Identification of functional ionotropic glutamate receptor proteins in pancreatic beta-cells and in islets of Langerhans.
The presence of ionotropic glutamate receptor proteins in islets of Langerhans and pancreatic beta-cell lines (MIN6, HIT T15, RINm5F) was investigated. For this purpose immunoblot analysis of beta-cell membranes was performed with subunit-specific antibodies. We identified NMDAR1 subunits of the NMDA and KA-2 subunits of the kainate receptors, but did not detect GluR1 subunits of the AMPA receptor. The receptor subunits present were shown to be glycosylated. beta-cell membranes contained specific binding sites for glutamate receptor ligands, and NMDA increased insulin secretion. These results demonstrate that ionotropic glutamate receptor proteins, similar to those in the central nervous system, are expressed in rat pancreatic beta-cells.
Molnár
E
E
Medical Research Council, Anatomical Neuropharmacology Unit, Oxford, UK.
Váradi
A
A
McIlhinney
R A
RA
Ashcroft
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D002460:Cell Line; D002462:Cell Membrane; D005260:Female; D018698:Glutamic Acid / Q000494:pharmacology; D015151:Immunoblotting; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000737:chemistry* / Q000378:metabolism; D007608:Kainic Acid / Q000494:pharmacology; D008969:Molecular Sequence Data; D016202:N-Methylaspartate / Q000494:pharmacology; D010446:Peptide Fragments / Q000276:immunology; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D017470:Receptors, Glutamate / Q000032:analysis* / Q000187:drug effects / Q000276:immunology; D018092:Kainic Acid Receptors / Q000032:analysis
D000906:Antibodies; D018698:Glutamic Acid; D007328:Insulin; D007608:Kainic Acid; D016202:N-Methylaspartate; D010446:Peptide Fragments; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors