Angiotensin receptors in the cardiovascular system.

The angiotensin II receptors mediate the effects of the renin-angiotensin system, which has an important role in cardiovascular (patho)physiology. Four types of angiotensin receptors are known, of which the type 1 (AT1) and the type 2 (AT2) receptors are the most important. Stimulation of the AT1 receptor leads to a cascade of signalling pathways in several cell types, which finally leads to processes such as vasoconstriction, inflammation and proliferation. These processes are of great importance in various cardiovascular diseases, including hypertension, atherosclerosis and ventricular hypertrophy. The AT2 receptor is expressed mainly in the fetal stage. In adults, the AT2 receptor is minimally expressed under normal circumstances. Its role in the adult cardiovascular system is not well established, but its effects seem to oppose those of the AT1 receptor. This overview discusses the pathophysiological role of the angiotensin II receptors in various cardiovascular diseases with the emphasis on the signal transduction of the AT1 and the AT2 receptors.