At2 receptor

AT2 receptors are ubiquitously expressed during the foetal period. After birth, they are only found in low density in the adrenal glands, CNS, vascular endothelium and uterus. They are apparently of minor importance under physiological conditions, but seem to play a pathogenetic role in cardiovascular diseases.

The physiological effects consist in an inhibition of growth of endothelial cells in coronary vessels. In blood vessels, stimulation of the AT2 receptor usually leads to a reduction in blood pressure, but sometimes only under a blockade of the AT1 receptor. Most AT2-mediated effects are G-protein independent. Thus, the induced vasodilation is caused by an increase in the expression of eNOs and by an increase in bradykinin synthesis.

In principle, the AT2 receptors behave like antagonists of the AT1 receptors with regard to their effects. An exception is the release of renin which reduces angiotensin II via both AT1 and Ate receptors.