Metabotropic glutamate receptor/phospholipase C pathway is increased in rat brain at the end of pregnancy

• Published in: Neurochemistry international 2007-04, Vol.50 (5), p.681-688
• Main Authors: León, D., Castillo, C.A., Ruiz, M.A., Albasanz, J.L., Martín, M.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Brain - enzymology; Brain - metabolism; Female; Fundamental and applied biological sciences. Psychology; G q/11 protein; GTP-Binding Protein alpha Subunits, Gq-G11 - metabolism; Isoenzymes - metabolism; Metabotropic glutamate receptor; Phospholipase C; Phospholipase C beta; Pregnancy; Pregnancy, Animal - genetics; Pregnancy, Animal - metabolism; Rats; Rats, Wistar; Receptors, Metabotropic Glutamate - metabolism; Signal Transduction; Type C Phospholipases - metabolism; Up-Regulation; Vertebrates: nervous system and sense organs
• ISSN: 0197-0186; 1872-9754
• DOI: 10.1016/j.neuint.2006.12.012

Wistar pregnant rats were sacrificed at the end of pregnancy and the status of metabotropic glutamate receptors/phospholipase C (mGluR/PLC) pathway was studied in brain from pregnant and non-pregnant female rats. Pregnancy causes a significant increase in metabotropic glutamate receptors number, determined by radioligand binding assay, without significant changes on receptor affinity. Similar increase in mGluR 1 type was obtained by immunoblotting assay using specific anti-mGluR 1 antibody. However, no significant differences were observed in mGluR 5 type, suggesting that the increase detected by radioligand assays could be due to mGluR 1 up-regulation. On the other hand, a significant increase in the α subunit of G q protein was also detected in pregnant rats by immunoblotting assays. Real-time PCR experiments revealed a significant increase in gene expression of metabotropic glutamate receptors and G q proteins. Neither protein level nor gene expression of phospholipase C β 1 isoform was altered in pregnant rats. However, an increase in basal and agonist-stimulated phospholipase C activity was observed in membranes from pregnant rats. These results suggest that gestational period causes the up-regulation of both metabotropic glutamate receptors and coupled G q-protein and, in turn, an increase in phospholipase C activity.