Determination of kallikrein by radioimmunoassay in human body fluids.

A sensitive and specific radioimmunoassay for human urinary kallikrein was developed, which allows tissue kallikrein determination in human urine, saliva, pancreatic juice, bile and sweat. In several body fluids a kallikrein-like antigen was found, but not in gastric juice and breast milk. According to gel filtration studies, complex formation of kallikrein with serum proteins or different molecular weight forms of kallikrein in serum and urine may be assumed. Pancreatic kallikrein secretion follows the same pattern after stimulation with secretin and cholecystokinin as trypsin and chymotrypsin in normal individuals. In chronic pancreatitis the kinetic behaviour remains unchanged with respect to the enzyme secretion, but the secretion of kallikrein is reduced to about 20%.