The Effect of Spironolactone on the Renal Arterioles Remoderling in Nω-nitro-L-arginine-methyl ester（L-NAME）/salt induced hypertensive rats

Objective To determine the effect of spironolactone, a nonselective aldosterone antagonist on renal arterioles remoderling in Nω-nitro-L-arginine-methyl ester（L-NAME） and salt induced hypertension . Methods Thirty male SD rats were randomly received tap water group C（n7）, L-NAME （50 mg/kg·d）（group L n7）, L-NAME （50 mg/kg·d） plus spironolactone （20 mg/kg·d） （group S n8）, or L-NAME （50 mg/kg·d） plus high dose of spironolactone （100 mg/kg·d） （group B n8）. All rats were fed with 1 salt water except group C. Eight weeks later all the rats were sacrificed and the left kidney was separated. Plasma aldosterone level was measured. The renal rascular vessel chamber diameter （CD）, area（CA）, the vessel middle layer thickness（MT） and area（MA） and the ratio of middle layer thickness to chamber diameter（M/C） were calculated. The ratio of middle layer fiber area to middle layer area was determined. Results There were significant differences in the tail blood pressure among the four groups （F19.799, P＜0.001）. Hypertension was established in group L,S,B. The blood pressure in group B were lower than that in group L and S（P＜0.05）. Significant differences were found in the CD（F6.314,P0.003）, MT（F11.363,P＜0.001）, CA（F4.592,P0.012）, M/C（F22.544,P＜0.001）and the fibrosis in the middle layer（F18.729,P＜0.001）of the renal arterioles among the four groups. Conclusion Spironolactone prevent the renal arterioles remoldeling in Nω-nitro-L-arginine-methyl ester（L-NAME） and salt induced hypertensive rat. This favorable effect was analogous in both low and high doses of spironolactone and appeared to be independent of the blood pressure.