Representative isolated mitochondrial ultrastructural changes assessed by electron microscopy at 24 h after resuscitation. Blue arrowheads, mitochondrial ultrastructural exhibited normal membrane integrity and no signs of swelling or injury; red arrowheads, mitochondrial ultrastructural exhibited swelling, decreased matrix density, and cristae disintegration. S, sham; N, normothermia; HOE, HOE-642; Hypo, hypothermia; HOE+Hypo, HOE-642 plus mild hypothermia. Magnification, 30,000X. Scale bar, 1 µm.