of this study were to assess the sequential dynamics of the endometrial polymorphonuclear cells (PMN) after calving by endometrial cytology, and clarify the factors that cause prolonged endometrial inflammation in lactating dairy cows. A total of 33 lactating Holstein dairy cows were used from -4 to 8 wk relative to calving (0 wk: the calving week). Endometrial samples were obtained sequentially from 2 to 8 wk. Body condition score and backfat thickness were obtained weekly from -4 to 8 wk. Blood samples collected from -4 to 8 wk were analyzed for indicators of energy status, hepatic function, systemic inflammation, and calcium. Blood amino acids were measured at 2 wk. Daily milk production was determined between 5 and 65 d postpartum. Based on the sequential cytological analysis, the endometrial inflammation threshold was set at ≥5.0% PMN, and the median wk of PMN% lower than 5.0% was 4.5 wk in this study; therefore, we classified the cows into the early group (cows with endometrial inflammation converged within 4 wk: n = 17) and the late group (cows with endometrial inflammation converged at or after 5 wk: n = 16). There were no differences in daily milk production, energy status, hepatic function, blood calcium concentration, and systemic inflammatory response. The late group had lower body condition scores and backfat thickness during the experimental period, and a higher blood concentration of 3-methyl histidine, indicating muscle breakdown, was observed in the late group at 2 wk. Our findings indicated that the lack of body fat reservation during the peripartum period and the increased muscle breakdown after calving were risk factors for prolonged endometrial inflammation.
  • Azusa Gin, Takumi Sato, Atsushi Tohei, Ryotaro Miura, Hisashi Mizutani, Hiromi Amao, Yutaka Yamada, Shinji Kamiya, Itaru Yosimura, Mariko Mochizuki
    Japanese Journal of Veterinary Research, 66(2) 63-70, May, 2018  Peer-reviewed
    © 2018, Hokkaido University. All rights reserved. We investigated changes in cortisol (COR) concentration, which is well known as an index of stress in the serum of dairy cattle. The COR concentrations in serum obtained from dairy cattle were collected during practical training of first-year students on a farm attached to the Nippon Veterinary and Life Science University. Mean COR concentration in serum determined after practical training was significantly higher (P <0.001) than that in serum collected before training. Discriminant analysis was used to classify the relation between COR concentration of serum collected before and after practical training. In conclusion, the data was bipartite according to the percentage of rise (rise rate) of COR concentration. Although the percentage of the rise was more than 300% in the high-rise-rate group, there was a significant negative correlation (P < 0.05) between age and COR concertation. It was thought that the high-rise-rate group has a chance to decrease stress after more experience. In contrast, the low-rise-rate group included 3 cattle indicating high COR concentration before and after practical training. Those 3 cattle were thought to be stressed easily. It is suggested that there was individual difference to stress.
  • Hitomi Oda, Akihiro Mori, Yuji Hirowatari, Toshie Takoura, Daisuke Manita, Tomoya Takahashi, Saori Shono, Eri Onozawa, Hisashi Mizutani, Yohei Miki, Yukiko Itabashi, Toshinori Sako
    Research in Veterinary Science, 114 163-169, Oct 1, 2017  Peer-reviewed
    © 2017 Anion-exchange (AEX)–high-performance liquid chromatography (HPLC) for measurement of cholesterol can be used to separate serum lipoproteins (high-density lipoprotein (HDL); low-density lipoprotein (LDL); intermediate-density lipoprotein (IDL); very-low-density lipoprotein (VLDL)) in humans. However, AEX–HPLC has not been applied in veterinary practice. We had three objectives: (i) the validation of AEX-HPLC methods including the correlation of serum cholesterol concentration in lipoprotein fraction measured by AEX–HPLC and gel permeation–HPLC (GP–HPLC) in healthy dogs and those with hypercholesterolemia was investigated; (ii) the reference intervals of lipoprotein fractions measured by AEX–HPLC from healthy dogs (n = 40) was established; (iii) lipoprotein fractions from the serum of healthy dogs (n = 12) and dogs with hypercholesterolemia (n = 23) were compared. Analytic reproducibility and precision of AEX–HPLC were acceptable. Positive correlation between serum concentrations of total cholesterol (Total-Chol), HDL cholesterol (HDL-Chol), LDL cholesterol (LDL-Chol) + IDL cholesterol (IDL-Chol), and VLDL cholesterol (VLDL-Chol) was noted for AEX–HPLC and GP–HPLC in healthy dogs and dogs with hypercholesterolemia. Reference intervals measured by AEX–HPLC for serum concentrations of Total-Chol, HDL-Chol, and LDL-Chol were determined to be 2.97–9.32, 2.79–6.57, 0.16–3.28 mmol/L (2.5–97.5% interval), respectively. Furthermore, there was significant difference in lipoprotein profiles between healthy and dogs with hypercholesterolemia. These results suggest that AEX–HPLC can be used to evaluate lipoprotein profiles in dogs and could be a new useful indicator of hyperlipidemia in dogs.
  • Hisashi Mizutani, Toshinori Sako, Hiroko Okuda, Nobuaki Arai, Koji Kuriyama, Akihiro Mori, Itaru Yoshimura, Hidekazu Koyama
    Journal of Veterinary Medical Science, 78(8) 1277-1281, Aug, 2016  Peer-reviewed
    © 2016 The Japanese Society of Veterinary Science. Density gradient ultracentrifugation (DGUC) and gel electrophoresis are conventionally used to obtain lipoprotein profiles of animals. We recently applied high-performance liquid chromatography with a gel permeation column (GP-HPLC) and an on-line dual enzymatic system to dogs for lipoprotein profile analysis. We compared the GP-HPLC with DGUC as a method to obtain a feline lipoprotein profile. The lipoprotein profiles showed large and small peaks, which corresponded to high-density lipoprotein (HDL) and low-density lipoprotein (LDL), respectively, whereas very low-density lipoprotein (VLDL) and chylomicron (CM) were only marginally detected. This profile was very similar to that of dogs reported previously. Healthy cats also had a small amount of cholesterol-rich particles distinct from the normal LDL or HDL profile. There was no difference in lipoprotein profiles between the sexes, but males had a significantly larger LDL particle size (P=0.015). This study shows the feasibility of GP-HPLC for obtaining accurate lipoprotein profiles with small sample volumes and provides valuable reference data for healthy cats that should facilitate diagnoses.
