The Effect Of Piyanning On Insulin Resistance And The Release Of Nitric Oxide From Endothelial Cells In Rats With Impaired Glucose Regulation

Purpose:To study the effect of Chinese herbal compound Pidan Ning on insulin resistance and release of nitric oxide from vascular endothelial cells in rats with impaired glucose regulation.Materials and methods:One hundred SPF grade Wistar male rats aged 60 to 70 days were randomly selected 20 as normal control group according to their body weight,and the rest were models of impaired glucose regulation.After 12 weeks of basal diet and high sugar and high fat diet,the oral glucose tolerance test(OGTT)was carried out.After confirming the success of impaired glucose regulation model,the rats with impaired glucose regulation were randomly divided into model group,Pidan Ning treatment Group and metformin treatment group.each group randomly selected six rats for weight,Six rats in each group were randomly selected to measure their body weight,fasting blood glucose(FBG)and fasting insulin(FINS).Insulin resistance was evaluated by hyperinsulinemic euglycemic clamp technique,and then blood was collected from abdominal aorta.Nitric oxide were determined by the colorimetric method of nitrate reductase,and then the rats were killed.The other rats in each group were treated with the corresponding drugs for 4 weeks.After the treatment,6 rats in each group were randomly selected for the same operation.At the end of the experiment,all rats were killed and the correlation between nitric oxide and insulin resistance was analyzed.Results: 1.Evaluation of rat model of insulin resistance: Before the drugs intervention,glucose infusion rate of model control group,Pidan Ning group and metformin group rats was significantly lower than that in normal control group,and between the three groups of fasting insulin and glucose infusion rate had no significant difference(P>0.05).After drug treatment,glucose infusion rate Pidan Ning group and metformin group was significantly lower than that in normal control group(P<0.01),but were significantly higher than those in the model control group(P<0.01),and glucose infusion rate between the two groups had no significant difference(P>0.05).2.Evaluation of nitric oxide release from vascular endothelial cells: Before drugs treatment,the levels of serum nitric oxide of model group,Pidan Ning group and metformin group rats were significantly lower than the normal control group(P<0.01),and there was no significant difference between the serum NO levels of three groups(P>0.05);after drug treatment,the levels of serum nitric oxide of Pidan Ning group and metformin group were significantly lower than the normal control group(P<0.01),but were significantly higher than those in the model control group(P<0.01),and there was no significant difference of treatment between Pidan Ning group and metformin treatment group(P > 0.05).3.The correlation between insulin resistance and the level of nitric oxide released by endothelium.There is a significant positive correlation between the level of nitric oxide released from the endothelium and the rate of glucose infusion(r=0.785,P<0.01).Conclusion:1.Pidan Ning can obviously improve the insulin resistance of the rats with impaired glucose regulation.2.Pidan Ning can significantly increase the level of nitric oxide released by vascular endothelial in rats with impaired glucose regulation.3.The Pidan Ning can increase the level of nitric oxide released by vascular endothelial by ameliorating insulin resistance in rats with impaired glucose regulation.