ABSTRACT
BACKGROUND AND OBJECTIVES: Acute hypotension induces expression of c-Fos protein and phosphorylated extracellular signal-regulated kinase (pERK), and glutamate release in the vestibular nuclei. Expression of c-Fos protein and pERK is mediated by the excitatory neurotransmitter, glutamate. In this study, the signaling pathway of glutamate in the vestibular nuclei following acute hypotension was investigated. MATERIALS AND METHODS: Expression of metabotropic glutamate receptors (mGluRs) was measured by Western blotting in the medial vestibular nucleus following acute hypotension in rats. RESULTS: Expression of pGluR1 Ser831, a subtype of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, peaked at 30 minutes after acute hypotension insult, and expression of pNR2B, a subtype of N-methyl-D-aspartate (NMDA) receptors, peaked at 2 hours after acute hypotension insult. Acute hypotension induced expression of Homer1a and group I mGluR in the medial vestibular nucleus. Expression of mGluR1 and mGluR5 peaked at 6 hours following acute hypotension insults. CONCLUSION: These results suggest that afferent signals from the peripheral vestibular receptors, resulting from acute hypotension insult, are transmitted through group I mGluRs as well as AMPA and NMDA receptors in the vestibular system.
Subject(s)
Animals , Rats , alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid , Blotting, Western , Glutamic Acid , Hypotension , N-Methylaspartate , Neurotransmitter Agents , Phosphotransferases , Receptors, Metabotropic Glutamate , Receptors, N-Methyl-D-Aspartate , Vestibular NucleiABSTRACT
El receptor ionotrópico de glutamato activado por N-metil-D-aspartato (iGluR-NMDA) está conformado por tres tipos diferentes de subunidades NR1, NR2A a D y NR3A y B codificadas por los genes GRIN1, GRIN2 y GRIN3. Dado que la variabilidad genómica de los GRIN está estrechamente asociada con la historia genética de la población analizada, era necesario realizar un estudio detallado del gen GRIN1 en la población colombiana. Por ello, en este trabajo se identificaron polimorfismos presentes en la región 5-UTR y en el exón 6 del gen GRIN1, en 101 muestras de sangre de cordón umbilical de recién nacidos sanos del Hospital Universitario San Ignacio de Bogotá, y se encontró que el polimorfismo A1970G con una frecuencia del alelo menor de 28,21%, no difiere de las poblaciones de caucásicos y nativos americanos. El polimorfismo G1140A, con una frecuencia del alelo menor de 1,49%, no mostró diferencias estadísticamente significativas con la población de Taiwán. El polimorfismo A1160G sólo mostró una forma alélica...
The ionotropic glutamate receptor activated by Nmethyl-D-aspartate is composed by three different kinds of subunits NR1, NR2A to D and NR3A and B, which are codified by GRIN1, GRIN2 and GRIN3 genes. Since the GRIN genomic variability is closely related to the genetic history of the studied population, it was necessary to develop a detailed study of the frequency of the polymorphisms of the gene GRIN-1 in Colombian population. The main goal of this research was to identify polymorphisms present in 5-UTR region and exon 6 of gene GRIN1, among 101 samples of umbilical cord taken on filter paper of healthy newborns at the University Hospital San Ignacio in Bogota. It was found that polymorphism A1970G with minor allele frequencies of 28.21%, doesn't differ significantly from the frequencies in Caucasian and native American populations. Polymorphism G1140A with minor allele frequencies of 1.49% did not show any significant statistic difference with the Taiwan population. Polymorphism A1160G just showed one allelic form, the A allele...
Subject(s)
Mucopolysaccharidosis IV , Receptors, GlutamateABSTRACT
Objective To establish and optimize three-cube FRET assay in living cells and analyze subunit assembling of iGluR receptors. Methods Taking HEK293 cells cotransfed with pECFP and pEYFP as negative control, and those transfected with pECFP-YFP as positive control,different calculation methods using fluorescence microscopy were compared. Results These calculation methods were all suitable for FRET measurement in the system. but the measurement results were affected by the ratio of Donor/Acceptor (D/A) in some degree,and different calculation methods have different optimized conditions. FRET measurement using FR value showed subunit specific assembly of iGluR subtypes.Conclusion There are different optimized conditions for these different calculation methods in the three-cube FRET measurement system,and a further evidence is provided for subunit specific assembling of iGluR subtypes from the FRET assay.