富氧对缺氧大鼠心肌琥珀酸脱氢酶及超微结构的影响

目的：探讨富氧对缺氧大鼠心肌损伤的保护作用及机理。方法：雄性Wistar大鼠32只随机分为平原对照组、低氧组、富氧组，低氧组在模拟海拔5400m低压舱内24h，富氧组在模拟5400m的低压舱内12h，然后富氧（27．0％的氧混合气）12h，观察心肌琥珀酸脱氢酶（SDH）及超微结构的改变。结果：低氧组心肌细胞灶性变性坏死，肌丝溶解凝固，间质水肿液和纤维素样渗出。富氧组心肌无明显病变，仅滑面内质网轻度扩张。富氧组SDH活性明显高于低氧组。结论：低氧导致心肌SDH活性及超微结构的改变，富氧对心肌有保护作用。

Effects of oxygen - enrichment on myocardial succinate dehydrogenase and ultrastructure in hypoxic rats

Objective: To investigate the mechanisms of oxygen -enrichment and its protective effects on hypoxic rats with myocardial impairment. Methods: 32 male Wistar rats were divided randomly into normoxic group, hypoxic group and oxygen -enrichment group. The animals of normoxic group were put into a chamber with normal atmospheric pressure at altitude of 390 m. The hypoxic group was put into a low -pressure chamber that had a mimetic altitude of 5400 m for 24 h, and the oxygen -enrichment group into an oxygen -enriched chamber(27% of oxygen concentration) for 12 h after into the low -pressure chamber for 12 h. The changes of ultrastructure were observed and the level of myocardial succinate of two groups was detected. Results: The hypoxic group had focal degeneration and necrosis in myocardial cells, lysis or coagulation of myofilament, exudation of interstitial edema fluid and cellulose. The oxygen -enrichment group did not have any obvious lesion besides of mild distension of smooth endoplasmic reticulum. The level of SDH in oxygen -enrichment group was higher than that in hypoxic group. Conclusion: Hypoxia can result in lesion of myocardial cells through decreasing SDH activity, while oxygen -enrichment is of protective effects against the hypoxia.