AbstractsBiology & Animal Science

Obesity affects about 520 million people world-wide and more recently studies have shown that fat cells produce proteins called adipokines which have various influences on the human metabolism and has helped to change the perspectives of researchers on the concept of the adipose tissue being just a store of energy. As a result of this, adipokines have been reported to represent a connection between obesity and cardiovascular diseases (CVD) and diabetes mellitus. The concentrations and the bases of the effects of the adipokines in beta cell failure of diabetes mellitus and endothelial cell dysfunction of cardiovascular diseases are still not fully understood. The effect of leptin and adiponectin, which are two adipokines with opposing effects, has been explored in this study. In the present study, therefore, the concentrations of leptin and adiponectin with significant effect on beta cell and endothelial cell function and the basis of these functions were explored. Also, attempts were made in the present study to correlate the concentrations of leptin and adiponectin with possible clinical pointers to complications. In order to achieve this, beta cells (BTC) were grown, made into pseudo-islets (which are said to produce more insulin) and treated with various concentrations of leptin and adiponectin and cells assayed for insulin and amylin (to investigate the role of amylin in insulin secretion). Also the cells were collected and mRNA extracted from these cells, reverse transcription PCR carried out to find out the role of protein phosphatase 1 (PP-1) in the effect of leptin on insulin secretion. PP-1 is a substrate that increases insulin secretion by allowing calcium influx into the cell and is said to be blocked by leptin). Leptin at 500ng/ml was found to significantly (p<0.05) inhibit the secretion of insulin and the expression of PP1 gene, thus supporting this as a basis for the effect of leptin on insulin secretion. Adiponectin however increased insulin secretion significantly but was not as consistent in its effect as leptin was in inhibiting insulin secretion. In order to explore the role of adipokines in cardiovascular diseases, EAHY human endothelial cells were cultured and treated with various concentrations of adiponectin and leptin both individually and in combinations and cells collected and mRNA extracted in order to carry out a reverse transcription PCR for the expression of angiogenic (TIMP2, TIMP3 and MMP2) genes and atherosclerotic (LPA and LPL) genes. Leptin (1nM) was shown to increase the expression of atherosclerotic and angiogenic genes while adiponectin (100nM) inhibited the expression of the atherosclerotic and angiogenic genes. A combination of leptin and adiponectin caused a reduction in the stimulatory effect of leptin on the expression of atherosclerotic and angiogenic genes. This shows that leptin may predispose to CVD while adiponectin reduces the risk of CVD. The clinical part of this study involved recruiting 150 patients with diabetes after the ethical approval for the clinical…