AGTR1 and endothelial dysfunction: It acts on angiotensin II type 1 receptor to promote vasoconstriction of corporal smooth muscles, induce vascular hypertrophy and endothelial dysfunction via the activation of nicotinamide adenine dinucleotide phosphate (NADPH) resulting in the generation of reactive oxygen species (ROS), which deplete nitric oxide (NO) required for vasodilation, necessary during sexual excitation for erection [18-19].