森 昭博

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol, thereby lowering primarily low density lipoprotein-cholesterol (LDL-chol) in human studies. This study aimed to investigate the effects of ezetimibe on dyslipidemia control in nine dogs with hypercholesterolemia. Changes in total cholesterol (T-chol) and each lipoprotein fractions were evaluated at 0, 2, and 4 months following initiation of ezetimibe treatment. A significant decrease in T-chol was observed, and a mean T-chol concentration below 400 mg/dL was achieved at 2 and 4 months. Furthermore, a significant decrease in LDL-chol was observed (-53.3% and -64.3% at 2 and 4 months, respectively). Taken together, treatment of ezetimibe could lower LDL-chol levels in dogs with hypercholesterolemia.

A 10-year-old castrated male cat showing behavioral (irritation, prowling, and tumbling) and cutaneous abnormalities such as dermal fragility was diagnosed as hyperadrenocorticismwith pituitary macroadenoma, concurrent with insulin dependent diabetes mellitus. Pituitary enlargement (18.0 mm) was observed during magnetic resonance imaging. High endogenous adrenocorticotropic hormone levels (>2,500 pg/ml) were also observed.Although trilostane treatment (5-10 mg/head, daily) was commenced, the clinical signs did not disappear. Insulin and trilostane treatment were discontinued on day 86 after first day of radiation therapy (4 Gy/12 fractions). After radiation therapy, a decreased pituitary tumor size (10.7 mm) was observed on day 301; neurological and dermatological signs exhibited remission. Radiation therapy is the treatment of choice for feline hyperadrenocorticismwith pituitary macroadenoma with neurological signs.

In the present study, we used next-generation sequencing to investigate the impacts of two commercially available prescription diet regimens on the fecal microbiomes of eleven client-owned healthy pet dogs. We tested an anallergenic diet on 6 dogs and a low-fat diet on 5 dogs. Before starting the study, each dog was fed a different commercial diet over 5 weeks. After collecting pre-diet fecal samples, the anallergenic or low-fat diet was administered for 5 weeks. We then collected fecal samples and compared the pre- and post-diet fecal microbiomes. In the dogs on the anallergenic diet, we found significantly decreased proportions of Bacteroides, Ruminococcaceae, and Fusobacteriaceae, belonging to the phyla Bacteroidetes, Firmicutes, and Fusobacteria, respectively. The proportion of the genus Streptococcus belonging to the phylum Firmicutes was significantly increased upon administering the anallergenic diet. In the dogs on the low-fat diet, although the phyla Actinobacteria and Bacteroidetes tended to increase (p=0.116) and decrease (p=0.147) relative to the pre-diet levels, respectively, there were no significant differences in the proportions of any phylum between the pre- and post-diet fecal microbiomes. The anallergenic diet induced a significantly lower diversity index value than that found in the pre-diet period. Principal coordinate analysis based on unweighted UniFrac distance matrices revealed separation between the pre- and post-diet microbiomes in the dogs on the anallergenic diet. These results suggest that, even in pet dogs kept indoors in different living environments, unification of the diet induces apparent changes in the fecal microbiome.

BACKGROUND: Hyperadrenocorticism (HAC) is a common endocrine disorder in dogs; however, there are no reports on the use of the corticotropin-releasing hormone test (CRHT) to differentiate between pituitary-dependent hyperadrenocorticism (PDH) and cortisol-producing adrenal tumors (CPATs), both causative of HAC. OBJECTIVES: To evaluate the usefulness of CRHT as a tool to differentiate between PDH and CPAT in dogs and to determine the reference intervals for CRHT in healthy, PDH, and CPAT dogs. ANIMALS: Dogs diagnosed with PDH (n = 21), CPAT (n = 6), and healthy beagle dogs (n = 33). METHODS: This prospective study included dogs with a definitive diagnosis of PDH and CPAT and healthy beagle dogs, in which CRHT was performed, were prospectively evaluated. We investigated the correlations of CRHT (endogenous adrenocorticotropic hormone [ACTH] concentration, endogenous ACTH concentration [EAC], and poststimulation ACTH concentration [PAC]) with pituitary-to-brain ratio (PBR) (in PDH) and with indices of adrenal ultrasonography (smaller and larger adrenal gland dorsoventral thickness in PDH and CPAT). RESULTS: For EAC, the area under the curve (AUC) was 0.95, with a cutoff value of 26.3 pg/mL (sensitivity: 90.62%, specificity: 87.50%). The AUC for PAC was 0.96 with a cutoff value of 54.5 pg/mL (sensitivity: 100.00%, specificity: 66.67%). The 95% reference interval for CRHT in healthy (control) dogs ranged 5.00 to 79.8 pg/mL (1.10-17.57 pmol/L) for EAC, and 1.92 to 153.42 pg/mL (0.42-33.78 pmol/L) for PAC. There was no significant correlation between PBR and CRHT, nor adrenal size and CRHT. CONCLUSIONS AND CLINICAL IMPORTANCE: CRHT appears to be a rapid and reliable test for differentiating PDH from CPAT in dogs.

