Peripheral effect of a kappa opioid receptor antagonist on nociception evoked by formalin injected in TMJ of pregnant rats
Peripheral effect of a kappa opioid receptor antagonist on nociception evoked by formalin injected in TMJ of pregnant rats
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DOI：
10.1016/j.lfs.2004.10.019
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发表时间：
2005-01-21
期刊：
影响因子：
6.1
通讯作者：
Veiga, MCFD
中科院分区：
文献类型：
--
作者：
Arthuri, MT;Gameiro, GH;Veiga, MCFD
性激素对口面部疼痛调节的影响尚不清楚。因此，本研究旨在探讨妊娠引起的激素变化以及阿片受体拮抗剂kappa （kappa）对雌性大鼠颞下颌关节（TMJ）福尔马林试验敏感性的影响。最初，发情的雌性大鼠和怀孕第19天的雌性大鼠在右侧TMJ注射50多福尔马林（1.5%）。与发情期相比，怀孕雌性对TMJ福尔马林试验的伤害性反应有所减少。然后，选择性kappa-阿片受体拮抗剂- binaltorphimine （no - bni）与福尔马林共同施用。接下来，其他组在关节周围注射福尔马林前24小时接受kappa（200杯）受体拮抗剂或0.9% NaCl。非bni与福尔马林联合应用于颞下颌关节区无显著影响。预注射选择性kappa-阿片受体拮抗剂（no - bni）可显著增强孕妇的伤害性行为反应。当应用于对侧TMJ时，非bni不影响福尔马林诱导的伤害性反应的大小。结果表明：1)妊娠导致性激素水平升高，导致颞下颌关节福尔马林试验伤害性行为反应降低；2)外周kappa阿片受体的激活，通过内源性阿片受体激动剂的释放，参与了妊娠诱导的TMJ福尔马林试验的抗痛觉作用。(C) 2004爱思唯尔公司版权所有。
The effect of sex hormones on orofacial pain modulation is poorly understood. Therefore, this study aimed to investigate the effect of hormonal changes as a result of pregnancy, as well as that of the kappa (kappa) opioid receptor antagonist on female rats' sensitivity to the temporomandibular joint (TMJ) formalin test. Initially, female rats at estrus and pregnant females on day 19 of pregnancy received a 50 mul formalin (1.5%) injection in the right TMJ. The pregnant females showed a reduction in nociceptive responses to the TMJ formalin test when compared with those at estrus. Then, the selective kappa-opioid receptor antagonist nor-Binaltorphimine (nor-BNI), was co-administered with the formalin. Next, additional groups received the kappa(200 mug) receptor antagonist or 0.9% NaCl 24 hours prior to the periarticular injection of formalin. Co-administration of nor-BNI with formalin into the TMJ region had no significant effect. The pre-injection of selective kappa-opioid receptor antagonist, nor-BNI, significantly enhanced the nociceptive behavioral responses in pregnant females. When applied in the contralateral TMJ, nor-BNI did not affect the magnitude of the nociceptive response induced by formalin. It can be concluded that: 1) The increase of the sex hormone levels, as result of pregnancy, induces a reduction of nociceptive behavioral responses to the TMJ formalin test; 2) the peripheral kappa opioid receptor activation, by endogenous opioid agonists release, is involved in the antinociception to TMJ formalin test, induced by pregnancy. (C) 2004 Elsevier Inc. All rights reserved.