The Effect Of Angiotensin(1-7) On The Expression Of PDX-1 Protein In Pancreatic Islets Of Diabetic Rats

Objective:1.To compare the levels of blood glucose,serum insulin,angiotensin II and the expression of PDX-1 protein in islet tissue of three groups.2.To investigate whether the ACE2-Ang-(1-7)-Mas axis can improve the function of islet ?cells by up-regulating the expression of PDX-1 protein.Methods:A total of 34 healthy,male Wistar rats(8 weeks old,weighing160-200g)were selected and fed the normal diet for 1 week.10 rats were selected randomly as normal control group(group A,n = 10),and the normal diet was fed until the experiment was terminated.The other 24 rats were given high-fat and high-calorie diet.After 8 weeks,a single intraperitoneal injection of low-dose streptozotocin(30mg/kg)induced type 2diabetic rat models.20 diabetic rats were survival and randomly divided into two groups:10 rats in diabetic control group(group B,n = 10)and 10 rats in Ang-(1-7)intervention group(group C,n = 10).Group C was subcutaneously injected with Ang-(1-7)300ug/kg/d,group A and B were given equal volume of normal saline intervention,three groups of each intervention for 8 weeks.After the above treatments were completed,testing the body weight,fasting blood glucose,serum insulin and serum angiotensin II levels in the three groups,calculating homeostasis model assessment of insulin resistance index(Homa-IR).Anatomically removing rat islet tissue,using western blot to detect the protein expression of PDX-1 in islets.Results:Compared with group A,the weight in group B was increased(P <0.05);the levels of fasting blood glucose,angiotensin II and Homa-IR were increased(P <0.05);the serum insulin was decreased(P <0.05).Compared with group B,there was no significantdifference in body weight between group C(P> 0.05).However,fasting blood glucose,angiotensin ? and Homa-IR were decreased(P <0.05)and serum insulin was increased(P <0.05).Using ?-actin as a reference,the results of Western blot of PDX-1 in islet tissue of three groups of rats showed that the content of PDX-1 in islet tissue of group C was increased.The expression level of PDX-1 in the pancreatic tissue of group A was set to1,and group B was 0.66±0.06,group C was 0.75±0.04.Conclusions:The results showed that Ang-(1-7)-Mas axis activity was up-regulated after treatment with Ang-(1-7)in diabetic rats,which could increase the expression of PDX-1,improve the function of islet ? celll,Delay the development of type 2 diabetes.