Intracellular calcium mobilization triggered by a glutamate receptor in rat cultured hippocampal cells.
1. Intracellular free calcium ([Ca2+]i) was monitored by means of Fura-2 fluorescence measurements in hippocampal cells in primary cultures from newborn rats. 2. In external media containing 200 microM-DL-2-amino-5-phosphonovalerate and 1 mM-kynurenate, but no added Ca2+, an increase in [Ca2+]i was observed in 30-40% of cells examined in response to quisqualate or L-glutamate. 3. Under such conditions, [Ca2+]i often increased gradually with a latency of a few seconds after application of the agonists. 4. Pre-treatment of the cultured cells with pertussis toxin reduced the extent of quisqualate-stimulated [Ca2+]i increase in Ca2+-free media, but the percentage of the responsive cells was not affected appreciably. 5. It is concluded that quisqualate and L-glutamate can trigger the release of Ca2+ from intracellular Ca2+ stores, most likely by activating a glutamate receptor coupled to a pertussis toxin-sensitive G-protein.
Furuya
S
S
Department of Cellular Physiology, National Institute for Physiological Sciences, Okazaki, Japan.
Ohmori
H
H
Shigemoto
T
T
Sugiyama
H
H
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D010069:Oxadiazoles / Q000494:pharmacology; D037342:Pertussis Toxin; D011188:Potassium / Q000494:pharmacology; D016318:Quisqualic Acid; D051381:Rats; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D005971:Glutamates; D010069:Oxadiazoles; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D010566:Virulence Factors, Bordetella; D018698:Glutamic Acid; D016318:Quisqualic Acid; D037342:Pertussis Toxin; D011188:Potassium; D002118:Calcium