Effect of thyrotrophin-releasing hormone on serum prolactin levels in men with azoospermia.

Infertile men with azoospermia and low testosterone levels because of Klinefelter's or Sertoli cell-only syndrome responded to a single injection of TRH by an increase in serum prolactin levels. The degree of this response was not as great as in fertile men with normospermia and normal testosterone levels, although initial prolactin levels had been similar in both groups. The results demonstrate a link between testosterone and prolactin levels in fertile and infertile men.