Radioimmunoassay of human urinary kallikrein: determination of human urinary kallikrein, II.

A radioimmunoassay for the determination of human urinary kallikrein was developed. The sensitivity of the assay was 0.5 microgram/l. Dose-response curves of human submandibular and parotid saliva, sweat, pancreatic juice and bile paralleled the standard curve obtained with purified human urinary kallikrein. Substances with similar antigenic determinants were also found in human serum, ascites, seminal plasma, amniotic fluid, cervical mucus, tears, liquor and faeces, but not in human breast milk and gastric juice. Moreover, immunoreactive material was detected in the urine of guinea pigs, orangoutangs and chimpanzees, but not in the urine of rats, cats and rabbits. Porcine acrosin and kallikrein, as well as bovine trypsin and chymotrypsin, showed no cross reactivity.