Angiotensin II and retinal pericytes migration

Angiotensin II (Ang II) appears to participate in the regulation of neovascularization processes in the retina. Migration of perimural cells such as pericytes plays a key role in regulation of angiogenesis. We hypothesize that Ang II stimulates migration of retina pericytes. For this we studied the effects of Ang II on migration of bovine retinal pericytes using modified Boyden chambers and collagen IV-covered polyester membranes. Ang II stimulated migration of pericytes by 54.8 ± 9.7% (n = 10, p < 0.001). This effect was blocked by an AT₁ receptor antagonist (Losartan) but not by an AT₁ receptor antagonist (PD123319). We determined using checkerboard assays (n = 3) that Ang II induces migration of pericytes by chemotaxis (gradient-dependent), in opposition to chemokinesis (nondirected). Thus, Ang II via its AT₁ receptor acts as a chemotactic factor and stimulates migration of retina microvascular pericytes. This effect may contribute to Ang II-induced regulation of neovascularization processes in the retina.