Pentachlorophenol (PCP) is widely used as a biocide, although, its usage is limited to restricted regions in Japan because of its strong toxicity to fishes. With regard to the biochemical aspects of PCP toxicity, Weinbach1) found that PCP inhibited oxidative phosphorylation in vitro and postulated that the inhibition was at least partly responsible for the toxic effects of PCP. Since then, bioc...