Uncoupler- and hypoxia-induced damage in the working rat heart and its treatment. I. Observations with uncouplers of oxidative phosphorylation.

In the isolated working rat heart, the damaging effect of 0.05-0.06 microM Carbonylcyanide-p-trifluoro-methoxyphenylhydrazone (FCCP) was reversible within 20 sec by perfusion with fresh buffer. Cysteine 3 mM restored the aortic flow to the initial value within an additional 15-20 sec. Thereafter, the FCCP effect became irreversible due to a progressive structural membrane change. The structural change by FCCP is probably brought about by 'internalization' of polar groups (R-SH; R-NH3+) of the mitochondrial (and other) membrane.