P.004 Pharmacological activation of trace amine-associated receptor 1 decreases nicotine self-administration in rodents without development of tolerance

Abstract

Apelin, an adipocyte-derived factor, exhibited a number of cardioprotective properties; however, its effect in diabetes which is a major risk factor for cardiovascular disease (CVD) needs to be further studied. So this work was designed to evaluate the effect of apelin on diabetes and its associated cardiac hypertrophy with its possible underlying protective mechanisms.Thirty male adult Wistar rats were categorized into three groups, 10 rats each, normal control group: received standard food and water regime. Diabetic control group: received streptozotocin (STZ) at a dose of (55 mg/kg, i.p., once) dissolved in citrate buffer (pH 4.5). Apelin-13 treated diabetic group: STZ diabetic rats received an intra peritoneal injection of apelin-13 at a dose of (100 nmol/kg/day), and given daily for 8 weeks. at the end of the experiment, oral glucose tolerance test (OGTT) was assayed, then rats were sacrificed and serum glucose, insulin, triglyceride (TG), total cholesterol, high density lipoprotein (HDL) cholesterol, serum lactate dehydrogenase (LDH) and serum creatine kinase – MB (CK-MB) were measured, together with cardiac hypertrophy index (CHI), left ventricular hypertrophy index (LVHI) and left ventricular protein and collagen content levels. Myocardial superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and malondialdehyde (MDA) were determined in the myocardial tissue of experimental rats.Treatment with apelin-13 improved hyperglycemia and hyperlipidemia, and significantly protected against STZ-induced structural alterations in cardiac tissue, it also produced a significant reduction in MDA while it elevated the level of antioxidant enzymes in hearts of diabetic rats.This study suggested that apelin can ameliorate diabetes and its associated myocardial hypertrophy through mainly its anti diabetic, anti hyperlipidemic and anti oxidative stress properities.