Sex steroids, hypertension and menopause: Positive effects of angiotensin converting enzyme inhibition on aorta and renal nitric oxide system.

ZILBERMAN JUDITH; ROMERO MARIANA; ELESGARAY ROSANA; COSTA MARIA DE LOS ANGELES; ARRANZ CRISTINA

Colorado, USA

Conferencia; APS Conference: Sex and gender in cardiovascular -Renal Physiology and Pathophysiology.; 2009

American Physiology Society

Background: Sex steroids change and cardiovascular risk increases after menopause. Estradiol may provide cardiovascular protection by controlling the rennin-angiotensin system. Objective: To evaluate the effects of the ACE inhibitor enalapril on systolic blood pressure (SBP (mm Hg)), sex steroids and NO synthase (NOS) activity in the aorta and kidney in spontaneously hypertensive postmenopausal rats (SHR) Methods: 16-month old SHR received enalapril (SHR-E, 250 mg/L, drinking water) or tap water (SHR-C) for 30 days. At the end of treatment, NOS activity (pmol.14C-citrulline/g tissue.min) was measured in aorta and renal cortex and medulla. Plasma sex steroids: testosterone, estradiol, dehydroepiandrosterone and dehydroepiandrosterone sulfate were measured. Results: Enalapril decreased SBP and increased NOS activity in the kidneys and aorta of SHR. No changes in sex steroid levels were observed.   SBP NOS activity Aorta NOS activity Cortex NOS activity Medulla SHR-C n=6 174±8 362.4±9.2 395.3±7.1 496.0±7.3 SHR-E n=6 152±9# 412.3±14.9* 471.4±3.8* 584.8±7.4* * p<0.05 or #p<0.01 vs control.              Conclusions: Although sex steroid plasma levels were not modified by treatment, our results evidence that ACE inhibition improves vascular and renal NO system in kidneys of postmenopausal hypertensive rats. This fact could be beneficial for the renal functionin menopausal stage. These data clearly supports the therapeutic benefits of inhibition of renin angiotensin system in hypertensive menopausal women.