Abstract

It was well known that carbon monoxide induced significant derangements of various parameters of cardiac functions. Recently, Adams et al. reported considerably decreased myocardial oxygen consumption which suggested deranged function of myocardial mitochondria. In order to observe the morphologic changes of the myocardial myocardria, ten rabbits were exposured to the carbon monoxide: Three animals were exposured to 0.2％ CO gas for 2 hours: Three were exposured to 0.2％ for 4 hours: Four were exposures to 0.1％ for 2 hours daily for 5 days. Results obtained were summarized as follow: Mitochondria of myocardial fiber showed marked degenerative changes. Cristae were fragmented and decreased in number with partial disruption. Numerous electron dense granules were occurred in the site of cristae disruption. Mitochondria were fused together to form large irregular shaped body, chondriosphere of de Robertis. No significant changes were noted in the nuclei, myofilament and intercalated disc in all of the experimental groups. Sarcoplasmic reticulum is markedly dilated and glycogen particles and lipid droplets were slightly decreased.