Preparation of Blood-Free Tissue Proteins.

Abstract

It is well known that perfusion and other methods of extraction have hitherto failed to free organs from blood, and for that reason it has been impossible to study the specific proteins in the various tissues or to prepare antisera for them which were not also specific in high dilutions to blood proteins.

In a previous report 1 it was shown that under certain conditions blood-free proteins could be found in the urine which gave precipitin reactions in high dilutions with antisera prepared against liver proteins. It was also suggested 2 that in the early stages of certain nephritides, the liver leaked its proteins into the blood stream and that they were then excreted, as it is well known that the kidneys are permeable to foreign proteins. With these points in view attempts were made to secure larger quantities of this liver protein by animal passage. Solutions containing proteins extracted from dog livers were prepared and freed of non-protein material by dialysis as previously described. 1 This solution contained 0.16% protein. It was injected intravenously into dogs and large amounts of protein were passed in the urine which gave no reactions to blood antisera undiluted, but reacted to liver antisera in dilutions up to 1/100,000.

Injections up to 200 cc. of this solution can be used. Larger amounts tend to produce a blood protein excretion. The proteinuria is slow to begin, reaches its maximum in 12 to 24 hours and subsides after 48 to 69 hours. Reinjection of the same animal will produce a blood proteinuria.