951. Maternal low-level lead exposure reduces the expression of PSA-NCAM and the activity of sialyltransferase in the hippocampi of neonatal rat pups.
- Author
-
Hu Q, Fu H, Ren T, Wang S, Zhou W, Song H, Han Y, and Dong S
- Subjects
- Analysis of Variance, Animals, Animals, Newborn, Dose-Response Relationship, Drug, Female, Hippocampus metabolism, Male, Neural Cell Adhesion Molecule L1 genetics, Neural Cell Adhesion Molecules genetics, Neural Cell Adhesion Molecules metabolism, Pregnancy, Rats, Rats, Wistar, Shiga Toxin genetics, Shiga Toxin metabolism, Sialic Acids genetics, Sialyltransferases genetics, Gene Expression Regulation, Developmental drug effects, Hippocampus drug effects, Lead toxicity, Neural Cell Adhesion Molecule L1 metabolism, Prenatal Exposure Delayed Effects chemically induced, Prenatal Exposure Delayed Effects pathology, Sialic Acids metabolism, Sialyltransferases metabolism
- Abstract
Highly polysialylated neural cell adhesion molecule (PSA-NCAM) is transiently expressed specifically in newly generated cells, and is important for cell migration and neurite outgrowth. Developmental lead (Pb) exposure has been considered to affect the expression of PSA-NCAM, which contributes to the neurotoxicity of Pb exposure. However, the effect of maternal low-level Pb exposure on the expression of PSA-NCAM in neonatal rat pups has not been reported. In the present study, female Wistar rats were exposed to vehicle or different dosages of lead chloride (0.5-4mM PbCl2) 2 weeks before and during pregnancy. This exposure protocol resulted in neonatal rat pups blood Pb levels up to 12.12+/-0.38 microg/dl, and hippocampal Pb levels up to 9.22+/-0.81 microg/g at postnatal day 1 (PND 1). Immunohistochemistry analysis and Western blot analysis revealed that the expressions of PSA-NCAM and NCAM in the hippocampi of neonatal rat pups at PND 1 were significantly reduced by the maternal low-level Pb exposures. Furthermore, the mRNA levels of NCAM and polysialyltransferases (STX and PST), measured by the fluorescent real-time quantitative RT-PCR, dosage-dependently and significantly decreased by 13.26-37.62%, 25.17-59.67%, and 10.78-47.81%, respectively. In addition, the sialyltransferase activity in neonatal rat pups was significantly reduced by 6.23-32.50% in the presence of the low-level Pb exposure, too. Taken together, these results suggest that maternal low-level Pb exposure reduces the expression of PSA-NCAM, NCAM, and the activity of sialyltransferase in the hippocampi of neonatal rat pups, which might contribute to the learning and memory impairments in the developmental pups following maternal low-level Pb exposure.
- Published
- 2008
- Full Text
- View/download PDF