High level of Trx protects against I/R mediated LV dysfunction and infarction of aged myocardium. (A). Representative M-mode images taken from NT, Trx-Tg and dnTrx-Tg hearts of sham (top) and I/R (bottom). Ejection fraction; EF (B) and fractional shortening; FS (C), an index of cardiac contractile function, was determined by echocardiographic analysis. *p <0.05 versus NT sham; **p <0.05 versus NT or dnTrx-Tg I/R hearts, n=3-5. (D) NT, Trx-Tg and dnTrx-Tg mice were subjected to 60 min ischemia and 30 min reperfusion and then TTC staining was performed as described in the methods section. TTC stains viable tissue brick red and necrotic tissue as white. (E) Infarct area in relation to area-at-risk (AAR). *p <0.05 versus NT or dnTrx-Tg I/R; **p <0.05 versus NT or Trx-Tg I/R, n=4. Statistical significance was determined with the Student’s t-test.