INTEGRIN ALPHA(V)BETA(3) IS EXPRESSED IN SELECTED MICROVESSELS AFTER FOCAL CEREBRAL-ISCHEMIA

The endothelial and smooth muscle integrin alpha(v) beta(3), a recepto r for vitronectin and fibrinogen, participates in angiogenesis associa ted with wound healing and tumorigenicity. The microvascular expressio n of alpha(v) beta(3) and fibrin during experimental middle cerebral a rtery occlusion and reperfusion in a non-human primate model was exami ned by computer-assisted video imaging microscopy. No microvascular ex pression of alpha(v) beta(3) was seen in the control subjects (n=3) or the non-ischemic basal ganglia of subjects undergoing 2-hour MCA:O (m iddle cerebral artery occlusion) or 3-hour occlusion with 1-hour (n=3) , 4-hour (n=3), and 24-hour (n=3) reperfusion. In the ischemic territo ry, alpha(v) beta(3) appeared initially at 2 hours of middle cerebral artery occlusion. Up-regulation of alpha(v) beta(3) was confined to th e media of 30.0- to 50.0-mu m-diameter arterioles in the ischemic core and correlated significantly with fibrin deposition in those vessels (P < 0.0005). Integrin alpha(v) beta(3) and its ligand fibrinogen appe ar in a subpopulation of microvessels after focal cerebral ischemia.