EFFECT OF ANABIOSIS AUTOINDUCERS OF SOME MICROORGANISMS ON THE RESPIRATION OF RAT-LIVER MITOCHONDRIA

The effects of 2-(4-hydroxyphenyl) ethane-1-ol (tyrosol) and 5-alkyl ( C-19 or C-21) resorcins (ARs), which are produced by some microorganis ms as anabiosis autoinducers, on the respiration of rat liver mitochon dria has been studied. Tyrosol did not influence the rate of controlle d respiration when glutamate with malate or succinate or ascorbate wit h N,N,N',N' -tetramethyl-p-phenylenediamine (TMPD) were used as substr ates. With increasing AR concentration in the incubation medium, first stimulation and then suppression of controlled respiration was observ ed with the same substrates. The stimulating effect was largely suppre ssed by oligomycin, suggesting the involvement of ATPase in the increa se in the respiratory rate. Both AR preparations inhibited coupled and uncoupled respiration with succinate or with glutamate and malate as substrates, but did not change the rate of uncoupled respiration with ascorbate and TMPD in the presence of rotenone and antimycin A. The re duced respiration with NAD-dependent substrates was partially restored with vitamin K-3. These data suggest that ARs and tyrosol inhibit ele ctron transfer between NADH and cytochrome b. In addition, ARs inhibit electron transfer from the succinate dehydrogenase complex.