中波紫外线致雄性小鼠生殖系统损伤

目的]本文以小鼠为实验材料探讨中波紫外线（uhraviolet-B，UVB）对雄性小鼠生殖系统造成的光辐射损伤。方法]将36只雄性小鼠随机分为空白对照组、2h照射组和3h照射组，每组12只，照射组用UVB（285nm）连续照射30d。照射后称其体重并将小鼠处死，取出睾丸、附睾并称重，求睾体比，检测附睾中精子活率及精子畸形率，观察睾丸组织病理学变化，测定睾丸组织超氧化物歧化酶（superoxidedismutase，SOD）活性和丙二醛（malondialdehyde，MDA）含量。结果]照射组小鼠的体重和睾体比明显低于对照组（P〈0．01）；精子活率也下降，差异有统计学意义（P〈0．05）；精子的畸形率上升但差异无统计学意义（P〉0．05）.睾丸病理学变化：睾丸间质水肿与曲细精管分离；生精上皮排列疏松、脱落至管腔；管腔变窄；管腔中的精子数减少，并且3h照射组造成的辐射损伤更大。睾丸组织SOD活性和MDA含量变化：紫外辐射能够明显降低SOD活性、增加MDA含量（P〈0．01），并且呈现剂量效应。结论]UVB辐射可引起雄性小鼠体重和睾体比降低、精子活率下降、睾丸组织病变、SOD活性降低、MDA含量增加，但对小鼠的精子畸形率影响不明显，损伤主要是由于紫外线辐射产生的活性氧簇（ROS）间接引起。

Ultraviolet-B Radiation Damage to Reproductive System in Mice

To study possible damages of uhraviolet-B （UVB） to reproductive system of mice. Methods Thirty-six male mice were randomized into 3 groups： control group, 2 h irradiated group and 3h irradiated group, each with 12 animals. The mice were sacrificed after 30 days of UVB irradiation （285 nm） and measured testicle to body weight ratio, sperm motility and malformation rates, superoxide dismutase （SOD） activity and malondialdehyde （MDA） content, and recorded pathological changes. Results ] Compared with the control group, the body weights and the testicle to body weight ratios of the two irradiated groups were significantly declined （P〈0.01）; the sperm motility rates were significantly declined （P〈0.05）; the sperm malformation rates were increased but not significantly （P〉0.05）. The pathological changes in the testis samples showed： interstitial tissues swelled and were separated from convoluted tubules; spermatogenic epitheliums were loosely-arranged and fell into the tubules; tubules were narrowed; and the counts of sperm decreased. The damage in the 3 h irradiated group was more obvious. UVB radiation significantly and dose-dependently decreased SOD activity and raised MDA content in radiation groups as compared with the control group （P〈0.01）. Conclusion ] Radiation of UVB could decrease body weight and testicle to body weight ratio, cause pathological changes in the testis of mice, degrade SOD activity, raise MDA content, but couldn＇t affect sperm formation obviously. These injuries are possible results of reactive oxygen species （ROS） induced by UVB irradiation indirectly.