UTERINE RESPIRATION, CYTOCHROME OXIDASE AND COPPER

Abstract

Cytochrome oxidase was extracted from rabbit uteri in phosphate buffer pH 7.3. It could be obtained in true soln. rather than suspension but was unstable and became rapidly inactivated. By measuring activity of uterine oxidase in res-pirometers the oxidase was inhibited by a number of Cu poisons. The inhibition varied with the conc. of poisoning agent. Similar inhibition was obtained in the overall respiration of uterine tissues of rat and rabbit. The oxidase contained Cu and the reaction it catalyzed was fundamental in tissue respiration. It was not the sole system, however, since iodoacetate, which was an effective inhibitor of tissue respiration, did not affect the enzyme itself. This means that there were other basic systems involved in tissue respiration besides that of cytochrome oxidase-cytochrome.