The purine enzymes of the anthropoids and marsupials

Abstract

Previous studies have shown that the human organism contains no enzymes which will destroy uric acid in vitro, in which respect man differs from all other mammals hitherto investigated. This corresponds with the repeated observations, especially of Wiechowski, that man alone of all domestic mammals excretes uric acid rather than allantoin as the chief end product of purine metabolism. These facts have been especially emphasized of late by Andrew Hunter. One of us found that even the monkey has no demonstrable uricolytic enzymes in its tissues. Wiechowski made the interesting observation that the chimpanzee, like man, excretes only uric acid and little or no allantoin, while Hunter and Givens reported that monkeys resembled the other mammals in excreting chiefly allantoin, corresponding with our observations on the purine enzymes of the monkey. We have recently, through the kindness of Dr. W. T. Hornaday of the New York Zoölogical Society, come into possession of two fresh bodies of anthropoids—–a male chimpanzee and a female orang-utan. Examination of their tissues shows that, like man, they do not possess the uricolytic enzyme, uricase, demonstrable in vitro. They also resemble adult man in having guanase but no demonstrable adenase. Hence it seems that the anthropoids stand with men in constituting, in respect to uricolytic power, an exception to all other known mammals; the monkeys resemble the other lower mammals in possessing uricase, and hence in this property the anthropoids stand closer to man than to the monkeys, as they are also said to do in serological reactions. We have found a marsupial, the opossum, to have uricase, xanthine oxidase, guanase but no adenase. In respect to uric acid destruction our results agree perfectly with the urinary analyses of Hunter and others.