The Chemistry of Uric Acid and the Purin Bodies
Much of the vague philosophy of disease in past times may fairly be attributed to the complexity and mystery of action inherent in living matter. The subjects of physics, chemistry and biology, in their wider acceptation, were unevolved, and scientific pathology, the offspring of this ancestry, was yet unborn. How much we owe to physics, chemistry, and biology, those handmaids of medicine, is inestimable! But something at least of our debt thereto will be revealed in the following pages.
Of the purins in human urine, the most important is uric acid, and far behind comes xanthine, while traces of hypoxanthine, guanine, and adenine are also detectable. Some years ago the current view was that the metabolism of any protein gave rise to uric acid. This assumption has now proved to be erroneous, for it is known that only certain foodstuffs lead to an increase in the uric acid excretion; in other words, on a diet rich in purin the output thereof is considerably higher than on a purin-free diet, this being due to the large amount of nuclein and purin bases in flesh foods, especially those containing glandular substances. Under ordinary conditions the excretion of uric acid ranges from 0·3-1·2 gm. per diem, or 0·02-0·10 per cent. The oscillations in output vary with the state of health, diet, and personal idiosyncrasy.