Making of the animal model with sterilized testes

Objective: To explore the methods of making an animal model with sterilized testes. Methods: ① X-ray local irradiation. Seventy 8~10-week old male mice were equally divided into 6 experiment groups and a control group. The testes of the mice in the 6 experiment groups were irradiated sequentially by 1 000, 1 200, 1 400, 1 600, 1 800 and 2 000 cGy X-ray for 10 minutes, while those in the control group remained untreated. And then the pregnancy test was performed. ② Cyclophosphamide injection. Forty 4~5-week old male mice were divided into 3 experiment groups and a control group, the former treated with different doses of Cyclophosphamide via ip and the latter Natiichloridi Saline (N.S.) via ip, followed by the pregnancy test. ③ Diphereline injection. Twenty 8~10-week old male mice were equally divided into an experiment group and a control group, the former treated with Diphereline via ip and the latter N.S. via ip, followed by the pregnancy test. ④ Identification by such pathologic examinations as TUNEL technology, HE staining and immunohistochemical staining. Results: ①X-ray local irradiation. The male mice of Group 1 and 2 made their female partners pregnant respectively 10 and 15 days after the X-ray irradiation, but not those of Group 3 and 4 in our 3-month observation, and those of Group 5 and 6 died respectively 2 and 5 days after the X-ray irradiation. By comparison, the controls got their female partners pregnant within 3 days after placed together. ② Cyclophosphamide injection. The male mice of Group 1 gained weight about 7 g and achieved pregnancy 9~14 days after drug termination, those of Group 2 gained around 4g but failed to effect pregnancy, and those in Group 3 lost weight and died respective at 3, 4 and 5 weeks during the medication, while the controls all got their female partners pregnant within 3 days after put together. ③Diphereline injection. The 10 male mice of the experiment group effected pregnancy 3 weeks after drug termination, while the 10 controls achieved the same result with 3 days after placed together. ④Pathologic identification: TUNEL technology showed that apoptotic cells were occasionally seen (0.71±0.12) % in the testis tissue of the control group and remarkably increased (10.36±1.48) % in the model group, with significant difference between the two groups (P0.05). HE staining revealed normal testis tissues and convoluted seminiferous tubules with large numbers of germ cells in the control group, but atrophied convoluted seminiferous tubules and estranged cell linage with only Ledig's cells but no germ cells in the model group. Immunohistochemical staining showed that the positive expression rates of CD29, Hsp90α and CD117 were respectively (50.30±5.2)%, (41.6±3.5)% and (73.6±3.7)% in the control group, as compared with (1.3±0.2)%, 0 % and (1.6±0.3)% in the model group, with significant difference (P0.01). The positive expression rate of p53 was (19.7±0.8)% in the control group, significantly different from that of the model group, which was (39.4±2.9) % (P0.01). Conclusion: The animal model with sterilized testes can be made either by X-ray local irradiation of the testis or by Cyclophosphamide injection via ip.