the morphological changes of adult mouse testes after 60co γ-radiation

background: cytotoxic therapy can lead to prolonged azoospermia or even sterility. in the present study, we investigated the morphological changes of mouse testes after gamma-radiation. methods: after anaesthetizing of nmri mice, testes and their surrounding tissues were irradiated using a cobalt therapy machine. four experimental groups were irradiated with fractionated doses of: 1.5+8, 1.5+12 and 1.5+16 gy (with an interval of 24 h) and single dose of 14 gy. non-irradiated mice were considered as control group. testes were removed 4, 6 and 8 weeks following irradiation, weighed and processed for light microscopic study. diameters of seminiferous tubules and their lumens, epithelium thickness, percentage of different types of tubules and number of spermatogenic cell were measured. moreover, sperm count motility and viability rates were evaluated in epididymis. results: number of normal tubules, epithelium thickness, tubules diameter and lumen diameter were significantly reduced with high dose irradiation in comparison with control testes. the recovery was observed after 8 weeks. epididymal sperm count, motility and viability rates were significantly decreased in the irradiated mice comparing non-irradiated ones. these parameters were increased after 8 weeks. conclusion: according to the results, irradiation can cause temporary azoospermia in mouse and this effect is reversible after 8 weeks.