It is well established that estrogens and progestogens are able to influence the vasotonus
in postmenopausal women. The present study was undertaken to find out if the NO/cGMP-system
is involved in this hormone action. Urinary cGMP excretion which can reflect intracellular
cGMP production elicited by NO (EDRF) was investigated in 20 postmenopausal women.
In an open cross-over study design norethisterone acetate was administered orally
for 8 days, estradiol valerate orally for 9 days and a combination of both substances
for 12 days. After all three treatment phases urinary cGMP expressed as percentage
of the pretreatment value was increased at a statistically significant level. Due
to high individual variations no significant differences could be found among the
values after the three treatment phases. It was concluded that the NO/cGMP-system
may play a role in maintaining vasotonus in postmenopausal women under hormone replacement
therapy.
Postmenopausal women - hormone replacement therapy - urinary cGMP excretion
