William Pearl1, Joseph Cascarano1, Benjamin W. Zweifach1
1Department of Pathology, New York University Medical Center, New York, N. Y.
Tóm tắt
The cytochrome oxidase content of rat tissues was investigated, utilizing the accumulation of the free radical formed by the emzymatic, univalent oxidation of a stable, non-toxic substrate, N-phenyl- p-phenylenediamine ( p-aminodiphenylamine). This procedure eliminated the non-enzymatic coupling of the radical with α-naphthol, found in the classic Nadi reaction. Using homogenates, the following decreasing order of enzyme activity was found: heart, kidney, diaphragm, liver, rectus abdominis. A more sensitive assay was also developed, involving the reduction of cytochrome c by ascorbic acid, and using 2-( p-iodophenyl)-3-( p-nitrophenyl)-5-phenyl tetrazolium chloride to analyze unoxidized ascorbic acid. The same order of tissue activity was demonstrated. The cytochrome oxidase content of a tissue may be a reflection of its physiological role.
