INSULIN REGULATES PLASMA GHRELIN CONCENTRATIONS in STREPTOZOTOCIN-INDUCED DIABETIC RATS

Ghrelin, an orexigenic peptide produced in the stomach has shown to elicit peripheral actions including regulation of pancreatic β-cell function. The aim of the study is to clarify the regulation of plasma ghrelin concentrations by insulin in streptozotocin (STZ) induced diabetic rats. Adult male Wistar rats were divided into control and three experimental groups as each group had 7 rats (n=28). To investigate the role of ghrelin in the hyperphagic response to uncontrolled diabetes, experimental groups of rats were injected once daily for 7 days with either STZ (70 mg/kg i.p.) or insulin subcutaneously (5-7 U). Plasma insulin, ghrelin and glucose concentrations were measured. STZ-induced diabetic rats were markedly hyperphagic as accompanied by hyperglycemia. Treatment of diabetic rats with insulin reversed these changes. STZinduced diabetic rats had higher plasma ghrelin concentrations than control rats. Ghrelin levels were attenuated by the subcutaneous injection of insulin (5-7 U over 7 days). Insulin treatment also partially reversed hyperphagia observed in STZinduced diabetic rats and there was a decrease in plasma ghrelin concentrations compared with STZ-İNS pair fed rat. The results indicate that insulin treatment reverses elevated plasma ghrelin concentrations in STZinduced diabetic rats suggesting the pathophysiological significance of ghrelin in diabetes. Experimental article (J Int Dent Med Res 2014; 7: (3), pp. 78-82)