Changes in lipoprotein profiles occur in dairy cows during the periparturient period and in cows with transition cow disease. Here, the lipoprotein profiles of Holstein-Friesian dairy cows during the periparturient period were obtained by anion-exchange, high-performance liquid chromatography to evaluate the usefulness of lipoprotein profile evaluation during the periparturient period and in cows with fatty liver and milk fever. Lipoprotein levels (including total and high- (HDL-C) and low-density lipoprotein (LDL-C) cholesterol) in 10 healthy cows were low 4 weeks prepartum, with the lowest values at calving or within 1 week of calving; the values increased at 8 weeks postpartum. The lipoprotein levels were measured in 16 cows diagnosed with fatty liver (n=10) or milk fever (n=6) and compared to 10 healthy dairy cows. A significant difference was observed in HDL-C between healthy cows (at calving and 1 week postpartum), and the fatty liver and milk fever cows. Cows with fatty liver and milk fever had a lower mean HDL-C than the 10 healthy dairy cows at calving and 1 week postpartum. HDL-C might be a good indicator of energy balance for differentiating healthy cows from those with transition cow disease.

A 5-year-old castrated male domestic shorthair cat was diagnosed with diabetic ketoacidosis and severe insulin resistance. Although the conventional treatment for diabetic ketoacidosis was provided, the cat required frequent hospitalization because of severe dehydration and repeated diabetic ketoacidosis. We detected anti-insulin antibodies for human in this cat. Serum insulin-binding IgG levels were markedly elevated compared with those in healthy cats and other diabetic cats. We initiated prednisolone to suppress the effects of anti-insulin antibodies. After initiation of prednisolone, the cat was gradually recovered with increasing activity and appetite. Furthermore, satisfactory glycemic control was achieved with combined subcutaneous injection of insulin detemir and insulin degludec.

Insulin degludec (IDeg) is a long-acting basal insulin recently developed for use in humans. This study aimed to investigate the effects of IDeg on glycemic control in diabetic cats. Changes in body weight, IDeg dosage, and glycated albumin (GA) were evaluated at 0, 1, 3, 6, 9, and 12 months following initiation of IDeg. A significant decrease in GA was observed and a mean GA level below 25% was achieved between 3 and 12 months. Furthermore, a significant increase in body weight was observed between 3 and 12 months. The mean IDeg dose was 0.75 ± 0.68 IU/kg/day at 12 months. Taken together, long-term glycemic control was successfully achieved in diabetic cats using IDeg.

The effects of prescription diets on canine intestinal microbiota are unknown. In this study, we used next generation sequencing to investigate the impact of four commercially available prescription diet regimens on the fecal microbiome in six healthy dogs. The diet regimens used were as follows: weight-loss diet, low-fat diet, renal diet, and anallergenic diet. We found a significantly decreased proportion of phylum Actinobacteria with the weight-loss diet compared to the anallergenic diet. There were no significant differences in the proportion of phylum Bacteroidetes between the four diets. The proportion of phylum Firmicutes was significantly decreased with the weight-loss diet compared to the anallergenic diet. The proportion of phylum Fusobacteria was significantly increased with the weight-loss diet compared to the anallergenic diet. There were no significant differences in the proportion of phylum Proteobacteria after consumption of the four diets. We therefore demonstrated that commercial prescription diet influences the fecal microbiome in healthy dogs. These results might be useful when choosing a prescription diet for targeting a disease.

A 12-year-old, castrated male cat with diabetes mellitus was diagnosed with acromegaly and examined with magnetic resonance imaging (enlarged pituitary gland, 8 mm); serum hormone concentrations were measured. After the first course of radiation therapy (4 Gy, 12 fractions), insulin administration was not required from day 420 after diagnosis. Enlarged pituitary tumor (8 mm) recurred, and insulin dosage amount of the cat was increased on day 1,065. The second course of radiation therapy (6 Gy, 4 fractions) was performed on day 1,201 and insulin administration was again discontinued. However, the cat died from lymphoma on day 1,397. Postmortem examination revealed pituitary adenoma. Most tumor cells were positive for chromogranin A, synaptophysin, and growth hormone immunohistochemistry. The pancreatic islet cells revealed diffuse hyperplasia. We achieved long-term successful management of an acromegalic cat with two courses of RT. However, a protocol for a second course of RT for feline recurrent pituitary tumor should be further discussed.

Insulin degludec (IDeg) is a new insulin formulation that facilitates long-term control of glucose level in humans. In this study, we investigated the effects of IDeg on glycemic control in dogs. Its time-action profiles were monitored in healthy dogs using an artificial pancreas apparatus under euglycemic conditions. At 9.0-13.5 hr post-IDeg injection, an indistinct peak of glucose level was detected. Moreover, the action of IDeg was persistent for >20 hr. Both IDeg and neutral protamine Hagedorn insulin (NPH) lowered blood glucose concentrations in diabetic dogs, but IDeg caused postprandial hyperglycemia and a somewhat lower preprandial glucose level than that caused by NPH. IDeg might be ineffective in concurrently preventing postprandial hyperglycemia and preprandial hypoglycemia in a single-agent administration.

