TSP1 did not significantly contribute to initial platelet adhesion to injured arterioles either in presence or absence of VWF. Using intravital microscopy the number of fluorescent-labeled platelets that deposited on the 250 µm vessel wall segments within 3 to 4 minutes after FeCl3 injury was quantitated. Platelet counts >150 were counted as 150 for statistics. (A) Left panel shows representative photomicrographs of single platelet adhesion (3-4 minutes) after injury. Blue line delineates the vessel. Right panel shows quantification of platelets adhered to the injured mesenteric arteriole after injury. N = 10 to 14 mice/group. (B) Left panel shows representative photomicrographs of adhesion of platelets from WT (calcein green, AM labeled) and Tsp1−/− (calcein red-orange AM labeled) in recipient WT mice using 2-channel imaging. Right panel shows quantification of differential fluorescently labeled platelets that adhered within 3 to 4 minutes after injury. N = 6 mice/group. Data are represented as mean ± standard error of the mean. NS, nonsignificant.
