Figure 5

The expression of IL-4 mediated by HSV and its antinociceptive effect on morphine tolerance. (A) The expression of IL-4 mediated by HSV vectors S4IL4. Seven days after the vectors were inoculated into the hindpaws, the L4/5 DRGs were harvested. ELISA was conducted for testing the expression of IL-4 as described previously [12]. S4IL4 injection significantly induced the expression of IL-4. * p < 0.05 vs SHZ (control vectors), t test, n = 3-4. (B) The effect of S4IL4 and SHZ on chronic morphine tolerance. Seven days after the vector inoculation, rats received a repeated dose of morphine for 7 days. Thermal latency was tested at 60 min after each dose of morphine using a hotplate test. The percent maximum possible effect (MPE) of morphine in rats with S4IL4 was significantly higher than that with SHZ, * P < 0.05, **P <0.01 vs. SHZ, t test, n = 7. (C) The area under the curves in S4IL4 and SHZ were shown, **P <0.01 vs. SHZ, t test, n = 7.