Résumé
Objective To investigate the role of calcineurin(CaN)in inflammatory pain in rats.Methods Seventy-five male Harlan-Sprague-Dawley rats,weighting of 200-300 g were randomly divided into 3 groups (n=25): group control (group C),group CFA (complete Freunds adjuvant) (group F) and group CaN+CFA (group NF).100 μl CFA were injected on the right hind claw preparaing for inflammatory pain models in groups F and NF,100 μl saline were injected on the right hind claw in group C.CaN 10 U was intracerebroventricular injected 1 d before CFA injection in group NF.Paw withdrawal thermal latency (PWTL) were measured in 30 min prior to (T0),0.5 h (T1),1 h (T2),2 h (T3) and 4 h (T4) after injection.The expression of CaN and nuclear factor kappa B (NF-κB),IL-1β,TNF-α and IL-10 in spinal cord were measured at each time point.Results The PWTL was significantly shorter at T2-T4 in group F,at T3,T4 in group NF than that at T0and in group C (P<0.05);The PWTL at T2-T4 in group NF was significantly longer than that in group F (P<0.05).CaN protein expression in spinal cord at T1-T4 in group F,at T2-T4 in group NF was significantly lower than that of T0 and in the group C,NF-κB p65 protein expression was significantly higher than that of T0 and in the group C (P<0.05).CaN gene and IL-10 protein content at T2-T4 in groups F and NF were significantly lower than that of group C and at T0,NF-κB gene and IL-1β,TNF-α protein content was significantly higher than that of group C and at T0 (P<0.05).CaN protein and CaN gene expression,IL-10 protein content in spinal cord tissue at T1-T4in group NF was significantly higher than that of group F,NF-κB p65 protein and NF-κB gene expression and contents of IL-1β,TNF-α protein were significantly lower than that of group F (P<0.05).Conclusion CaN adjusts pro-inflammatory and anti-inflammatory cytokines by reducing NF-κB and inhibiting the process of inflammatory pain in rats.
Résumé
Objective To investigate the role of CaM/CaMK-Ⅱ signaling pathways in inflammatory pain in mice.Methods Sixty male C57BL6 mice,weighing 25-27 g,were randomly divided into 3 groups (n =20):control group (group C),complete freunds adjuvant (CFA) group (group F) and KN-93+CFA group (group KF).Saline 50 μl were injected into the right side of the claw in group C.CFA 50 μl were injected into the right claw foot for the preparation of inflammatory pain models in group F.KN-93 45 nmol was injected i.c.v.30 min before CFA injection in group KF.The thermal withdrawal latency (TWL) were measured 30 min before injection,1 h and 4 h after injection.The protein expressions of CaMK-Ⅱ,c-fos and CREB in the spinal cord were measured at above time by Western blot.Results Compared with group C,TWL were lower in groups F and KF 1 h and 4 h after injection (P＜0.05).Compared with groups F,TWL in group KF were higher 1 h and 4 h after injection (P＜0.05).Compared with group C,the protein expressions of p-CaMK-Ⅱ,p-CREB,e-fos and mRNA expression of CaMK-Ⅱ,CREB,c-fos were higher in group F and KF 1 h and 4 h after injection (P＜0.05).Compared with group F,the protein expression of p-CaMK-Ⅱ,p-CREB,c-fos and mRNA expressions of CaMK-Ⅱ,CREB,c-fos in group KF were lower 1 h and 4 h after injection (P＜0.05).Conclusion CaM/CaMK-Ⅱ signaling pathways involved in inflammatory pain in mice.
Résumé
The present investigation was designed to study, whether endogenous antinociceptive system is effective on mirror-image pain induced by peripheral inflammation. After Complete Freund's adjuvant (CFA) was subcutaneously injected into one hindpaw, besides heat hyperalgesia and mechanical allodynia from 1 h to 72 h at the injured site, contralateral mechanical allodynia was also induced at 1 h and significantly lasted for 24 h after injection, which was called mirror-image pain. To explore the effects of endogenous antinociceptive system on mirror-image pain, endomorphin (EM) 2 was intrathecally administered at doses of 0.2 μg, 2 μg, 20 μg and EM1 was given at the maximum dose of 20 μg by the same way, respectively, 10 min prior to CFA injection. The present results showed that three doses of EM2could reverse the decreased contralateral mechanical threshold from 48.03 ± 9.07 mN ( pre-treatment with vehicle) to 200.49 ± 53.68mN, 247.63 ± 49.43 mN and 250.57 ± 55.34 mN ( pre-treatments with EM2 ), respectively, but not in a significantly dose-dependent manner. On the other hand, intrathecal pre-treatment with EM1, the contralateral mechanical threshold was 51.24 ± 12.59 mN after CFA injection, which was similar to that pre-treatment with vehicle. It indicates that spinal EM1 did not have remarkable effect on mirror-image pain behavior. The present results provide evidence for that spinal EM2, but not EM1, mainly originated from the endogenous antinociceptive system might play an inhibitory role in mirror-image mechanical allodynia induced by peripheral tissue inflammation.