The purpose of this study was to determine the therapeutic and/or adverse effects of radiation therapy (RT) against pituitary tumors in dogs with pituitary-dependent hypercortisolism, as monitored by frequent post-RT detailed MRI examinations, clinical signs, and changes in hormone concentrations. Nine dogs with an adrenocorticotropic hormone (ACTH)-secreting pituitary mass diagnosed by magnetic resonance imaging (MRI) underwent RT for 4weeks (total of 48Gy in 4-Gy fractions). Pituitary height/brain area (P/B) value, clinical signs, basal plasma ACTH concentrations, serum cortisol concentrations (pre- and post-ACTH stimulation test) and adverse effects of RT were evaluated before and post-RT. The P/B value was significantly lower in all nine dogs post-RT. One dog lacking any neurological signs demonstrated no change in clinical signs pre and post-RT. Out of 8 dogs which exhibited neurological signs pre-RT, half of them demonstrated complete resolution of their signs, whereas the other half showed transient resolution. In all animals with recurrence of neurological signs, pituitary tumor regrowth was not observed; however, MRI revealed moderate to severe pituitary hemorrhage. Late adverse effect (bilateral otitis media) was observed in three of nine dogs post-RT. RT did not induce any significant changes in the dogs' basal plasma ACTH concentration and pre- and post-ACTH serum cortisol concentrations. In conclusion, RT is effective to reduce pituitary size and the mass effect, but does not appear to affect blood hormone concentrations, necessitating additional medical treatment against hypercortisolism. Periodic MRI imaging post-RT enables early detection of adverse effects of RT.

A 12-year-old female Shih-Tzu with hyperadrenocorticism and hypothyroidism developed concurrent refractory generalized demodicosis that did not respond to doramectin treatment. Although amitraz treatment was effective, the dog developed severe diabetes, which resulted in the cessation of amitraz and trilostane. Attempts to control the diabetes were unsuccessful, and its hyperadrenocorticism was left untreated, leading to the recurrence of demodicosis. However, demodicosis went into complete remission with a single dose of fluralaner. Transient erythematous papules appeared on the trunk three days after the administration of fluralaner, but no other adverse reactions were noted. We demonstrated that fluralaner is a potent treatment for demodicosis, and skin eruptions are possible after the first dose of the drug.

Porphyromonas gulae, Tannerella forsythia and Campylobacter rectus are considered dominant periodontal pathogens in dogs. Recently, quantitative real-time PCR (qRT-PCR) methods have been used for absolute quantitative determination of oral bacterial counts. The purpose of the present study was to establish a standardized qRT-PCR procedure to quantify bacterial counts of the three target periodontal bacteria (P. gulae, T. forsythia and C. rectus). Copy numbers of the three target periodontal bacteria were evaluated in 26 healthy dogs. Then, changes in bacterial counts of the three target periodontal bacteria were evaluated for 24 weeks in 7 healthy dogs after periodontal scaling. Analytical evaluation of each self-designed primer indicated acceptable analytical imprecision. All 26 healthy dogs were found to be positive for P. gulae, T. forsythia and C. rectus. Median total bacterial counts (copies/ng) of each target genes were 385.612 for P. gulae, 25.109 for T. forsythia and 5.771 for C. rectus. Significant differences were observed between the copy numbers of the three target periodontal bacteria. Periodontal scaling reduced median copy numbers of the three target periodontal bacteria in 7 healthy dogs. However, after periodontal scaling, copy numbers of all three periodontal bacteria significantly increased over time (p?0.05, Kruskal-Wallis test) (24 weeks). In conclusion, our results demonstrated that qRT-PCR can accurately measure periodontal bacteria in dogs. Furthermore, the present study has revealed that qRT-PCR method can be considered as a new objective evaluation system for canine periodontal disease.

This study evaluated the accuracy of a newly developed veterinary portable blood glucose meter (PBGM) with hematocrit correction in dogs and cats. Sixty-one dogs and 31 cats were used for the current study. Blood samples were obtained from each dog and cat one to six times. Acceptable results were obtained in error grid analysis between PBGM and reference method values (glucose oxidation methods) in both dogs and cats. Bland-Altman plot analysis revealed a mean difference between the PBGM value and reference method value of -1.975 mg/dl (bias) in dogs and 1.339 mg/dl (bias) in cats. Hematocrit values did not affect the results of the veterinary PBGM. Therefore, this veterinary PBGM is clinically useful in dogs and cats.

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, 0.16-3.28mmol/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.

ヒトのがん患者の研究において、化学療法前後の血漿遊離アミノ酸濃度（PFAAs）が変化することが知られているが、イヌにおいては明らかではない。そこで本研究では、移行上皮癌（TCC）罹患犬における化学療法前後のPFAAsの変化を検討することを目的とした。TCC罹患犬3頭を用いた。TCC罹患犬にミトキサントロンを診断時および診断から3週間後に静脈内投与した。また、化学療法中はピロキシカムも6週間目まで毎日投与した。そして、0（抗がん剤投与前）、1、3、6週間目に採取した絶食時の血漿を高速液体クロマトグラフィー質量分析法にて異なる30種類のアミノ酸濃度を測定した。結果として化学療法前後で血漿中のシスタチオニン濃度に有意な変化が認められた。シスタチオニンは0週目と比較し、1および3週間後で減少、6週間後に増加した。TCC罹患犬の血漿中のシスタチオニンは、腫瘍細胞で利用された可能性が考えられた。以上より、TCC罹患犬におけるPFAAsは抗がん剤投与に影響されることが示された。今後は症例数を増やし、さらに長期間にわたり調べることで、TCCとPFAAsの関係をさらに検討していく必要がある。

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.

