Quench effect of metallothionein on free radical signal in post-ischemic reperfusion of isolated rat hearts]

Signals of N-tert-butyl-phenyl-nitrone (PBN) spin adducts were observed during post-ischemic reperfusion in isolated rat hearts using electron spin resonance (ESR) spectroscopy and ESR spin-trap PBN. The intensity of signals was related to the time course of ischemia. The intensity of the signals produced during reperfusion after 40 minutes of ischemia was remarkably higher than that of 20 minutes of ischemia. Metallothionein (MT) did quench the adduct signals and the extent of quenching of the signals by this protein was dose-dependent. The signal intensity was decreased to 40% of corresponding control at the concentration of 5 x 10(-6) mol/L. It is a kind of endogenetic protein rich in cysteine residue and divalent metal ions. It is believed to be a promising cytoprotective drug in clinical medicine.