Effects of angiotensin II on endothelial cell growth: role of AT-1 and AT-2 receptors.

Angiotensin II (AngII) is a main mediator in the regulation of vascular tone. Although its effects on vascular smooth muscle cells are well known, data on its role on endothelial biology are still insufficient. The present study examined the effect of endogenous and exogenous AnglI on bovine aortic endothelial cells possessing both AT- 1 and AT-2 receptors. A DNA synthesis-promoting effect of AT-2 block- ade by PDl233l9 (l0� to l0� M) was demonstrated. This effect was transduced through an AT- 1-mediated pathway, as shown by using the AT- I antagonist, losartan. In addition, an AT-I -mediated effect of AnglI was demonstrated on bovine aortic endothelial cell proliferation, which occurred despite the absence of AnglI-induced Ca2� transients. In summary, the present study disclosed relevant characteristics of the effect of Angil on endothelial cell growth that have potential pathophys- iologic projections, particularly for the use of selective AngIl