Figure 2.

NGF rapidly suppresses free radical formation in a trkA-dependent manner. Generation of ROS in the absence of NGF results in increased DHR fluorescence in GT1-1 trk cells (A), which possess functional trkA receptors, as well as in parental GT1-1 cells (B), which lack the trkA receptor. However, DHR oxidation in GT1-1 trk cells was suppressed within 10 min of adding NGF (A), and this suppression was blocked by trkA–IgG, which competes with native trkA receptors for NGF. In contrast, NGF failed to suppress ROS formation in parental GT1-1 cells that do not express trkA receptors (B). Values presented represent the change in DHR fluorescence as a percentage of time 0 values. Values are the mean ± SEM; n = 25–75 cells total from 5 fields imaged per condition per time point. Significance was determined by ANOVA, followed by Bonferroni test for multiple comparisons. ∗, P < 0.05.