Nuclear uptake of sex steroid hormones in the cardiovascular system of the baboon.

Cardiac and arterial tissues of six male and six female adult baboons were examined for nuclear uptake of tritiated 5-alpha-dihydrotestosterone (3H-DHT) or tritiated estradiol-17 beta (3H-E2) by autoradiography. 3H-DHT uptake occurred in nuclei of most atrial and ventricular myocardial fibers, no cardiac interstitial tissues, some arterial endothelial cells, most smooth muscle cells of the intima and inner arterial media, and a few smooth muscle cells of the outer arterial media. 3H-E2 uptake occurred in nuclei of a few atrial and ventricular myocardial fibers, many cardiac interstitial cells, occasional arterial endothelial cells, a few smooth muscle cells of the intima and inner arterial media, smooth muscle cells of the outer arterial media, and nearly all adventitial cells. These observations are consistent with other autoradiographic and biochemical findings which indicate that the heart and major arteries of several mammalian species contain androgen and estrogen receptors in distinctive patterns of distribution among muscle and connective tissue cells.