Effect of extracellular calcium on inhibition of dye coupling among cardiac myocytes by halogenated hydrobarbons.
FASEB J 1991 Mar; 5(6):A1571
The role of extracellular calcium on halogenated hydrocarbon inhibition of dye coupling in cardiac myocytes was examined. Myocytes, derived from neonatel rat heart, were perfused with HEPES buffer containing varying amounts of Ca++ (0.1-2.0 mM) or 0.5 mM EGTA, and increasing concentrations of carbon tetrachloride or halothane. Single cells were microinjected with Lucifer Yellow CH (5% in 0.1 mM LiCl) and dye transfer to adjacent cells was monitored. Both chemicals inhibited dye coupling in a concentration-dependent fashion. 100% inhibition of dye coupling in high Ca++ occurred at 1 mM carbon tetrachloride or 4.8 mM halothane. Decreasing the Ca++ concentration of the buffer markedly reduced carbon tetrachloride inhibition of dye coupling in myocytes, but negligibly reduced halothane inhibition of dye coupling. Measurement of intercellular C++ with FURA 2 suggested that the reduced inhibition of dye coupling in myocytes by carbon tetrachloride as extracellular Ca++ declines is not accompanied by a parallel decrease in intracellular Ca++.
Cardiac-function; Heart; Cardiac-function; Cardiovascular-function; Cell-function; Cellular-function; Cell-cultures; Analytical-processes
The FASEB Journal