Salinska E, Pluta R, Lazarewicz J W
Department of Neurochemistry, Polish Academy of Sciences, Warsaw, Poland.
Biomed Biochim Acta. 1989;48(2-3):S170-3.
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.
采用体内透析灌注技术，研究了尼莫地平和2-氨基-5-磷酸缬氨酸（APV）对家兔海马在缺血期间以及局部应用N-甲基-D-天冬氨酸（NMDA）时Ca2+通量的影响。缺血引起的细胞外钙下降，在未经治疗的动物中为30%，静脉注射尼莫地平后降至7.5%，局部应用APV后降至9%，而局部应用尼莫地平仅有轻微作用。NMDA引起的细胞外钙浓度下降对APV高度敏感，而静脉注射尼莫地平无效，局部应用时仅轻微降低此效应。这些结果表明，与NMDA敏感的谷氨酸受体偶联的钙通道，而非电压依赖性钙通道，在缺血时海马神经元钙内流中起关键作用。
