DETERMINATION OF R-DNA HIRUDIN AND ALPHA-HUMAN THROMBIN-HIRUDIN COMPLEX IN PLASMA SAMPLES - ENZYME LINKED IMMUNOSORBENT ASSAYS FOR HIRUDIN AND COMPLEX VS CHROMOGENIC THROMBIN SUBSTRATE ASSAY

rDNA hirudin plasma concentrations in man and rhesus monkeys were determined over a period of 15 and 24 h. The plasma concentration of alpha-human thrombin-hirudin complex was measured after administration of the complex to rhesus monkeys. The complex was also determined after administration of hirudin to man and rhesus monkeys to study a possible formation of a complex with alpha-human thrombin in blood. The determination of hirudin was performed by a sandwich ELISA, using polyclonal and monoclonal antibodies and the chromogenic thrombin substrate assay. The alpha-human thrombin-hirudin complex concentration in the plasma of rhesus monkeys was measured over a period of 48 hours. The results of a sandwich ELISA were compared with those of the chromogenic thrombin substrate assay. A good agreement between the total hirudin concentrations analyzed by the hirudin ELISA and the alpha-human thrombin-hirudin complex ELISA and those of the chromogenic thrombin substrate assay, measuring total hirudin, too, was observed.