Skip to main content
. 2016 Jun 6;37(8):1054–1062. doi: 10.1038/aps.2016.33

Figure 4.

Figure 4

Anti-nociceptive effects of oral QO58-lysine on inflammatory pain induced by CFA in rats. (A) Development of mechanical allodynia in CFA-induced rats (n=8). Paw withdrawal mechanical threshold was measured using an electric von Frey anesthesiometer over a 9-d period for the saline control and CFA groups. CFA was injected at time 0 and the withdrawal threshold was measured once a day for 9 d. The lowest withdrawal threshold occurred 1 d after CFA injection and was maintained for approximately 5 d. Student's t-test was used to indicate statistical significance between the saline group and the CFA group as **P<0.01. The right panel shows the effect of oral QO58-lysine on mechanical allodynia in CFA-induced rats (n=10) 24 h after intraplantar injection of CFA, retigabine (RTG, 25 mg/kg) or QO58-lysine (QO58L, 12.5, 25, and 50 mg/kg) was administered, and rats in the CFA group received 10% Tween-80-Saline. Paw withdrawal mechanical threshold was measured at 0, 0.5, 1, 2, 3, 4, 6, 8, 12, and 18 h after oral administration. (B) Development of thermal hyperalgesia in CFA-induced rats (n=8). The paw withdrawal latency of thermal hyperalgesia was measured using an automatic plantar analgesia tester over a 9 d period for the saline control group and the CFA group. CFA was injected at time 0, and the withdrawal thermal latency was measured once a day for 9 d. The lowest withdrawal latency occurred 1 d after CFA injection and was maintained for approximately 4 d. Student's t-test was used to indicate statistical significance between the saline group and the CFA group as **P<0.01. In the right panel, the effect of oral QO58-lysine on thermal hyperalgesia in CFA-induced rats is shown (n=10). Twenty-four hours after the intraplantar injection of CFA, retigabine (RTG, 25 mg/kg) or QO58-lysine (QO58L, 12.5, 25, and 50 mg/kg) was administered. Rats in the CFA group received 10% Tween-80-Saline. The paw withdraw latency of thermal hyperalgesia was measured at 0, 1, 2, 4, 6, and 8 h after oral administration. (C) Anti-nociceptive effect of oral QO58-lysine on CFA-induced pain in rats (n=10) using the incapacitance analgesia assay that measures the difference in weight bearing between the ipsilateral affected limb and the contralateral control limb. Measurements were obtained for 20 s, and they are represented as the weight difference summation (g). Twenty-four hours after the intraplantar injection of CFA, retigabine (RTG, 25 mg/kg, po) and QO58-lysine (QO58L, 12.5, 25, and 50 mg/kg, po) were administered. Rats in the CFA group were orally administered 10% Tween-80-Saline. The weight difference summation was measured at 0, 0.5, 1, 2, 3, 4, 6, 8, 12, and 18 h after oral administration. In the right panel, the weight difference summation was measured at 1 h. The data are expressed as the mean±SEM.