妊娠期腹腔注射多氯联苯对大鼠生长发育的影响

将50只同期怀孕的大鼠分为5组，在怀孕第7—18d，每天给两组大鼠腹腔分别注射1和20mg／kg体重2，2’，4，4’-四氯联苯(PCB47)；给另两组分别注射0．25和1mg／kg体重3，3’，4，4’-四氯联苯(PCB77)；对照组注射0．1mL芝麻油。幼鼠出生时记录每窝产仔数和性比；出生后每隔7d称体重直到第119d；出生后第15天时检查幼鼠的睁眼率。与对照组相比，PCB47和PCB77所有剂量组每窝产仔数和性比无显著差异；PCB47(20g／kg体重组)和PCB77(两个剂量组)雌幼鼠肛门一生殖孔距离显著增加，出生后15d幼鼠的睁眼率显著降低；PCB77(1mg／kg体重组)雄幼鼠从出生后第35至119天体重显著降低。提示PCB77主要影响雄鼠的生长发育。

Developmental Effects of Intraperitoneal Injection of Polychlorinated Biphenyls in Rats During Pregnancy

Polychlorinated biphenyls (PCBs) are widespread environmental contaminants that are possible health hazards for human beings through a variety of pathways.In the present study,50 time mated pregnant rats were divided into five groups and injected daily from gestational days 7 to 18 with either 2,2,4,4-tetrachlorobiphenyl (PCB 47) or 3,3,4,4-tetrachlorobiphenyl (PCB 77) or seseme oil (control) to evaluate the effects of these PCBs on prenatal and postnatal development.Offspring were examined for malformations of genitalia at birth and in adulthood.Body weight gains of these animals were checked every 7 days through postnatal day (PND) 119.There were no clinical signs of toxicity in the PCB-treated dams or their offspring throughout the experiment.Litter size and sex ratio of the litters were not affected.Both PCBs produced a significant increase in the females anogenital distance,suggesting a modification of androgen responsiveness in females resulting from PCB exposure during development.Similar effects were not seen with the males.The proportion of individuals with eyes open by PND 15 was significantly reduced by both PCBs.Exposure to 1 mg/kg body weight of PCB 77 significantly reduced body weight gains in male pups from PND 35 to 119.However,no significant differences were found in body weight gains of the pups exposed to PCB 47.