EDN1 and hypertensive disorder: Second, the conclusion of the involvement of ET-1/ETAR pathway in such protective actions of quercetin could be strengthened by employing pharmacological method to active the ET-1/ETAR pathway in quercetin-treated RUPP rats, to check whether the activation of the ET-1/ETAR pathway will abolish the protective effect of quercetin on RUPP induced hypertensive rats.