Fig. 6.

TNFα enhancement of the capsaicin response is blocked by inhibition of cyclo-oxygenase. A, The sensitizing effects of TNFα on the normalized response to capsaicin and its inhibition by indomethacin. The focal response to 100 nm capsaicin is expressed as the fraction of the maximal response obtained with the bath application of 1 μmcapsaicin. The bars represent the following experimental conditions: the control is shown as the open bar(n = 8); the fine-hatched bar, labeled TNF, is after a 24 hr treatment with 10 ng/ml TNFα (n = 10); the coarse-hatched bar is after treatment with 30 μm indomethacin and 10 ng/ml TNFα (n = 4); and thefine-hatched bar, labeled INDO, is after a 24 hr treatment with 30 μm indomethacin alone (n = 4). B demonstrates in another set of sensory neurons inhibition of the TNFα-induced sensitization by treatment with the selective COX-2 inhibitor SC-236. The open bar represents the untreated control neurons (n = 3). The fine-hatched barrepresents results obtained after a 24 hr treatment with 10 ng/ml TNFα (n = 5); the coarse-hatched bar is after treatment with 300 nm SC-236 and 10 ng/ml TNFα (n = 5). The asterisksindicate statistical significance at p < 0.05.