Mineralocorticoid activity of 19-hydroxyaldosterone, 19-nor-aldosterone, and 3 beta-hydroxy-delta 5-aldosterone: relative potencies measured in two bioassay systems.
The mineralocorticoid (MC) activities of 19-hydroxyaldosterone (19-OH-Aldo) and 19-nor-aldosterone (19-nor-Aldo) were tested in adrenalectomized male rats. Potency was assessed by three criteria. Overall MC activity is expressed as the ability to decrease the urinary Na+ to K+ ratio; antinatriuretic activity is represented by decreases in the urinary Na+ to creatinine ratio, and kaliuretic activity by increases in the K+ to creatinine ratio. All measurements were made on urine collected 1-3 h postinjection. In this assay, 19-OH-Aldo was 1/100th to 1/140th as active as Aldo, and 19-nor-Aldo possessed MC activity similar to that of Aldo; both steroids possessed antinatriuretic and kaliuretic activities. In contrast, when assayed in vitro in the isolated toad urinary bladder, the natriferic responses of both 19-OH-Aldo and 19-nor-Aldo (10(-8), 10(-7), and 10(-6) M) were not significantly different from those caused by equivalent concentrations of Aldo. 3 beta-Hydroxy-delta 5-Aldo is active as a MC in the adrenalectomized male rat, being 1/20th to 1/35th as active as Aldo, but, in contrast to 19-OH-Aldo, was less active in the isolated toad bladder system. 19-OH-Aldo, 19-nor-Aldo, and 3 beta-hydroxy-delta 5-Aldo could represent important new classes of Aldo analogs.
D000315:Adrenalectomy; D000450:Aldosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001681:Biological Assay; D002024:Bufo marinus; D004305:Dose-Response Relationship, Drug; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D011188:Potassium / Q000652:urine*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism
C048926:3-hydroxy-delta(5)-aldosterone; C046369:19-hydroxyaldosterone; D000450:Aldosterone; C027514:19-noraldosterone; D012964:Sodium; D011188:Potassium