Impact of enalapril on blood pressure and the nitric oxide system in normotensive menopausal rats

ZILBERMAN JUDITH; VEIRAS LUCIANA; MINOTTI N; BIANCCIOTTI A; VILLAMIL A; COSTA MARIA DE LOS ANGELES; ARRANZ CRISTINA

Berlín. Alemania.

Congreso; Eighteenth European Meeting on Hypertension.; 2008

European Society of Hypertension. International Society of Hypertension.

Several studies suggest that oxidative stress, renin-angiotesin system activation and an impaired nitric oxide (NO) system associated to the sexual hormones status play a role in hypertension during menopause in experimental models. However, the mechanisms involved are still unknown. Objective: The aim of the present study was to evaluate the effects of enalapril, an inhibitor of the angiotesin-converting enzyme (ACE), on systolic blood pressure (SBP), NO syntase (NOS) activity and sexual hormones in normotensive menopausal rats. Methods: Normotensive female Wistar rats were ovariectomized, and ten weeks later were divided into two groups: one was treated with enalapril for 30 days (15 mg/Kg/ day) whereas the control group received tap water. We measured indirect SBP, NOS activity (14C-arginine) in the kidney, aorta and heart, and androgen, estradiol and FSH plasma levels at the end of treatment. Results: SBP showed no changes in response to enalapril. Similarly, this treatment did not induce any changes in estradiol, androgen and FSH plasma levels. NOS activity (pmol/min 100g tissue), * p<0.01 vs Control Renal Cortex Renal Medulla Right Atria Left Ventricle Aorta Artery Control 370.5±8.1 430.7±16.3 318.3±3.2 218.5±5.3 267.0±4.2 Enalapril treatment 396.0±6.7* 498.3±5.8* 341.8±5.8* 243.8±7.2* 306.2±7.0* Conclusion: Enalapril treatment significantly improved NOS activity in all the tissues studied. However, the ACE inhibition did not modify either SBP or sexual hormones in normotensive menopausal rats. Enalapril treatment might improve both renal and cardiovascular function during menopause.