  • Takahiro Teshima, Takashi Hata, Yoko Nezu, Masaki Michishita, Hirotaka Matsumoto, Hisashi Mizutani, Kimimasa Takahashi, Hidekazu Koyama
    Journal of Feline Medicine and Surgery, 14(2) 147-150, Feb, 2012  Peer-reviewed
    A 9-year-old spayed female domestic shorthair cat presented with a skin lesion of the left tarsus. The lesion was biopsied and, based on the microscopic appearance and immunohistochemical characteristics, histiocytic sarcoma was diagnosed. Amputation was performed with improved demeanor seen postoperatively. However, between 44 and 60 days following the surgery, relapse of skin lesions appeared in multiple locations, including at the previous amputation site, and euthanasia was elected. This is the first report of a histiocytic sarcoma treated with amputation in a cat. © 2011, International Society of Feline Medicine and American Association of Feline Practitioners. All rights reserved.
  • Hiroko Fukuta, Akihiro Mori, Nazarbek Urumuhan, Peter Lee, Hitomi Oda, Kaori Saeki, Miyuki Kurishima, Satoshi Nozawa, Hisashi Mizutani, Suguru Mishina, Toshiro Arai, Toshinori Sako
    Journal of Veterinary Medical Science, 74(11) 1527-1530, 2012  
    Euglycemic-hyperinsulinemic glucose clamp (EHGC) method is a gold standard for assessing insulin resistance in humans. However, this method has yet to be commonly used with dogs, due to the requirement of frequent blood sampling for glucose measurement and adjusting glucose infusion rate (GIR). The purpose of this study was to evaluate insulin resistance, induced either by Cushing Syndrome (CS) or diestrus in dogs, as determined by GIR by EHGC, using an artificial pancreas apparatus. Twenty animals were used in this study with ten (7 females and 3 males) serving as healthy controls, four (3 females, 1 male) diagnosed with CS, and six (all females) undergoing diestrus. A higher GIR value indicates increased insulin sensitivity and lower insulin resistance. GIR of healthy control animals was determined to be within a reference range of [10.6-21.3] with a median of 15.2 mg/kg/min. In comparison, the CS group had a median of 5.4 mg/kg/min; whereas the diestrus group exhibited a median of 8.9 mg/kg/min. Insulin resistant animals suffering from CS and undergoing diestrus demonstrated reductions of 65 and 40% in GIR, respectively; thus indicating differences in degree of insulin insensitivity can be discerned using the EHGC method. © 2012 The Japanese Society of Veterinary Science.
  • T. Sako, A. Mori, P. Lee, H. Oda, K. Saeki, Y. Miki, M. Kurishima, K. Mimura, S. Nozawa, H. Mizutani, Y. Makino, K. Ishioka, T. Arai
    Research in Veterinary Science, 90(3) 396-403, Jun, 2011  Peer-reviewed
    Insulin detemir is the first member of a new class of long-acting soluble insulin analogues capable of maintaining the basal level of insulin in humans. In this preliminary study, we investigated the time-action profiles of insulin detemir in normal and diabetic dogs since the use of insulin detemir in canines has yet to be determined. Eight animals were used in our study (three normal and five insulin dependent diabetic dogs). Time-action profiles of insulin detemir were monitored in normal dogs using an artificial pancreas apparatus under euglycemic condition. Blood sampling was performed at 2. h intervals post feeding, with insulin administration, in insulin dependent diabetic dogs. Time-action profiles of insulin detemir, in normal dogs, demonstrated that insulin detemir is a long-lasting preparation similar to what has been observed in humans. A pronounced peak was detected at 8-10. h while the glucose-lowering effect lasted for over 24. h after insulin injection, thus illustrating its longer prolonged peak activity time. Furthermore, intensive glycemic control was achieved with insulin detemir in insulin dependent diabetic dogs, using a lower dosage than NPH insulin and insulin glargine therapeutic doses. Our results indicate that insulin detemir has a greater effect than either NPH insulin or insulin glargine in canines, requiring a lower dose than either insulin preparation. However, using insulin detemir also carries a higher risk of inducing hypoglycemia as compared to either NPH insulin or insulin glargine. © 2010 Elsevier Ltd.
  • 水谷尚, 左向敏紀, 栗山恒二, 大友理宣, 唐澤志乃, 吉村格, 廣瀬昶
    日本伝統獣医学会誌, 18(2) 2-7, Jan 25, 2011  
  • Hisashi Mizutani, Toshinori Sako, Noriaki Arai, Koji Kuriyama, Itaru Yoshimura, Akihiro Mori, Kenji Iwase, Hisashi Hirose
    Journal of Veterinary Medical Science, 72(6) 813-817, Jun, 2010  Peer-reviewed
    A high performance liquid chromatography system with a gel permeation column (GP-HPLC) and an on-line dual enzymatic system was applied to lipoprotein analysis in dogs. A high density lipoprotein (HDL) fraction obtained by conventional ultracentrifugation gave a single peak at around 28-29 min. Similarly, a low density lipoprotein (LDL) fraction gave single peak at around 24-25 min. The lipoprotein profiles of healthy dogs were contained large HDL peaks and small LDL peaks, and VLDL and CM were only marginally detected. In diabetic dogs, concentrations of VLDL-triglyceride and VLDL-total-cholesterol were elevated significantly. The lipoprotein profile analysis by GP-HPLC method would be useful in explication of abnormality of lipid metabolism in dogs.
