[Immunohistochemical study of glutathione S-transferase in normal and experimental cryptorchid testes rats]

Using the antibody for glutathione S-transferase (GST) purified from human kidney, normal testes and experimental cryptorchid testes from newborn to 20-week-old rats were immunohistochemically stained by the peroxidase antiperoxidase (PAP) method. The cryptorchidism was surgically created at 1 week of age. The localization of GST was particularly examined by light microscopy, and the amount of Leydig cells was measured by a stereological method. 1. Leydig cells in the normal and cryptorchid testes showed strong GST activity at all ages. The amount of these cells in normal testes increased from 4 to 8 weeks of age and then slightly decreased, whereas in cryptorchid testes it was significantly larger than in the normal testes at 20 weeks of age, indicating hyperplasia of Leydig cells. 2. In the normal and cryptorchid testes, degenerating primary spermatocytes with GST activity appeared in the seminiferous tubules at 2 to 4 weeks of age. In the cryptorchid testis, degenerating germ cells with GST activity were also found in the regressing seminiferous tubules after 4 weeks of age. It is possible that GST acts as a detoxification system in the degenerating germ cells. 3. The PAP staining of GST in the rat testes is considered to be useful method for evaluating metabolic function of the spermatogenic cells and the distribution and amount of Leydig cells. 4. Experimental cryptorchidism showed that germ cells become sensitive after 4 weeks of age.