Role of Angiotensin II in Nucleus Tractus Solitarius

There are local renin-angiotensin systems (RAS) in regions such as the kidney and heart, and dysfunction of these systems may lead to changes in the regulation of blood pressure. It is likely that all components of the RAS are present in the brain, and local production of angiotensin peptides has been shown in several brain areas. Stimulation of brain RAS leads to increases in blood pressure, attenuation of the baroreceptor heart-rate reflex, stimulation of drinking, and release of various hormones including vasopressin. Nucleus tractus solitarius (NTS), located within the dorso-medial medulla, is the site of termination for primary afferent fibers originating from a wide variety of peripheral organs and tissues and is essential in the integration of autonomic nervous system functions. Several demonstrations suggest that the NTS contains all of the components of the RAS including angiotensinogen, angiotensin-converting enzyme (ACE), AngiotensinII (AngII) and AngII receptors. This review reports the role of AngII in NTS.