Effects of inhibitors on FITC-FN deposition and Alexa-FGN binding.

Shown are fluorescence micrographs of washed platelets adherent on FN-coated coverslips for 15 minutes and then incubated with FITC-FN or Alexa-FGN. Upper panel: platelets were incubated for 1 hour with 20 mg/L FITC-FN in the presence of no agonist and no inhibitor (0), 0.5 μM LPA, 0.5 μM LPA plus 30 mg/L 70-kd FN fragment, 0.5 μM LPA plus 0.5 mM RGDS, 0.5 μM LPA plus 0.5 μM integrilin (I), or 0.5 μM LPA plus 0.2 g/L L8 mAb. Lower panel: platelets were incubated for 1 hour with 20 mg/L Alexa-FGN and 0.5 μM LPA, 0.5 μM LPA plus 30 mg/L 70-kd FN fragment, 0.5 μM LPA plus 0.5 mM RGDS, or 0.5 μM LPA plus 0.2 μM integrilin (I). Phase contrast microscopy (not shown) revealed monolayers of platelets under all conditions. Bar = 10 μm.