Figure 2From: PK20, a new opioid-neurotensin hybrid peptide that exhibits central and peripheral antinociceptive effects Effect of increasing doses of hybrid peptide PK20 on analgesia in the rat tail-flick test. The test was performed within 2 h after the i.t. injection of the compound. % MPE ± SEM of six animals per group. *p < 0.05; **p < 0.001 as compared to saline controls.Back to article page