Inhibition of Endothelin (ET)-1- and ET-2-Induced Vasoconstriction by Anti-ET-1 Monoclonal Antibody

Abstract

We produced a monoclonal antibody to endothelin (ET)-1, tested cross-reactivities with the related peptides by enzyme immunoassay, and invenstigated the effects of the antibody on ET-1- or ET-2-inducced vasocontriction of rat isolated thoracic aorta. The antibody recognized ET-1, ET-2 and ET-3, and the immunoreactive site proved to be the N-terminal region but not the C-terminal region of ET-1. Moreover, at an approximate molar-equivalent concentration, the antibody absorbed ET-1 and ET-2, and significantly inhibited ET-1- and ET-2-induced vasoconstriction notwithstanding the presence of the endothelin receptor.