Effect of different nutritional composition on incretin secretion and glucose metabolism in healthy cats

Abstract

Incretins such as glucose-dependent insulinotropic peptide（GIP）and glucagon like peptide-1（GLP-1）were shown to exert their insulinotropic effects through a variety of mechanisms. In the presence of matched glucose concentrations, insulin secretion is greater following ingestion of glucose than following infusion of glucose. This was referred to as “the incretin effect”and GIP and GLP-1 are released by gut endocrine cells in response to a meal and regulate blood glucose levels by stimulating glucose-dependent insulin secretion. The purpose of this study was to investigate the effect of incretin secretion for glucose and insulin metabolism in healthy cats. In order to determine changes in incretin secretion with different nutritional composition （control, high-carbohydrate, high-fat, high-fiber）, different diets were fed in 5 healthy cats. We measured postprandial glucose, insulin, GIP and GLP-1 concentrations. No significant changes in mean glucose and insulin concentrations. Furthermore, GLP-1 concentration was not significantly difference in 4 type diets. Meanwhile, GIP secretion was increased in high-fat diet. Furthermore, GIP was increased in direct proportion to fat content of these diets. As the result of GIP secretion was increased in high- fat diet, similarly as with humans and rodents. However, GLP-1 was not consistent with human objects, and we suggest that cats have been different digestive tissue and feeding habit.