STUDIES ON ALBUMIN SYNTHESIS: THE EFFECTS OF DEXTRAN AND CORTISONE ON ALBUMIN METABOLISM IN RABBITS STUDIED WITH ALBUMIN-I131*

Abstract

Following plasmapheresis, the depressed serum albumin concentration rapidly returns to normal (1) indicating alterations in albumin synthesis or degradation. Both dextran administration (2-6) and elevation of serum globulin levels produced by means of hyperimmunization (7, 8) are asso- ciated with hypoalbuminemia; a colloid osmotic regulatory mechanism has been suggested as re- sponsible for the reciprocal changes in serum proteins observed after hyperimmunization (7, 9). If such a mechanism does exert control over the concentration of serum albumin, alterations of albumin metabolism either in the rate of synthesis or in the rate of degradation might be expected when osmotically active molecules other than al- bumin are added to the circulation. The present study represents an attempt to define, more specifi- cally than heretofore reported, the changes in albumin metabolism resulting from such a proce- dure. Dextran was administered to rabbits to de- press albumin concentration. After the develop- ment of hypoalbuminemia, the rates of albumin synthesis and degradation were studied and com- pared with control values. Cortisone acetate was then given to increase the rate of albumin degra- dation (10), and the rates of albumin synthesis were remeasured.