Participation of NMDA-receptors in ischemic changes of calcium homeostasis in rabbit brain.
The effects of nimodipine and of 2-amino-5-phosphonovalarate (APV) on Ca2+ fluxes in rabbit hippocampus during ischemia and during local application of N-methyl-D-aspartate (NMDA) were studied by in vivo dialysis-perfusion technique. The drop of extracellular calcium evoked by ischemia was reduced from 30% in untreated animals to 7.5% by nimodipine applied i.v. and to 9% by local APV administration, whereas local nimodipine application had only slight effect. NMDA-evoked decrease of extracellular calcium concentration was highly sensitive to APV, whereas nimodipine had no effect when applied i.v. or only slightly reduced this effect during local administration. These results indicate that calcium channels coupled to NMDA-sensitive glutamate receptors, rather than voltage-dependent calcium channels play a key role in ischemic calcium influx to hippocampal neurons.
Salinska
E
E
Department of Neurochemistry, Polish Academy of Sciences, Warsaw, Poland.
Pluta
R
R
Lazarewicz
J W
JW
D015763:2-Amino-5-phosphonovalerate; D000818:Animals; D000927:Anticonvulsants / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D006706:Homeostasis; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D009553:Nimodipine / Q000494:pharmacology; D011817:Rabbits; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D012016:Reference Values; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D000927:Anticonvulsants; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; D009553:Nimodipine; D015763:2-Amino-5-phosphonovalerate; D014633:Valine; D002118:Calcium