A study of changes of testis tissue and the sexual behavior according to aging

点击翻译按钮获取中文摘要

Histological changes of testes and changes of the sexual behavior by aging were investigated in the Japanese macaque. Five aged males (over than 19 years old), five adult males (10 to 15 years old) as the control and five females as pairing partners, that were kept at Primate Research Institute, Kyoto University, were used. Testis tissues were obtained from aged males by biopsy in both the mating and the non-mating seasons. Pairing tests were performed in two seasons among all males and all females. Testis samples were (1) fixed by 10% formalin, embedded in paraffin, cut, and stained with PAS and hematoxylin and also HE,(2) stained with TUNEL to detect cells in the process of apoptosis, (3) stained for lipofuscin granules such as Hueck method, and (4) fixed by mixture of paraformaldehyde and glutaraldehyde, embedded in methacrylate resin, cut with glass knives for semithin sections and stained PAS and hematoxylin for both light and electron microscopy. The results revealed that the seasonal change of sexual behavior of aged and adult males, but the significant difference could not be noticed between groups. Several findings were obtained by observations of the testis tissue of aged males as follows : (1) The cycle of seminiferous epithelium could not be detected in the aged males, (2) Some spermatids contained abnormal small acrosomic granules with low electron density, or no acrosomic granules. Acrosomic system were not generated in some case. (3) In Sertoli cells, there were many fat granules at the base and tight junctions were lost. (4) Cells of all types in the seminiferous epithelium included cells under the apoptotic process. These findings suggest that spermatogenic activities of aged males are quite decreased, although active sexual behavior is maintained. This discrepancy should be explained in future studies.