Histochemical and Biochemical Studies on the Respiratory Enzymes Part 3. Histochemical Studies on Cytochrome Oxidase System in Various Tissues

Basing on the theory presented in the previous report, the author described the new methods for the histochemical and cytochemical demonstration of cytochrome c oxidase and of cytochrome c-cytochrome oxidase system using neotetrazolium chloride in the presence of p-phenylenediamine with or without additional cytochrome c, respectively. The reaction in fresh cell suspensions or in fresh tissue blocks appears as a distinct violet granules coinciding with the sites of mitochondria. The reaction in frozen tissue sections is not so distinct as that in cell suspensions and fresh tissue blocks, but histochemical observation on the distribution of the enzyme activity in the tissue can be made. By the combination of the histochemical method and the colorimetric method for the estimation of the enzyme activity, integrating studies on the morphologic structure and biochemical function in the respiratory activity in the living tissues are possible.