Adipokines secretion in feline primary adipose tissue culture in response to dietary fatty acids.

BACKGROUND: Obesity in cats has been associated with alterations in adipokines including: adiponectin, interleukin-6 (IL6), and tumor necrosis factor-α (TNFα). Omega-3 polyunsaturated fatty acids have multiple beneficial effects on obesity-associated disorders, and therefore may alleviate these alterations. This study aimed to determine the effects of body condition, fat depot, troglitazone, and different fatty acids on secretion of adiponectin, IL6 and TNFα from adipose tissue of healthy cats. Subcutaneous and visceral adipose tissue samples were collected from 18 healthy intact female cats, and body condition score (Range 3-7/9) was determined. Concentrations of adiponectin were measured in mature adipocytes cultures and concentrations of IL6 and TNFα were measured in stromovascular cells cultures following treatment with control medium, troglitazone at 10 µM, eicosapentaenoic acid, arachidonic acid, or palmitic acid, at 25, 50, or 100 µM. RESULTS: Stromovascular cells of visceral origin secreted higher concentrations of IL6 than corresponding cells of subcutaneous origin (P = 0.003). Arachidonic acid treatment at 25, 50, and 100 µM increased IL6 secretion in subcutaneous (P = 0.045, P = 0.002, and P < 0.001, respectively) and visceral (P = 0.034, P = 0.001, and P < 0.001, respectively) stromovascular cells. Eicosapentaenoic acid treatment increased TNFα secretion in subcutaneous stromovascular cells at 25, 50, and 100 µM (P = 0.002, P = 0.001, and P = 0.015, respectively) and in visceral stromovascular cells at 50 µM (P < 0.001). No significant effect on medium adiponectin concentration was observed following troglitazone treatment (P = 0.4) or fatty acids treatments at 25 (P = 0.2), 50 (P = 0.8), or 100 (P = 0.7) µM. Body condition score did not have significant effects on medium concentrations of adiponectin (P = 0.4), IL6 (P = 0.1), or TNFα (P = 0.8). CONCLUSIONS: This study demonstrated higher basal secretion of IL6 from visceral compared to subcutaneous adipose tissue, a stimulatory effect of arachidonic acid on secretion of IL6 and a stimulatory effect of eicosapentaenoic acid on TNFα from feline adipose tissue.

Differential secretion of adipokines from subcutaneous and visceral adipose tissue in healthy dogs: Association with body condition and response to troglitazone.

This study aimed to determine the effects of body condition, fat depot, and a peroxisome proliferator-activated receptor γ-agonist (troglitazone) on secretion of adiponectin, interleukin-6 (IL6), and tumor necrosis factor-α (TNFα) from adipose tissue of healthy dogs. Subcutaneous and omental visceral adipose tissue samples were collected from 16 healthy intact female dogs, and body condition score (range 4-8/9) was determined. Concentrations of adiponectin were measured in mature adipocytes cultures and concentrations of IL6 and TNFα were measured in stromovascular cells cultures after 48 h incubation in fresh control medium, or fresh medium containing 10 µM troglitazone. Mature adipocytes and stromovascular cells of subcutaneous origin secreted higher concentrations of adiponectin and lower concentration of IL6 and TNFα, respectively, than corresponding cells of visceral origin, in both the control (P = 0.015, P = 0.004, and P = 0.016, respectively) and troglitazone-treated cultures (P <0.001, P = 0.004, and P = 0.016, respectively). Troglitazone increased adiponectin secretion from mature adipocytes in visceral (P = 0.019), but not in subcutaneous fat cultures (P = 0.4). Troglitazone decreased IL6 and TNFα secretion from stromovascular cells both in visceral (P = 0.047 and P = 0.016, respectively) and subcutaneous (P = 0.047 and P = 0.016, respectively) fat cultures. Higher body condition score was associated with lower secretion of adiponectin from mature adipocytes (P = 0.007), lower secretion of IL6 (P = 0.040) and higher secretion of TNFα (P = 0.040) from stromovascular cells. This study showed differential secretion of adipokines by subcutaneous and visceral fat depots in dogs and association between body condition and adipokine secretion. Activation of PPARγ altered adipokine secretion.

Fish oil supplementation increases concentration of adiponectin in healthy dogs.

OBJECTIVE: To determine the effect of fish oil supplementation on circulating concentrations of adiponectin, leptin, insulin, glucose, triglyceride and cholesterol in healthy dogs. METHODS: Twenty healthy adult dogs were administered 220 mg/kg of a fish oil supplement once daily for 30 days. At baseline, on supplement and 10 to 20 weeks off supplement, dogs were examined, body condition scores determined (range: 4 to 6), body measurements recorded for % body fat calculation and fasted blood samples collected. RESULTS: Serum concentrations of the measured individual and total n-3 polyunsaturated fatty acids increased following supplementation (P<0·001). Mean serum adiponectin concentration on supplement was 3·4 µg/mL (95% confidence interval: 0·8 to 6·0; P=0·006) higher than baseline, and 5·3 µg/mL (2·0 to 8·7; P<0·001) higher than off supplement. Concentrations of adiponectin off supplement were not different from baseline. There were no significant differences in weight, body condition scores, % body fat and concentrations of other measured analytes between baseline and on supplement. CLINICAL SIGNIFICANCE: Fish oil supplementation significantly increased circulating concentration of adiponectin in healthy non-obese dogs. Further investigation is warranted to determine whether this effect may be extended to obese dogs and to evaluate the potential role of fish oil supplementation in the management of disorders associated with low circulating adiponectin concentrations.

