【摘要】 为探讨低氧应激下甘肃鼢鼠心脏对抗氧化损伤和电生理紊乱的可能机制,对甘肃鼢鼠和SD大鼠在4.5%氧浓度下分别进行2h、4h、6h、8h、10h、16h低氧应激,比较常氧和各时程低氧下二者心脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)和Ca2+-ATP酶、Ca2+-Mg2+-ATP酶、Na+-K+-ATP酶活性,以丙二醛(MDA)含量作为机体氧化损伤指标。结果显示,常氧组甘肃鼢鼠GR活性比SD大鼠高,SOD、CAT、Ca2+-ATP酶、Ca2+-Mg2+-ATP酶和Na+-K+-ATP酶活性及MDA含量与SD大鼠相比均无显著性差异;低氧组甘肃鼢鼠SOD、CAT、GR、Ca2+-ATP酶、Ca2+-Mg2+-ATP酶和Na+-K+-ATP酶活性迅速升高,显著高于SD大鼠,MDA含量则显著低于SD大鼠。说明甘肃鼢鼠心脏通过提高抗氧化酶活性清除低氧诱导产生的多余自由基,并通过提高ATP酶活性保证心电活动正常、心率稳定,应对低氧应激。更多还原

【Abstract】 The purpose of this study was to investigate the mechanisms of anti-oxidative damages and electrophysiological disorder during low oxygen stress in Myospalax cansus.Myospalax cansus and Rattus norvegicus were stressed under low oxygen(4.5%)conditions for 2 h, 4 h, 6 h, 8 h, 10 h,or 16 h.The activities of three heart antioxidases including superoxide dismutase(SOD), catalase(CAT)and glutathione reductase (GR) and three ATPases including Ca2+ -ATPase, Ca2+ -Mg2+ -ATPase and Na+ -K+ -ATPase were measured at each time point.Malondialdehyde(MDA)was used as indicator of oxidative damage.The results are as follows:under normal oxygen conditions, there was no significant difference in SOD,CAT, Ca2+ -ATPase, Ca2+ -Mg2+ -ATPase, Na+ -K+ -ATPase activities and MDA content between Myospalax cansus and Rattus norvegicus, but GR activity in Myospalax cansus was significantly higher than that in Rattus norvegicus.Under low oxygen conditions, the activities of all of the three heart antioxidases and the three ATPases in Myospalax cansus increased rapidly, and they were significantly higher than those in Rattus norvegicus, but Myospalax cansus had significantly lower MDA content than did Rattus norvegicus.We conclude that Myospalax cansus can maintain normal cardiac electrical activity, heart rate and good heart condition through increasing the activity of antioxidase, removing excessive free radicals induced by low oxygen condition and improving ATPase activity.更多还原