Postprandial response of plasma insulin, amylin and acylated ghrelin to various test meals in lean and obese cats

The propensity of diets of different composition to promote obesity is a current topic in feline medicine. The effects of three meals with different protein:fat ratios on hormones (insulin, acylated ghrelin and amylin) involved in the control of food intake and glucose metabolism were compared. Five lean (two females and three males, 28·6 (sd 3·4) % body fat mass (BFM), mean body weight (BW) 4590g) and five obese (two females and three males, 37·1 (sd 4·1) % BFM, mean BW 4670g) adult cats were studied. Only BFM differed significantly between obese and lean cats. The cats were fed a high-protein (HP), a high-fat and a high-carbohydrate diet in a randomised cross-over design. Food intake did not differ between cats fed on the different diets, but obese cats consumed significantly more energy, expressed as per kg fat-free mass, than lean cats. After a 6-week adaptation period, a test meal was given and blood samples were collected before and 0, 30, 60 and 100min after the meal. Baseline concentrations of glucose, amylin and acylated ghrelin were higher in obese cats than in lean cats, and obese cats showed the highest postprandial responses of glucose and amylin. The HP diet led to higher postprandial amylin concentrations than the other diets, indicating a possible effect of amino acids on β-cell secretion. Postprandial ghrelin concentrations were unaffected by diet composition. The relationship between insulin, amylin and ghrelin secretion and their relevant roles in food intake and glucose metabolism in cats require further stud

Acute hormonal response to glucose, lipids and arginine infusion in overweight cats

In cats, the incidence of obesity and diabetes is increasing, and little is known about specific aspects of the endocrine control of food intake in this species. Recent data suggest that ghrelin has an important role in the control of insulin secretion and vice versa, but this role has never been demonstrated in cats. Here we aimed to improve our understanding about the relationship between insulin, amylin and ghrelin secretion in response to a nutrient load in overweight cats. After a 16h fast, weekly, six overweight male cats underwent randomly one of the four testing sessions: saline, glucose, arginine and TAG. All solutions were isoenergetic and isovolumic, and were injected intravenously as a bolus. Glucose, insulin, acylated ghrelin (AG), amylin and prolactin were assayed in plasma before and 10, 20, 40, 60, 80 and 100min after the nutrient load. A linear mixed-effects model was used to assess the effect of bolus and time on the parameters. A parenteral bolus of glucose or arginine increased insulin and ghrelin concentrations in cats. Except for with the TAG bolus, no suppression of ghrelin was observed. The absence of AG suppression after the intravenous load of arginine and glucose may suggest: (1) that some nutrients do not promote satiation in overweight cats; or that (2) AG may be involved in non-homeostatic consumption mechanisms. However, the role of ghrelin in food reward remains to be assessed in cat

Postprandial response of plasma insulin, amylin and acylated ghrelin to various test meals in lean and obese cats

The propensity of diets of different composition to promote obesity is a current topic in feline medicine. The effects of three meals with different protein:fat ratios on hormones (insulin, acylated ghrelin and amylin) involved in the control of food intake and glucose metabolism were compared. Five lean (two females and three males, 28.6 (sd 3.4) % body fat mass (BFM), mean body weight (BW) 4590 g) and five obese (two females and three males, 37.1 (sd 4.1) % BFM, mean BW 4670 g) adult cats were studied. Only BFM differed significantly between obese and lean cats. The cats were fed a high-protein (HP), a high-fat and a high-carbohydrate diet in a randomised cross-over design. Food intake did not differ between cats fed on the different diets, but obese cats consumed significantly more energy, expressed as per kg fat-free mass, than lean cats. After a 6-week adaptation period, a test meal was given and blood samples were collected before and 0, 30, 60 and 100 min after the meal. Baseline concentrations of glucose, amylin and acylated ghrelin were higher in obese cats than in lean cats, and obese cats showed the highest postprandial responses of glucose and amylin. The HP diet led to higher postprandial amylin concentrations than the other diets, indicating a possible effect of amino acids on beta-cell secretion. Postprandial ghrelin concentrations were unaffected by diet composition. The relationship between insulin, amylin and ghrelin secretion and their relevant roles in food intake and glucose metabolism in cats require further study

