Direct determination of plasma endothelin-I by chemiluminescence enzyme immunoassay
Iwata, R.; Hayashi, T.; Nakao, Y.; Yamaki, M.; Yoshimasa, T.; Ito, H.; Saito, Y.; Mukoyam, M.; Nakao, K.
Clinical Chemistry 42(8 Pt 1): 1155-1158
1996
ISSN/ISBN: 0009-9147 PMID: 8697570 Document Number: 464814
A highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-1 (ET-1), involving no extraction steps, has been developed. Two populations of polyclonal antibodies were used in the present study: One is specific to the C-terminus of the endothelin family of peptides; the other, a Fab' fragment against the N-terminal core region of ET-1, is coupled with horseradish peroxidase (HRP). Labeled HRP activity was measured by using an enhanced chemiluminescence reaction of luminol/hydrogen peroxide. The assay was sensitive enough to detect 0.5 ng/L (0.05 pg/well) of plasma ET-1 and had no significant cross-reactivities with other related peptides, including endothelin-3 and the endothelin precursor peptide, big ET-1. Reliability of the assay was confirmed by comparison with an extraction-based procedure and a commercial kit.