Abstract
Summary and Conclusions
Mammary tissues from A/Crgl and C3H/Crgl strains of mice were transplanted into mammary gland-free fat pads of female hybrids (C3H × A, AX C3H). The hosts were hypophysectomized-ovariectomized, and treated with estradiol + progesterone + somatotropin for 21 days. Half of them received an additional 5 days treatment with Cortisol + somatotropin. On the basis of the lobuloalveolar mammogenic and lactogenic responsiveness of the A, C3H, and hybrid mammary tissues to the hormone combinations used, the following general conclusions were drawn: 1. There is a quantitative difference in lobuloalveolar mammogenic response of A/Crgl and C3H/Crgl mammary tissues to the somatotropin-containing hormone combination, degree of response being greater in the C3H/Crgl mammary gland. 2. There appears to be a qualitative difference in lactogenic response of A and C3H mammary tissue to the somatotropin-containing combination. 3. The occurrence of milk secretion in mammary glands of hybrids (A × C3H, C3H × A) and in C3H mammary transplants, and its absence from A transplants, indicate that the genetic determinant for mammary gland sensitivity to the somatotropin-containing hormone combination must lie in the mammary tissue itself, and that this can be transmitted by either male or female C3H parent to the hybrid offspring.
Get full access to this article
View all access options for this article.