The feminisation of gonadotrophin responses in intact male transsexuals.

In castrated animals and hypogonadal men other workers have shown an LH surge following oestrogen administration similar to that found in the normal female. However, there is no evidence that this can be achieved in intact males. We have therefore studied male transsexual patients before and after chronic oestrogen therapy given for at least three months to feminise the body habitus before undergoing plastic surgery. Subjects were assessed for the acute effects of oestradiol valerate on sex steroid hormone levels and gonadotrophin responses to gonadotrophin releasing hormone. The results showed that longterm treatment could transform the normal male pattern of a suppressive effect of oestrogen on gonadotrophin release to one where the oestrogen increased LH levels and amplified the effect of LHRH on gonadotrophin release. This pattern is similar to that found in normal women and indicates that longterm oestrogen treatment to males can feminise gonadotrophin responses.