Research Article

Ligand-Specific Regulation of the Endogenous Mu-Opioid Receptor by Chronic Treatment with Mu-Opioid Peptide Agonists

Figure 1

Time-course of the acute antinociceptive effect of graded doses of EM2 (a) and ACHC-EM2 (b) in rat tail-flick assay. The peptides were administered icv and assayed as described in Methods. Control groups received CSF. Data are shown as mean ± S.E.M; . Statistical significance was determined by ANOVA and set at * compared to appropriate control values.
501086.fig.001a
(a)
501086.fig.001b
(b)