RESUMEN
Objective To study the correlation between level of nitric oxide/ nitricoxide synthase(NO/NOS) on placenta homogenate and ultra-structure changes of placenta in pregnancy lead exposure in rats.Methods Seventeen normal pregnant rats and 46 rats of exposured in lead which were divided into A,B,C groups were studied.The level of NO/NOS of placenta were measured by nitrate reductase and NOS kit.Placentas were randomly selected from each group to detect ultra-structure by electron-microscope.Results There were significant difference among A,B and control groups on level of NO/NOS(all P0.05).Compensation hyperplasy or minor injury were observed in lead exposure of stage groups.Lead exposure during whole gestation period,the lead level was maxmum,and decompensation were observed on placental construction.Conclusions There is a close correlations between level of lead,NO/NOS and pathological change of placental tissue,and both of them may play an important role in the pathogenesis of peripartum lead exposure.