[Bromocriptine and prostatic carcinoma: testosterone metabolism in relation to tumor grading (author's transl)].

Since Prolactin has intra- and extrapostatic effects on growth and function of the prostate, the influence of the anti-prolactin bromocriptine (PRAVIDEL) was investigated in 15 patients with untreated prostatic carcinoma of various grades of differentiation in vivo. A five-days treatment with 15 mg Pravidel daily significantly suppressed prostatic androgen uptake, unrelated to tumor grading. 5 alpha-Reductase was favored in poorly differentiated lesions with a decreased testosterone/dihydrotestosterone ratio. The pretherapeutic accumulation of 5 alpha-androstanediol was diminished after Pravidel and the tissue/plasma ratio decreased. The 17 beta-hydroxy-pathway of testosterone is predominant as compared to the 17-keto pathway; both pathways are favored after Pravidel in poorly differentiated tumors. Intraprostatic metabolic effects of Pravidel are not related to peripheral androgen levels nor are they dependent on altered prostatic hormone uptake. In the poorly differentiated prostatic tumors Pravidel initiates a metabolic situation as observed in prostate cancer responding to androgen depletion or estrogen therapy.