ヒトにおいて中鎖脂肪酸は代謝速度が速く、効率の良いエネルギー源とされ、また 脂肪蓄積抑制効果などが認められている。そこで、本研究では健常猫に対し、中鎖脂肪酸を豊富に含むココナッツオイルを添加した食事を給与し、脂質代謝に与える影響について比較検討した。ココナッツオイル添加食では有意差は認められなかったがインスリン濃度が他の脂肪添加食よりやや低い傾向を示した。その他の血液検査項目は明らかな変化は見られなかった。試験期間中、ココナッツオイル添加食による肝障害や消化器症状等の副作用は認められず、体重・体脂肪率・その他全身の栄養状態いずれにおいても明らかな変化が見られなかった。以上のことから、健常猫においてココナッツオイルは他の脂肪と同様に少量でもエネルギーを得ることができるかつ、安全で膵臓への負担が少ないエネルギー源として有効に利用できる可能性が示された。

血清中のアセトアミノフェン（以下APAP）濃度を簡易に測定できるAPAP検出キッ トを用い、イヌにおける本キットの有用性および検出可能なAPAP投与量を検討した。健常犬にウェットフード100gと粉末のAPAPを混ぜたものを同時に給与し、血中濃度の上昇した血清検体を得た。得られた血清を用いて同時再現性、日差再現性、および希釈直線性を検討した。 同時再現性の変動係数（CV）は7.65％、希釈直線性は、r2＝0.98と良好な数値が得られた。日差再現性試験は、CV値（n＝6）が20.61％と、今回用いたAPAP検出キットは、摂取直後に測定することが望ましいと考えられた。APAP投与量の検討では、10mg/kg投与試験で、有意な血中APAP濃度の上昇は認められなかったが、20mg/kg投与試験で有意な上昇が認められたため、APAPの投与量は20mg/kgが推奨されると考えられた。

This study investigated the changes in lymphocyte subsets during the trilostane medication of Pituitary-dependent hyperadrenocorticism (PDH) dogs. The cortisol level and lymphocyte subsets of eight dogs with PDH were monitored 0, 1, 3, 6, 9 and 12 months after the initiation of trilostane treatment. White blood cells (WBC), lymphocytes, CD3(+) (T lymphocyte), CD4(+) (helper T lymphocyte), CD8(+) (cytotoxic T lymphocyte) and CD21(+) (B lymphocyte) cells were measured. Although the post-ACTH stimulation test cortisol level was significantly lower during trilostane treatment, changes in the CD3(+), CD4(+), CD8(+) and CD21(+) counts were not observed. Meanwhile, significant decrease was observed in WBC counts during trilostane treatment. These indicate that long-term trilostane treatment has little effect on the lymphocyte subsets in PDH dogs.

Acarbose (AC) and Sitagliptin (STGP) are oral hypoglycemic agents currently used either alone or in conjunction with human diabetic (Type 2) patients. AC has been used with diabetic cats, but not STGP thus far. Therefore, the objective of this study was to determine the potential use of AC or STGP alone and in combination for diabetic cats, by observing their effect on short-term post-prandial serum glucose, insulin, and incretin hormone (active glucagon-like peptide-1 (GLP-1) and total glucose dependent insulinotropic polypeptide (GIP)) concentrations in five healthy cats, following ingestion of a meal with maltose. All treatments tended (p<0.10; 5-7.5% reduction) to reduce postprandial glucose area under the curve (AUC), with an accompanying significant reduction (p<0.05, 35-45%) in postprandial insulin AUC as compared to no treatment. Meanwhile, a significant increase (p<0.05) in postprandial active GLP-1 AUC was observed with STGP (100% higher) and combined treatment (130% greater), as compared to either AC or no treatment. Lastly, a significant reduction (p<0.05) in postprandial total GIP AUC was observed with STGP (21% reduction) and combined treatment (7% reduction) as compared to control. Overall, AC, STGP, or combined treatment can significantly induce positive post-prandial changes to insulin and incretin hormone levels of healthy cats. Increasing active GLP-1 and reducing postprandial hyperglycemia appear to be the principal mechanisms of combined treatment. Considering the different, but complementary mechanisms of action by which AC and STGP induce lower glucose and insulin levels, combination therapy with both these agents offers great potential for treating diabetic cats in the future.

