Changes of eNOS and Ser1179 activity in myocardial tissue of hypertensive rats at different stages

Abstract

Objective To observe endothelial nitric oxide synthase (eNOS) protein expression in myocardial tissue of hypertension rats at different periods and its related regulation with loci Ser1179 phosphorylation levels,NOS activity and NO yield changes,to explore the relationship between blood pressure and eNOS in myocardial tissue.Methods 24 SD rats were randomly divided into four groups,control group 2 w,4 w and hypertension group 2 w,4 w,6 in each group,producing two-kideny two-clip renovascular hypertensive rats model (2k2c RH model).Blood pressure of rats was detected by rat tail pressure measuring method,eNOS,P-NOS (P-Ser1179) protein expression in myocardial tissue by Western Blot,NO in myocardial tissues by nitrate reductase method.Result Compared with the control group,eNOS protein expression and Ser1179 phosphorylation level in myocardial tissue of RH rats didn't obviously change after 2 weeks (P ＞ 0.05),but increased significantly after 4 weeks (P ＜ 0.01).Conclusions 2k2c RH rats myocardial tissue exists eNOS changes in protein expression and activity,has an important compensatory eNOS adjust action,which may be related to stimulation of Ser1179 phosphorylation level and NOS activity caused by increased blood pressure. Key words: Nitric oxide synthase; Phosphorylation; Renovascular hypertension