Angiotensin II and retinal pericytes migration

Angiotensin II (Ang II) appears to participate in the regulation of neovasc ularization processes in the retina. Migration of perimural cells such as p ericytes plays a key role in regulation of angiogenesis. We hypothesize tha t Ang II stimulates migration of retina pericytes. For this we studied the effects of Ang II on migration of bovine retinal pericytes using modified B oyden chambers and collagen IV-covered polyester membranes. Ang II stimulat ed migration of pericytes by 54.8 +/- 9.7% (n = 10, p < 0.001). This effect was blocked by an AT, receptor antagonist (Losartan) but not by an AT, rec eptor antagonist (PD123319). We determined using checkerboard assays (n = 3 ) that Ang II induces migration of pericytes by chemotaxis (gradient-depend ent), in opposition to chemokinesis (nondirected). Thus, Ang II via its AT, receptor acts as a chemotactic factor and stimulates migration of retina m icrovascular pericytes, This effect may contribute to Ang II-induced regula tion of neovascularization processes in the retina. (C) 1999 Academic Press .