[Extracorporeal uric clearance for the demonstration of in vivo bound uric acid]

Although numerous in vitro experiments demonstrated a variable degree of urate bound to human serum albumin and other macromolecules of human plasma, only few data are available on in vivo bound urate. Extracorporal clearances of uric acid, urea nitrogen, creatinine and phosphorus were performed at the beginning, the midtime and the end of 10 hours of hemodialysis. A continuous decrease of uric acid clearance was observed in ratio with the capacity of the artificial kidney used. In contrast to uric acid the clearances of urea nitrogen, creatinine and phosphorus remained constant during the time of dialysis. From the fall of uric acid clearance, the authors conclude a partial binding of uric acid in human plasma.