Isolated hearts were subjected to ischemia-reperfusion as described in
Methods. (A) Recovery from reperfusion measured as the left
ventricular rate-pressure product (RPP). (B) Infarcted area of the
left ventricle. The groups are wild type without preconditioning (− PC),
6 female and 6 male; quadruple knockout without preconditioning, 4 male and 4
female; wild type with preconditioning (+PC), 2 male and 2 female; quadruple
knockout with preconditioning, 2 male and 2 female. Without preconditioning, the
quadruple knockout had a significantly higher RPP (p<0.0001) and lower
infarct area (p<0.0001) than the wild type. With preconditioning, there
was no significant difference in RPP (p=0.50) nor infarct area (p=0.88).
Comparisons were made with the unpaired t-test. The line and bars show the mean
and SD.