Study on the Effects of Prenatal Exposure to Low Level Lead on the Physical and Neuro-behavioral Development of Mice and the Interaction Between Lead and Zinc / 环境与健康杂志

ABSTRACT

Objective To study the effects of prenatal exposure to low level lead on the physical and neuro-behavioral development of mice and the interaction between lead and zinc. Methods Kunming pregnant mice were provided with drinking water containing lead, zinc and lead-zinc jointly and respectively. The body weight of maternal mice, offspring's survival rate and body weight were observed. Neuro-behavioral development of offspring was assessed by observation of offspring's behavior performance. The levels of dopamine (DA), 5-hydroxytryptamine (5-HT) and malonaldehyde (MDA) in offspring's brains were measured. Results At the doses of lead and zinc which did not effect the increase of maternal body weight during pregnancy, the lead exposure group showed low survival rate, growth retardation and delay of physiological development and neonatal reflexes in the offspring, the levels of DA and MDA in offspring's brains increased compared with the control group. Offspring's low survival rate and growth retardation couldn't be antagonized by zinc, but equal mole as lead of zinc could inhibit the harmful effects on neuro-reflex development. Zinc could also inhibit the increase of DA and MDA levels in offspring's brains induced by lead . However joint exposure to lead and half dosage as much as lead of zinc could deteriorate the effects on delay of physical, neuro-behavioral development and accelerate the DA and 5-HT decompose compared with that in the lead exposure group. Conclusion The harmful effects on offspring's growth and neuro-behavioral development could be induced by prenatal exposure to low level of lead. The types of joint-effect of lead and zinc were different according to the concentration of zinc, which indicated that the zinc-lead interaction was very complicated and it should be very prudent to antagonize lead toxicity using zinc.