A new approach to the direct detection of free radicals in the intact myocardium.
A new method for the direct ESR detection of free radicals in rat myocardial tissue is described. Isolated rat atria are continuously monitored for heart rate and contractile force; at the end of the experimental period the beating organs are inserted into quartz ESR tubes and immediately frozen in liquid nitrogen. Spectra obtained from these preparations show the presence of very weak radical signals. When ESR spectra are recorded on samples obtained from pools of rat atria pulverized under liquid nitrogen, the radical lines are markedly stronger than those observed for intact organs; contaminating metals are also frequently detected. These findings indicate that crushing or grinding procedures carried out under liquid nitrogen produce artifactual ESR active species. The new method described in the present paper does not involve mechanical interventions and therefore should yield reliable artifact-free results.
Monti
E
E
Institute of Pharmacology, University of Milano, Italy.
Morazzoni
F
F
Perletti
G
G
Piccinini
F
F
D000818:Animals; D016275:Atrial Function; D004578:Electron Spin Resonance Spectroscopy; D005189:False Positive Reactions; D005609:Free Radicals; D005615:Freezing; D006325:Heart Atria / Q000032:analysis; D006339:Heart Rate; D009200:Myocardial Contraction; D009206:Myocardium / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains
D005609:Free Radicals