High concentrations of free kinins and kinin system components in abdominal transudate of a patient with nephrotic syndrome.

High levels of bradykinin (60--80 ng/ml) were found in abdominal transudate from a patient with nephrotic syndrome caused by chronic glomerulonephritis. The abdominal transudate contained neutral kininogenase and its precursor, identified with plasma kallikrein and prekallikrein, respectively, as well as both forms of kininogen, the low-molecular-weight form predominating. The abdominal transudate was characterized also by very low kininase activity and low levels of alpha 1-antitrypsin (0.46 g/l) and alpha 2-macroglobulin. Large amounts of very low density lipoproteins were present in the transudate. Despite the difference in total protein content between the abdominal transudate and the patient's serum (4.3 g/l and 48 g/l, respectively) their protein fraction composition was similar. The data obtained suggest that bradykinin is important in maintenance of long-lasting blood vessel hyperpermeability, which, in turn, is a driving force in the pathogenesis of refractory nephrotic edema.