2023, Vol. 27 ›› Issue (5): 720-725

Physiological function of the testis in rats undergoing different parts of vasectomy

Yang Heng1, 2, Zheng Liying2, Liu Zhili1, Wang Qinzhang2, Hao Zhiqiang1, 2, Wang Jingshen1, 2, Wang Yuan1, 2, Li Yongle1, 2, Tan Minghui1, 2, Zou Xiaofeng2, Zhang Guoxi2, Huang Ruohui2, Jiang Bo2, Qian Biao1, 2   

Abstract: BACKGROUND: Vasectomy is currently an effective method of male birth control, and the main concern is clinical complications after vasectomy.
OBJECTIVE: To study the effects of different surgical methods of vasectomy on physiological function of the testis in rats.
METHODS: After 1-week adaptive feeding, 12 male Sprague-Dawley rats were randomly selected and randomly divided into 4 groups with 3 rats in each group, including negative control group, sham-operation group, operation group and traditional group. The rats in the operation group were subjected to bilateral oblique vasectomy, the proximal end of the vas deferens was ligated and the distal end was separated but not ligated. The rats in the traditional group underwent bilateral oblique vasectomy, with both ends of the vas deferens ligated. In the sham-operation group, the both ends of the vas deferens were separated without ligation. The negative control group had no special treatment. Three months after the operation, methylene blue was injected and observed. After anesthesia, the rats were sacrificed and their testicles were collected for routine pathological examination using hematoxylin-eosin staining.   Testicular tissue was collected and the expressions of Bax, Bcl-2, 3βHSD and human epididymal protein 4 were detected by immunohistochemistry. Apoptosis in testicular tissue was detected by TUNEL assay. Serum interleukin-1 and testosterone levels were detected using ELISA/biochemical detection.
RESULTS AND CONCLUSION: Hematoxylin-eosin staining: compared with the sham operation group, the testis was swollen and hard in texture in the traditional and operation groups; the incidence of testicular aseptic inflammation in the traditional group was higher than that in the negative control group; no spermatogenic granuloma was found in the testis of the operation group and the histological structure of the testis in the traditional group was remarkably changed. TUNEL detection: Compared with the negative control and sham operation groups, apoptosis was increased in the operation and traditional groups; and there was less apoptosis in the operation group than the traditional group. Immunohistochemical detection: Compared with the negative control group, the expression of Bax changed insignificantly in the sham operation group and increased in the operation and traditional groups, especially in the traditional group. Compared with the negative control group, the expression of Bcl-2 was decreased in the operation and traditional groups, especially in the traditional group. Compared with the negative control and sham operation group, the protein expression of 3βHSD and epididymal protein 4 in the rat testis was lower in the operation and traditional groups and there was no significant difference between the operation and traditional groups. ELISA/biochemical detection: Compared with the negative control group, the levels of serum interleukin-1 and testosterone were significantly increased in the operation group (P < 0.05) but significantly decreased in the traditional group (P < 0.05). These findings indicate that pelvic vasectomy has little effect on the physiological function of the testis in rats.
Key words: vasectomy, different surgical methods, testis, physiological function, epididymal protein 4, rat