Porphyrins, porphyrinuria, and porphyria.

Abstract

Dermatologists have particular interest in the porphyrins for several reasons. First, the porphyrins have been recognized for many years to be powerful photosensitizing substances. Secondly, they are important because the porphyrias, i.e., clinical syndromes associated with abnormal porphyrin metabolism, sometimes involve the skin. From the biologic point of view protoporphyrin III is the most important of the porphyrins both in the animal and in the vegetable kingdom. It is tetramethyl divinyl dipropionic acid porphin. It is present in respiratory pigments such as hemoglobin, chlorophyll, cytochrome, and catalase. It is soluble in ether and in chloroform and is normally present in erythrocytes but not in urine. In order properly to appreciate the porphyrias, it is necessary to have some understanding of the chemistry of the porphyrins. The basic structure of all the porphyrins is the porphin nucleus which consists of four pyrrole units bound together by four