Ostadal Petr, Elmoselhi Adel B, Zdobnicka Irena, Lukas Anton, Elimban Vijayan, Dhalla Naranjan S
Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, and Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Antioxid Redox Signal. 2004 Oct;6(5):914-23. doi: 10.1089/ars.2004.6.914.
The aim of this study was to assess whether depression of cardiac Na+,K(+)-ATPase activity during ischemia/reperfusion (I/R) is associated with alterations in Na+,K(+)-ATPase isoforms, and if oxidative stress participates in these I/R-induced changes. Na+,K(+)-ATPase alpha1, alpha2, alpha3, beta1, beta2, and beta3 isoform contents were measured in isolated rat hearts subjected to I/R (30 min of global ischemia followed by 60 min of reperfusion) in the presence or absence of superoxide dismutase plus catalase (SOD+CAT). Effects of oxidative stress on Na+,K(+)-ATPase isoforms were also examined by perfusing the hearts for 20 min with 300 microM hydrogen peroxide or 2 mM xanthine plus 0.03 U/ml xanthine oxidase (XXO). I/R significantly reduced the protein levels of all alpha and beta isoforms. Treatment of I/R hearts with SOD+CAT preserved the levels of alpha2, alpha3, beta1, beta2, and beta3 isoforms, but not that of the alpha1 isoform. Perfusion of hearts with hydrogen peroxide and XXO depressed all Na+,K(+)-ATPase alpha and beta isoforms, except for alpha1. These results indicate that the I/R-induced decrease in Na+,K(+)-ATPase may be due to changes in Na+,K(+)-ATPase isoform expression and that oxidative stress plays a role in this alteration. Antioxidant treatment attenuated the I/R-induced changes in expression of all isoforms except alpha1, which appears to be more resistant to oxidative stress.
本研究的目的是评估缺血/再灌注（I/R）期间心脏钠钾ATP酶活性降低是否与钠钾ATP酶同工型的改变相关，以及氧化应激是否参与这些I/R诱导的变化。在存在或不存在超氧化物歧化酶加过氧化氢酶（SOD+CAT）的情况下，对经历I/R（30分钟全心缺血后再灌注60分钟）的离体大鼠心脏测量钠钾ATP酶α1、α2、α3、β1、β2和β3同工型的含量。还通过用300微摩尔过氧化氢或2毫摩尔黄嘌呤加0.03单位/毫升黄嘌呤氧化酶（XXO）灌注心脏20分钟来研究氧化应激对钠钾ATP酶同工型的影响。I/R显著降低了所有α和β同工型的蛋白质水平。用SOD+CAT处理I/R心脏可保留α2、α3、β1、β2和β3同工型的水平，但不能保留α1同工型的水平。用过氧化氢和XXO灌注心脏会降低所有钠钾ATP酶α和β同工型，但α1除外。这些结果表明，I/R诱导的钠钾ATP酶降低可能是由于钠钾ATP酶同工型表达的变化，并且氧化应激在这种改变中起作用。抗氧化剂处理减弱了I/R诱导的除α1之外的所有同工型表达的变化，α1似乎对氧化应激更具抗性。
