Figure 5.

EGF blocks PGE₂ induced mechanical hyperalgesia. Intradermal injection of 1 μg EGF and 1 μg Hb-EGF led not to a significant decrease in the nociceptive threshold in contrast to intradermal injection of 100 ng PGE₂ or 100 ng Epinephrine. EGF and Hb-EGF abolished subsequent PGE₂ but not epinephrine induced sensitization (p < 0.001). Reduction of paw-withdrawal threshold in EGF/PGE₂ data series by 3.6 ± 1.9% after EGF treatment, 33.0 ± 3.8% after PGE₂ treatment, 2.6 ± 1.3% after EGF+PGE₂. (n = 6). Reduction of paw-withdrawal threshold in EGF/epinephrine data series by 8.5 ± 4.1% after EGF treatment, 36.2 ± 1.8% after epinephrine and 35.9 ± 1.5% after EGF+epinephrine (for all treatments n = 6). Reduction of paw-withdrawal threshold in Hb-EGF data series (3.0 ± 1.8% after Hb-EGF (n = 12), 36.0 ± 0.8% after PGE₂ treatment, 3.6 ± 2.9% after Hb-EGF+PGE₂, 38.6 ± 2.9% after epinephrine and 35.6 ± 1.7% after Hb-EGF+epinephrine (for all treatments n = 6)).