Superoxide dismutase activity of Ehrlich ascites tumor cells.

A crude extract of Ehrlich ascites tumor cell homogenate was found to contain three distinct bands of superoxide dismutase activity by polyacrylamide gel electrophoresis. Activity bands migrated approximately the same distance and were inhibited by cyanide ions. Isolated mitochondria produced two bands of activity that were also inhibited by cyanid. Ethanol-chloroform treatment of the homogenate had no observable effect on these bands of activity, which suggested that the cyanide-insensitive mitochondrial superoxide dismutase activity in these malignant cells was either present in concentrations below detectable levels or completely absent. Normal liver was used as a control for the detection system.