小剂量氯化汞对小鼠的生殖毒性

Toxicity of Mercuric Chloride at Lower Dosage Exposure on Reproductive Function of Male Mice

目的观察小剂量氯化汞对雄性小鼠生殖功能的毒性作用以及氯化汞对小鼠精子数量和质量的影响。方法雄性ICR小鼠随机分为4组:阴性对照组,0.25、0.50、1.00mg/kg氯化汞组。分别以0.25、0.50、1.00mg/kg氯化汞腹腔染毒4周龄雄性小鼠每3天1次,共10次。50d后以雌雄2∶1合笼交配,观察雌鼠受孕率、生育子胎数、胎鼠重量,同时测定睾丸指数、附睾精子数量、精子活动率和精子畸形率。结果对照组、0.25、0.50和1.00mg/kg组合笼1周雌鼠受孕率分别为100%、100%、83.33%和66.67%,合笼3周雌鼠受孕率分别为100%、100%、83.33%和75%;其中1.00mg/kg组1周雌鼠受孕率显著低于对照组(P<0.05)。以上各组母鼠生育子胎数分别为127、142、113、95只,异常妊娠率分别为0%、1.41%、2.65%和4.21%;1.00mg/kg组异常妊娠率显著高于对照组(P<0.05)。0.50、1.00mg/kg组附睾精子数显著低于对照组和0.25mg/kg组(P<0.05);0.25、0.50、1.00mg/kg组睾丸指数、精子活动率与对照组比较差异无显著性(P>0.05)附睾精子畸形率显著高于对照组(P<0.05)。结论1.00mg/kg氯化汞染毒可降低雄性小鼠生育力,增加了受孕雌鼠异常妊娠率。氯化汞引起的这种雄性小鼠生育力的降低、异常妊娠率的增高可能与精子畸形率增高和精子数量下降有关。

Objective To observe the toxic effects of mercuric chloride (HgCl2) on the productive function of male mice with lower dosage exposune. Methods 4 week-aged male ICR mice were randomly divided into 3 exposure groups, and control group. The 3 exposure groups were treated with doses of 0.25, 0.50, 1.00 mg/kg HgCl2 by peritoneal injection respectively, one time per 3 days, 10 times in total. After exposure to HgCl2 for 50 days, the male mice were mated with female mice non-exposed to HgCl2 in a ratio 1∶2. The pregnant rate, number of pups whelped per group, body weight of offspring, testis index, sperm count, sperm motility rate, abnormal sperm rate were observed. Results The pregnant rates were 100%, 100%, 83.33% and 66.67% for control group, 0.25 mg/kg group, 0.50 mg/kg group and 1.00 mg/kg group respectively during 1-week conception, 100%, 100%, 83.33% and 75% for above corresponding groups respectively during 3-weeks conception respectively. The pregnant rate of 1.00 mg/kg group was significantly lower than that of control during 1-week conception (P<0.05). The number of offspring were 127, 142, 133 and 95, the abnormal pregnant rates were 0%, 1.41%, 2.65% and 4.21% for above corresponding groups respectively. The abnormal pregnant rate of 1.00 mg/kg group was significantly higher than that of control (P<0.05). The sperm counts of 0.50 mg/kg and 1.00 mg/kg groups were significantly lower than those of control group and 0.25 mg/kg group (P<0.05) respectively. HgCl2-exposure groups showed significantly higher abnormal sperm rates, and no significantly differences in thestis index and sperm motility rate compared with those of control (P<0.0005～0.05). Conclusions Exposure to 1.00 mg/kg HgCl2 might decrease the reproductive ability and increase the abnormal pregnancy rate, which might be due to the increased abnormal sperm rate and decreased sperm count.