  • Toshinori Sako, Akihiro Mori, Peter Lee, Hiroshi Goto, Hiroko Fukuta, Hitomi Oda, Kaori Saeki, Yohei Miki, Yuki Makino, Katsumi Ishioka, Hisashi Mizutani, Yuzo Kojima, Satoshi Koikeda, Toshiro Arai
    Veterinary Research Communications, 34(2) 161-172, Feb, 2010  Peer-reviewed
    Indigestible oligosaccharides have been shown to normalize blood glucose and insulin concentration thereby promoting good health and preventing diseases, such as diabetes. Transglucosidase (TG, a-glucosidase, enzyme code (EC) 3.2.1.20) is an enzyme capable of converting starch to oligosaccharides, such as iso-malto-oligosaccharides from maltose, via the action of amylase. The aim of this study was to evaluate whether oral administration of TG with maltose or dextrin is capable of reducing post-prandial serum glucose concentration in experimentally streptozotocin (STZ)-induced diabetic dogs fed on a high-fiber diet. Five healthy and five STZ-induced diabetic dogs were employed in this study. TG supplementation with dextrin or maltose had no detrimental effect in healthy dogs. In fact, TG and dextrin exhibited a flatlined serum glucose pattern, while reducing mean post-prandial serum insulin and glucose concentration as compared to control diet alone. When TG supplementation was tested in STZ-induced diabetic dogs under the context of a high fiber diet, a 13.8% and 23.9% reduction in mean glucose concentration for TG with maltose and dextrin, respectively was observed. Moreover, TG with dextrin resulted in a 13% lower mean post-prandial glucose concentration than TG with maltose, suggesting that dextrin may be a more efficient substrate than maltose when used at the same concentration (1 g/kg). Our results indicate that TG supplementation with diet can lead to lower postprandial glucose levels versus diet alone. However, the efficacy of TG supplementation may depend on the type of diet it is supplemented with. As such, TG administration may be useful for preventing the progression of diabetes mellitus and in its management in dogs. © 2010 Springer Science+Business Media B.V.
  • Mizutani Hisashi
    Journal of Pet Animal Nutrition, 13(1) 12-20, 2010  
  • Akihiro Mori, Peter Lee, Toshinori Sako, Hisashi Mizutani, Toshiro Arai
    Journal of Veterinary Medical Science, 71(8) 1017-1026, Aug, 2009  Peer-reviewed
    The purpose of this study was to investigate whether intensive insulin treatment of dogs suffering from type 1 diabetes mellitus, resulting in tight glycemic control, could be reflected by changes in peripheral leukocyte metabolism. Specifically, plasma metabolites and enzyme activities were assessed. In addition, quantitative RT-PCR was used to determine changes in insulin signaling gene (insulin receptor substrate (IRS)-1, IRS-2 and phosphatidylinositol 3-kinase (PI3-K) P85α) mRNA levels in peripheral leukocytes. Lastly, leukocyte enzymes involved in cellular energy metabolism were examined for changes in glucose utilization. Our results indicated that intensive insulin treatment was successful in type 1 DM dogs, leading to tight glycemic control. The mean glucose concentration and glycated albumin percentage significantly decreased to 156 mg/dl and 15.6%, respectively, following treatment. In peripheral leukocytes, the IRS-2 and PI3-K p85α mRNA levels significantly increased, and a significant increase in pyruvate kinase and pyruvate carboxylase activity, two enzymes involved in cellular energy metabolism, was also observed post treatment. Therefore, the observed changes in insulin signaling pathway activity and cellular energy metabolism enzyme activity in peripheral leukocytes are considered to be characteristics of amelioration of glucose metabolism by insulin action. As such, peripheral leukocytes are sufficiently sensitive to monitor for improving glycemic control during intensive insulin treatment of type 1 DM dogs. Blood cells such as leukocytes are much more readily available than muscle or adipose tissue for studies in dogs.
  • A. Mori, P. Lee, T. Yamashita, Y. Nishimaki, H. Oda, K. Saeki, Y. Miki, H. Mizutani, K. Ishioka, T. Honjo, T. Arai, T. Sako
    Veterinary Research Communications, 33(8) 957-970, Jan, 2009  Peer-reviewed
    Glimepiride and nateglinide are two common oral hypoglycemic agents currently being used with humans suffering from Type 2 diabetes mellitus. Neither drug has been tested with cats thus far and it is currently unknown whether either of these drugs exert any effect in cats or not. The objective of this study was to determine the effect of glimepiride and nateglinide on glucose and insulin responses in healthy control cats, in order to determine their potential use in diabetic cats. The intravenous glucose tolerance tests was carried out since it is an excellent test for evaluating pancreatic β-cell function for insulin secretion. Alterations in the insulin secretion pattern can be perceived as the earliest sign of β-cell dysfunction in many species, including cats. Nateglinide demonstrated a quick action/short duration type effect with serum glucose nadiring and insulin response peaking at 60 and 20 minutes, respectively. Alternatively, glimepiride is medium-to-long acting with serum glucose nadiring and insulin response peaking at 180 minutes and 60 minutes, respectively. Nateglinide's potency was evident allowing it to induce a 1.5-2 higher preliminary insulin peak (3.7±1.1 pg/ml) than glimepiride's (2.5±0.1 pg/ml), albeit only for a short period of time. Because glimepiride and nateglinide have a shared mode of action, no significant differences in overall glucose AUC 0-360min (24,435±2,940 versus 24,782±2,354 mg min/dl) and insulin AUC 0-360min (410±192 versus 460±159) in healthy control cats were observed. These findings may provide useful information when choosing a hypoglycemic drug suited for the treatment of diabetic cats depending on the degree of diabetes mellitus the cat is suffering from. © 2009 Springer Science+Business Media B.V.
  • A. Mori, T. Sato, P. Lee, M. Furuuchi, H. Tazaki, K. Katayama, H. Mizutani, T. Sako, T. Arai
    Veterinary Research Communications, 33(5) 439-451, 2009  Peer-reviewed
    Circulating levels of monosaccharides can act as a reflection of systemic glucose/energy metabolism. Characteristic changes observed in these levels can be seen in patients with diabetes and other metabolic disorders. There have been a few reports describing the significance of mannose metabolism as an energy source under physiological and pathological conditions. However, the relationship between circulating levels of mannose and the pathophysiology of diabetes mellitus are unknown in dogs. This study examined circulating levels of mannose between healthy control and diabetic dogs and evaluated the clinical significance of mannose levels in dogs. Diabetic dogs demonstrated a higher circulating level of mannose in comparison to normal healthy control dogs. Plasma mannose was positively correlated with plasma glucose and fructosamine, respectively. Interestingly, plasma mannose levels were affected by plasma insulin levels. In the context of feeding and glucose tolerance tests, plasma mannose levels responded to changes in circulating insulin levels. Circulating plasma mannose levels decreased after feeding in both control and diabetic animals in spite of observed insulin level differences. However, when glucose tolerance tests were given, a positive correlation between mannose levels and insulin levels was observed. Therefore, plasma mannose levels obtained via glucose tolerance testing may be used as a new diagnostic method for evaluating insulin resistance or deficiency in diabetic dogs. © Springer Science+Business Media B.V. 2008.
