Partial masculinization of rat liver enzyme activities following treatment with FSH

The metabolism of 4 [4 ¹⁴C]androstene 3,17 dione and 5α [4 ¹⁴C]androstane 3α,17β diol was studied in the microsomal fraction and that of 4 [4 ¹⁴C]androstene 3,17 dione in the 105,000 x g supernatant fraction of livers from castrated male and female rats treated with LH and FSH. Administration of LH led to significant decreases in 17 hydroxysteroid reduction and 7α hydroxylation of 4 androstene 3,17 dione in both male and female rats and in 6β hydroxylation of 4 androstene 3,17 dione in female rats. FSH on the other hand specifically stimulated (masculinized) the following sex dependent hydroxylations: 16α hydroxylation of 4 androstene 3,17 dione in female rats and 2α, 2β and 18 hydroxylation of 5α androstane 3α,17β diol in male rats. The metabolism of 4 androstene 3,17 dione and 5α androstane 3α,17β diol was also studied in castrated male and female rats given testosterone propionate in combination with LH or FSH. It was shown that neither LH nor FSH could compensate for the relative androgen unresponsiveness exhibited by female as compared to male rats. It is concluded that FSH but not LH may participate in the regulation of sex dependent hydroxylase systems in rat liver.