[Reduction of nitroblue tetrazolium by thiols in the presence of vitamin K].
Thiol-containing proteins and low molecular sulfhydryl-containing compounds reduced nitroblue tetrazolium (NBT) in presence of vitamin K3(2-methyl-1,4-naphthoquinone). Cysteine and dithiothreitol (but not glutathione) reduced NBT also in absence of the quinone. Reduction of NBT was accelerated in the weakly alkaline medium and occurred both via O2- -dependent and O2- -independent mechanism. In presence of quinones the thiols appear to affect the manifestation of oxidoreductase reactions estimated by means of NBT-test.