Figure 2.

3β‐OH applied as a hypnotic reduces thermal and mechanical hyperalgesia post‐incision. (a) A time course of experimental protocol. Rats were anaesthetized with either 2.5% isoflurane, combination of 2.5% isoflurane with 10 mg·kg⁻¹ i.p. of morphine, or a combination of 60 mg·kg⁻¹ 3β‐OH i.p. and 1% isoflurane. (b) 60 mg·kg⁻¹ i.p. 3β‐OH significantly reduced thermal hyperalgesia when applied with 1% isoflurane, as compared to the vehicle group that received 2.5% isoflurane with 25% β‐cyclodextrin (n = 9 animals in vehicle and n = 13 animal in treatment group; P < .05, two‐way RM‐ANOVA). (c) 60 mg·kg⁻¹ i.p. 3β‐OH significantly reduced mechanical hyperalgesia when applied with 1% isoflurane, as compared to the vehicle group that received 2.5% isoflurane with 25% β‐cyclodextrin (n = 5 animals per group, P < .05, two‐way RM‐ANOVA). (d) When 10 mg·kg⁻¹ i.p. morphine was applied pre‐emptively, it did not exert analgesic effect in thermal nociceptive testing (n = 6 animals per group, P > .05, two‐way RM‐ANOVA). (e) When 10 mg·kg⁻¹ i.p. morphine was applied pre‐emptively, it did not exert analgesic effect in mechanical nociceptive testing (n = 6 animals per group, P > .05, two‐way RM‐ANOVA). Data are presented as mean ± SEM