Estradiol valerate therapy and the renin--aldosterone system in castrated women

The effect of estradiol valerate (Progynova, 2 mg daily) on the renin--aldosterone system was studied in nine women after bilateral oophorectomy. Plasma renin activity (PRA) and the daily urinary excretion of aldosterone (dU-Ald) were determined 4 mth after the operation -- during which no estrogen was given -- and after 3 mth on estrogen therapy. Plasma estradiol concentration rose in 7 subjects to the normal postovulatory level. No changes were found in PRA or dU-Ald. The results suggest that an effective estradiol valerate therapy is not accompanied with activation of renin--aldosterone system, while synthetic and non-human natural estrogens (Premarin) were shown earlier to increase PRA.