High affinity aldosterone binding sites (type I receptors) in rat heart.
1. The use of the receptor stabilizing agent sodium molybdate, and of RU26988 to exclude [3H]-aldosterone binding from Type II glucocorticoid receptors, has enabled the characterization of high affinity Type I aldosterone binding sites in rat atrial and ventricular cytosols. 2. In adult male and female rats the affinity of binding (Kd 4 degrees C) is approximately 1-2 nmol/l for both atria and ventricles; specificity of binding is similar to that for Type I sites in classical aldosterone target tissues (aldosterone = corticosterone much greater than dexamethasone). 3. Levels of atrial Type I sites are higher than the corresponding levels in ventricle in both males and females, whereas for Type II (classical glucocorticoid) receptors the reverse is the case; levels of both Type I and Type II sites fall over the age range examined (40 days-6 months). 4. The physiological function(s) of cardiac Type I sites, and their in vivo mineralocorticoid or glucocorticoid selectivity, remain to be explored.
Pearce
P
P
Medical Research Centre, Prince Henry's Hospital, Melbourne, Victoria, Australia.
Funder
J W
JW
D000315:Adrenalectomy; D000375:Aging / Q000378:metabolism; D000732:Androstanols / Q000494:pharmacology; D000818:Animals; D005260:Female; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D018161:Receptors, Mineralocorticoid; D012737:Sex Factors
D000732:Androstanols; D011965:Receptors, Glucocorticoid; D018161:Receptors, Mineralocorticoid; C038341:RU 26988