Figure 3. The effects of geldanamycin on CB2 receptor–mediated extracellular-signal-regulated kinases 1/2 (ERK1/2) activation in trabecular meshwork (TM) cells. Serum-deprived intact TM cells were pretreated with 10 μM geldanamycin for 2 h or 1 μM SR144528 (SR2) for 30 min followed by stimulation with 100 nM of JWH 015 for 15 min. Cell lysates were prepared and subjected to western blot analysis using antiphospho-ERK1/2 and total ERK1/2 antibodies. Blots shown are representative of three independent experiments. In the bar graphs, results are normalized to the density of total ERK1/2 bands in the corresponding samples (n=3). * Significant different p<0.05, one-way ANOVA with Newman-Keuls post-test). JWH 015 treatment led to a marked increase in ERK1/2 phosphorylation. SR144528 and geldanamycin significantly inhibited the JWH 015–induced ERK1/2 activation.