不同强度短期间歇性减压低氧对血液及心血管组织抗氧化物质的影响

目的研究不同强度的短期间歇性减压低氧（IHH）对大鼠血液及心血管组织中抗氧化物质的影响。方法将30只6周龄雄性SD大鼠分为对照组（n=10）、IHH 3 500 m组（n=10）和IHH 5 000 m组（n=10）。IHH 3 500 m组和IHH 5 000 m组动物置于低压氧舱分别接受相当3 500 m和5 000 m海拔高度的减压低氧处理,每天4 h,共持续8 d。对照组动物除不接受低氧处理外,其他条件与低氧动物相同。低氧实验结束后,测定血浆、心肌及主动脉组织中的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性与丙二醛（MDA）含量,并测定血浆中尿酸含量。结果与对照组相比,IHH 5 000 m组大鼠血浆CuZn-SOD活性增强,Mn-SOD活性降低,心肌总SOD及Mn-SOD活性均增强,血浆和心肌中的CAT活性增强,MDA含量增加,血浆尿酸含量增加（P〈0.05）;但IHH 5 000 m组大鼠的主动脉SOD、CAT、MDA与对照组相比,差异均无统计学意义（P〉0.05）。与对照组相比,IHH3 500 m组大鼠血浆Mn-SOD活性增强,差异有统计学意义（P〈0.05）;但血浆尿酸、心肌与主动脉的CAT、MDA差异均无统计学意义（P〉0.05）。结论中等强度的短期IHH可诱导血液及心肌组织抗氧化物质升高。

Effects of different levels of short-term intermittent hypobaric hypoxia on antioxidants of blood and cardiovascular tissues in rats

Objective To investigate the effects of different levels of short-term intermittent hypobaric hypoxia (IHH) on the antioxidant activity of blood and cardiovascular tissues in rats. Methods A total of 30 SD rats were assigned to control group, IHH 3 500 m group and IHH 5 000 m group (n=10 in each group). Rats in IHH 3 500 m group and IHH 5 000 m group were treated with IHH mimicking 3 500 m and 5 000 m altitude in a hypobaric chamber for a consecutive of 8 d, with 4 h each day. Rats of control group were treated under the same condition except for hypoxia intervention. After IHH treatment, the activity of superoxide dismutase (SOD) and catalase (CAT) and contents of malondialdehyde (MDA) in plasma, myocardium and aorta were measured, and the contents of plasma uric acid were detected. Results Compared with control group, the activity of plasma CuZn-SOD and myocardial total SOD and Mn-SOD increased in IHH 5 000 m group, while that of plasma Mn-SOD decreased (P<0.05). The activity of CAT and contents of MDA in plasma and myocardium increased in IHH 5 000 m group, and the contents of plasma uric acid increased as well (P<0.05). However, there was no significant difference in the activity of SOD and CAT and contents of MDA in aorta between IHH 5 0 00 m group and control group (P>0.05). The activity of plasma Mn-SOD in IHH 3 500 m group was significantly higher than that in control group (P<0.05), while there was no significant difference in the contents of plasma uric acid, activity of CAT and contents of MDA in myocardium and aorta between these two groups (P>0.05). Conclusion Moderate level of short-term IHH may enhance the endogenous antioxidants activity in plasma and myocardium in rats.