Immunohistochemical observation on luteinizing hormone in rat testes before and after testicular capsulotomy.

Aim: In the testicular capsulotomized rats, although there was a significant increase in the luteinizing hormone (LH) levels, the secretion of testosterone remained low. In order to clarify the mechanisms of this phenomenon, the binding of endogenous LH to the testes were observed before and after testicular capsulotomy.

Methods: Peroxidase-antiperoxidase (PAP) method was used to detect the binding of LH to the testes in rats.

Results: An intense positive staining of LH was found in the Leydig cells of both the normal and sham-operated control testes. However, at 40 d after operation, the LH immunoreactivity was decreased in the Leydig cells of the capsulotomized testis. By d 60, only very weak positive staining could be observed in these cells.

Conclusion: A progressive reduction of endogenous LH binding to the testis cccurred in the capsulotomized rat.