title: Mineralocorticoid activity of 19-nor-corticosterone and 19-nor-progesterone in the toad bladder.
abstract: 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.
mesh_terms: D000450:Aldosterone / Q000494:pharmacology; D000818:Animals; D002024:Bufo marinus; D003345:Corticosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D004594:Electrophysiology; D009652:Norpregnenes / Q000494:pharmacology*; D009653:Norprogesterones / Q000494:pharmacology*; D001743:Urinary Bladder / Q000187:drug effects* / Q000502:physiology
chemical_list: D009652:Norpregnenes; D009653:Norprogesterones; C030703:19-norprogesterone; C027516:19-norcorticosterone; D000450:Aldosterone; D003345:Corticosterone