氯氰菊酯和甲基对硫磷混配对大鼠生殖发育的影响

目的]探讨妊娠期氯氰菊酯和甲基对硫磷混配染毒,对母鼠的生殖毒性和对子代大鼠生殖和发育的影响。方法]Wistar孕鼠112只随机均分为4组,于孕1～15天连续经口灌胃染毒不同剂量农药(两种农药以相当于0、1/300、1/95、1/30LD50的剂量等毒混配),对照组采用溶剂灌胃。56只孕鼠(每组14只)妊娠19天时处死,测定胚胎毒性;另56只孕鼠自然分娩,记录空孕率、每窝活产数、妊娠天数、平均产仔数和性别比;测量其371只仔鼠的体重增长和生长发育情况;10周龄时随机抽取雌鼠32只(每组8只)、雄鼠40只(每组10只)处死,称量生殖腺重量,计数睾丸每日生精量和附睾精子数。结果]孕鼠胚胎毒性指标中仅高剂量组活胎比低于中剂量组和对照组(P<0.05);各剂量组分娩孕鼠的空孕率、妊娠天数、产仔数、平均活产数、仔鼠性别比与对照组相比无差异(P>0.05)。各剂量组仔鼠体重增长与对照组一致(P>0.05);高剂量组仔鼠出生第一天尾长比对照组长(P>0.05);雌性仔鼠的卵巢脏器系数与混配农药剂量之间存在剂量-效应关系(rs=0.3144,P=0.0172);各剂量组雄鼠睾丸每日精子生成量和附睾精子数与对照组相比无差异(P>0.05)。结论]妊娠期甲基对硫磷和氯氰菊酯混配染毒,对母鼠有一定的胚胎毒性,并对仔鼠生长发育有轻微的影响。

Effects on Reproduction and Development in Dam and Offspring of Rats Exposed to Methylparathion and Cypermethrin During Gestation

Objective] To study the effects on reproduction and development of rats exposure to methylparathion and cypermethrin during gestation.Methods] 112 pregnant Wistar rats were divided randomly into 4 groups,and force-fed with cypermethrin and methylparathion in a dose of 0,1/300,1/95,1/30 LD50 once a day to each group respectively during pregnant day 1 to day 15,and the control group fed with vehicle solvent only.56 pregnant rats were sacrificed at gestation day 19th and the embryo toxicity was observed.The other 56 pregnant rats gave their natural dilivery and then their reproductive process was determined.The body weight gain and early developmental landmarks were measured in all 371 offspring.32 female offspring(8 in each group)and 40 male rats(10 in each group)were sacrificed at 10-weeks-old.Their reproductive organs were weighed.The quantity of daily sperm production in testes and sperm numbers in epididymis were measured.Results] The percentage of live birth in high dose group was significantly lower than that of controls(P < 0.05)and for other indices of reproductive toxicity,no significant difference were observed in each group of pregnant rats(P > 0.05).The body weight gain of offspring in exposure groups was similar with that of the controls.The tail length of offspring in high dose group was longer than that of controls(P < 0.05).There is a dose-effect relationship between dose and relative weight of ovary(rs = 0.314 4,P = 0.017 2).The quantity of daily sperm production of testes and the quantity of sperm in epididymis in exposure groups had no difference with those of the controls(P > 0.05).Conclusion] Exposure to methylparathion and cypermethrin during gestation might have reproductive toxicity to pregnant rats and slightly affected the early development of offspring.