Acute hormonal response to glucose, lipids and arginine infusion in overweight cats

In cats, the incidence of obesity and diabetes is increasing, and little is known about specific aspects of the endocrine control of food intake in this species. Recent data suggest that ghrelin has an important role in the control of insulin secretion and vice versa, but this role has never been demonstrated in cats. Here we aimed to improve our understanding about the relationship between insulin, amylin and ghrelin secretion in response to a nutrient load in overweight cats. After a 16 h fast, weekly, six overweight male cats underwent randomly one of the four testing sessions: saline, glucose, arginine and TAG. All solutions were isoenergetic and isovolumic, and were injected intravenously as a bolus. Glucose, insulin, acylated ghrelin (AG), amylin and prolactin were assayed in plasma before and 10, 20, 40, 60, 80 and 100 min after the nutrient load. A linear mixed-effects model was used to assess the effect of bolus and time on the parameters. A parenteral bolus of glucose or arginine increased insulin and ghrelin concentrations in cats. Except for with the TAG bolus, no suppression of ghrelin was observed. The absence of AG suppression after the intravenous load of arginine and glucose may suggest: (1) that some nutrients do not promote satiation in overweight cats; or that (2) AG may be involved in non-homeostatic consumption mechanisms. However, the role of ghrelin in food reward remains to be assessed in cats

Resistant starch modulates in vivo colonic butyrate uptake and its oxidation in rats with dextran sulfate sodium-induced colitis

International audienceWe previously demonstrated improvements of colonic lesions due to dextran sulfate sodium (DSS) in rats after 7 d of supplementation with resistant starch (RS) type 3, a substrate yielding high levels of butyrate (C(4)), a colonic cell fuel source. In the present study, we hypothesized that if inflammation is related to decreased C(4) utilization by the colonic mucosa, RS supplementation should restore C(4) use simultaneously with an increase in the amount of C(4) present in the digestive tract. Hence, we compared, in vivo, the cecocolonic uptake of C(4) and its oxidation into CO(2) and ketone bodies in control and DSS-treated rats fed a fiber-free basal diet (BD) or a RS-supplemented diet. Sprague-Dawley rats (n = 60) were used. DSS treatment was performed to induce acute colitis and then to maintain chronic colitis. After cecal infusion of [1-(13)C]-C(4) (20 micro mol in 1 h), concentrations and (13)C-enrichment of C(4), ketone bodies, and CO(2) were quantified in the abdominal aorta and portal vein. Portal blood flow was recorded. During acute colitis, (13)C(4) uptake and (13)CO(2) production were lower in DSS rats than in controls. During chronic colitis, DSS rats did not differ from controls. After 7 d of chronic colitis, RS-DSS rats exhibited the same C(4) uptake as BD-DSS rats in spite of higher C(4) cecocolonic disposal. After 14 d, C(4) uptake was higher in RS-DSS than in BD-DSS rats. Thus, the increased utilization of C(4) by the mucosa is subsequent to evidence of healing and appears to be a consequence rather than a cause of this RS healing effec

Simultaneous measurement of plasma concentrations and 13C-enrichment of short-chain fatty acids, lactic acid and ketone bodies by gas chromatography coupled to mass spectrometry

International audienceA new method has been developed for the simultaneous measurement, in a reduced plasma sample, of concentration and 13C-isotopic enrichment of acetic, propionic, butyric, lactic, acetoacetic and beta-hydroxybutyric acids by gas chromatography coupled to mass spectrometry. After plasma deproteinisation, a diethylic extraction and a N-tert.-butyldimethylsilyl-N-methyltrifluoroacetamide derivatisation were performed. Both diethyl extraction and derivatisation procedures were optimised using the central composite designs methodology. The optimised method provides good linearity, intra-day and within-day repeatability. Except for beta-hydroxybutyric (49 μM) and acetoacetic acid (5 μM), detection limits were ranging between 0.2 and 0.7 μM allowing uses of this method for colonic metabolism studies