Kiskin N I, Dumpis M A, Piotrovsky L B, Krishtal O A
Department of Physico-chemical Biology of Cellular Membranes, Academy of Sciences of the Ukrainian SSR, Kiev.
Neuroreport. 1991 Jan;2(1):29-32. doi: 10.1097/00001756-199101000-00007.
Ionic currents elicited by N-phthalamoyl-L-glutamic acid (PhGA) were investigated on freshly isolated hippocampal neurons with the whole-cell voltage clamp and concentration clamp techniques. PhGA elicited desensitizing inward currents in Mg(2+)-free salines only in the presence of glycine. The dose-response relationship for PhGA was close to a Langmuir isotherm with Kd = 3.7 mM and saturating level 0.75 of that for L-aspartate (L-Asp). PhGA-activated currents were blocked by Mg2+, D-2-amino-5-phosphonovalerate and kynurenate, and had the same reversal potential as L-Asp-activated currents. Complete cross-desensitization was obtained between the responses to PhGA and L-Asp. We conclude that PhGA is a new selective 'superacidic' agonist of the N-methyl-D-aspartate type of glutamate receptor.
采用全细胞膜片钳和浓度钳技术，在新鲜分离的海马神经元上研究了N-邻苯二甲酰-L-谷氨酸（PhGA）引发的离子电流。仅在甘氨酸存在的情况下，PhGA在无镁盐溶液中引发脱敏内向电流。PhGA的剂量反应关系接近朗缪尔等温线，解离常数（Kd）为3.7 mM，饱和水平为L-天冬氨酸（L-Asp）的0.75。PhGA激活的电流被镁离子、D-2-氨基-5-磷酸戊酸和犬尿烯酸阻断，并且与L-Asp激活的电流具有相同的反转电位。对PhGA和L-Asp的反应之间获得了完全交叉脱敏。我们得出结论，PhGA是N-甲基-D-天冬氨酸型谷氨酸受体的一种新型选择性“超酸性”激动剂。
