ABSTRACT
The etiology of hypertension is complex, involving both neuronal and hormone systems acting upon multiple organs.1 The octapeptide hormone angiotensin II (Ang II), the effector molecule of the renin-angiotensin system (RAS) which controls blood pressure, targets virtually all of these organs, including the heart, kidney, vasculature, and brain.2 In addition to the ‘classical’ endocrine function of Ang II in circulating blood, the essential components of RAS (except for renin) have been identified in the brain, lung, heart, kidney, pancreas, and blood vessels, providing evidence for paracrine, autocrine, and intracrine3 effects of Ang II acting locally in tissues.4-6 These local RAS, by acting independently of the circulating Ang II, provide tissuespecific regulatory mechanisms and multiple functional responses within individual organs and/or tissues.7