Serial plasma vasopressin concentration in healthy and hospitalised neonatal foals.

REASONS FOR PERFORMING STUDY: Vasopressin dysregulation occurs in critically ill human patients and in neonatal foals. Limited data about serial plasma vasopressin dynamics exist in sick neonatal foals. OBJECTIVES: To evaluate serial plasma arginine vasopressin (AVP) concentrations in sick neonatal foals. STUDY DESIGN: Prospective, longitudinal clinical study. METHODS: Plasma samples were collected from 7 healthy and 26 sick foals before and after initial fluid resuscitation and 12, 24, 36, 48 and 96 h after presentation. Foals with a modified sepsis score ≥ 11 were considered septic. RESULTS: Admission AVP was increased in septic foals compared to healthy and to sick, nonseptic foals. There were no significant differences between groups on subsequent days. Nonsurvivors had higher AVP concentrations than survivors. CONCLUSIONS: Plasma AVP concentrations are higher in septic foals on admission than in healthy and sick nonseptic foals. Higher early plasma AVP concentrations are associated with increased mortality.

Alterations in adipokines in feline hepatic lipidosis.

BACKGROUND: Feline hepatic lipidosis (HL) is associated with alterations in lipid and carbohydrate metabolism. The adipokines, adiponectin, and leptin have lipid-lowering and insulin-sensitizing effects. HYPOTHESIS: Serum concentrations of adiponectin and leptin are altered in feline HL. ANIMALS: Client-owned cats: 55 healthy and 45 with liver disease. METHODS: Cats with liver disease were categorized as having HL (n = 20), HL and concurrent disease (n = 19), or other liver disease (n = 6), based on clinical signs, laboratory findings, abdominal ultrasound examination as well as liver cytopathology, histopathology, or both. Serum samples were collected and body condition score determined. RESULTS: Mean serum concentrations of adiponectin were higher in overweight cats with HL (4.5 µg/mL), HL and concurrent disease (4.4 µg/mL), or other liver disease (6.1 µg/mL), as compared with healthy cats (1.5 µg/mL; P < .001, P < .001, and P = .04, respectively). Mean serum concentration of leptin was higher in cats with HL (9.8 ng/mL) or HL and concurrent disease (10.7 ng/mL) than healthy cats (4.9 ng/mL, P < .001 and P < .001, respectively). Cats with other liver disease had leptin concentration (4.9 ng/mL) similar to healthy cats. Concentrations of adiponectin were correlated with alanine aminotransferase activity (r = 0.40, P = .0069), and concentrations of leptin were correlated with alkaline phosphatase activity (r = 0.42, P = .0051) in cats with liver disease. CONCLUSIONS AND CLINICAL IMPORTANCE: Adipokine concentrations are altered in feline HL. Increased concentrations of adiponectin are related to liver disease, whereas increased concentrations of leptin are specifically related to HL.

Delta 8 desaturation in vivo of deuterated eicosatrienoic acid by mouse liver.

In vitro evidence has been reported for an alternate pathway that involves delta 8 desaturation of n-6 and n-3 polyunsaturated fatty acids (PUFA). The present study was designed to allow detection of delta 8 desaturation in vivo and to provide an estimation of the relative contribution of delta 8 desaturation to the in vivo synthesis of n-3 fatty acids. Male adult ICR mice were fed a semisynthetic fat-free diet for eight days, and then the diets were supplemented for three days with deuterated 11,14,17-eicosatrienoic acid (20:3-d8) labeled at the 3,3,4,4,8,8,9,9 carbon positions. Analysis of liver total lipid by gas chromatography/mass spectroscopy indicates that the total deuterated fatty acids contained 22.3% 20:3n-3-d8 and 28.9% of metabolites formed by elongation and delta 5 desaturation of 20:3n-3-d8. Deuterated metabolites resulting from retroconversion to 18:3-d6 and subsequent metabolism by classical pathways represented 35.3% of the total deuterated fatty acids. The retroconversion product (18:4n-3-d6) of 20:4n-3-d6 and/or -d8 was 9.0% of the total. A minor percentage (4.4%) of the products identified (20:4n-3-d6, 20:5n-3-d6, 22:5n-3-d6, 22:6n-3-d5 and 24:6n-3-d5) were formed by delta 8 desaturation. This study provides the first clear evidence of delta 8 desaturation in vivo in the mouse liver. Whether delta 8 desaturation would have a greater importance in vivo when the delta 6 desaturase pathway is disrupted remains to be determined.

Fractionation of canine serum calcium, using a micropartition system.

