Hyperprolactinemia and steroid metabolism by rat mammary adenocarcinomas.

The metabolism of both testosterone and dehydroepiandrosterone by 10 adenocarcinomas induced and grown in the presence of high prolactin (plasma prolactin greater than 220 ng/ml) was compared with the metabolism of 10 adenocarcinomas induced and grown in the presence of normal levels (plasma prolactin less than 60 ng/ml). The tumors associated with high prolactin significantly metabolized more testosterone to both 5alpha-dihydrotestosterone and 5alpha-androstanediol. The metabolism of dehydroepiandrosterone was similar in both groups of tumors. It is concluded that prolactin may differentially influence the metabolism of C19 steroids by rat mammary adenocarcinomas.