LEP and obesity due to melanocortin 4 receptor deficiency: Moreover, it has been reported that overweight and obese people with endothelial dysfunction have enhanced levels of ET-1 (Weil et al., 2011), and that an ETA receptor antagonist attenuated the hypertension observed in a experimental model of rats with obesity induced by a high fat diet, that also had increased leptin levels (da Silva et al., 2004).