EFFECT OF APELIN ON INSULIN RESISTANCE, BETA CELL FUNCTION AND LIPID PROFILE IN HEALTHY AND DIABETIC RAT MODELS

Abstract

Background: Apelin acts as a regulating peptide of cardiovascular, hypothalamus-hypophysis, metabolic, gastrointestinal and immune systems. Objective: The goal of this study was to clarify the effect of apelin on insulin resistance, beta cell function and lipid profile in healthy and diabetic rats. Design: 60 healthy adult male albino rats were divided into 3 equal groups: group I (normally fed group), group II (HFD –obese and diabetic or type II diabetes group) and Group III: A Streptozotocin (STZ) induced diabetic (type I diabetes) group, each group was subdivided into 2 subgroups (distilled water injected controls and apelin injected group). In all groups the sera were examined for glucose, insulin, triglycerides, total, HDL and LDL cholesterol levels. These data were used to measure the homeostasis model assessment of insulin resistance [HOMA-IR] and β-cell function [HOMA- β]. Results: Intraperitoneal injection of apelin decreased significantly serum insulin, glucose and HOMA-IR with insignificant change in HOMA-β and significantly increased total cholesterol, LDL and TG but it decreased significantly serum HDL in healthy lean and type II diabetic rat model. In type I diabetic rat model, apelin decreased significantly serum glucose and increased significantly HOMA- β with insignificant change in serum insulin and HOMA-IR and it produced significant decrease in serum TG with insignificant change in serum total cholesterol, LDL and HDL. Conclusion: Apelin has a detectable role in glucolipidemic metabolism in healthy and diabetic rat models. Further studies are needed to convert these effects into pharmacological trials in management of obesity and diabetes. Key words: Apelin, glucose, lipid profile, insulin resistance, type I & II diabetes.