Figure 5.

Ultrastructural examination of perfused rat heart. A: Typical myocardial structure in sham-treated myocardium after 35 minutes of perfusion with intact mitochondria interspersed around regular myofibril structures. B: Mitochondrial swelling and derangement accompanied by structural disruption to myotubule formation in the reperfused sham-treated myocardium. C and D: Heat-stressed pre-ischemic and reperfused myocardium. The overall appearance resembles that seen in pre-ischemic sham-treated controls. Arrows indicate transverse tubule formation. Scale bar, 2 μm.