On indican in the blood of uremic patients

A demonstration of the constant presence in uremic blood of an abnormal aromatic body such as indican would be highly significant since this would be suggestive of the nature of the abnormal metabolism. Hence a recent report 1 to the effect that indican is present in the blood in uremia invited confirmation, and especially as the amounts present are stated to be sufficient to give the ordinary blue color with chloroform when only 10 c.c. of serum are used for the test. Considering the total volume of blood this would mean an enormous concentration.

The method for detecting indican employed by Obermayer, was, in brief, to separate all of the proteins from the serum by means of alcohol, which after filtration is evaporated on the steam bath. The residue from the alcohol filtrate is taken up in water, freed of salts with lead acetate and the latter in turn removed by sodium phosphate. A water clear filtrate is the final result which is tested by the usual method employed for urine with Obermayer's reagent.

In repeating Obermayer's experiments the method above mentioned was used, also the separation of the proteins was conducted by means of phosphotungstic and hydrochloric acids and in a third series a method was used which is based on that of Rona for the precipitation of colloids in blood, by means of kaolin. The clinical material consisted of ten typical cases of uremia, all of the convulsive type. It was noted that indican could not be detected in fresh serum when 10 C.C. was used for tests; with larger amounts, 25 c.c., a questionable coloration of the chloroform resulted in one instance. If instead of using fresh serum or blood, the material be allowed to stand twenty-four to thirty-six hours many of the uremic bloods then gave a fairly definite reaction.