  • T. Sako, A. Mori, P. Lee, T. Sato, H. Mizutani, T. Takahashi, Y. Kiyosawa, H. Tazaki, T. Arai
    Veterinary Research Communications, 33(5) 473-479, 2009  Peer-reviewed
    Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) complement serum glucose concentration for better management of diabetes mellitus (DM). Especially, the serum fructosamine test has long been used for diagnosing and monitoring the effect of treatment of DM in dogs. However, fructosamine tests are currently not performed in veterinary medicine in Japan. GA and fructoasmine levels have been shown to strongly correlate. However, the clinical implications of using GA remain to be elucidated. Therefore, the purpose of the current study was threefold: 1) Determine whether GA% is altered by acute hyperglycemia in normal dogs, simulating stress induced hyperglycemia; 2) Demonstrate that GA% does not dynamically change with diurnal variation of blood glucose concentration in diabetic dogs; and 3) Investigate whether GA% is capable of providing an index of glycemic control for 1-3 weeks in diabetic dogs as is the case with diabetic human patients. Our study demonstrated that serum GA% remains very stable and unaltered under acute hyperglycemic conditions (intravenous glucose injection) and in spite of diurnal variation of blood glucose concentration. Furthermore, serum GA% can reflect long-term changes (almost 1-3 weeks) in blood glucose concentration and the effect of injected insulin in diabetic dogs. © Springer Science+Business Media B.V. 2008.
  • Akihiro Mori, Peter Lee, Hisashi Mizutani, Tomoya Takahashi, Daigo Azakami, Mina Mizukoshi, Hiroko Fukuta, Noriko Sakusabe, Arihito Sakusabe, Yoshio Kiyosawa, Toshiro Arai, Toshinori Sako
    Journal of Veterinary Diagnostic Investigation, 21(1) 112-116, Jan 1, 2009  Peer-reviewed
    Measurements of glycated proteins such as serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. For example, the degree of glycemic control in diabetic cats can be determined by evaluating fructosamine concentration. Unfortunately, fructosamine tests are currently not performed in Japan, and as such, the measurement of GA may serve as a replacement test. The objectives of the current study were 2-fold. First, serum GA and fructosamine level were evaluated for positive correlation in cats as a preliminary gauge on whether serum GA use is applicable. Second, a GA percentage reference range was determined from healthy control cats for possible future diagnostic use. A positive correlation was determined for fructosamine and GA in both normal and diabetic cats. Moreover, the serum GA percentage reference interval based on control cats was determined to be 7.5-13.9% (95% nonparametric interfractile interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic cats with excellent glycemic control and control cats. However, good, fair, and poor glycemic control diabetic cats resulted in a significant increase in serum GA percentages in comparison to control cats. Therefore, these results indicate that serum GA may be a useful glycemic control indicator that could substitute for fructosamine to monitor glycemic control in diabetic cats.
  • A. Mori, T. Sako, P. Lee, Y. Nishimaki, H. Fukuta, H. Mizutani, T. Honjo, T. Arai
    Veterinary Research Communications, 33(7) 669-680, 2009  Peer-reviewed
    Dietary therapy is an important treatment component for diabetes mellitus (DM). In this study, the impact of three different commercially available diet regiments (1 general use and 2 aimed for treating obesity and DM) on short-term post-prandial serum glucose and insulin concentrations of five healthy cats to better understand what impact each of these diets may have for diabetic cats. The diet regiments used in this study were as follows: C/D dry (General Use- Low protein, High fat, High carbohydrate, and Low fiber), M/D dry (DM- High protein, High fat, Low carbohydrate, and High Fiber), and W/D dry (DM- Low Protein, Low Fat, High Carbohydrate, and High Fiber). No significant difference in post-prandial serum glucose levels were observed with the C/D (84.6±1.5 mg/dl) and W/D (83.8±1.4 mg/dl) dry diets when compared to pre-prandial fasting levels (83.9±1.4 mg/dl). However, a significant reduction was observed with the M/D diet (78.9±0.8 mg/dl) which had 50-60% less carbohydrates than either C/D or W/D diet. Unlike what was observed with post-prandial glucose levels, an interesting pattern emerged with post-prandial insulin levels, which were increasing with W/D, C/D, and M/D diets in that order (1.1±0.2, 1.7±0.2, and 2.3±0.2 ng/ml respectively). Most surprising, though, was the fact that the W/D diet did not seem to stimulate insulin secretion as compared to pre-prandial levels (1.1±0.1 ng/ml) in healthy cats. Interestingly, the W/D diet had high levels of carbohydrate and low levels of protein. Coincidentally, the only diet (M/D) which had a significant reduction in post-prandial glucose also showed the highest increase in post-prandial insulin in healthy cats. Therefore, dietary amounts of carbohydrate, fat, protein and fiber can all have an individual impact on post-prandial glycemia and subsequent insulin requirement levels. Just as concepts regarding dietary management of people with DM are evolving, investigators are reassessing what constitutes the ideal diet for the diabetic feline. As such, having a better understanding for each dietary component, may lead us to better understand how we can synergize certain dietary components to aid in DM management. © Springer Science+Business Media B.V. 2009.
