母鼠妊娠期铅镉联合暴露对仔鼠脑损伤病理学变化的影响

Combined exposure to lead and cadmium on pathologic damage in neonatal brain to pregnant rats

为探讨母鼠妊娠期铅镉联合暴露对新生鼠生长发育及脑组织病理学变化的影响,20只怀孕SD母鼠被随机分为4组,即A组为对照组(饮用蒸馏水)、B组为铅组(300mg/L)、C组为镉组(10mg/L)、D组为铅+镉组(300mg/L+10mg/L)。采用饮水染毒,期间记录母鼠体质量及临床症状,染毒结束后记录新生鼠体质量及脑质量,并采集新生鼠大脑皮质观察其病理组织学变化,染毒时间为21d。结果表明,与对照组比较,各染毒组母鼠体质量均低于对照组,但差异不显著(P>0.05);而新生鼠体质量均显著低于对照组(P<0.05),脑质量也明显下降,除C组无显著性差异外,其余各组差异显著(P<0.05);病理组织学变化显示,光学显微镜观察大脑皮质未见明显异常,透射电镜下可见各染毒组神经细胞核染色质浓缩,线粒体肿胀、嵴部分或完全消失。铅镉联合毒性明显强于铅镉单独作用,铅镉联合表现协同毒性效应,镉在铅镉联合毒性损伤中发挥主要作用。

In order to observe the effects of female rats perinatal exposure to lead and cadmium to growth and development and pathology changes of brain in neonatal rats,twenty pregnant female rats were randomly separated into control group,lead acetate group（300 mg/L）,cadmium acetate group（10 mg/L）,group of lead and cadmium 300 mg/L＋10 mg/L）,and the additives were given in the drinking water.Body weight of pregnant rats and clinical symptom are recorded during experiment,body weight growth and the brain weight growth and pathology changes of cerebral cortex in neonatal rats are observed after poisoning.The results showed that,in comparison with control group,there was a decrease tendency on body weight of pregnant rats in each poisoning group（P0.05）;However,significant decrease are observed in the body weight growth and the brain weight growth of neonatal rats except for C group（P0.05）;Obvious pathological change of cerebral cortex is not observed at light microscope,through transmission electron microscope,it is observed of ultrastructure of the cerebral cortex which displayed as cytomembrane disappearance and neuron nucelus concentration,mitochondrial swelling,disruption and total cristae loss.The toxicity originated by combined lead and cadmium was significantly higher than that caused by lead or cadmium alone exposure.The results indicated that combined lead and cadmium appear the synergistic effect,and cadmium played a great role in combining lead with cadmium.