Nesfatin-1 is an anorexic peptide derived from a precursor, nucleobindin-2 (NUCB2), which is distributed in various organs, coexists with ghrelin in the gastric X/A-like cells and closely relates to an appetite control in rodents and humans. Nesfatin-1 may be a significant factor addressing the satiety also in veterinary medicine, however, there are few reports about nesfatin-1 in dogs. In the present study, we detected canine NUCB2/nesfatin-1 mRNA in various tissues, especially abundant in pancreas, gastrointestinal tracts, testis and cerebellum. We examined circulating nesfatin-1 concentrations and NUCB2/nesfatin-1 mRNA expressions in upper gastrointestinal tracts (gastric corpus, pyloric antrum and duodenum) in dogs fed on different types of diets. Plasma nesfatin-1 concentrations in the dogs were approximately 4 ng/ml and they did not change after feeding through the study, however, NUCB2/nesfatin-1 mRNA expressions in pyloric antrum were 1.84-fold higher in the dogs fed on a High fiber/High protein diet (P<0.001), 1.48-fold higher in the dogs fed on a High fat/Low protein diet (P<0.05) and 1.02-fold higher in the dogs fed on a Low fat/High carbohydrate diet (not significant) comparing to those on a control diet. It was concluded that High fiber/High protein and High fat/Low protein diets increased NUCB2/nesfatin-1 production in canine gastrointestinal tracts. These results may set the stage for further investigations of canine NUCB2/nesfatin-1, which may relate to satiety effects in dogs.

Carbohydrate is an important source of energy, which can significantly affect postprandial blood glucose and insulin levels in cats. In healthy animals, this is not a big concern; however, in obese and diabetic animals, this is an important detail. In the present study, the impact of four different carbohydrate sources (glucose, maltose, corn starch, and trehalose) on short-term post-prandial serum glucose, insulin, and non-esterified fatty acid (NEFA) concentrations was investigated with four obese cats. Each of the carbohydrate sources was added to a commercial wet food diet for feeding the animals. A significant difference was observed in postprandial glucose, insulin, and NEFA area under the curve (AUC) values between each carbohydrate source in obese cats. Furthermore, glucose and maltose induced the highest postprandial glucose and insulin AUC values, whereas trehalose induced the lowest postprandial glucose and insulin AUC value amongst all carbohydrate sources, respectively, in obese cats. However, trehalose has a higher risk of inducing side effects, such as diarrhea, as compared to other carbohydrate sources. As such, different carbohydrate sources appear to have a very significant impact on post-prandial glycemia and subsequent insulin requirement levels in obese cats. These results might be useful when selecting a prescription diet for obese or diabetic cats. In addition, maltose appears to be capable of inducing experimentally evoked postprandial hyperglycemia in obese cats, which may serve as a good tool for use to check the impact and effectiveness of newly developed oral hypoglycemic drugs or supplements for cats in future experiments.

This study evaluated the accuracy and reproducibility of a human portable blood glucose meter (PBGM) for canine and feline whole blood. Reference plasma glucose values (RPGV) were concurrently measured using glucose oxidation methods. Fifteen healthy dogs and 6 healthy cats were used for blood sampling. Blood glucose concentrations and hematocrits were adjusted using pooled blood samples for our targeted values. A positive correlation between the PBGM and RPGV was found for both dogs (y = 0.877, x = -24.38, r = 0.9982, n = 73) and cats (y = 1.048, x = -27.06, r = 0.9984, n = 69). Acceptable results were obtained in error grid analysis between PBGM and RPGV in both dogs and cats; 100% of these results were within zones A and B. Following ISO recommendations, a PBGM is considered accurate if 95% of the measurements are within +/- 15 mg/dl of the RPGV when the glucose concentration is &lt;100 mg/dl and within +/- 15% when it is &gt;= 100 mg/dl; however, small numbers of samples were observed inside the acceptable limits for both dogs (11%, 8 of 73 dogs) and cats (39%, 27 of 69 cats). Blood samples with high hematocrits induced lower whole blood glucose values measured by the PBGM than RPGV under hypoglycemic, normoglycemic, and hyperglycemic conditions in both dogs and cats. Therefore, this device is not clinically useful in dogs and cats. New PBGMs which automatically compensate for the hematocrit should be developed in veterinary practice.

G protein-coupled receptor (GPR) 120 is an unsaturated fatty acid receptor, which is associated with various physiological functions. It is reported that the genetic variant of GPR120, p.Arg270His, is detected more in obese people, and this genetic variation functionally relates to obesity in humans. Obesity is a common nutritional disorder also in dogs, but the genetic factors have not ever been identified in dogs. In this study, we investigated the molecular structure of canine GPR120 and searched for candidate genetic variants which may relate to obesity in dogs. Canine GPR120 was highly homologous to those of other species, and seven transmembrane domains and two N-glycosylation sites were conserved. GPR120 mRNA was expressed in lung, jejunum, ileum, colon, hypothalamus, hippocampus, spinal cord, bone marrow, dermis and white adipose tissues in dogs, as those in mice and humans. Genetic variants of GPR120 were explored in client-owned 141 dogs, resulting in that 5 synonymous and 4 non-synonymous variants were found. The variant c.595C&gt;A (p.Pro199Thr) was found in 40 dogs, and the gene frequency was significantly higher in dogs with higher body condition scores, i.e. 0.320 in BCS4-5 dogs, 0.175 in BCS3 dogs and 0.000 in BCS2 dogs. We conclude that c.595C&gt;A (p.Pro199Thr) is a candidate variant relating to obesity, which may be helpful for nutritional management of dogs.