  • A. Mori, P. Lee, T. Izawa, H. Oda, H. Mizutani, H. Koyama, T. Arai, T. Sako
    Veterinary Research Communications, 33(7) 757-769, 2009  Peer-reviewed
    In order to evaluate the immune state of dogs suffering from pituitary-dependent hyperadrenocorticism (PDH), peripheral lymphocyte subsets were examined. Twenty seven PDH dogs and eight healthy control dogs were used in the current study. Eight healthy dogs served as the control group. Twenty seven PDH dogs were categorized into 4 groups based on their post serum cortisol concentrations by ACTH stimulation test: 2-5, excellent control (n = 8); 5-20, fair control (n = 7); >20, poor control (n = 4); and untreated (n = 8). Cell counts were executed with white blood cells (WBC), lymphocytes, CD3+ (T lymphocytes), CD4+ (Helper T lymphocytes), CD8+ (Cytotoxic T lymphocytes), CD21+ (B lymphocytes) cells in addition to calculating CD4+/CD8+ ratio. Results indicated a significant difference in lymphocyte numbers and lymphocyte subset populations (CD3+, CD4+, CD8+, and CD21+ cells) between PDH and control dogs. Moreover, comparison of the PDH groups (excellent control; fair control; poor control; untreated) demonstrated that all groups had a significant decrease in lymphocytes numbers (CD3+, CD4+ and CD21+ cell counts) as compared to control group. Meanwhile, no significant differences were observed in WBC counts and CD4+/CD8+ ratio between groups. Furthermore, lymphocyte subset distribution in excellent control PDH dogs without concurrent disease (n = 4) better resembled that of control dogs as compared to PDH dogs with concurrent disease (n = 4). PDH dogs may be suffering from an immuno-depressed state as evidenced by significant differences in lymphocyte subset populations. Furthermore, treatment of both PDH and concurrent disease might improve lymphocyte subset distribution. © Springer Science+Business Media B.V. 2009.
  • Masahiro OSADA, MIZUTANI Hisashi, KURAUCHI Munekazu
    東京農業大学農学集報, 53(3) 189-193, Dec, 2008  
    Three dairy farms at Nishifuji Area in Shizuoka Prefecture raise their cows in barns, but allow them to graze about 5 times in a small pasture area of 10-20 ares per head. The results of dairy herd performance test in this area indicated the following : Those farms were able to lengthen the number of years of milk production of their cows compared with those on farms that raised their animals indoors. But a decrease in reproductive performance was observed, i.e., JMR (jours moyen retard), the services per conception and so on. We carried out metabolic profile tests (MPTs) of cows during two periods (when raised indoors and when allowed to graze outside) at the farm which recorded the worst reproductive performance out of the three surveyed. The results revealed that when grazing, values disassociated from the norm : energy metabolism, protein metabolism and liver function. The cause was thought to be due to insufficient dry matter intakes and total calorie intake in open grazing management, as well as variation in feed uptake during the cows' dry period. It was suggested that this results in delays in conception and a negative influence on reproductive performance in cows on these farms.
  • Yoji Toyoda, Toshinori Sako, Hisashi Mizutani, Mieko Sugiyama, Noriyuki Hayakawa, Hiroya Hasegawa, Hisashi Hirose
    Journal of Veterinary Medical Science, 70(10) 1091-1093, Oct, 2008  Peer-reviewed
    When a solution of xylitol was rapidly administered intravenously (bolus infusion) to healthy cattle or those with ketosis, different results were obtained. In healthy cattle, a temporary surge in insulin secretion was observed, whereas in ketotic cattle no such surge was found, but instead a moderate level of secretion continued for a lengthy period. No significant difference in the areas under the insulin curve (AUC) was found between healthy cattle and ketotic cattle up to 120 min after xylitol infusion. These results clearly demonstrated that a bolus infusion of xylitol solution in ketotic cattle does not cause a temporary surge in insulin secretion unlike in healthy animals, but rather results in a continuous, gradual rise in secretion.
  • A. Mori, T. Sako, P. Lee, T. Motoike, K. Iwase, Y. Kanaya, H. Fukuta, H. Mizutani, T. Arai
    Veterinary Research Communications, 32(7) 563-573, Sep, 2008  Peer-reviewed
    Intermediate insulin injections are commonly used for glycemic control in insulin dependent diabetic dogs acting as a replacement for natural insulin. Neutral Protamin Hagedorn (NPH) insulin and insulin glargine are two types of injectable insulin preparations commonly used in humans. In our study, we investigated the time-action profiles of both aforementioned insulin preparations in normal dogs in order to determine whether co-administration of NPH and glargine would be of benefit to insulin dependent diabetic dogs as it is for humans suffering from insulin dependent diabetes. Time-action profiles of NPH insulin and insulin glargine in normal dogs demonstrated a clear difference between both insulin preparations confirming that NPH insulin is an intermediate-acting preparation whereas insulin glargine is a long-lasting preparation. In addition, co-administration of NPH insulin and insulin glargine resulted in tight glycemic control as compared to NPH insulin alone in insulin dependent diabetic dogs. However, co-administration result in hypoglycemia at the dosages tested. © Springer Science+Business Media B.V. 2008.
  • Toshinori Sako, Akihiro Mori, Peter Lee, Tomoya Takahashi, Takehito Izawa, Sino Karasawa, Miho Furuuchi, Daigo Azakami, Mina Mizukoshi, Hisashi Mizutani, Yoshio Kiyosawa, Toshiro Arai
    Journal of Veterinary Diagnostic Investigation, 20(5) 634-638, Sep 1, 2008  Peer-reviewed
    Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) are increasingly used to complement serum glucose concentration for better management of diabetes mellitus. Fructosamine tests are currently not performed in veterinary medicine in Japan. As such, the measurement of GA may serve as a replacement test. Therefore, in the current study, serum GA and fructosamine were evaluated for a positive correlation in dogs, and, depending on the correlation, a reference range of GA percentage would also be determined from healthy control dogs. The degree of glycemic control in diabetic dogs was determined by fructosamine concentration. A positive correlation between GA and fructosamine was observed with both normal and diabetic animals. In addition, the reference interval of serum GA percentage in control dogs was determined to be 11.4-11.9% (95% confidence interval). Interestingly, no significant difference in serum GA percentages was observed between samples from diabetic dogs with excellent glycemic control and control dogs. However, good, fair, and poor glycemic control diabetic dogs resulted in a significant increase in serum GA percentages in comparison with control dogs. These results suggest that serum GA may be a useful diagnostic indicator, substituting for fructosamine, to monitor glycemic control in diabetic dogs.
