Mode of Action of Triphenyltetrazolium Chloride on Mitochondrial Respiration

抄録

1. Like amytal, 2, 3, 5-triphenyltetrazolium chloride (TTC) inhibited aerobic oxidation of many of NAD⁺-linked substrates but not that of succinate.
2. The site of TTC inhibition was as-sumed to be located between flavoprotein and the ubiquinone-cytochrome b region on the electron transport pathway. The inhibition of respiration by TTC was not relieved by 2, 4-dinitrophenol (DNP).
3. TTC was found to uncouple the phos-phorylation associated with the succinate oxida-tion in agreement with the previous observa-tion of Otori.
4. Unlike amytal, TTC did not inhibit choline oxidation. Further, TTC enhanced the rates of oxidation of both succinate and choline in the absence of hexokinase and glucose, presumably being due to its uncoupl-ing effect.
5. Some of the implications concerned with the above results were discussed.