Skip to main content
. Author manuscript; available in PMC: 2018 Sep 1.
Published in final edited form as: J Pain. 2017 Apr 27;18(9):1046–1059. doi: 10.1016/j.jpain.2017.04.001

Figure 4.

Figure 4

OPRM1 expression prevented morphine tolerance after morphine pellet implantation. (A) The bar graph depicts morphine doses required to achieve complete thermal antinociception. Although morphine pellet implantation in the Ad-GFP group increased morphine requirement from 6.5 mg to 11.7 mg, signifying morphine tolerance, the reverse trend was seen in the Ad-OPRM1 group. OPRM1 expression in the HNSCC tumor prevented development of morphine tolerance after morphine implantation. (B) The graph depicts total morphine dosage used versus the level of thermal antinociception, with 0% on the y-axis representing a return to thermal threshold baseline. Abbreviation: SEM, standard error of the mean.