  • Akihiro Mori, Fumi Sagara, Sumire Shimizu, Hisashi Mizutani, Toshinori Sako, Hisashi Hirose, Itaru Yoshimura, Yosuke Uematsu, Tomohiro Yamaguchi, Toshiro Arai
    Journal of Veterinary Medical Science, 70(2) 185-187, Feb, 2008  Peer-reviewed
    Plasma metabolites and peripheral lymphocyte subsets were measured in ten diabetic and ten control dogs to investigate their significances as indicators to evaluate immune states in the diabetic dogs. Diabetic dogs were treated with insulin injections, however their plasma glucose and fructosamine concentrations were significantly higher than those of the controls. There were no significant differences in counts of total white blood cells (WBC) and lymphocyte CD8 + cells (cytotoxic T cells) between the control and the diabetic dogs. In the diabetic dogs, the counts of CD3+ (T cells), CD4 + (Helper T cells) and CD21+ (B cells) cells and the peripheral lymphocytes CD4/CD8 ratio were significantly lower than those in the control dogs. We confirmed abnormality of lymphocyte subsets in insulin treated diabetic dogs and it may relate to depression of immunocompetence and high susceptibility to common infectious diseases.
  • 水谷尚
    動物臨床医学会年次大会プロシーディング, 28th(3) 222-224, Nov 16, 2007  
  • 森昭博, 清水須美礼, 吉村格, 新井敏郎, 水谷尚, 左向敏紀, 山口智宏
    獣医東洋医学会誌, 15(1) 39, Jun 1, 2007  
  • N. Kimura, E. Fujino, S. Urabe, H. Mizutani, T. Sako, S. Imai, Y. Toyoda, T. Arai
    Research in Veterinary Science, 82(1) 7-10, Feb, 2007  Peer-reviewed
    To investigate the effect of Agaricus mushroom meal on the energy metabolism in animal tissues; plasma glucose, triglyceride, cholesterol and immunoreactive insulin (IRI) concentrations and activities of enzymes related to energy metabolism in plasma and peripheral leukocytes were measured in Japanese Black Wagyu × Holstein F1 calves supplemented with Agaricus blazei Murill (A. blazei) extract in milk-replacer at the dose of 60 g/head/day for 4 weeks. Activities of malate dehydrogenase and aspartate aminotransferase in cytosol and glutamate dehydrogenase in mitochondria, and the malate dehydrogenase/lactate dehydrogenase ratio in cytosol in peripheral leukocytes of calves with A. blazei were significantly higher than those in control calves without A. blazei. It was concluded that supplementation of Agaricus mushroom meal extract was effective in activation of enzymes related to energy metabolism in peripheral leukocytes of calves. © 2006 Elsevier Ltd. All rights reserved.
  • SAKO Toshinori, MABUCHI Tuyoshi, MORI Akihiro, MOTOIKE Toshihito, MIZUTANI Hisashi, HIROSE Hisashi
    Journal of Animal Clinical Medicine, 16(3) 77-81, 2007  
    Compact blood glucose monitors are widely used by diabetics to self-monitor their blood glucose levels. The authors assessed the performance of one of these devices, the Medisafe Mini, for use on dogs and cats. Simultaneous reproducibility, using venous blood, yielded good results, with CV values for dogs in the normal and high blood sugar ranges of 4.2% and 7.9%, respectively; and for cats in the normal and high blood sugar ranges of 2.8% and 5.3%, respectively. The relationship between canine and feline venous blood glucose values derived from the Medisafe Mini and those derived using liquid reagents showed a significant level of correlation, with the correlation coefficient of r = 0.990 (p < 0.0001) and r = 0.993 (P < 0.0001) respectively. The blood glucose levels of two different sources of canine blood-venous blood and blood taken from ear pricks-also showed a significant degree of correlation, with a correlation coefficient of r = 0.983 (p < 0.0001). Cat blood glucose readings from the Medisafe Mini were compared with values derived using liquid reagents and a correlation was determined. Glucose level measurements of both venous and blood taken from ear pricks were also found to be correlated, although the readings derived using liquid chemical reagents were higher, in the case of cats. Errors were reduced by careful adherence to the proper measurement procedures. The Medisafe Mini blood glucose monitor was considered sufficiently accurate for measuring glucose levels in blood taken from ear pricks of diabetic cats and dogs.
  • Hisashi Mizutani, Hidekazu Koyama, Toshifumi Watanabe, Hitoshi Kitagawa, Masakazu Nakano, Keita Kajiwara, Jonathan N. King
    JOURNAL OF VETERINARY INTERNAL MEDICINE, 20(5) 1074-1079, Sep, 2006  Peer-reviewed
    Background: Chronic renal insufficiency (CRI) is a common disease in cats. Angiotensin-converting enzyme inhibitors (ACEI) have beneficial effects in humans with CRI by reducing the loss of protein in the urine and increasing life expectancy. Hypothesis: The ACEI benazepril has beneficial effects on survival, clinical variables, or both as compared with placebo in cats with CRI. Animals: 61 cats with naturally occurring CRI. Methods: The cats were enrolled into a prospective, randomized, double-blind, placebo-controlled clinical trial. Cats received placebo or 0.5-1 mg/kg benazepril once daily for up to 6 months. Results: Urine protein/urine creatinine ratios were significantly (P &lt;.05) lower with benazepril as compared with placebo at days 120 and 180. Three cats with placebo and 1 cat with benazepril were removed prematurely from the study because of deterioration of CRI or death. Cats were classified into 4 stages of CRI according to the International Renal Interest Society (IRIS) classification scheme. Incidence rates of cats with IRIS classification stage 2 or stage 3 that remained in stage 2 or 3 without progressing to stage 4 were higher with benazepril (93 +/- 5%) as compared with placebo (73 +/- 13%). Clinical Importance: These results suggest a potential for benazepril to delay the progression of disease, extend survival time, or both in cats with CRI.
