Effect of chronic glutamate administration to pregnant rats during gestation on metabotropic glutamate receptors from mothers and full-term fetuses brain

摘要

Chronic glutamate treatment during gestational period caused a significant decrease in total metabotropic glutamate receptors(mGluR)number.Similar results were observed on the steady-state level of mGlui receptor detected by immunoblotting assays,suggesting that this is the main receptor subtype modulated by agonist exposure.Furthermore,no variations on mRNA coding mGlui receptor were found,suggesting post-transcriptional modulation as a possible mechanism of the lost of receptor detected at the membrane surface.On the other hand,western-blotting to determine level of G_q/11 protein and phospholipase C beta_1 revealed a significant decrease of both proteins in mothers brain.This decrease was associated with significant variation in glutamate and DHPG-stimulated phospholipase C activity.No significant differences on mGluR transduc-tion pathway components were observed in fetuses brain.These results suggest that glutamate intake during pregnancy causes a down-regulation of different proteins involved in glutamate response mediated by mGluR only in mothers brain without significantly affecting fetuses brain.