The chromogen of melanuria

Abstract

Subcut. injection of 5:6-dihydroxyindole into rabbits caused the secretion in the urine of a melanogen with the same properties as the melanogen found in some cases of human melanotic sarcoma. Injected 5:6-dihydroxyindole-2-carboxylic acid was secreted unchanged. The dipotassium sulphate of 5:6-dihydroxyindole was synthesized but is not identical in properties with the melanogen of melanotic sarcoma.