SENSITIVE RADIOIMMUNOASSAY METHOD FOR URINARY KININS IN MAN

Abstract

A sensitive and specific radioimmunoassay method for urinary kinins was developed, which uses antiserum against synthetic bradykinin in combination with labeled tyr8-bradykinin. The assay detects as little as 6 pg/tube of bradykinin. The dose-response curves of bradykinin, lysyl-bradykinin (kallidin) and methionyl-lysyl-bradykinin were almost identical. This suggests that the values estimated with bradykinin as the standard exhibit the total urinary kinins which contain these 3 peptides. The assay was performed without extraction of urinary samples, since a chromatographic study demonstrated that no interfering substances in urine samples remain in the assay system. The urinary levels of total kinins in 10 normal male subjects, 3 male patients with chronic renal failure and 12 male patients with essential hypertension were 37.9 .+-. 3.9 .mu.g/day, 9.0 .+-. 5.1 .mu.g/day and 24.2 .+-. 5.2 .mu.g/day, respectively.