Mitochondrial membrane polarization is better maintained in HIF-1α-expressing adult cardiomyocytes during anoxia. A: typical fluorescent image of WT, noninduced (Non-I), 2 day-induced (2D-I), and 6 day-induced (6D-I) mouse heart cardiomyocytes after 0, 0.5, 1, 1.5, and 2 h of anoxia. B: cells with polarized mitochondria relative to the amount before anoxia expressed as means ± SE (n = 3–8). *P < 0.05.