Effects of 6- and 7-hydroxy metabolites of 3β,17β-dihydroxy-5α-androstane on gonadotrophin and prolactin secretion and on sex accessories weight of male rats

It has recently been shown that 3β,17β-dihydroxy-5α-androstane (3β-diol), a known testosterone metabolite, may be further hydroxylated in position 6 and 7. Because of the possible involvement of 3β-diol in the control of gonadotrophin secretion, this work was aimed at investigating the effects of 3β,6α,17β-trihydroxy-5α-androstane (6α-triol), 3β,7α,17β-trihydroxy-5α-androstane (7α-triol), 3β,6β,17β-trihydroxy-5α-androstane (6β-triol) and 3β,7β, 17β-trihydroxy-5α-androstane (7β-triol) on the secretion of LH, FSH and prolactin in long term castrated male rats. The four triols, 3β-diol and 3α,17β-dihydroxy-5α-androstane (3α-diol), used for comparison, were given in a single subcutaneous dose of 2 mg/rat. Animals were killed 2, 5, 8 and 24 h after injection. None of the six steroids produces any significant effect on serum levels of FSH and prolactin at the 4 time intervals considered. On the contrary, LH levels are significantly reduced 2, 5 and 8 h after the injection of 7β-triol. This effect appears rapidly but is short lasting, since it disappears in the 24 h blood sample. 3α-Diol also inhibits LH secretion but at later time intervals (8 and 24 h). None of the other steroids has any significant effect on serum LH levels. The four triols administered at the daily dose of 2 and 4 mg/rat for 6 days are totally ineffective in increasing the weight of the ventral prostate and of the seminal vesicles of prepuberal castrated male rats.