Pflügers Archiv : European journal of physiology
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The aim of the study was to correlate intracellular Ca(2+) transients with Ca(2+) uptake and efflux characteristics of the sarcoplasmic reticulum (SR) in ventricular myocytes isolated from rabbits with left-ventricular dysfunction (LVD). Chronic (8 weeks) ligation of a coronary artery caused marked LVD in rabbits. Measurements of intracellular [Ca(2+)] were made using Fura-2 on intact, single, left-ventricular myocytes. ⋯ Increased background Ca(2+) leak with ionomycin decreased the frequency of spontaneous release. It is concluded that partial inhibition of SERCA2 mimics some aspects of altered SR function in LVD, but reduced RyR2 function cannot explain the other functional alterations observed. Reduced background Ca(2+) leak from the SR may compensate partly for the reduced Ca(2+) uptake capacity of the SR in the LVD group.