OBJECTIVETo observe the effect of estrogen and progestin on the blood levels of nitric oxide and angiotensin II in aid of the application of hormone replacement therapy in postmenopausal women.

METHODSThe serum nitric oxide and plasma angiotensin II levels in postmenopausal women were determined before and 3 months after oral intake of estradiol valerate 1 mg/day (n = 10) or estradiol valerate, 1 mg/d plus medroxyprogesterone acetate, 2 mg/d (n = 30).

RESULTSThe serum nitric oxide levels of postmenopausal women were significantly increased by 3 months of oral estradiol valerate 1 mg/d (P < 0.05), whereas the plasma levels of angiotensin II tended to decrease. The positive correlation between the increases of nitric oxide and the changes of estradial 3 months after oral intake of estradiol valerate 1 mg/d was significant. Compared with the baseline, no significant changes were observed in both serum nitric oxide levels and plasma angiotensin II levels 3 months after oral intake of estradiol valerate, 1 mg/d plus medroxyprogesterone acetate, 2 mg/d (P < 0.05).

CONCLUSIONSThe vascular functions can be improved through increasing the serum nitric oxide level after 3-month oral intake of estradiol valerate, 1 mg/d in postmenopausal women, and estradiol valerate plus medroxyprogesterone acetate intake may attenuate the beneficial effects.