Abstract
Using gel filtration on Sephadex G-200 and the immunochemical method of Bouma et al., the urinary FDP in uraemia and after renal transplantation were found to be mainly of high molecular weight type. Their concentration did not vary with the urinary concentration of lysozyme or albumin. The findings suggest that the urinary FDP are not the results of glomerular filtration or further degradation in the lower urinary tract of filtered fibrinogen. The urine from patients receiving thrombolytic therapy contained low molecular weight products. They were thought to result from an overloading of the tubular reabsorption mechanism.