The Effects of Testosterone Treatment on Structure of Mouse Testes

Purpose: There is a great need for a safe male contraceptive method, which can provide an alternative to the female contraceptive. Efforts to develop new method for men have been made during recent decads, but the most reliable method is still sterlization by vasectomy. The ue of GnRH antagonist for fertility regulation requites androgen supplementation to offset the decrease in serum testosterone level. In the present study, administration of testosterone was studied in mouse testis as a animal model. For this purpose, the effects of 25 mg/mouse of testosterone enanthate (single dose per week) on the structure of testis were assessed. Materials and Methods: Testes from three individual mice for each control and experimental group were analyzed. The following groups were studied: control group that received 25 mg/weekly normal salin during 6 weeks, Experimental group that received 25 mg/weekly testosterone enanthate during 6 weeks. To study the reversibility of azoospermia two groups were studied three weeks without any injection after the last testosterone treatment. Sperm parameters (viability rate, motility rate and sperm count) and also histological morphometry were evaluated in all the groups. To do these, the adult male NMRI mice were killed by cervical dislocation and epidydymal sperm was obtained and viability, motility rate and sperm count were assessed. The left testis was chosen for morphometirc study and after fixation, processing, embedding in paraffin, sectioning and staming with Hematoxilin & Eosin, morphometirc measurement including tubular diameter, epithelium height, numbers of spermatogonia, spermatocyte and round spermatid cells were done. The data were analyzed using ANOV A and post hoc (TUKEY) tests. Results: The results showed that high dose of testosterone could induce azoospermia and normospermia was observed after finishing of injection. The same resuts obtained at histology level of testes. The results of the present study clearly show that proper dosage of testosterone that is critical in the induction of uniform long-term azoospermia is 25 mg/mouse weakly. This is first report where this dose of testosterone is sage and reversible in mouse. Conclusion: Reversible azoospermia or oligozoospermia can be induced by high doses of testosterone. Testosterone can decrease the numbers of spermatogonia, spermatocyte and spermatid cel. And as a result spermatozoa production diminished.