Angiotensin type-2 receptors and cardiovascular function: are angiotensin type-2 receptors protective?
OBJECTIVE
The renin-angiotensin system is a coordinated hormonal cascade of critical importance to the regulation of blood pressure and cardiovascular function. The major effector peptide, angiotensin II, binds to two major receptors, angiotensin type-1 and angiotensin type-2. Most of the actions of angiotensin II are mediated by the angiotensin type-1 receptor, but recent evidence strongly suggests that the angiotensin type-2 receptor opposes the angiotensin type-1 receptor, particularly by promoting vasodilatation instead of vasoconstriction.


RESULTS
Conclusive evidence has been presented indicating that the angiotensin type-2 receptor mediates vasodilatation in small resistance arterioles as well as in the coronary microcirculation. Substantial evidence also is available that the angiotensin type-2 receptor dilates large capacitance vessels, including the aorta, subjected to pressure-overload. The angiotensin type-2 receptor has recently been found to inhibit renin biosynthesis and secretion similar to the action of the angiotensin type-1 receptor. The angiotensin type-2 receptor appears to be cardioprotective, particularly in limiting cardiac remodeling following ischemic injury.


CONCLUSIONS
The angiotensin type-2 receptor represents an important area of cardiovascular investigation with potential therapeutic implications for cardiac disease and hypertension.
Carey
Robert M
RM
Division of Endocrinology and Metabolism, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA. mc4c@virginia.edu
D002318:Cardiovascular Diseases / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D044139:Receptor, Angiotensin, Type 2 / Q000502:physiology*; D012084:Renin-Angiotensin System / Q000502:physiology; D014664:Vasodilation / Q000502:physiology*
D044139:Receptor, Angiotensin, Type 2