Ligand-Specific Regulation of the Endogenous Mu-Opioid Receptor by Chronic Treatment with Mu-Opioid Peptide Agonists
Figure 2
Development of antinociceptive tolerance to chronic ACHC-EM2 given at 20 μg/2 μL twice daily for the indicated time periods. Rats were tested in the tail-flick assay 5 min (a, white columns) and 15 min (b, striped columns) after injection. Mean ± S.E.M.; . Significance was determined by ANOVA; * labels compared to the first day.
