Electrolysis-induced myocardial dysfunction. A novel method for the study of free radical mediated tissue injury.
Oxygen-derived free radicals and other oxidizing species are thought to be involved in inflammation and ischemic tissue injuries. Recently, oxygen-derived free radicals also have been implicated in tissue injury of the myocardium subjected to ischemia/reperfusion. The purpose of this investigation was to determine if electrolysis of a physiological buffer would serve as a source of free radicals, and if these radicals would lead to alterations in myocardial function. Isolated Langendorff-perfused rabbit hearts perfused with buffer subjected to a 20 mA D.C. current for 2 min demonstrated significant increases in coronary perfusion pressure (37 +/- 6 mmHg), left ventricular end diastolic pressure (41 +/- 7 mmHg), and loss in left ventricular developed pressure (35 +/- 5%). The free radical scavengers, superoxide dismutase and a combination of tryptophan plus glycine, were effective in protecting the hearts from the effects of electrolysis. The presence of free radicals was semiquantitated with a radical-luminol chemiluminescent assay. In this assay a variety of radical scavengers and antioxidants were effective (i.e., dimethyl sulfoxide, nitro blue tetrazolium, ascorbate, superoxide dismutase, 1, 3-diphenylisobenzofuran, and glycine, catalase), whereas mannitol and tryptophan were not effective. The data indicate that electrolysis of a physiological buffer produces a milieu containing several reactive oxygen species or free radicals that have the potential to produce alterations in a biological system. This method has the advantage over existing protocols for the generation of radicals in that it is a blood-free and an enzyme-free system.
D000818:Animals; D002021:Buffers; D002374:Catalase / Q000494:pharmacology; D004558:Electric Stimulation; D004572:Electrolysis; D005609:Free Radicals; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008297:Male; D008722:Methods; D009206:Myocardium / Q000473:pathology*; D011817:Rabbits
D002021:Buffers; D005609:Free Radicals; D006861:Hydrogen Peroxide; D002374:Catalase