Fluorometric assay of kininase activities in rat tissues

A simple method for the assay of bradykinin (BK)-degrading enzymes was investigated. The procedure of the method includes enzymatic degradation of BK, separation of the residual BK on a small P-cellulose column (0.6 X 3 cm), and its fluorometrical determination based on the reaction with fluorescamine. BK was separated completely from its fragments produced during enzymatic reaction by the column chromatography. The recovery rate of BK was 96 +/- 3%. Quantitative determinations could be carried out on 0.2 nmol of BK, at least in the fluorometry. This method was available for the assay of the enzymes in tissue homogenates as well as in purified preparations, and its usefulness for the study of the enzymes is presented.