Direct determination of plasma endothelin-I by chemiluminescence enzyme immunoassay.
A highly sensitive sandwich-type chemiluminescence enzyme immunoassay for plasma endothelin-I (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.
Iwata
R
R
Pharmaceutical Research Laboratory, Hitachi Chemical Co., Ibaraki, Japan. HCN00974@niftyserve.or.jp
Hayashi
T
T
Nakao
Y
Y
Yamaki
M
M
Yoshimasa
T
T
Ito
H
H
Saito
Y
Y
Mukoyam
M
M
Nakao
K
K
D000328:Adult; D016232:Endothelins / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000706:statistics & numerical data; D008163:Luminescent Measurements; D008875:Middle Aged; D011786:Quality Control; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D016232:Endothelins; D011933:Reagent Kits, Diagnostic