Figure 4

SB203580 inhibits p38 phosphorylation, mechanical allodynia, and the percentage of SP-positive LDRG neurons in db/db mice. A: Representative immunoblots of pp38, p38 and actin from db+ and db/db LDRG at 8 wk of age after 1 wk of intrathecal treatments of vehicle (control CSF with 10% DMSO) (C) or vehicle with SB203580. SB203580 treatment decreased levels of p38 phosphorylation in db/db mice but not in db+ mice. B: Densitometric studies of pp38 immunoblots demonstrated significant inhibition of p38 phosphorylation in db/db mice. C: SB203580 treatment reversed the decrease in mechanical thresholds (allodynia) in db/db mice. D: SB203580 treatment also lowered the elevated percentages of SP-positive LDRG neurons in control db/db mice compared to control db+ mice. E: SB203580 treatment had no effect on the percentage of IB4-labelled LDRG neurons in db+ and db/db mice. N = 4, **p < 0.01.