Excretion of Coproporphyrin in Hepatic Disease

Porphyrins are red pigment substances, the chemical structure of which is based on a ring formed by four pyrrole nuclei which are connected in the form of a closed system by four methine bridges. It has long been recognized1that small amounts of porphyrin are excreted normally in the urine of healthy persons and that these amounts may be increased in the urine of patients suffering from a variety of diseases. Porphyrinuria (increased proportion of porphyrin in the urine) has been described as accompanying many forms of hepatic disease,2including cinchophen hepatitis, atrophic cirrhosis, obstructive jaundice, chronic passive congestion, lymphosarcoma of the liver, infectious icterus, melanosarcoma of the liver, hemolytic icterus and hemochromatosis. It has been suggested that porphyrinuria observed in the presence of various other diseases and toxic states is caused by associated hepatic damage or dysfunction.3Much evidence has accumulated which would indicate that porphyrin