EFFECT OF HYPOPHYSIAL ISOGRAFTS ON THE MAMMARY GLANDS OF INTACT AND HYPOPHYSECTOMIZED MICE.

A single hypophysial isograft stimulated mammary lobulo-alveolar development and altered vaginal cycles of intact (RIII×CBA)F1 hybrid virgin mice. The in situ hypophysis was necessary for this graftinduced mammary growth in the intact host, since the transplants could not induce a lobulo-alveolar development in hypophysectomized mice. A hypophysial graft could partially maintain this lobulo-alveolar development after removal of the host’s own hypophysis. There appears to be a significant functional interdependence in the mouse between a hypophysial isograft and the host’s own hypophysis and ovaries. (Endocrinology 74: 586, 1964)