长期食入低剂量贫铀对大鼠的生殖毒性研究

Reproductive toxicity in rats after chronic oral exposure to low dose of depleted uranium

目的 研究长期食入低剂量贫铀对大鼠的生殖毒性。方法给予初断乳大鼠含贫铀饲料，食入贫铀的剂量分别为0、0．4、4和40mg·k^-1·d^-1，4个月后，采用两代-窝法观察整体生殖毒性效应；放射免疫法检测睾酮（T）、黄体生成素（LH）、卵泡刺激素（FSH）等血清性激素水平；比色法测定睾丸中乳酸脱氢酶同工酶（LDH—X）、琥珀酸脱氢酶（SDH）及Na^＋-K^＋’ATPase、ca2’-ATPase等精子生成和代谢有关酶的比活性。结果亲代（F0代）大鼠各项指标未见显著改变。子代（F1代）高剂量组的受孕率、正常分娩存活率、幼仔出生存活率、幼仔哺育存活率均下降，与对照组相比，差异有统计学意义。食入贫铀的F0代大鼠血清性激素含量较正常组增加，但F1代除T升高外，其余性激素均下降。Fn代高剂量组睾丸中LDH含量降低；F1代大鼠中、高剂量组SDH、LDH和Na^＋-K^＋-ATPaSe含量降低。结论长期食入低剂量的贫铀对F0代大鼠未见明显生殖毒性，但F1代大鼠的生殖毒性效应显著增加。

Objective To study the reproductive toxicity in rats induced by low dose of depleted uranium （DU）. Methods Male and female rats（F0 generation） were exposed to DU in food at doses of 0, 0.4, 4 and 40 mg·k^-1·d^-1for 160 days, respectively. Then the activities of enzymes in testis and sexual hormone contents in serum were detected. Mature male rats were mated with female rats exposed to the same doses for 14 days. Pregnant rate and normal labor rate in F0 rats were detected, as well as the survival rate and weight of F1 rats within 21 d after birth. Results No adverse effects of DU on fertility were evident at any dose in F0 rats. Compared with control group, the rate of pregnancy, normal labor, survival of offspring birth and offspring nurture in F1 generation of high-dose group reduced to 40.0%, 33.3%, 33.3%, and 33.3%, respectively. The sexual hormone contents in Fo generation exposed increased, but those in F1 rats decreased significantly. The activities of lactate dehydrogenase-X （LDH-X） decreased in Fo rats exposed to high-dose of DU, and those of sorbitol dehydrogenase （SDH）, LDH and Na^＋ -K^＋ -ATPase decreased in F1 rats exposed to DU. Conclusions Reproduction function, growth and development of F0 rats are not obviously affected after chronic oral exposure to DU, while the toxicity effects in F1 generation was observed at any dose.