5Alpha-reduction and binding of testosterone in androgen-dependent and -independent mouse mammary tumors.

Abstract

5α-Reduction and intracellular binding of testosterone in the mouse mammary androgen-dependent Shionogi carcinoma 115 (SC-115) and nonresponsive Shionogi carcinoma 42 (SC-42) were examined by in vitro and in vivo methods. Experiments in vitro demonstrated that the capacity of SC-42 cells to form 5α-reduced products from testosterone was less than that of combined seminal vesicle and ventral prostate tissue and greater than that of SC-115 cells. The capacity of nonsex accessory tissues such as muscle, liver and spleen was much less. In in vivo experiments, in which 3H-testosterone (2 μg⁄310 μCi⁄ mouse) was injected into mice bearing SC-115 or SC-42, the retention at 1 hr of 3H-testosterone † 3H-5α-reduced products per g tissue in SC-115 tumor and seminal vesicle † prostate was 5–10 times that in SC-42 tumor, muscle, liver and blood. 3H-Testosterone was the main steroid found in SC-115, whereas 3H-17β-hydroxy-5α-androstan- 3-one was the main steroid in seminal vesicle† prostate. By gel filtration of nuclei ...