Association of gastric emptying with expression of ghrelin receptor in model of rats with type 2 diabetes meilitus

Objective To investigate the relationship between expression of ghrelin receptor and gastric emptying.Methods The rats were divided into normal control group,simple obesity group and type 2 diabetes group.The rats in simple obesity group and type 2 diabetes group were given highglucose and high-fat diet.At the end of 8th week,the rats in type 2 diabetes group were injected with STZ into peritoneal cavity.The body weight and the levels of blood glucose and insulin were detected.Gastric emptying was measured by intragastric administration of phenolred.Moreover,real-time PCR was used to examine the expression of ghrelin receptor mRNA in the hypothalamus and gastric tissue.Results At the end of 8th week,the body weight and insulin level in type 2 diabetes and simple obesity groups were increased significantly compared with normal control group (P＜0.01),whereas the increase of blood glucose level in type 2 diabetes and simple obesity groups was no statistical difference with that of normal control group (P＞0.05).The insulin level was decreased in type 2 diabetes group after injection of STZ,and blood glucose level was increased significantly (P＜0.01).Gastric emptying was delayed in type 2 diabetes and simple obesity groups (P＜0.05).The mRNA expression of ghrelin receptor in hypothalamus and gastric tissue of type 2 diabetes rats was decreased,which showed a positive correlation with decrease of gastric emptying (P＜0.05).Conclusion The decreased expression of ghrelin receptor mRNA in hypothalamus and gastric tissue may involve in the delayed gastric emptying by reducing the effect of ghrelin.\r\n\r\nKey words: \r\nDiabetes mellitus; type 2; Receptors; ghrelin; Gastric emptying; Disease models; animal