Figure 6

Tick saliva increases intracellular cAMP levels in macrophages. Cells were pretreated with AH 6809 (10 μM) for 15 min and challenged with vehicle (DMSO), saliva (1.2 and 3.6 μg protein/ml), or PGE₂ (3 μM) for 7.5 min. Saliva increased macrophage intracellular cAMP production and signifcance (p < 0.05) was achieved at 3.6 μg protein/ml with stimulatory effects similar to that of PGE₂, (**) p < 0.001 when compared to vehicle control. The stimulatory effects were reversed by AH 6809, (*) p < 0.01 when PGE₂ was compared to PGE₂ + AH 6809 and when saliva was compared to saliva + AH 6809. Data are means ± SEM, n = 3 assayed in duplicate.