Calcium is permeable through a maitotoxin-activated nonselective
cation channel in mouse l-cells.
Estacion, Mark, H. Bryant Nguyen & J. Jay Gargus.
Department of Physiology & Biophysics, University of California,
Irvine, Irvine, CA 92717
APStracts 2:0399C, 1995.
The shellfish poison maitotoxin causes the irreversible opening of
nonselective cation channels in mouse L-cell fibroblasts, consistent
with the action of this toxin in other cell types, and the previously
demonstrated existence of 28pS voltage-insensitive nonselective
cation channels that are activated by PDGF in these cells. Toxin
induced opening of these nonselective cation channels led to
increases of intracellular calcium and secondary activation of a
calcium-activated potassium channel. These effects were completely
dependent upon influx of extracellular calcium, supporting the
conclusion that the maitotoxin-activated nonselective cation channels
are permeable to calcium as well as to sodium and potassium. The
implication of this finding is that calcium signaling through this
channel underlies its links into the growth factor response.
Received 23 June 1995; accepted in final form 10 October 1995.
APS Manuscript Number C369-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 November 95