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） at the dosage of 1.00 or 20.00 mg/kg body weight; or ...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） at the dosage of 1.00 or 20.00 mg/kg body weight; or 3,3＇ ,4,4＇-tetrachlorobiphenyl （PCB 77） at the dosage of 0.25 or 1.00 mg/kg body weight; or sesame oil （control） to investigate the effects of fetal and lactational PCB exposure on reproductive behavior in male and female laboratory rats. Offspring were then tested for male sexual behavior： mount frequency, MF; mount latency, ML; intromission frequency, IF; intromission latency, IL; ejaculation latency, EL; post ejaculatory interval, PEI; hit rate and female sexual behavior; approach latency, AL; mount return latency, MRL; intromission return latency, IRL; post ejaculatory refractory period, PER; lordosis quotient, LQ. Measures were made at the age of postnatal days 70 to 91, and 97 to 101, respectively. The results showed that exposure to both PCB 77 and PCB 47 significandy reduced the LQ （84.4% for control, 76.0%, 67.8% for PCB 47 groups and 64.4%, 53.3% for PCB 77 groups; P〈0.05） in the female offspring. There were no significant effects on AL, MR, IRL, PER （P〉0.05） of the female offspring, or on MF, ML, IF, IL, EL, PEI and hit rate （P〉0.05） of the male offspring.展开更多
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 ...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.展开更多
文摘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） at the dosage of 1.00 or 20.00 mg/kg body weight; or 3,3＇ ,4,4＇-tetrachlorobiphenyl （PCB 77） at the dosage of 0.25 or 1.00 mg/kg body weight; or sesame oil （control） to investigate the effects of fetal and lactational PCB exposure on reproductive behavior in male and female laboratory rats. Offspring were then tested for male sexual behavior： mount frequency, MF; mount latency, ML; intromission frequency, IF; intromission latency, IL; ejaculation latency, EL; post ejaculatory interval, PEI; hit rate and female sexual behavior; approach latency, AL; mount return latency, MRL; intromission return latency, IRL; post ejaculatory refractory period, PER; lordosis quotient, LQ. Measures were made at the age of postnatal days 70 to 91, and 97 to 101, respectively. The results showed that exposure to both PCB 77 and PCB 47 significandy reduced the LQ （84.4% for control, 76.0%, 67.8% for PCB 47 groups and 64.4%, 53.3% for PCB 77 groups; P〈0.05） in the female offspring. There were no significant effects on AL, MR, IRL, PER （P〉0.05） of the female offspring, or on MF, ML, IF, IL, EL, PEI and hit rate （P〉0.05） of the male offspring.
文摘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.
