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» Veterinary Session
Veterinary sessionLengyel Péter - year 4 SZIU Faculty of Veterinary Science, Department of Physiology and Biochemistry Supervisors: Dr. Gábor Mátis, Dr. Zsuzsanna Neogrády The carbohydrate homeostasis in chicken is greatly different from that of mammals: the physiological blood glucose level is higher, and the insulin sensitivity of the extrahepatic tissues is decreased compared to mammals. Since chickens have high growth and muscle protein synthesis rates, regulated mostly by insulin, the investigation of insulin’s homeostasis and the examination of possible ways for affecting its regulation can be of special importance. The insulin release is regulated by many endocrine factors, primarily by incretins, which are the GIP (Glucose-dependent Insulinotropic Peptide) and the GLP-1 (Glucagon-like Peptide 1). In the present study, we aimed to examine the role of incretins in the regulation of insulin homeostasis in chicken, as well as to focus on its modulation by nutritional factors, such as the commonly applied feed additive, sodium butyrate in our case. Twenty-four-day old, male Ross 308 type broiler chickens were included in our experiment. Twenty-one chickens were housed in groups (n=7/group) and fed with starter diet according to the Ross standard. On day 24, following an overnight feed deprivation, the animals were treated with a single orally applicated sodium butyrate bolus (0; 0,25; 1,25 g/kg BW). Before the treatment, blood samples were drawn from the wing veins (0. min) and this was repeated after the treatment three times (10., 30., 60. min). From plasma samples the insulin, GIP and GLP1 hormone concentrations were determined with ELISA method, and the glucose concentrations with a spectrophotometric assay. According to our results, we found that in the case of insulin, both doses, and in the case of GIP, only the higher dose of butyrate lowered the plasma concentrations of hormones compared to the 0. minute control, while in the case of GLP-1 and glucose, no significant changes were found. Our findings aren’t in full consonence with other researchers’ results, where the orally applied butyrate raised the plasma concentration of incretins and insulin in mice. These can be associated with the species-related significant differences in carbohydrate metabolism. Our results show that the incretins are only partially responsible for the regulation of insulin release in chicken, and also reveal that the insulin homeostasis can be modified by nutritional factors. This study justifies that the butyrate has a significant role in regulating the insulin homeostasis of chickens, which role may be partly mediated by incretins. List of lectures |