[Nitric oxide changes aortic function in rats with renal hypertension].

Abstract

This work was undertaken to investigate the effect of nitric oxide (NO) on aortic function of two-kidney and one-clip (2K1C) rats with renal hypertension. Animals were divided into 5 groups: the sham operation, 2K1C, captopril, L-arginine and L-NAME groups. The results are as follows. At the 4th week after constriction of the left renal artery, the mean arterial pressure was significantly elevated. In isolated aortic rings, acetylcholine-induced dilation was attenuated, and phenylephrine induced contractile response was markedly enhanced. The level of aorta cGMP content was significantly lowered. These changes were abolished in 2K1C rats treated with captopril. L-arginine partially reversed the aortic vascular reactivity of 2K1C rats, and elevated aortic cGMP content. In 2K1C rats treated with nitric oxide synthase inhibitor, L-NAME, blood pressure was increased further, acetylcholine-induced aorta diastolic response was attenuated further and cGMP content reduced, while phenylephrine-induced contractile response was unaffected. These results suggest that deficiency of nitric oxide production and increase in renin-angiotensin system activity may contribute to vascular endothelial dysfunction of 2K1C rats, and these factors may be involved in development and maintenance of 2K1C renal hypertension.