AJP - Endocrinology and Metabolism, Vol 239, Issue 2 109-E112, Copyright © 1980 by American Physiological Society
Adrenal of male dog secretes androgens and estrogens
R. J. Santen, E. Samojlik, L. Demers and E. Badder
In the absence of functioning gonads, the adrenal is an important source of
androgens and estrogens. In order to precisely quantitate the adrenal
secretion rates of the sex steroids, we cannulated the adrenal veins and
measured venous blood flow and arterial venous steroid gradients in adult
male beagle dogs under pentobarbital anesthesia. Celite chromatography and
specific radioimmunoassays were utilized to measure steroid levels. During
basal conditions, the adrenal produced larger amounts of the androgens (667
ng/min of androstenedione, 5.45 ng/min of testosterone, and 3.43 ng/ min of
dihydrotestosterone) than of the estrogens (1.245 ng/min of estradiol and
0.239 ng/min of estrone. These secretion rates were 20- to 50,000-fold less
than that of cortisol (12,360 ng/min). Studies were also carried out during
adrenal suppression with hydrocortisone to block ACTH release and with the
adrenal steroidogenesis inhibitor, aminoglutethimide, plus hydrocortisone.
The secretion rates of each androgen measured fell during ACTH inhibition.
Significant suppression of estrone and estradiol, however, required
addition of aminoglutethimide. This study provides direct evidence that the
adrenal in the male dog can secrete estrogens, a previously controversial
issue.
