Figure 2: A2AR and its effects on blood pressure regulation. Activation of A2AR by adenosine can reduce blood pressure because it: 1. influences negatively the sympathetic tonus (inhibition of norepinephrine release); 2. induces vasodilatation through NO release on endothelial cells; 3. promotes membrane hyperpolarization on smooth muscle cells; 4. reduces renal flow (renal vessel vasodilation) and salt excretion. AC: adenilate ciclase. cAMP: ciclic adenosine monophosphate. ATP: adenosine triphosphate. NO: nitric oxide. NTS: nucleus of the solitary tract. SNS: sympathetic nervous system. Gs: stimulatory G protein NOR: norepinephrine.