title: Glutamate-induced cobalt uptake elicited by kainate receptors in rat taste bud cells.
abstract: Glutamate-induced cobalt uptake reveals non-N-methyl-D-aspartate (non-NMDA) glutamate receptors (GluRs) in rat taste bud cells. However, it is not known which type of non-NMDA glutamate receptors is involved. We used a cobalt staining technique combined with pharmacological tests for kainate or alpha-amino-3-hydroxy-5-methyl-isoxazole-propionic acid (AMPA) receptors and/or immunohistochemistry against subunits of GluRs to examine the presence of non-NMDA receptors in rat foliate tastebud cells. Cobalt uptake into taste cells was elicited by treating taste buds with glutamate, kainate or SYM 2081, a kainate receptor agonist. Treating taste buds with AMPA or fluorowillardiine did not stimulate significant cobalt uptake. Moreover, 6-cyano-7-nitro-quinoxaline-2, 3-dione significantly reduced cobalt staining elicited by glutamate or kainate receptor agonists, but SYM 2206, an AMPA receptor antagonist, did not. Immunohistochemistry against subunits of GluRs reveals GluR6 and KA1-like immunoreactivity. Moreover, most glutamate-induced cobalt-stained cells showed GluR6 and KA1-like immunoreactivity. These results suggest that glutamate-induced cobalt uptake in taste cells occurs mainly via kainate type GluRs.
authors.affiliation: Department of Physiology and Neuroscience, College of Dentistry, Kangnung National University, 123 Chibyun-dong, Kangnung, Kangwon-do, 210-702, Republic of Korea.
authors.forename: Ki-Myung
authors.initials: KM
authors.lastname: Chung
authors.forename: Sang-Bok
authors.initials: SB
authors.lastname: Lee
authors.forename: Ryang
authors.initials: R
authors.lastname: Heur
authors.forename: Young-Kyung
authors.initials: YK
authors.lastname: Cho
authors.forename: Cil-Han
authors.initials: CH
authors.lastname: Lee
authors.forename: Hye-Young
authors.initials: HY
authors.lastname: Jung
authors.forename: Se-Hwan
authors.initials: SH
authors.lastname: Chung
authors.forename: Seung-Pyo
authors.initials: SP
authors.lastname: Lee
authors.forename: Kyung-Nyun
authors.initials: KN
authors.lastname: Kim
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D003035:Cobalt / Q000378:metabolism* / Q000493:pharmacokinetics; D018698:Glutamic Acid / Q000378:metabolism / Q000494:pharmacology*; D007150:Immunohistochemistry; D007552:Isotonic Solutions / Q000494:pharmacology; D007608:Kainic Acid / Q000494:pharmacology; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism; D018092:Kainic Acid Receptors / Q000187:drug effects / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013194:Staining and Labeling; D013650:Taste Buds / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000099273:Neurabins
chemical_list: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D003035:Cobalt; D018698:Glutamic Acid; D007552:Isotonic Solutions; D007608:Kainic Acid; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors; D000099273:Neurabins; C037692:Tyrode's solution