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Carnosine and β‐alanine release is stimulated by glutamatergic receptors in cultured rat oligodendrocytes
Author(s) -
Bakardjiev Anastasia
Publication year - 1998
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/(sici)1098-1136(199811)24:3<346::aid-glia9>3.0.co;2-#
Subject(s) - kainate receptor , dnqx , glutamate receptor , carnosine , biology , alanine , agonist , biophysics , homomeric , nmda receptor , biochemistry , receptor , ampa receptor , pharmacology , amino acid , protein subunit , gene
Oligodendrocytes obtained from rat brain 0‐2 A progenitor cells and differentiated in culture take up β‐alanine and synthesize carnosine (β‐Ala‐His). The present study was designed to determine whether carnosine and β‐alanine are released from such cultures in response to some stimuli. An evoked release of these substances was not observed when the cells were incubated with 1mM glutamate or 0.3 mM kainate. Addition of 0.1 mM cyclothiazide (CTZ) to the corresponding stimulus was accompanied by a distinct peak of release consisting of both carnosine and β‐alanine. The efflux was blocked completely in the case of kainate and to 80% in the case of glutamate when 50 μM 6,7‐ dinitroquinoxaline‐2,3 (1H,4H)‐dion (DNQX) was added to the cells at the same time as the receptor agonist. An increase of the efflux was observed in the presence of Zn 2+ . This effect was concentration‐ dependent. Total substitution of NaCl in the efflux medium by LiCl caused only a partial reduction of the release. GABA or 55 mM KCl showed only negligible effect. A large release of carnosine and β‐alanine was observed when oligodendrocyte cultures were treated with Ca 2+ ionophore A 23187. These results suggest that oligodendrocytes exhibit a glutamate receptor‐mediated release of carnosine and β‐alanine. The release is dependent on elevated intracellular Ca 2+ concentration. GLIA 24:346–351, 1998. © 1998 Wiley‐Liss, Inc.