ヒトの研究において、血糖値、インスリンやインクレチン濃度には日周リズムが存在することが知られているが、犬においては明らかではない。したがって、本研究の目的は、朝夜での健常犬の血糖値、インスリン、インクレチン濃度を比較検討することとした。朝7時から夜7時の朝試験と、夜7時から朝7時までの夜試験を比較した。本研究では、4頭の健常犬を用い、朝夜7時の12時間ごとに同じフードを同じ量給与した。そして、食後の血糖値、インスリン、インクレチン濃度（glucose-dependent insulinotropic polypeptide〔GIP〕and glucagon-like peptide-1〔GLP-1〕）を測定した。血糖値は朝夜で有意な変化は認められなかった。一方、インスリン濃度は食後1時間目に夜試験で有意に上昇していた。GIP、GLP-1濃度は食後数時間で増加し、徐々に低下していく日内変動をとったが、朝夜で最高濃度が異なっていた。これらの結果より、健常犬においてもこれらのパラメーターに日周リズムが存在することが明らかとなった。

Sitagliptin is a dipeptidyl peptidase-4 inhibitor aimed at treating Type 2 diabetes mellitus (T2DM) and T1DM, by increasing blood levels of Glucagon-like peptide 1 (GLP-1) and insulin. The objective of this preliminary study is to characterize Sitagliptin's ability for glycemic control, in healthy dogs under an oral glucose tolerance test (OGTT) environment. Overall, Sitagliptin did not result in any significant changes to temporal glucose and insulin concentrations. However, a similar to 55% increase in median total GLP-1 AUC(0-120min) was observed, as compared to baseline control in healthy dogs (n=5), thus indicating a similar mode of action of Sitagliptin between healthy dogs and humans. Future studies to validate the use of Sitagliptin with dogs suffering from insulin independent diabetes are warranted.

Hyperadrenocorticism (HAC) is a common endocrine disorder in dogs, in which excess glucocorticoid causes insulin resistance. Disturbance of insulin action may be caused by multiple factors, including transcriptional modulation of insulin signal molecules which lie downstream of insulin binding to insulin receptors. In this study, gene expressions of insulin signal molecules were examined using neutrophils of the HAC dogs (the untreated dogs and the dogs which had been treated with trilostane). Insulin receptor substrate (IRS)-1, IRS-2, phosphatidylinositol 3-kinase (P13-K), protein kinase B/Akt kinase (Akt)-2 and protein kinase C (PKC)-lambda were analyzed in the HAC dogs and compared with those from normal dogs. The IRS-1 gene expressions decreased by 37% and 35% of the control dogs in the untreated and treated groups, respectively. The IRS-2 gene expressions decreased by 61% and 72%, the P13-K gene expressions decreased by 47% and 55%, and the Akt-2 gene expressions decreased by 45% and 56% of the control dogs, similarly. Collectively, gene expressions of insulin signal molecules are suppressed in the HAC dogs, which may partially contribute to the induction of insulin resistance.

Background: Photoperiod is known to cause physiological changes in seasonal mammals, including changes in body weight, physical activity, reproductive status, and adipose tissue gene expression in several species. The objective of this study was to determine the effects of day length on the adipose transcriptome of cats as assessed by RNA sequencing. Ten healthy adult neutered male domestic shorthair cats were used in a randomized crossover design study. During two 12-wk periods, cats were exposed to either short days (8 hr light: 16 hr dark) or long days (16 hr light: 8 hr dark). Cats were fed a commercial diet to maintain baseline body weight to avoid weight-related bias. Subcutaneous adipose biopsies were collected at wk 12 of each period for RNA isolation and sequencing. Results: A total of 578 million sequences (28.9 million/sample) were generated by Illumina sequencing. A total of 170 mRNA transcripts were differentially expressed between short day-and long day-housed cats. 89 annotated transcripts were up-regulated by short days, while 24 annotated transcripts were down-regulated by short days. Another 57 un-annotated transcripts were also different between groups. Adipose tissue of short day-housed cats had greater expression of genes involved with cell growth and differentiation (e. g., myostatin; frizzled-related protein), cell development and structure (e. g., cytokeratins), and protein processing and ubiquitination (e. g., kelch-like proteins). In contrast, short day-housed cats had decreased expression of genes involved with immune function (e. g., plasminogen activator inhibitor 1; chemokine (C-C motif) ligand 2; C-C motif chemokine 5; T-cell activators), and altered expression of genes associated with carbohydrate and lipid metabolism. Conclusions: Collectively, these gene expression changes suggest that short day housing may promote adipogenesis, minimize inflammation and oxidative stress, and alter nutrient metabolism in feline adipose tissue, even when fed to maintain body weight. Although this study has highlighted molecular mechanisms contributing to the seasonal metabolic changes observed in cats, future research that specifically targets and studies these biological pathways, and the physiological outcomes that are affected by them, is justified.

