Fig. 3

Influence of particle instillation on thrombogenesis. Diesel exhaust (DEP; black colums) or control (carbon black (CB), light grey columns; DQ12 quartz, dark grey columns) particles were administered by intra-tracheal instillation 2, 6 or 24 h before induction of arterial thrombosis. (i) Instillation of DEP (0.5 mg/rat) reduced time to occlusion (P < 0.05), compared with the vehicle (open columns) 6 h after administration. Apparent reductions in time to occlusion 2 h and 24 h after administration did not achieve significance. (ii) Control particles (CB (0.5 mg/rat) or DQ12 quartz (125 mg/rat;)) did not alter time to occlusion 6 h after instillation. (iii) The ratio of tissue plasminogen activator (t-PA) to plasminogen activator inhibitor (PAI)-1 was reduced in the plasma of rats following intra-tracheal (IT) instillation of DEP, CB or DQ12 quartz. (iv) IT instillation of DEP, but not CB or DQ12 quartz increased platelet-monocyte interactions. Data are mean ± s.e.mean (n = 6) and were compared with relevant controls using one-way ((ii, (iii), (iv)) or two way (i) ANOVA. *P < 0.05, **P < 0.01 and ***P < 0.001