杨梅黄酮对铅染毒雄性小鼠生精功能及激素水平的影响#br#

目的 研究杨梅黄酮（myricetin）对铅染毒所致雄性小鼠生精障碍的影响，并探讨其作用机制。方法 选 取昆明种小鼠60只，随机分成对照组、染铅组、甲睾酮组（10 mg/kg，即阳性对照组）及杨梅黄酮低、中、高剂量组，每组 10只，除对照组外，其他5组采用腹腔注射醋酸铅（20 mg/kg，7 d）建立雄性小鼠生精障碍模型，造模第2天始，杨梅黄 酮低、中、高剂量组分别灌胃杨梅黄酮 100、200、400 mg/kg，连续 42 d。观察雄性小鼠的睾丸指数、精子密度、精子畸 形率变化，检测血清中睾酮（T）、卵泡刺激素（FSH）、黄体生成素（LH）及睾丸组织中的山梨醇脱氢酶（SDH）、丙二醛 （MDA）水平的变化，HE染色观察睾丸组织的病理改变。结果 与染铅组比较，杨梅黄酮各剂量组的精子密度增高、 睾丸指数增大、精子畸形率降低，杨梅黄酮各剂量组血清LH、FSH含量降低，T升高，睾丸组织中MDA含量降低、SDH 活性增高（P＜0.05）。睾丸组织镜下可见染铅组生精上皮变薄，生精细胞层次和数量减少，生精小管腔见少量精子形 成，而杨梅黄酮中、高剂量可改善醋酸铅所致的睾丸组织改变。结论 杨梅黄酮可通过抗氧化作用、减轻醋酸铅所 致睾丸组织氧化应激损伤，促进睾酮的分泌，提高睾丸及精子活性，从而改善睾丸的生精功能。

Effects of myricetin on spermatogenesis and hormone levels in male#br# mice exposed to lead poisoning #br#

Objective To study the effect of myricetin on spermatogenesis impairment in male mice exposed to lead and discuss its mechanism. Methods Sixty Kunming mice were randomly divided into control group, lead group, methyltestosterone group, myricetin (low, medium and high doses) groups, 10 mice in each group. The spermatogenic disorder model was established by intraperitoneal injection of lead acetate (20 mg/kg, 7 d). From the second day of modeling,different doses of myricetin (100, 200 and 400 mg/kg, for 42 d) were given to low, medium and high dose myricetin groups.The sperm density, the testis index and changes of sperm aberration rate were observed in mouse groups. The serum levels oftestosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), sorbitol dehydrogenase (SDH) and malondialdehyde (MDA) in the testis tissue were detected. The pathological changes of testicular tissues were observed by HE staining. Results Compared with lead exposed group, the sperm density increased, the testis index increased and the distortion rate of sperm reduced in myricetin groups. The serum levels of LH and FSH decreased and T increased, the content of MDA in testis decreased and the activity of SDH increased in myricetin groups (P＜0.05). Pathological results showed that there were decline of spermatogenic cells, and few spermiogenesis in most of seminiferous tubule in lead exposed group. No above changes were found in high dose myricetin group. Conclusion Myricetin can improve spermatogenesis, reduce the oxidative stress damage of testicular tissue caused by lead acetate and promote testosterone secretion, increase testicular and sperm activity, thereby improving the spermatogenic function of testes.