運動療法は、インスリン感受性を改善し、骨格筋へのブドウ糖取り込みを増加させることから、糖尿病患者において有用な治療法である。本研究では、糖尿病犬に対する運動療法が血液生化学パラメーターおよび骨格筋遺伝子発現にどのような影響を及ぼすかを検討した。空腹時血糖値は運動前後で有意な変動は認められなかった。しかし、糖化アルブミン（GA）および遊離脂肪酸は運動後有意に低下した。インスリンシグナリングおよび糖代謝に関連する遺伝子（インスリンレセプター基質1および2、ホスファチジルイノシトール3キナーゼ、aktキナーゼ2、グルコーストランスポーター4、AMP活性化プロテインキナーゼ、脱共益蛋白3およびアセチルCoAカルボキシラーゼ）の発現には運動前後で有意な変化は認められなかった。本実験結果より、運動療法を行うことでGAの低下をもたらし、糖尿病犬において血糖コントロールが改善された。

Glucagon-like peptide 1 (GLP-1) is a glucose-lowering, intestinal-derived factor with multiple physiological effects, making it attractive for diabetes therapy. However, the therapeutic potential of endogenous GLP-1 is limited, because of rapid inactivation by dipeptidyl peptidase-4. Recently, enhanced incretin preparations, such as liraglutide, have emerged, which are more resistant to degradation and longer lasting. Liraglutide is a long-acting acylated human GLP-1 receptor agonist, with a 97% amino acid sequence identity to endogenous human GLP-1, and 100% amino acid sequence homology with canine GLP-1.Since liraglutide has yet to be examined for use in dogs, and the incretin effect has been reported to exist in dogs, we sought to initially characterize liraglutide's ability for glycemic control in healthy dogs, under an oral glucose tolerance test (OGTT) environment initially. This was followed up a more realistic scenario involving food with insulin injection +/- liraglutide injection resulting in a glucose curve based study involving dogs suffering from Type 1 diabetes mellitus (T1DM). Overall, liraglutide had a stabilizing effect on glucose levels, maintaining circulating levels between 77.0 and 137.0mg/ml throughout the OGTT test period, resulting in a significant reduction of 13.8% in glucose AUC0-120min (total area under the curve for 0-120min) as compared to baseline control in healthy dogs (n=5). Interestingly, the liraglutide associated reduction in circulating glucose was not accompanied by any significant increase in insulin. Moreover, T1DM dogs (n=4) responded favorably to liraglutide treatment, which lead to a significant reduction of 46.0% in glucose AUC0-12h (total area under the curve for 0-12h), and a significant reduction of 66.5% in serum glucose as compared to baseline controls (insulin treatment only). Therefore, liraglutide's prandial glucagon suppressive ability appears to play a key role in its glucose-lowering capability, and offers great potential for use with dogs suffering from T1DM. © 2013 Elsevier Ltd.

Diet therapy is an important treatment component available for obese cats. In this study, the impact of four commercially available prescription diet regimens (1 for general use and 3 aimed at treating obesity and diabetes mellitus (DM)) on short-term postprandial serum glucose, insulin, triglyceride and nonesterified fatty acid (NEFA) concentrations was investigated with five obese cats. The diet regimens used were as follows: C/D dry (general use: moderate protein, moderate fat, high carbohydrate and low fiber), M/D dry (DM: high protein, high fat, low carbohydrate and high fiber), W/D dry (DM: high protein, low fat, high carbohydrate and high fiber) and Diabetic dry (DM: high protein, low fat, low carbohydrate and high fiber). A significant reduction (10-13%) in postprandial glucose (area under the curve; AUC) was observed with the MID and Diabetic diets, which both contained lower concentrations of carbohydrates than the C/D diet. An accompanying significant reduction (30-36%) in postprandial insulin AUC was also observed with the three DM diets, which all had higher amounts of fiber, as compared with the C/D diet. Lastly, a significant increase (32-65%) in postprandial NEFAAUC was observed with the M/D and Diabetic diets as compared with the C/D diet. Therefore, dietary amounts of carbohydrates and fiber, as opposed to protein content or dietary fat, appear to have a very significant impact on postprandial glycemia and subsequent insulin requirement levels in obese cats. In addition, dietary amounts of carbohydrates may also impact lipid metabolism in obese cats.

Australian Burmese cats are predisposed to diabetes mellitus and, compared to other breeds, have delayed triglyceride clearance that may result in subtle changes within cells and tissues that trigger specific alterations in gene expression within peripheral blood leucocytes (PBLs). Expression of genes involved in energy metabolism (glucose-6-phosphate dehydrogenase and malate dehydrogenase), lipogenesis (ATP citrate lyase [ACL], fatty acid synthase [FAS] and sterol regulatory binding protein-1c [SREBP-1c]), and insulin signalling (insulin receptor substrates 1 and 2, and phosphatidylinositol-3 kinase), as well as cholesterol lipoprotein subfraction profiling were carried out on PBLs from lean Burmese cats and compared with similar profiles of age and gender matched lean and obese Australian domestic shorthaired cats (DSHs) in an attempt to identify possible biomarkers for assessing obesity.For the majority of the genes examined, the lean Burmese cats demonstrated similar PBL gene expression patterns as age and gender matched obese Australian DSH cats. Lean Burmese had increased expression of ACL and FAS, but not SREBP-1c, a main upstream regulator of lipid synthesis, suggesting possible aberrations in lipogenesis. Moreover, lean Burmese displayed a 3- to 4-fold increase in the very low density cholesterol fraction percentage, which was double that for obese DSH cats, indicating an increased degree of lipid dysregulation especially in relation to triglycerides. The findings suggest that Burmese cats may have a particular propensity for dysregulation in lipid metabolism. © 2012 Elsevier Ltd.

