GRIP1^-/- platelets do not have decreased velocity in ionophore-stimulated blood vessels.

<p>A) GRIP1^-/- platelets do not have a decreased velocity in an ionophore-stimulated pinna vessel. WT murine pinna vessels were stimulated with A23187 and the change in fluorescent-labeled WT and GRIP1^-/- platelet velocity determined over time. As a control, platelets were treated with GPIbα blocking antibody (N = 4; *P < 0.05 by students T-test GRIP1^-/- vs WT). B) Representative images of WT and GRIP1^-/- platelets before and 6 minutes after vessel ionophore treatment (smaller, rounder platelets are rolling (arrow), magnification 20X). C) GRIP1^-/- platelets do not have decreased velocity in an ionophore-stimulated mesenteric vessel (N = 4 ± S.E.M; *P < 0.05 by students T-test GRIP1^-/- vs WT). D) Representative images of WT and GRIP1^-/- platelets before and after ionophore treatment in mesenteric arterioles (smaller, rounder platelets are rolling (arrow), magnification 20X). E) GRIP1^-/- platelets have a trend toward reduced vWF adhesion in vitro. Platelets in whole blood from WT and GRIP1^-/- mice were labeled with a fluorescent antibody. Blood was then pumped over a mouse vWF-coated MatTek chamber. Platelet adhesion was determined at multiple time points (N = 4–6 per time point, P < 0.1 at 15 sec).