Tsuzuki K, Iino M, Ozawa S
Department of Physiology, School of Medicine, Gunma University, Maebashi, Japan.
Neurosci Lett. 1989 Nov 6;105(3):269-74. doi: 10.1016/0304-3940(89)90632-0.
The calcium permeability of receptor channels activated by quinolinic acid (QUIN) in cultured rat hippocampal neurons was investigated using the whole-cell voltage-clamp method. In Na+-free, 10 mM Ca2+ solution with the internal solution containing 165 mM Cs+, QUIN elicited prominent inward currents at -60 mV, and the reversal potential of the QUIN-induced current was -5.8 +/- 1.2 mV, indicating that QUIN-activated channels are highly permeable to Ca2+ (permeability ratio PCa2+/PCs+ = 5.9). This result was substantiated by microfluorometry using fura-2, which revealed that QUIN caused a marked increase in the intracellular Ca2+ concentration even after the voltage-dependent Ca2+ channels had been suppressed by La3+.
采用全细胞膜片钳方法，研究了喹啉酸（QUIN）激活的培养大鼠海马神经元受体通道的钙通透性。在无钠、含10 mM Ca2+的溶液中，内部溶液含有165 mM Cs+，QUIN在-60 mV时引发明显的内向电流，QUIN诱导电流的反转电位为-5.8±1.2 mV，表明QUIN激活的通道对Ca2+具有高通透性（通透性比PCa2+/PCs+ = 5.9）。使用fura-2的微量荧光测定法证实了这一结果，该方法显示即使在电压依赖性Ca2+通道被La3+抑制后，QUIN仍导致细胞内Ca2+浓度显著增加。
