['Chronic intermittent hypoxia is the most important pathophysiologic feature of sleep apnea syndrome. The present study aimed to determine whether chronic intermittent hypoxia, which is associated with sleep apnea syndrome, can cause or increase damage to liver cell ultrastructure induced by isoniazid and rifampicin in mice.', 'Based on a 2 × 2 full factorial design consisting of two factors of chronic intermittent hypoxia and isoniazid plus rifampicin, 32 male C57B6J mice were randomized into the control group, the chronic intermittent hypoxia group, the isoniazid plus rifampicin group, and the chronic intermittent hypoxia + isoniazid plus rifampicin group. Twelve weeks after treatment, we examined the ultrastructure of liver cells and quantitatively analyzed mitochondrial morphology in C57B6J mice.', 'Chronic intermittent hypoxia did not significantly affect the ultrastructure of liver cells. The main effect of chronic intermittent hypoxia did not lead to an increase of mean profile area or mean perimeter of mitochondria, and a decrease of numerical density on area of mitochondria (all P > 0.05). Isoniazid plus rifampicin significantly affected liver cell ultrastructure. The main effect of isoniazid plus rifampicin resulted in an increase of mean profile area and mean perimeter of mitochondria, and a decrease of numerical density on area of mitochondria (all P < 0.05). Moreover, there was a positive interaction among the chronic intermittent hypoxia and the isoniazid plus rifampicin groups for mean profile area, mean perimeter, and numerical density on area of mitochondria (all P < 0.05).'] Do intermittent hypoxia and isoniazid plus rifampicin affect hepatic ultrastructure in mice?