ENZYME-IMMUNOASSAY OF MOTILIN IN HUMAN PLASMA

A sensitive and specific double-antibody enzyme-linked immunoassay (EI A) for detecting a motilin-like immunoreactive substance (M-IS) in hum an plasma has been developed. In competitive reactions, the motilin an tibody was incubated with a plasma sample (or motilin standard) and be ta-D-galactosidase-linked synthetic motilin. Free and antibody-bound e nzymes were separated using an anti-rabbit IgG-coated immunoplate. Enz yme activity on the plate was determined by fluorophotometric analysis . This immunoassay allows the detection of 20 to 200 fmol/ml (54 to 54 0 pg/ml) of motilin. The mean level of M-IS detected in human plasma w as 53.9 +/- 25.6 pg/ml.