Effects of adrenalectomy and spironolactone on urinary metabolites of aldosterone in rats

• Published in: Steroids Vol. 51; no. 1-2; p. 81
• Main Authors: Gorsline, J, Morris, D J
• Format: Journal Article
• Language: English
• Published: United States 01-01-1988
• Subjects: Adrenal Glands - physiology; Adrenalectomy; Aldosterone - urine; Animals; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Injections, Subcutaneous; Rats; Rats, Inbred Strains; Spironolactone - pharmacology
• ISSN: 0039-128X
• DOI: 10.1016/0039-128X(88)90186-9

The quantities and temporal sequences of appearance of aldosterone metabolites in the urine of adrenalectomized rats, and adrenalectomized rats treated with spironolactone, were compared following subcutaneous administration of a physiological dosage (0.05 microgram) of [1,2,-3H]aldosterone. Large amounts of radiometabolites were rapidly excreted during 0-1 and 1-3 h and only small quantities by 3-4 h in urine of both groups of rats. The majority of the urinary radiometabolites (70-85%) were identified by Sephadex DEAP-LH-20 chromatography as neutral metabolites of aldosterone (NMA), together with lesser quantities of acidic, sulfate, and glucuronide conjugates. Further characterization by high pressure liquid chromatography (HPLC) showed that 90% of the NMA excreted by adrenalectomized rats were polar metabolites which could be separated into at least 15 peaks eluting in regions of increasing polarity (designated A, B, C, and D). Only small quantities of unaltered [3H]aldosterone and no ring-A-reduced metabolites were excreted by the adrenalectomized rats. Spironolactone treatment caused large changes in the excretion of acidic and sulfate derivatives of aldosterone, as well as discrete alterations in the HPLC patterns of the polar NMA (particularly those metabolites in regions A and B). Such discrete changes in these metabolic pathways which occur at the same time as the hormonal actions of aldosterone in the kidney may provide further insight into understanding the biological role of aldosterone metabolism.