Exogenous lysophosphatidylcholine increases non-selective cation current in guinea-pig ventricular myocytes.

Abstract

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.