Calcium transients in isolated cardiac myocytes are altered by 1,1,1- trichloroethane.
Hoffmann-P; Breitenstein-M; Toraason-M
J Mol Cell Cardiol 1992 Jun; 24(6):619-629
The effects of 1,1,1-trichloroethane (71556) (TCE) on intracellular calcium transients were studied in electrically stimulated neonatal rat ventricular myocytes. The role of the sarcolemma and the sarcoplasmic reticulum in the altered calcium dynamics was also examined. Myocytes were isolated from 2 to 4 day old Sprague-Dawley- rats, and exposed to TCE. Calcium transients were found to be reversibly inhibited in a concentration dependent manner by TCE exposure. At dose levels of 0.25 to 9 millimolar, TCE reduced the height of electrically induced calcium transients in a concentration dependent manner and reversibly reduced them to about 50%, while having no effect on diastolic calcium concentration. Contractility was also inhibited in the same concentration range. Calcium increase in response to potassium-chloride induced depolarization was inhibited by TCE which also further decreased the limited calcium transients in ryanodine pretreated myocytes. Increasing external calcium concentrations antagonized the effect of TCE on the calcium transients. The caffeine releasable calcium pool in myocytes was reduced by TCE as well. The authors conclude that calcium transients are concentration dependently and reversibly inhibited by TCE exposure. The effect appears mediated via actions of calcium fluxes at the sarcolemma and sarcoplasmic reticulum.
NIOSH-Author; Metabolic-study; Ethanes; Alkanes; Chlorinated-hydrocarbons; Organic-solvents; Cardiovascular-system-disorders; Myocardium;
Author Keywords: Myocytes; Ca transient; Fura-2; Myocardial contraction; Cardiac arrhythmia; 1,1,1-trichloroethane
Journal of Molecular and Cellular Cardiology