Effects of angiotensin- (1-7) on endothelial dysfunction in rats with coarctation-induced hypertension

Objective: To investigate the effects of angiotensin- (1-7) on endothelial dysfunction in rats with coarctation-induced hypertension. Methods: Hypertensive rat models were induced by constriction of abdominal aorta. Forty-five male Sprague Dawley rats were randomly divided into sham-operation group, model control group and angiotensin- (1-7) group. They were treated with intravenous infusion of angiotensin- (1-7) (25 microgram/kg per hour) or saline after operation. The levels of blood pressure and plasma NO2 -/NO3 - were determined at 4 weeks after operation. Acetylcholine (Ach) -induced vasodilation was measured in thoracic aorta. Western blot analysis was performed to valuate the eNOS and iNOS protein expression of aorta. Results: The levels of blood pressure and plasma NO2 -/NO3 - in model control group were significantly higher than those of sham-operation group. Compared with sham-operation group, Ach-induced vasodilation was decreased, the expression of eNOS was decreased and the expression of iNOS was increased in model control group. The levels of blood pressure and plasma NO2 -/NO3 - in angiotensin- (1-7) group didn't change compared with those in model control group. However, angiotensin- (1-7) improved the vasdilation response of aorta to Ach, and normalized the expression of eNOS and iNOS. Conclusion: Angiotensin- (1-7) can improve vascular endothelial dysfunction by promoting eNOS protein expression in rats with coarctation induced hypertension.