Cytochemical studies of respiratory enzymes in carcinoma of the cervix uteri after irradiation by radium and cobalt 60.

Enzymological studies of succinic dehydrogenase and cytochrome oxidase were made on human squamous cell carcinoma of the cervix uteri before, during and after radiation therapy by radium and 60CO. The enzymatic activities of the two enzymes were higher in cells of stage III than in the corresponding cells of stage II. In addition, after treatment, no enzymatic activity could be detected. These changes may be explained on the basis of mitochondrial damage as a result of radiation effect.