[Immunohistochemical study on glutathione S-transferase in experimental cryptorchid testes in rats]

Using the antibody for glutathione S-transferase (GST) purified from the human kidney, the normal testes and experimental cryptorchid testes from newborn to 20 weeks-old rats were immunohistochemically stained by the peroxidase antiperoxidase (PAP) method. The cryptorchidism was surgically created at 1 week of age by cutting the gubernaculum testis. The localization of GST were particularly examined by light microscopy, and the amount of Leydig cells were 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's 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 testes, degenerating germ cells with GST activity were also found in the regressing seminiferous tubules after 4 weeks of age. This is a possibility that GST act as a detoxification system in the degenerating germ cells. 3. The PAP staining of GST in the rat testes is considered to be an 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 to the abdominal environment after 4 weeks of age.