Effects of aging on the leakage of ATPase from coronary vascular bed by ischemia-reperfusion. In the ischemia-reperfusion experiments shown in Figure 7, the effluents immediately after reperfusion (20 second-fraction for 1 min) were collected and ATPase activity in each sample was determined by incubating with ATP (100 μM) for 5 min (A). Data shown are levels of substrate ATP that remained in the reaction mixture of young adult rats (gray column) and aged rats (black column). Values are means ± S.E.M (n = 5). *Significantly different from the control value at *P < 0.05 by Student’s t-test. (B): A correlation analysis was performed on the results presented in Figure 7 and Figure 8A from both young adult and aged rats (n = 20).