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Effects of calcium-free perfusion and calcium-free perfusion followed by reperfusion with calcium on sarcolemmal structure, sarcolemmal permeability, and creatine phosphokinase loss were investigated in isolated perfused rat hearts. Release of creatine phosphokinase was significant (P less than 0.0002) after 4-5 minutes of perfusion with Ca++-free medium,(More)
EDTA-chelated ferrous chloride (Fe(2+)-EDTA) mixed with ascorbic acid (VC) was shown in vitro to produce 2,3-dihydroxybenzoic acid (2,3-DHBA), one of the hydroxyl radical (.OH) derivatives formed from reaction with 1 mM salicylic acid. The .OH generating system of Fe(2+)-EDTA (5, 25 and 50 microM) mixed with VC (50, 250 and 500 microM) was perfused for 15(More)
The three major calcium channel blocking agents, diltiazem, nifedipine and verapamil, inhibit calcium entry into excitable cells. Despite this apparent common action at the cell membrane, these drugs produce quantitative and frequently qualitative differences in cardiovascular variables (for example, heart rate, atrioventricular [A-V] conduction and(More)
Scanning electron microscopy and transmission electron microscopy were used together with tannic acid and ruthenium-red staining to examine connective tissue damage caused by acute myocardial ischemia for 20, 40 and 120 min in pig hearts. The microsphere blood flow technique revealed that blood flow was approximately 0.02 ml/min/g in inner, middle and outer(More)
The formation of hydroxyl radical in the post-ischemic reperfused heart was measured with high performance liquid chromatography and ultraviolet detection using salicylic acid. Hydroxyl radicals react with salicylic acid yielding 2,3- and 2,5-dihydroxybenzoic acid, which can be separated by the liquid chromatography. Isolated rat hearts were perfused with 1(More)
Cellular damage caused by calcium (Ca++) paradox is of significant importance under both experimental and clinical conditions. Electron microscopy was used to study the surface changes of the isolated rat hearts perfused with normal Krebs-Henseleit (KH) medium, Ca++-free KH medium, Ca++-free KH medium followed by normal KH medium. The hearts perfused with(More)
The ultrastructural effects of perfusing ischemic myocardium with calcium-free blood were determined in 12 dogs. In 6 dogs, the left anterior descending coronary artery was ligated for 45 minutes and was released for 5, 10, or 20 minutes. In 6 other dogs, the ischemic zone was perfused with blood free of calcium which was chelated with EGTA (ethylene glycol(More)
Repeated Ca2+ depletion and repletion of short duration, termed Ca2+ preconditioning (CPC), is hypothesized to protect the heart from lethal injury after exposing it to the Ca2+ paradox (Ca2+ PD). Hearts were preconditioned with five cycles of Ca2+ depletion (1 minute) and Ca2+ repletion (5 minutes). These hearts were then subjected to Ca2+ PD, ie, one(More)
We wished to determine whether histidine scavenges hydroxyl radical, H2O2, and superoxide anion in vitro and to investigate the protective effect of histidine on isolated perfused rat hearts after global ischemia (40 min) and reperfusion (30 min) (I/R). Left ventricular (LV) function was recorded and coronary effluent was collected for measurement of(More)