The angiotensin II type 2 receptor and the kidney

Abstract

Recent knowledge demonstrated that the renin-angiotensin system (RAS) functions as a local renal paracrine system. All components of the RAS are present within the kidney and include angiotensinogen, renin, angiotensin I, angiotensin-converting enzymes, angiotensin II, the angiotensin II type 1 (AT1) receptor and the angiotensin II type 2 (AT2) receptor. Angiotensin II is the major effector hormone of the RAS and contributes to a variety of renal and cardiovascular physiologic and pathologic mechanisms through stimulation of AT1 and AT2 receptors. Angiotensin receptor blockers were developed based on the advanced knowledge of the AT1 receptor contribution to development of a variety of kidney, vascular and cardiac diseases including but not limited to hypertension, diabetic nephropathy, heart failure, myocardial infarction and atherosclerosis. In contrast, knowledge concerning the role of the AT2 receptor in health and disease is still emerging. The AT2 receptor is believed to counterbalance the effects of the AT1 receptor through influencing cellular differentiation, vasodilation, inhibition of cellular proliferation and hypertrophy, nitric oxide production and natriuresis. Thus, the pursuit of a specific AT2 receptor agonist is a potentially fruitful area for combating renal and cardiovascular diseases. This review focuses on the role of the AT2 receptor in the kidney.