抄録
After gonadectomy and subsequent daily supplements of 17β-estradiol or testosterone propionate, the anterior pituitary of rats was excised intact, incubated in vitro with 14C-leucine, and the radioactivity incorporated into prolactin and growth hormone was counted. Employing appropriate parameters calculated from hormone radioactivity counts both in the incubated tissue and the incubation medium, two unit functions of the anterior pituitary, hormone synthesis and release, were studied. The results showed that in female rats both estrogens and androgens enhance prolactin synthesis and release functions, and also growth hormone release function, but depress the growth hormone synthesis function. In male rats, androgens do not appear to be effective with any of the pituitary functions studied, but estrogens are similarly effective as in female rats. These findings indicate that estrogens play an essential role in controlling both synthesis and release of prolactin and also of growth hormone in female rats, but androgens do not play any significant role in male rats. Our results, obtained from direct measurements of two unit functions of the pituitary, were compared with numerous previous studies, in which indirect functional parameters of the pituitary were employed. In addition, acute effects of the gonadal steroids as the result of a single injection were presented, the results of which were partially consistent with chronic effects mentioned above.
