PMID: 8593249Nov 1, 1995Paper

A significant fraction of calcium transients in intact guinea pig ventricular myocytes is mediated by Na(+)-Ca2+ exchange

Cellular Signalling
C M SantiA Hernández-Cruz

Abstract

Ca2+ mobilization elicited by simulation with brief pulses of high K+ were monitored with confocal laser scanned microscopy in intact, guinea pig cardiac myocytes loaded with the calcium indicator fluo-3. Single wavelength ratioing of fluorescence images obtained after prolonged integration times revealed non-uniformities of intracellular Ca2+ changes across the cell, suggesting the presence of significant spatial Ca2+ gradients. Treatment with 20 microM ryanodine, an inhibitor of Ca2+ release from the SR, and 10 microM verapamil, a calcium channel blocker, reduced by 42% and 76% respectively the changes in [Ca2+]i elicited by membrane depolarization. The overall spatial distribution of [Ca2+]i changes appeared unchanged. Ca2+ transients recorded in the presence of verapamil and ryanodine (about 20% of the size of control responses), diminished in the presence of 50 microM 2-4 Dichlorbenzamil (DCB) or 5 mM nickel, two relatively specific inhibitors of the Na+/Ca2+ exchange mechanism. Conversely, when the reversal potential of the Na+/Ca2+ exchange was shifted to negative potentials by lowering [NA+]o or by increasing [Na+]i by treatment with 20 microM monensin, the amplitude of these Ca2+ transients increased. Ca2+ transients e...Continue Reading

References

Mar 1, 1979·The American Journal of Physiology·L J Mullins
Mar 1, 1992·The American Journal of Physiology·D A WilliamsT O Morgan
Jun 14, 1991·Cell·J R GeiserT N Davis
Apr 20, 1990·Science·W J LedererR W Hadley
Feb 1, 1990·Cell Calcium·T Takamatsu, W G Wier
May 27, 1986·European Journal of Pharmacology·M NishioI Muramatsu
Jul 1, 1987·Circulation Research·L Barcenas-Ruiz, W G Wier
Nov 1, 1988·The Journal of Physiology·D J Beuckelmann, W G Wier
Oct 1, 1989·Medical Hypotheses·D M Gersten, V J Hearing
Apr 1, 1989·The Journal of Physiology·T M EganV W Twist
Mar 1, 1988·Proceedings of the National Academy of Sciences of the United States of America·G CallewaertM Morad
Sep 1, 1988·The Journal of Physiology·S M Baylor, S Hollingworth
Aug 1, 1986·Proceedings of the National Academy of Sciences of the United States of America·J A Connor
Feb 13, 1986·Nature·J KimuraH Irisawa
Feb 1, 1994·The Journal of Physiology·P Lipp, E Niggli

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