Time-dependent aldosterone metabolism in toad urinary bladder

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Am. J. Physiol.; (United States)

OSTI ID:6939311

Brem, A S; Pacholski, M; Morris, D J

Aldosterone (Aldo) metabolism was examined in the toad bladder. Bladders were incubated with (/sup 3/H)aldosterone (10(-7) M) for 5 h, 1 h, or 10 min. Tissues were analyzed for metabolites using high-pressure liquid chromatography (HPLC). In separate experiments, Na+ transport was assessed by the short-circuit current (SCC) technique. Following a 5-h tissue incubation, about 25% of the (/sup 3/H)-aldosterone was converted into metabolites including a polar monosulfate metabolite, 20 beta-dihydroaldo (20 beta-DHAldo), small quantities of 5 beta-reduced products, and a variety of 5 alpha-reduced Aldo products including 5 alpha-DHAldo, 3 alpha,5 alpha-tetrahydroaldo (3 alpha,5 alpha-THAldo), and 3 beta,5 alpha-THAldo. Tissues metabolized approximately 10% of the labeled hormone into the same compounds by 1 h. Measurable quantities of these metabolites were also synthesized by bladders exposed to Aldo for only 10 min and then incubated in buffer for an additional 50 min without Aldo. Bladders pretreated with the spironolactone, K+-canrenoate (3.5 X 10(-4) M), and stimulated with Aldo (10(-7) M) generated a peak SCC 44 +/- 6% of that observed in matched pairs stimulated with Aldo (P less than 0.001; n = 6). K+-canrenoate also markedly diminished (/sup 3/H)aldosterone metabolism at both 5 and 1 h. Thus, metabolic transformation of Aldo begins prior to hormone-induced increases in Na+ transport. Both the generation of certain metabolites (e.g., 5 alpha-reductase pathway products) and the increase in Na+ transport can be selectively inhibited by K+-canrenoate.

• Research Organization: Rhode Island Hospital, Providence (USA)
• OSTI ID: 6939311
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 254; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ALDEHYDES
ALDOSTERONE
ALKALI METALS
BLADDER
BODY
CHROMATOGRAPHY
CORTICOSTEROIDS
ELEMENTS
HYDROXY COMPOUNDS
IN VITRO
KETONES
LABELLED COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MEMBRANE TRANSPORT
METABOLISM
METABOLITES
METALS
MINERALOCORTICOIDS
ORGANIC COMPOUNDS
ORGANS
PREGNANES
RESPONSE MODIFYING FACTORS
SEPARATION PROCESSES
SODIUM
STEROIDS
TIME DEPENDENCE
TRITIUM COMPOUNDS
URINARY TRACT