A. Experimental protocol for measuring calcium retention capacity. At the onset of reperfusion, isolated hearts are perfused with Krebs Henseleit (KH, control group, CTRL), 1% Intarlipid (ILP) or 1% Intralipid+LY294002 (ILP+LY) for 10 min. B. Typical recording of the mitochondria permeability transition pore opening in isolated mitochondria from control (black trace), ILP (light gray trace) and ILP+LY (dark gray trace). Fourteen pulses (gray arrows) of 20 nM calcium were required to trigger the opening of mitochondria permeability transition pore in ILP group compared to 7 pulses (black arrows) in CTRL and 8 pulses in ILP+LY. C. Calcium retention capacity (CRC) in CTRL (circles, n=7), ILP (squares, n=7) and ILP+LY (triangles, n=6). The individual measurements in each groups are shown in open shapes whereas the averages (Mean±SEM) are shown in filled shapes.**P<0.01 vs. CTRL and ILP+LY.