Effect of chronic intermittent hypoxia on the activities of apoptosis regulating factor cysteine-containing aspartate-specific protease-3 and oxidative stress marker myeloperoxidase in cardiomyocyte in rats fed a high-fat diet / 中华老年医学杂志

ABSTRACT

Objective To investigate the effect of chronic intermittent hypoxia (CIH) on myocardial tissue pathology,oxidative stress and apoptosis in rat fed a high-fat diet,and to explore the possible mechanism of CIH induced cardiomyocyte injury.Methods A total of 24 male Wistar rats were randomly divided into 3 groups (n=8 each).The control group was fed common rat forage,the high-fat group was fed high-fat forage,and the high-fat plus intermittent hypoxia group was fed high-fat forage combined with a 7h/d intermittent hypoxia treatment.The changes of myocardial tissue pathology and ultrastructure of cardiomyocyte,and the activities of apoptosis regulating factor cysteine-containing aspartate-specific proteases-3 (caspase-3) and oxidative stress marker myeloperoxidase (MPO) were observed in the 3 groups after 4 weeks of treatment.Results There were significant differences in the activities of caspase-3 and MPO among the three group (F=89.94,71.24,both P＝0.001).The activities of caspase-3 and MPO were lower in the control group than in the high-fat group and in high fat plus intermittent hypoxia group [(0.21±0.06) vs.(0.80±0.11),(1.15±0.21),(3.20±0.58) vs.(10.87±1.96),(13.17±2.22),P＜0.01].The activities of caspase-3 and MPO were higher in the high-fat plus intermittent hypoxia group than in the high fat group[(1.15±0.21) vs.(0.80±0.11),(13.17±2.22) vs.(10.87±1.96),P＜0.01].No abnormal findings in the structure of cardiomyocyte were observed in the control group,while multiple pathologic damages in cardiomyocyte were detected in the high-fat group,and more obvious injuries in the high-fat plus intermittent hypoxia group.Conclusions The pathologic damages to cardiomyocyte are more serious in high fat and intermittent hypoxia group than in the high-fat group.Apoptosis induced by oxidative stress may play an important role in the pathogenesis of these injuries.