THE RELATION OF URICOLYSIS TO SUBOXIDATION

The later investigations in purin metabolism have disclosed the fact that there are clearly defined differences between man and other animals with respect to the ultimate products of the disintegration of the purin nucleus. In all mammals, man excepted, uric acid undergoes oxidation prior to excretion, so that in the dog, for example, a large part of the preformed uric acid is found in the urine as allantoin. Likewise in those mammals that excrete allantoin in appreciable amounts, it has been possible to demonstrate in the organs, usually liver and kidney, an enzyme that is capable of destroying uric acid—uricase. Up to the present all efforts directed toward disclosing uricase in man have met uniformly with negative results, and Wiechowsky has shown that if uric acid is destroyed at all in the human body it can hardly be by oxidation, since the diurnal allantoin excretion averages only a milligram. There