Magishi K, Kimura J, Kubo Y, Abiko Y
First Department of Surgery, Asahikawa Medical College, Asahikawa 078, Japan.
Pflugers Arch. 1996 Jun;432(2):345-50. doi: 10.1007/s004240050142.
Whole cell, patch-clamp studies were performed to examine the effect of lysophosphatidylcholine (LPC) on the membrane current in guinea-pig ventricular myocytes. The addition of 10 microM LPC to the external solution induced a membrane current which had a reversal potential of 0 mV. When Na+, the main cation in the external solution, was replaced by either K+, N-methyl-D-glucamine (NMG) or 90 mM Ca2+, LPC induced a current with the reversal potential near 0 mV, indicating that the current passed through a Ca2+-permeable non-selective cation channel. The order of the cationic permeability calculated from the reversal potential of the current was Cs+ > K+ > NMG > Na+ > Ca2+. Cl- did not pass through the LPC-induced channel. The LPC-induced current was not blocked by Gd3+ in the external solution, nor by the absence of Ca2+ in the pipette solution. In conclusion, LPC induces a Ca2+-permeable non-selective cation channel in guinea-pig ventricular myocytes.
采用全细胞膜片钳技术研究溶血磷脂酰胆碱（LPC）对豚鼠心室肌细胞膜电流的影响。向细胞外溶液中加入10微摩尔/升的LPC可诱导产生一种膜电流，其反转电位为0毫伏。当细胞外溶液中的主要阳离子Na+被K+、N-甲基-D-葡萄糖胺（NMG）或90毫摩尔/升的Ca2+取代时，LPC诱导产生的电流反转电位接近0毫伏，表明该电流通过一个Ca2+通透的非选择性阳离子通道。根据电流反转电位计算出的阳离子通透性顺序为Cs+>K+>NMG>Na+>Ca2+。Cl-不通过LPC诱导的通道。细胞外溶液中的Gd3+或移液管溶液中无Ca2+均不能阻断LPC诱导的电流。总之，LPC可诱导豚鼠心室肌细胞产生一个Ca2+通透的非选择性阳离子通道。
