Objective: To 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.
Methods: The 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).
Results: The 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).
Conclusions: The 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.