The uric acid content of the blood of the stellar sea-lion.

Abstract

A year ago, in the course of a general investigation of the body fluids of the Stellar sea-lion, indigent to the coast of northern California, it was observed, quite accidentally, that the uric acid of the blood apparently undergoes a considerable increase on standing. A recent and more complete study of the same question has confirmed the earlier results completely. The uric acid content of the fresh blood of four animals was found to vary from a bare trace to two milligrams per hundred cubic centimeters, according to the method of determination used. After standing for eight days on ice the apparent uric acid content had increased to as high as seven milligrams per hundred cubic centimeters, and remained at approximately this level until the thirtieth day, when the experiments were discontinued. Even after eight hours of standing at room temperature the apparent uric acid content had increased considerably.

The determinations were made by three different methods, the direct colorimetric method of Benedict; the zinc precipitation method of Morris and hlacleod; and the silver precipitation method of Folin and \Vu. The three methods did not give concordant results for the same samples of blood, the amounts of uric acid indicated in each case being in the descending order in which the methods are listed above. It is significant, however, that the difference in the results from the three different methods remained practically constant, irrespective of the absolute uric acid level. In other words, the substance which accumulates in the blood on standing is precipitated by both zinc and silver. Whether or not these discrepancies in the results from the three methods are inherent in the methods themselves is of no concern in this present investigation.