Figure 4. Administration of metformin decreased cardiac injury in aged mouse hearts. (A) Shows the experimental protocol. Metformin feeding was the same as in Figure 1. Isolated perfused hearts received no ex vivo treatment. The isolated mouse hearts underwent 25 min. global ischemia at 37° C and 60 min. reperfusion. Metformin treatment decreased the infarct size in aged 24 mo. hearts compared to vehicle (B), supporting that metformin treatment decreased cardiac injury in 24 mo. hearts following ischemia-reperfusion. Mean ± SEM. †p<0.05 vs. 24 mo. vehicle. n=9 in vehicle treated group. n=10 in metformin treated group.