The purpose of this study was to evaluate the relationship between the circadian profile of plasma levels of ET1, CGRP and EETs and circadian rhythms of CHI and BRS in the 1 kidney-1 clip (1K-1C) model of hypertension in rats, which is characterized by modest changes in renin and pronounced reduction in glomerular filtration rate, sodium retention and high volume [36–37]. Here, EDN1 is linked to Hypertension.