1997 Volume 61 Issue 2 Pages 151-160
The aim of this study was to determine whether myocardial injury resulting from temporary ischemia followed by reperfusion can be measured by assaying sulfhydryl groups in the affected tissue of a rat model of myocardial infarction. We studied 3 groups: a control group (n=6), which underwent surgery without left coronary artery (LCA) ligation; group NoR (n=9), in which the LCA was ligated for 3 h; and group I+R (n=7), in which 30 min LCA ligation was followed by 3 h reperfusion. The sulthydryl group content of myocardial tissue was assayed by measuring the fluorescence produced by incubating heart sections with N-(7-dimethylamino-4-methyl-3-coumarinyl) maleimide (DACM), which binds sulfhydryl groups. The fluorescence intensity (FI) of normal and infarcted myocardium was quantified by our computerized system of microscopic fluorophotometry. Indices such as sulthydryl group content, the size of the low-FI area [%AREA(lower FI)] and the relative decrease in FI [%FI(decrease)]) in the infarct zone were calculated. Both %AREA(lower FI) and %FI(decrease) were significantly higher in the infarcted zone of animals in NoR and I+R groups than in control animals. Both indices were higher in infarct tissue from animals in the I+R group than in the NoR group. These changes suggest that sulfhydryl group content is significantly reduced in tissue that has been subjected to ischemia-reperfusion. Microscopic fluorophotometry, as defined by DACM staining of myocardial tissue, may help to delineate areas of myocardial reperfusion injury. (Jpn Circ J 1997; 61: 151 - 160)