OBJECTIVE: To determine usefulness of a micropartition system for calcium fractionation of canine serum, and to establish reference values for protein-bound, complexed, and ionized calcium fractions in clinically normal dogs. DESIGN: Performance characteristics of a micropartition system were evaluated, using serum from clinically normal dogs. This micropartition system was then used to determine a reference range for calcium fractions. ANIMALS: 13 clinically normal dogs. PROCEDURE: Dog serum was placed in the micropartition system, and spun for 20 minutes at 1,300 x g. Total calcium concentration, ionized calcium concentration, and pH were measured in whole serum, and total calcium concentration was measured in the ultrafiltrate. The protein-bound fraction was calculated by subtracting total calcium of the ultrafiltrate from total calcium of whole serum. The ionized calcium measurement of whole serum was subtracted from the total calcium measurement of the ultrafiltrate, determining the complexed calcium fraction. RESULTS: During validation of the ability of the micropartition system to separate calcium fractions, no significant amount of serum calcium was adsorbed by the plastic micropartition system or membrane. The micropartition membrane separated the protein-bound calcium fraction (retentate) from the ultrafiltrate, which contained ionized and complexed fractions of calcium. Concentrations of protein-bound, ionized, and complexed calcium from clinically normal dogs were determined to be 3.40 +/- 0.63, 5.49 +/- 0.17, and 1.01 +/- 0.30 mg/dl, representing 34, 56, and 10% of the total calcium concentration, respectively. CONCLUSIONS: This method is a rapid, repeatable means to completely fractionate serum calcium, and most importantly provides accurate assessment of the protein-bound and complexed calcium fractions. CLINICAL RELEVANCE: Complete assessment of calcium fractions may increase sensitivity for detection of disease processes that affect calcium metabolism.

Effects of storage on serum ionized calcium and pH values in clinically normal dogs.

The stability of ionized calcium (CaI) concentration and pH in sera (n = 14) stored at 23 or 4 C for 6, 9, 12, 24, 48, or 72 hours, or -10 C for 1, 3, 7, 14, or 30 days was evaluated. Also studied were the effects of oxygen exposure, cold handling, and feeding on CaI and pH values. Results indicated that serum CaI concentration was stable throughout 72 hours of storage at 23 or 4 C, and for 7 days at -10 C. Serum CaI concentration significantly (P < 0.05) decreased by 14 days of storage at -10 C. Serum pH was stable for 6 hours at 23 or 4 C, and for 24 hours at -10 C, but significantly (P < 0.05) increased by 9 hours of storage at 23 or 4 C and by 3 days at -10 C. Exposure of the surface of the serum to air immediately before measurement had no effect on CaI or pH values, but mixing serum with air resulted in significantly (P < 0.05) decreased CaI concentration and increased pH. Handling of blood on ice resulted in significantly (P < 0.05) higher serum pH, compared with blood handled at 23 C, but serum CaI concentration was unaffected. Serum obtained at 2 hours after feeding did not have any significant changes in CaI, total calcium, or pH values. It appears that if canine serum is obtained, handled, and stored anaerobically, CaI concentration can be accurately measured after 72 hours at 23 or 4 C, or after 7 days at -10 C.

Nutritional management of hepatic disease.

The successful management of hepatic diseases of dogs and cats requires an understanding of hepatic metabolism and nutritional processes. General aspects of dietary therapy for hepatic diseases are described, along with specific recommendations for the promotion of tissue regeneration. Special considerations, including the role of diet in encephalopathy, hepatic lipidosis, and copper-associated hepatic toxicosis, are also discussed.

Effect of body weight on osteopenia in ovariectomized rats.

Bilateral ovariectomies or sham surgeries were performed in female Sprague Dawley rats that were 78 days of age and weighed an average of 210 g. Food was available ad libitum to the control rats and to a group of ovariectomized rats (obese OVX). The food consumption of a second group of ovariectomized rats (weight-matched OVX) was restricted to match their body weights to those of the control rats. All rats were sacrificed at 14 weeks postovariectomy. Radioimmunoassay of terminal serum estradiol confirmed the success of ovariectomy. The estradiol concentration in control rats was 24.9 +/- 20.2 pg/ml, whereas the hormone was undetectable (less than 10 pg/ml) in both groups of OVX rats. The final body weights of control and weight-matched OVX rats were nearly identical (approximately 260 g). In contrast, obese OVX rats weighed significantly more than both of the above groups (approximately 320 g, P less than 0.001). The proximal tibia and lumbar vertebra were processed undecalcified for quantitative bone histomorphometry. Tibial trabecular bone volume (TBV) was determined to be 17.6 +/- 4.5%, 7.9 +/- 5.3%, and 3.6 +/- 3.1% for the control, obese OVX, and weight-matched OVX groups, respectively. Tibial TBV for both OVX groups was significantly less than the control value (P less than 0.001). The difference in tibial TBV between obese OVX and weight-matched OVX rats was also statistically significant (P less than 0.02). Histologic indices of bone resorption and formation were indicative of increased bone turnover in the proximal tibia of both OVX groups.(ABSTRACT TRUNCATED AT 250 WORDS)