Aerobic Exercise Dietary Control Of Type 2 Diabetes In Rat Vascular Endothelial Cells Of Endocrine Function

Experimental Objective:To explore the change of the endocrine function of endothelial cell in SD rats with type 2diabetes and the interactive effects of aerobic exercise training and dietary control on the endocrine malfunction of the endothelial cells and the possible mechanisms. Experimental method:62 male SD rats were 6-week-old, 8 rats were randomly selected as normal control group (Control, C group), which fed with normal standard diet. The remaining 54 SD rats were feed high-fat and high-carbohydrate diet for 6 weeks and then were injected low-dose streptozotocin though abdominal cavity to establish animal models of type 2 diabetes. and then the rats with type 2 diabetes were randomly divided into 4 groups : DM control group (DM,n=9),DM+ aerobic exercise training group (DME,n=10), DM+ Diet control group (DMD,n=10), DM+ aerobic exercise training + Diet control group (DMED,n=10). The rats in DM group were continued to feed high-fat and high-charbohydrate diet and did not exercise training. Exercise training used 60 minutes'unload swimming, 6 times per week. The dietary control used the standard diet with the same dose in the DM group. 13 weeks later, the indice of the FPG, FINS, ET-1, AGEs, NO and NOS were measured.Experimental result:(1)The 13th week after the establishment of type 2 diabetes model, compared with the control group, the FPG in DM group increased significantly (P﹤0.01), And serum insulin concentration decreases markedly(P <0.01).(2)After the model of type 2 diabetes rats were established, aerobic exercise training, dietary control and aerobic exercise united dietary control were uesd to intervent for 13 weeks. Through the two-factor analysis of variance, aerobic exercise traing could significantly lower the FPG level in type 2 diabetic rats (P <0.05 ), although the FINS level could be improved in diabetic rats but no significant difference (P> 0.05). Dietary control could significantly improve the FINS content, but not a significant reduction in FPG.. Dietary control united aerobic training could further reduce FPG and increase FINS level in diabetic rats, but there was no significant interaction(P> 0.05).(3)Compared with the control group, the plasma ET-1 concentration in DM group increased remarkably(P <0.05) and the serum NO concentration reduced significantly(P <0.01), which resulting in ET-1/NO increased significantly(P<0.01). And the SBP and DBP also rised remarkably(P <0.01). In the maintime, the aortic ET-1 concent in DM group rises markedly(P <0.05), total NOS and cNOS activity were significantly reduced (P <0.05 vs P <0.01).(4)Aerobic exercise training could reduce plasma ET-1 level (P <0.05) and raise plasma NO level (P <0.05) , improve the disproportion of ET-1 and NO(P <0.01), and lower the SBP and DBP in T2DM rats (P <0.05). At the same time, aerobic exercise training could decreased plasma AGES and aortic ET-1 levels in T2DM rats, but there were no significant difference(P> 0.05).However aortic cNOS activity increased significantly(P <0.05).(5)Although dietary control did not have a remarkable effect on the NO level (P> 0.05)in T2DM rats, it could lower the plasma ET-1level (P <0.01) and improve the disproportion of the ET-1 and NO(P <0.05), which could lower the SBP and DBP in T2DM rats(P <0.01,P <0.05). At the same time, dietary control had no significant impact on aortic ET-1 levels (P> 0.05) in T2DM rats, but significantly increased total aortic NOS and cNOS activity (P <0.05) , and significantly reduced plasma AGES concentration (P <0.05).(6)Although aerobic exercise training united dietary control could raise plasma NO concent, it had no marked interactive effects(P> 0.05), However, it had a remarkable interactive effects on lowering plasma ET-1 concentration(P <0.01)and ET-1/NO(P <0.05). Although dietary control united aerobic exercise training could further reduce plasma AGEs content and aortic ET-1 content in diabetic rats, there were no significant interaction (P> 0.05).Conclusion:(1)A 8-week of high fat and high carbohydrate as well as small dose of STZ could indued the normal rats to form T2DM.(2)On the base of the dietary control, aerobic exercise training was more effective to reduce the fasting plasma glucose levels in diabetic rats.(3)The increase of plamsa AGES might result in disorder of the endocrine function of endothelial cells by inducing the injury of endothelial cells in T2 DM rats.(4)Aerobic exercise training could increase the synthesis and secretion of the NO by increasing the cNOS activity in aorta to improve the endocrine disorder in T2DM rats,mainwhile it play an important role in maintaining a normal blood presure in the diabetes rats. It remains unclear whether can improve the endocrine function of the endothelial cells by decreasing the generation of the AGEs.(5)Dietary control might improve the endocrine fuction of the endothelial cells by increaseing NOS activity in aorta and decreasing the generation of the AGEs,which in favor of maintainning the stable of blood pressure.(6)To some extent, aerobic exercise training united dietary control play an interactive role on improving the endothelial cells in T2 DM rats. But the interactive effect of aerobic exercise training and dietary control on plasma AGEs concentration in T2 DM rats had to be further studied yet.