K. Magishi et al., EXOGENOUS LYSOPHOSPHATIDYLCHOLINE INCREASES NONSELECTIVE CATION CURRENT IN GUINEA-PIG VENTRICULAR MYOCYTES, Pflugers Archiv, 432(2), 1996, pp. 345-350
Whole cell, patch-clamp studies were performed to examine the effect o
f lysophosphatidylcholine (LPC) on the membrane current in guinea-pig
ventricular myocytes. The addition of 10 mu M LPC to the external solu
tion 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 cur
rent with the reversal potential near 0 mV, indicating that the curren
t passed through a Ca2+-permeable non-selective cation channel. The or
der of the cationic permeability calculated from the reversal potentia
l of the current was Cs+ > K+ > NMG > Na+ > Ca2+. Cl- did not pass thr
ough 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 pi
pette solution. In conclusion, LPC induces a Ca2+-permeable non-select
ive cation channel in guinea-pig ventricular myocytes.