Tissue interaction in androgen response of embryonic mammary rudiment of mouse: identification of target tissue for testosterone.

Abstract

In the androgen response of the embryonic mammary rudiment of the mouse, both gland epithelium and surrounding mesenchyme were visibly involved. The question whether this was due to a direct action of testosterone on both tissues was investigated in experimental combinations of mammary epithelium and mammary mesenchyme, derived either from normal or from androgen-insensitive (XTfm/Y) embryos. A typical androgen response occurred in combinations of androgen-insensitive epithelium with normal mesenchyme, whereas all combinations of normal epithelium with androgen-insensitive mesenchyme failed to respond. Only the mesenchyme of the mammary rudiment was the target tissue for testosterone, and all changes in the gland epithelium, including its necrosis, were secondarily caused by testosterone-activated mesenchymal cells.