Fig. 9.
Effect of YNT-185 on the analgesic effect of morphine in the tail flick test. Rats received intraperitoneal administration of YNT-185 (40 mg/kg) or vehicle concomitantly with subcutaneous administration of morphine (5 mg/kg; n = 7 for YNT-185 and n = 6 for vehicle). Baseline latencies were obtained 10 min before the administrations of the study drugs, and tail flick latencies were obtained again 60 min after the administrations of the study drugs. The analgesic effect of morphine did not attenuate by YNT-185 administration (time effect, P < 0.001; group effect, P = 0.335; time × group effect, P = 0.315; ***P < 0.001 vs. baseline within the same group, two-way repeated measures ANOVA with Bonferroni multiple comparison tests; error bars = SD).