[The effect of estrogen replacement therapy on plasma nitric oxide levels in postmenopausal women].

OBJECTIVE

To investigate the effect of estrogen replacement therapy (ERT) on plasma nitric oxide (NO) levels in postmenopausal women (PMW).

METHODS

The plasma concentrations of NO and serum concentrations of estradiol (E2) were assessed before and 4 weeks after placebo or ERT administration in 10 cases of healthy PMW (control group), 17 cases of healthy PMW (healthy group) and 21 cases of PMW with hyperlipidemia (hyperlipidemia group) respectively.

RESULTS

There was no difference in NO concentrations between before and after placebo administration in control group. In healthy and hyperlipidemia groups, the mean concentrations of NO were significantly higher 4 weeks after ERT administration than baseline. The positive correlation between the mean percent increase of NO and the E2 concentrations after ERT administration was statistically significant in healthy group.

CONCLUSION

The increase of plasma NO concentrations caused by ERT may contribute to it cardiovascular protective effect in PMW.