Effect of LPA on platelet thrombus formation on collagen under shear conditions. A suspension of platelets and red blood cells was premixed without or with 50 μg/mL soluble fibronectin (FN) and/or 5 μM LPA, and perfused over surfaces coated with 20 μg/mL collagen at a wall shear rate of 1250 s^–1 for 5 minutes. Microscopy was performed as in Figure 2. Bar = 100 μm. Thrombus volume and number of adherent platelets were calculated as described in “Materials and methods.” Values represent the mean ± SD (n = 3-5). #P < .05 compared with a control (the absence of LPA and fibronectin). *P < .05 compared with LPA or fibronectin alone.