  • A Tanaka, S Urabe, A Takeguchi, H Mizutani, T Sako, S Imai, Yoshimura, I, N Kimura, T Arai
    VETERINARY RESEARCH COMMUNICATIONS, 30(1) 29-38, Jan, 2006  
    Activities of enzymes related to energy metabolism and isoenzyme patterns of lactate dehydrogenase (LDH) were determined in peripheral leukocytes and livers of Holstein dairy cows and Institute of Cancer Research (ICR) mice. In dairy cow liver, activities of enzymes in glycolysis, malate-aspartate shuttle and lipogenesis were lower, but activities of glucose-6-phosphatase in gluconeogenesis were higher than those in mouse liver. Glucokinase activities were below detection limit in leukocytes and liver of the cows. Dairy cow leukocytes and liver showed the isoenzyme patterns with dominance of LDH-1, -2 and-3, whereas mouse leukocytes and liver showedthat LDH-5 was dominant. The LDH isoenzyme patterns were very similar between leukocytes and liver in each animal species. Some enzymes in leukocytes may reflect those enzymes activities in liver and be a useful indicator for energy metabolism in animals.
  • E Magori, M Nakamura, A Inoue, A Tanaka, N Sasaki, H Fukuda, H Mizutani, T Sako, N Kimura, T Arai
    RESEARCH IN VETERINARY SCIENCE, 78(1) 39-44, Feb, 2005  
    The activities of the enzymes in the malate-aspartate shuttle were measured in peripheral leucocytes of spontaneous type 1 diabetic dogs and cats treated with insulin injections. In the diabetic does and cats, fasting plasma glucose concentrations were three or fourfold greater than the control levels in spite of insulin injections and the activities of cytosolic malate dehydrogenase (MDH), one of pivotal enzymes in the malate-aspartate shuttle, were remarkably lower than the controls. Depressed expression of cytosolic MDH mRNA was confirmed by RT-PCR analysis in the diabetic animals. The cytosolic ratio of MDH/lactate dehydrogenase (LDH) activity (M/L ratio) in leucocytes of the diabetic animals was significantly lower than that of normal control animals. The smaller M/L ratio appeared to reflect depression of energy metabolism in the diabetic animals. Intrinsically lower and further decreased MDH activities may be factors that induce insulin resistance observed in diabetic cats. (C) 2004 Elsevier Ltd. All rights reserved.
  • 左向敏紀, 太田亮, 石丸邦仁, 植松一良, 山内一男, 水谷尚
    小動物臨床, 23(5) 301-304, Sep 1, 2004  
  • H Mizutani, T Sako, Y Toyoda, H Fukuda, N Urumuhang, H Koyama, H Hirose
    VETERINARY RESEARCH COMMUNICATIONS, 27(8) 633-641, Dec, 2003  
    Xylitol is a five-carbon sugar alcohol that is often used for treatment of ketosis in dairy cattle in Japan. An intravenous xylitol tolerance test (IVXTT, 0.1 g/kg, bolus injection through the jugular vein) was performed in 4 non-lactating cows (n = 4) and the results were compared with those of an intravenous glucose tolerance test (IVGTT) performed under equivalent conditions. The serum xylitol concentration reached a peak value (41.4 +/- 9.0 mg/dl) at 5 min, and then rapidly decreased and almost disappeared within 2 h. The C-0 for xylitol was 56.9 +/- 16.6 mg/dl and the t(1/2) was 8.5 +/- 0.9 min. The administration of xylitol appeared to cause similar secretion of insulin to that caused by glucose. There was also a reduction in the concentration of free fatty acids. It seems that xylitol has value for the treatment of ketosis. However, rapid administration of xylitol appeared to have an osmotic diuretic action and might be a cause of dehydration.
  • SAKO Toshinori, FUKUTA Hiroko, MIZUTANI Hisashi, KOYAMA Hidekazu, HIROSE Hisashi
    Journal of the Japan Veterinary Medical Association, 56(11) 733-735, Nov 20, 2003  
    Four dogs with spontaneous hyperadrenocorticism were treated with incremental administrations of o, p'-DDD. The initial dosage was 5mg/kg. Subsequent doses were administered at intervals of 3 to 5 days with a stepwise increase of 5mg/kg. After the dosage level reached 25 mg/kg, doses were raised at 2 to 3mg/kg increments. When such clinical signs as polyposia and polyuria had improved, the adrenocorticotropic hormone (ACTH) stimulation test confirmed the effectiveness of the therapy. The goal of treatment with o, p'-DDD was to achieve an ACTH stimulation result suggesting a normal range of responses. Possibly gradual o, p'-DDD dosage increases made it possible to achieve optimum individual dosages that resulted in high efficacy.
  • Toshiro Arai, Akira Inoue, Akira Takeguchi, Hisashi Mizutani, Megumi Shimoo, Toshinori Sako, Itaru Yoshimura, Nobuhiro Kimura
    The Journal of veterinary medical science, 65(11) 1241-3, Nov, 2003  Peer-reviewed
    Concentrations of plasma glucose, immunoreactive insulin (IRI) and free fatty acid (FFA) and activities of enzymes related to energy metabolism and lactate dehydrogenase (LDH) isoenzyme pattern in plasma and leukocytes were investigated in lactating Holstein cows (dairy cattle) and fattening Japanese Black Wagyu x Holstein steers (beef cattle). IRI concentrations and LDH and malate dehydrogenase (MDH) activities in the plasma of beef cattle were significantly higher than those in dairy cattle. The cytosolic ratio of MDH/LDH activity in the leukocytes of beef cattle was significantly higher than that of dairy cattle. These findings might be associated with the different energy metabolism between dairy and beef cattle.
  • 水谷尚, 左向敏紀, 金井洋子, 福田博子, 広瀬ひさし
    獣医東洋医学会誌, (9) 1-4, Mar 31, 2003  
  • T Arai, M Nakamura, E Magori, H Fukuda, H Mizutani, E Kawakami, T Sako
    RESEARCH IN VETERINARY SCIENCE, 73(2) 183-186, Oct, 2002  
    Changes in plasma glucose, immunoreactive insulin (IRI), and free fatty acids (FFA) concentrations and activities of enzymes related to energy metabolism in peripheral leukocytes were measured in type 1 diabetic dogs induced by streptozotocin administration before and after intensive insulin treatments. Before the insulin treatment, the plasma glucose concentrations were over 16.7 mmol/L and the activities of enzymes remarkably decreased in leukocytes of the diabetic dogs. In particular, malate dehydrogenase (MDH) activities decreased significantly. After glycemic control was achieved by insulin treatment, the plasma glucose concentrations were maintained between 6.8 and 7.7 mmol/L and the activities of enzymes restored to those in the control dogs. The changes in ML ratio (cytosolic MDH/lactate dehydrogenase specific activity ratio) reflected faithfully to metabolic conditions of animals and were considered to be a useful parameter to evaluate glycemic control and the effect of injected insulin in the diabetic dogs. (C) 2002 Elsevier Science Ltd. All rights reserved.
