目的 研究大豆异黄酮对醋酸铅致雄性小鼠生殖系统损伤的保护作用及作用机制。方法 采用ip醋酸铅（20 mg/kg）连续7 d的方法制备雄性小鼠生殖系统损伤模型，造模第2 天开始，大豆异黄酮低、中、高剂量（150、300、600 mg/kg）组分别ig给药，连续30 d。检测雄性小鼠的睾丸指数、精子密度、精子畸变率，血清中NO的量，睾丸组织中乳酸脱氢酶（LDH）和丙二醛（MDA）的量及Na⁺, K⁺-ATP酶及Ca²⁺-ATP酶活性等指标，并观察睾丸、附睾组织的病理改变。结果 与模型组比较，大豆异黄酮中、高剂量组的睾丸指数、精子密度增加，精子畸变率降低（P＜0.05、0.01），睾丸组织中Na⁺, K⁺-ATP酶和Ca²⁺-ATP酶活性增强（P＜0.05、0.01），血清中NO的量降低（P＜0.05、0.01）；大豆异黄酮低、中、高剂量组睾丸组织中MDA的量降低（P＜0.05、0.01），高剂量可提高睾丸组织中LDH的活性（P＜0.05）。病理观察可见，模型组睾丸组织生精上皮明显变薄，生精细胞层次和数量减少，多数生精小管腔未见精子形成，附睾液内未见精子，可见大量圆细胞，而大豆异黄酮可改善醋酸铅所致生精细胞的损伤。结论 大豆异黄酮对醋酸铅致小鼠睾丸组织损伤有一定保护作用，作用机制与抗氧化及降低NO的量有关。

Objective To explore the protective effect of soybean isoflavone on reproductive injury in male mice caused by lead acetate and its mechanism. Methods The reproductive toxicity model in male mice was established by ip injection with lead acetate (20 mg/kg) for 7 d. The model mice were treated with low-, mid-, and high-dose (150, 300, and 600 mg/kg) soybean isoflavone, respectively through gavage for 30 d. The mice were sacrificed on day 31 for the measurement of testis index, sperm density, and sperm aberration rate. The contents of nitric oxide (NO) in serum and malondialdehyde (MDA), and the activities of lactate dehydrogenase (LDH), Na⁺, K⁺-ATPase, and Ca²⁺-ATPase in testicular tissue homogenate were assayed with spectrophotometry respectively. The pathological changes of testicular and epididymal tissues were observed. Results Compared with the model group, mid- and high-dose soybean isoflavone could increase the testis index and sperm density, decrease the sperm aberration rate and NO content in serum (P < 0.05, 0.01), and improve the activities of Na⁺, K⁺-ATPase and Ca²⁺-ATPase in testicular tissue homogenate (P < 0.05, 0.01). The content of MDA in testicular tissue homogenate was decreased (P < 0.05, 0.01) in the soybean isoflavone groups, and the LDH activity was increased (P < 0.05) in the high-dose soybean isoflavone group. In the model group, cell number of spermatogenic epithelium were lower than those in the control group on morphological testis; There was a decline of spermatogenic cells in levels and numbers; No spermiogenesis was observed in most seminiferous tubule; There were plenty of round cells and none of spermatozoon in the epididymal liquid. The changes above could be reversed by soybean isoflavone. Conclusion Soybean isoflavone has certain protective effects on the testicular tissue injury in mice caused by lead acetate, and its mechanism is related to anti-oxidation and decreasing NO.

吉林省教育厅“十一五”科技研究资助项目（2010254）