Akt mediates long-term VEGF inhibition of exocytosis. (A) Dose response. HAECs were pretreated with 0, 0.5, 5, and 50 ng/mL VEGF for 2 hours. Cells were then washed and treated with 50 ng/mL VEGF for 1 hour, and the release of VWF was measured as above (n = 3 ± SD; **P < .01 versus 0 ng/mL VEGF). (B) Time course. HAECs were pretreated with 50 ng/mL VEGF for 0, 1, 2, 4, or 8 hours. Cells were then washed and treated with 50 ng/mL VEGF for 1 hour, and the release of VWF was measured as above (n = 3 ± SD; **P < .01 versus 0 hours).