  • 左向敏紀, 水谷尚, 流石真美子, 長谷川承, 新井敏郎, 広瀬ひさし
    獣医東洋医学会誌, 8(8) 1-4, Aug 7, 2002  
  • H. Kishimoto, A. Taniguchi, M. Fukushima, M. Sakai, K. Tokuyama, T. Oguma, K. Nih, I. Nagata, R. Hayashi, M. Kawano, K. Hayashi, Y. Tsukamoto, T. Okumura, S. Nagasaka, H. Mizutani, Y. Nakai
    Hormone and Metabolic Research, 34(1) 27-31, 2002  
    The aim of the present study was to investigate the effects of short-term physical exercise that did not change body mass on insulin sensitivity, insulin secretion, and glucose and lipid metabolism in 39 non-obese Japanese type 2 diabetic patients. Insulin sensitivity and insulin secretion were estimated with homeostasis model assessment insulin resistance (HOMA-IR) and HOMA-B-cell function proposed by Matthews et al., respectively. All patients were hospitalized and were engaged in low-intensity exercise that consisted of walking and dumbbell exercise for successive 7 days. There were no changes in hospital diet and the dose of any medications used throughout the study. Fasting glucose, insulin, and lipids were measured before and after exercise. After exercise, serum triglyceride levels significantly decreased, but no significant changes were observed in total and HDL cholesterol concentrations. Fasting glucose, insulin, and HOMA-IR levels significantly decreased after exercise, but HOMA-B-cell function did not change during the study. There was no significant difference between BM1 levels before and after exercise. From these results, it can be concluded that short-term (7 days) low-intensity physical exercise combined with hospital diet reduces serum triglycerides, insulin resistance, and fasting glucose levels without affecting BM1 in non-obese Japanese type 2 diabetic patients.
  • 久枝 啓一, 園部 隆久, 杉山 美恵子, 井原 晴喜, 豊田 洋治, 佐々木 金裕, 水谷 尚, 左向 敏紀, 広瀬 昶
    動物臨床医学会年次大会プロシーディング, 22回(5) 16-16, Nov, 2001  Peer-reviewed
  • 豊田 洋治, 園部 隆久, 井伊 善仁, 村上 慶政, 杉山 美恵子, 久枝 啓一, 井原 晴喜, 佐々木 金裕, 水谷 尚, 左向 敏紀, 廣瀬 昶
    日本獣医学会学術集会講演要旨集, 132回 90-90, Sep, 2001  Peer-reviewed
  • 左向敏紀, 流石真美子, 水谷尚, 長谷川承, 広瀬あきら
    獣医東洋医学研究会誌, (7) 8-13, Jul 5, 2001  
  • H Mizutani, T Sako, Y Toyoda, T Kawabata, N Urumuhang, H Koyama, S Motoyoshi
    VETERINARY RESEARCH COMMUNICATIONS, 23(8) 475-480, Dec, 1999  
    The hepatic mitochondrial carnitine palmitoyltransferase (CPT) activity was measured by fluorimetric assay in dairy cows with or without fatty liver. CPT activities in 13 lactating cattle and in 6 non-lactating cows were 304.4 +/- 86.6 mu mol CoA/min per g protein and 169.3 +/- 84.8 mu mol CoA/min per g protein, respectively. This difference was significant (p &lt; 0.05). CPT activities in early lactation (0-110 days after calving), mid-lactation (111-220 days after calving) and late lactation (over 220 days after calving) were 278.9 +/- 68.0, 312.4 +/- 124.1 and 320 +/- 59.3 mu mol CoA/min per g protein, respectively. There was no significant difference between the values at different stages of lactation. The CPT activity in 10 lactating cows with fatty liver unrelated to calving was 201.3 +/- 80.0 mu mol CoA/min per g protein. CPT activity in 10 cattle with fatty liver was significantly lower than that in normal lactating cattle. Based on these findings, clinical fatty liver unrelated to calving appears to be associated with a decrease in hepatic CPT activity.
  • 左向 敏紀, 水谷 尚, 吾魯木汗 那孜尓別克, 豊田 洋治, 久枝 啓一, 佐々木 金裕, 吉川 信, 宇都宮 三誠, 廣瀬 昶
    日本獣医学会学術集会講演要旨集, 128回 110-110, Sep, 1999  Peer-reviewed
  • 豊田 洋治, 久枝 啓一, 佐々木 金裕, 水谷 尚, 左向 敏紀
    日本獣医学会学術集会講演要旨集, 126回 31-31, Aug, 1998  Peer-reviewed
  • MIZUTANI Hisashi, SAKO Toshinori, TAKEMURA Naoyuki, KOYAMA Hidekazu, YAMAGUCHI Mamoru, MOTOYOSHI Shigekatsu
    Journal of Veterinary Medical Science, 59(11) 1067-1069, Nov 25, 1997  
    A fluorometric assay for the determination of hepatic carnitine palmitoyltransferase (CPT) activity was slightly modified for use with cattle samples. With this assay, the Km value was 0.56 &plusmn; 0.10 mM with respect to L-carnitine (mean &plusmn; SD, n=4) and was 9.6 &plusmn; 2.2 &mu;M (n=3) with respect to palmitoyl-CoA. The average hepatic CPT activity was 33.6 &plusmn; 2.0 &mu;mol CoASH/min/g protein in 38 healthy cattle and was similar in both sexes and among breeds. Hepatic CPT activity showed no correlation with serum phospholipid, free fatty acid, triglyceride or total cholesterol concentrations.

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