Fig. 1.

Effects of chronic intermittent hypobaric hypoxia (CIHH) on mitochondrial ultrastructure of cardiomyocytes after ischemia/reperfusion (I/R), revealed by transmission electron microscopy (×20,000). a Control heart without I/R with normal structure of mitochondria. b control heart with I/R: mitochondria are markedly swollen, and cristae are disrupted, dissolved or have disappeared, and are markedly reduced in number. c, d The mitochondria of the hearts of CIHH28 (28-day CIHH treatment) and CIHH42 (42-day CIHH treatment) rats showed much less I/R injury