Monocyte chemoattractant protein-1 (MCP-1) is a member of the C-C family chemokines, which mobilizes monocytes from bone marrow to the site of inflammation. To evaluate the clinical utility of canine MCP-1 as a blood test item, we measured serum MCP-1 concentrations in normal and ill dogs. Reference interval of canine MCP-1 was established as 115.6-176.9 pg/ml. Serum MCP-1 concentrations increased in the dogs affected with neoplastic (518.0 ± 84.8 pg/ml), inflammatory (257.0 ± 42.5 pg/ml) or other diseases (360.3 ± 45.2 pg/ml). The results showed high sensitivity of MCP-1 to detect neoplasia and inflammation. Moreover, MCP-1 increased in some cases in which C-reactive protein didn't increase. MCP-1 might be helpful as a screening blood test marker for detection of neoplasia and inflammation in dogs.

Monitoring of blood glucose concentration is important to evaluate the diabetic status of dogs. Continuous glucose monitoring systems (CGMS) have been applied in veterinary medicine for glucose monitoring in diabetic dogs. The purpose of the study was to evaluate the daily glycemic profiles obtained with CGMS and compare glucose fluctuations between day- and night-time in diabetic dogs. Five diabetic dogs were used in this study and were treated with either NPH insulin or insulin detemir. For data analyses, day-time was defined as 9:00 am-9:00 pm and night-time as 9:00 pm-9:00 am. Using glucose profiles, we determined the mean glucose concentrations (1-and 12-hr intervals), and times spent in hyperglycemia &gt;200 mg/dl or hypoglycemia &lt;60 mg/dl. None of the parameters differed significantly between day-time and night-time in dogs treated with NPH insulin or insulin detemir. In conclusion, this study confirmed, using CGMS, that there are no differences in glucose fluctuations between day-and night-time, in diabetic dogs on a similar feeding regimen and insulin administration.

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.

飢餓状態などのケトン体生成が増加する状況では肝臓での酢酸生成が増加する。特に血糖維持を糖新生に依存するネコではケトン体、酢酸生成が増加しやすいと考えられる。本研究ではネコの栄養状態および病態評価に血中酢酸濃度を利用する目的で酢酸測定法を検討し、健常ネコでの標準値を測定するとともに糖尿病ネコでの変動を調べた。健常ネコの血中酢酸濃度は 0.71 ± 0.23mM であり、雌雄間で有意な差が認められた（p&lt;0.01）。また糖尿病 8 症例の平均は 0.91 ± 0.34mM であり、健常ネコよりも高値を示す傾向が見られた。

The effect of overweight status on the expression of SREBP-1c and downstream lipogenic genes, such as ATP citrate lyase (ACL) and fatty acid synthase (FAS), in abdominal adipose and liver tissues was determined in cats using a diet-induced weight gain model. ACL and SREBP-1c mRNA expression was significantly reduced (∼65% and 20%, respectively) in liver tissue, whereas FAS and SREBP-1c expression was significantly increased (∼80% and 45%, respectively) in abdominal omental adipose tissue of overweight animals as compared to healthy animals. Additionally, ACL, FAS, and SREBP-1c expression was significantly reduced by ∼50%, 75%, and 70%, respectively, in abdominal subcutaneous adipose tissue of overweight animals. Omental adipose tissue appeared to foster, whereas subcutaneous adipose and liver tissues appeared to defer lipid storage based on differences in SREBP-1c mRNA expression. Overall, reduced lipogenic gene mRNA expression patterns support the hypothesis that SREBP-1c expression is reduced in overweight and possibly obese cats, reflecting down-regulation of the lipogenic pathway to prevent further fat accumulation and weight gain. © 2011 Elsevier Ltd.

1,5-anhydro-D-glucitol (1,5AG) is a pyranoid polyol compound found in human circulating blood. Myo-inositol (MI) is a stereoisomer of inositol and serves as a precursor of inositol phospholipids. I,5AG and MI are filtered by the glomerulus and almost completely reabsorbed through the renal tubules. However, under hyperglycemic conditions, reabsorption through the renal tubules is competitively inhibited because the structures of I,5AG and MI resemble that of glucose. In this study, we investigated the kinetics of serum and urine 1,5AG and MI levels in healthy dogs. We demonstrated that 1,5AG and MI exist in canine serum and urine by gas chromatography-mass spectrometry. Under continuous hyperglycemic conditions, the serum 1,5AG concentration in healthy dogs decreased while the serum MI concentration remained unchanged. Urinary excretion of 1,5AG and MI increased significantly after blood glucose concentrations reached 200 to 220 mg/d/. A significant negative correlation was observed between serum 1,5AG and glucose concentrations during hyperglycemia. However, no significant correlation was observed between serum MI and glucose concentrations. In this study, we demonstrated that serum and urine 1,5AG and MI levels were changed by blood glucose concentrations. The serum I,5AG concentration was decreased by continuous hyperglycemia. However, the serum MI concentration does not reflect hyperglycemia.