Effects of unilateral cryptorchidism on the expression of gonadotropin receptor mRNA

Expression patterns of mRNAs of FSH and LH receptors were examined by Northern blot in adult rat testes after induction of unilateral cryptorchidism. At 4 weeks after the operation, signals of Northern blot were markedly increased in both receptor mRNAs in the abdominal testes as compared to those in the scrotal testes. In addition, there was a remarkable change in size pattern of LH receptor transcripts; the scrotal testes of cryptorchid rats and the intact testes of control rats expressed the transcripts of 7.0, 4.3, 2.5, and 1.8 kb, while the abdominal testes hardly expressed the transcript of 1.8 kb. This finding suggests that the expression of LH receptor mRNA is regulated locally within testis.