不同孕期铅暴露对大鼠妊娠结局及胎盘TIMP-1表达的影响

Effects of lead exposure during different gestation periods on pregnant outcomes and expression of tissue inhibitor of metalloproteinase-1 in rat placenta

目的:观察孕期不同时段铅暴露对妊娠结局及胎盘TIMP-1表达的影响,探讨孕早期、孕后期及孕全程铅暴露的毒性特点及毒性机制。方法:采用原子吸收光谱仪测定孕期不同阶段低水平铅暴露后的大鼠孕末期血铅水平。0.025%醋酸铅对实验组孕鼠染毒,根据大鼠孕期3周推算足月剖宫产,观察异常分娩情况,记录胎盘质量、仔鼠数、仔鼠质量。免疫组化法测定胎盘滋养细胞TIMP-1的表达。结果:孕早期染铅对孕末期血铅水平及胎盘质量的影响较大,孕晚期染铅对仔鼠重量的影响较明显,孕全程染铅对孕末期血铅水平、胎盘质量及仔鼠质量均有明显影响。孕全程染铅组其胎盘TIMP-1表达最强。结论:铅具有生殖毒性及胚盘毒性,孕期不同时段铅暴露导致不同的妊娠结局。胎盘TIMP-1表达增强可能是铅致胎盘损伤的病理机制之一。

Objective： To observe the effects of lead exposure during different gestation periods on pregnant outcomes and expression of tissue inhibitor of metalloproteinase - 1 （ TIMP - 1 ） in rat placenta, explore the mechanisms and venenatus characteristics of lead ex- posure in early pregnancy, late pregnancy and whole pregnancy. Methods： Atomic absorption speetrophotometer was used to detect the lead concentration of rats at the end of the pregnancy. 0. 025% of lead acetate was administrated to the rats, and all the rats underwent cesarean section after 3 weeks, then the placenta weight, number of newborn rats and their body weight were measured. The expression of TIMP - 1 in rat placenta was tested by immunohistoehcmistry. Results： Lead exposure to rats in early pregnancy affected lead concentration at the end of the pregnancy and placenta weight, and lead exposure to rats in late pregnancy affected body weight of newborn rats. Lead exposure to rats in whole pregnancy affected lead concentration at the end of the pregnancy, placenta weight and body weight of newborn rats. The expression lev- el of TIMP - 1 in rats exposure to lead in whole pregnancy was the highest. Conclusion ： Lead has biological toxicity and embryo toxici- ty. Lead exposure during different gestation periods may lead to different pregnancy outcomes. High expression of TIMP - 1 in placenta may play an important role in pathogenesis of placenta toxicity of lead exposure.