Endocrinology, Vol 115, 1235-1238, Copyright © 1984 by Endocrine Society

ARTICLES

Mineralocorticoid activity of 19-nor-corticosterone and 19-nor- progesterone in the toad bladder

MJ Schiff, JH Schwartz, HH Bengele, SL Dale, JC Melby and EA Alexander

19-Nor-corticosteroids are potentially important mineralocorticoids and hypertensive agents. We tested the mineralocorticoid potency of 19-nor- progesterone (19-NOR-P) and 19-nor-corticosterone (19-NOR-B) compared with aldosterone using the toad bladder short-circuit current as a measure of sodium transport. 19-NOR-B (10(-7) M) increased sodium transport to a degree not different from that caused by aldosterone (10(-7) M). The onset of action and duration of activity also were not different from those of aldosterone. 19-NOR-P (10(-7) M), however, had no effect on sodium transport. We conclude that 19-NOR-B has significant mineralocorticoid activity, while under the conditions of these studies, 19-NOR-P exhibited no effect on sodium transport.