Serum and urinary arginine-esterase activity in paediatric kidney diseases.

Serum and urinary kallikrein activities were determined from the arginine-esterase activities in various groups of kidney diseases and were compared with urinary beta-glucuronidase excretion, urinary output, urinary protein content and creatinine clearance. Serum arginine-esterase activity was significantly augmented in the active stage of diffuse renal diseases but was not related to the severity of parenchymal damage. The values improved during remission; the enzyme activity in chronic uraemic patient was as low as in the control sera. There was a positive correlation between urinary output and serum arginine-esterase activity, and consequently serum kallikrein might have an enhancing effect on diuresis.