Complete recovery of cytochrome oxidase and superoxide dismutase activities in the brain of brindled mice receiving copper therapy.

Abstract

To elucidate the roles played by copper-containing enzymes in the brain degeneration associated with Menkes disease, the brains of brindled mouse hemizygotes (BMs) were studied histochemically and biochemically before and after copper therapy. Light and electron microscopic histochemistry revealed that, while neuronal mitochondria in BM brains demonstrate only a weak diaminobenzidine reaction for cytochrome oxidase, these exhibit strong activity after therapy and in control mice. Biochemical assays of enzyme activity revealed only 30% of the normal level before a single subcutaneous application of 50 micrograms of CuCl2, whereas neuronal mitochondria of BMs surviving 8 months after the copper therapy displayed essentially no difference from the controls. Similar results were also gained for superoxide dismutase activity, although the reduction was less marked. The present findings provide direct support for decreased activities of copper-containing enzymes being responsible for the mitochondrial abnormalities and brain degeneration associated with Menkes disease.