Fig. 3. PtdOH and PtdIns(4,5)P₂ regulate integrin-mediated adhesion. Following the maintenance of cells in suspension for 60 minutes to reduce PLD activity to basal levels, cells were treated with 10 mg ml^–1 of function-blocking antibodies to either ß₁ or ß₂ integrins or vehicle (no antibody) and either 100 µM PtdOH, 100 µM PtdIns(4,5)P₂ or vehicle (no lipid) before their adhesion was quantified to wells coated with (A) serum, (B) FN or (C) ICAM1. Using a Student's t-test, P values of <0.01% were obtained (*, ** and ***). Similar results were obtained in at least three separate experiments and error bars represent the standard deviation from the mean.