[Electron transport particles from bovine heart as a test system in toxicological studies]

14 standard respiratory inhibitors and substances of toxicological interest were tested on the NADH oxidase and the succinate-cytochrome c oxidoreductase systems of beef heart electron transfer particles (ETP) in the presence and absence of human serum albumin (HSA). HSA did not influence the half-inhibition concentrations by cyanide, amytal and antimycin A. It had little effect on the inhibition by rotenone or carboxin, whereas the inhibition by free fatty acids and monoglyceride was greatly decreased. Lindan and DDT exerted a marked inhibition of the NADH oxidase system in the absence of HSA; the inhibition was weaker but still considerable in the presence of HSA. In the presence of HSA 10(-4) M DDT but not Lindan inhibited also the succinate-cytochrome c reductase system. The results show that ETP may be a useful test object in toxicological studies.