Figure 6

Effect of spinal PKCζ/PKMζ inhibition on PKCζ/PKMζ phosphorylation in the dorsal horn following intraplantar formalin. (a-c) Representative photomicrographs of increased expression of p-PKCζ/p-PKMζ in superficial laminae of the ipsilateral lumbar dorsal horn following intraplantar formalin in rats pre-treated with intrathecal (a) saline, (b) scrambled peptide (10 μg, n = 5) or (c) ZIP (10 μg, n = 5). Scale bars = 100 μm. (d) Quantification of p-PKCζ/p-PKMζ expression in lumbar dorsal horn presented as mean ± s.e.m. of immunofluorescent intensity (arbitrary unit) of p-PKCζ/p-PKMζ staining in ipsilateral and contralateral lumbar dorsal horn for each group. (e, f) Western immunoblots showing phosphorylation of PKCζ and PKMζ in formalin rats. Intraplantar injection of formalin induced a significant increase of ipisilateral PKMζ phosphorylation (e top panel, f) but not PKCζ (e bottom panel, f) compared with the contralateral side in the scrambled peptide treated group. Intrathecal injection of ZIP (10 μg) did not change the increased phosphorylation of PKMζ (e top panel, f). Results are expressed as mean ± s.e.m. of the densitometric analysis (arbitrary unit) of p-PKCζ and p-PKMζ expression levels in the ipsilateral and contralateral lumbar dorsal horn for each group.