Exogenous lysophosphatidylcholine increases non-selective cation current in guinea-pig ventricular myocytes.
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.
Magishi
K
K
First Department of Surgery, Asahikawa Medical College, Asahikawa 078, Japan.
Kimura
J
J
Kubo
Y
Y
Abiko
Y
Y
D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology; D002412:Cations / Q000493:pharmacokinetics / Q000494:pharmacology*; D004553:Electric Conductivity; D005260:Female; D005971:Glutamates / Q000494:pharmacology; D006168:Guinea Pigs; D008244:Lysophosphatidylcholines / Q000494:pharmacology*; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010539:Permeability; D016276:Ventricular Function / Q000187:drug effects*
D002412:Cations; D005971:Glutamates; D008244:Lysophosphatidylcholines; C014574:gamma-glutamylmethylamide; D002118:Calcium