Planas M E, Rodriguez L, Sanchez S, Pol O, Puig M M
Department of Pharmacology, University of Barcelona, Odontology School, Feixa Llarga s/n, Hospitalet de LLobregat, 08907 Barcelona, Spain Department of Pharmacology, University of Barcelona, School of Medicine, Avenida Diagonal n/n, Zona Universitaria, 08028 Barcelona, Spain Anesthesiology Research Unit, IMIM, Department of Anesthesiology, Hospital del Mar, Autonomus University of Barcelona, Aiguader 80, E-08003 Barcelona, Spain.
Pain. 1995 Jan;60(1):67-71. doi: 10.1016/0304-3959(94)00090-2.
We have investigated the role of the endogenous opioid system (EOS) on the inflammatory response induced by subplantar (s.p.) injection of saline (SS) and carrageenan (CA) in the hindpaw of the rat. The administration of intraperitoneal (i.p.) naloxone was used in order to unmask the effects of endogenous opiates released during peripheral inflammation. Three groups of rats received one of the following s.p. treatments: SS, CA, or no injection (NI). Pain pressure threshold (PPT), paw volume (edema) and local temperature were evaluated in baseline conditions and 3 h after treatment. In each group, the effects of i.p. vehicle, naloxone and (+)-naloxone (0.1 mg/kg) were also investigated. Both SS and CA induced a significant inflammatory response with hyperalgesia, edema and local hyperthermia. The i.p. administration of naloxone but not that of (+)-naloxone 15 min prior to testing, significantly increased edema in all groups of treatment (P < 0.05), without altering PPT or local temperature. Two-way ANOVA revealed that treatment and drugs, as well as their interaction, had a significant impact on edema which was related to the effects of CA and naloxone. Our findings illustrate the involvement of the EOS in the physiological response to local injury, regulating microvascular leakage in the inflamed tissues.
我们研究了内源性阿片系统（EOS）在大鼠后爪足底注射生理盐水（SS）和角叉菜胶（CA）所诱导的炎症反应中的作用。腹腔注射纳洛酮用于揭示外周炎症期间释放的内源性阿片类物质的作用。三组大鼠接受以下足底注射处理之一：SS、CA或不注射（NI）。在基线条件下以及处理后3小时评估疼痛压力阈值（PPT）、爪体积（水肿）和局部温度。在每组中，还研究了腹腔注射溶剂、纳洛酮和（+）-纳洛酮（0.1 mg/kg）的作用。SS和CA均诱导了伴有痛觉过敏、水肿和局部体温过高的显著炎症反应。在测试前15分钟腹腔注射纳洛酮而非（+）-纳洛酮，显著增加了所有处理组的水肿（P < 0.05），而未改变PPT或局部温度。双向方差分析显示，处理和药物及其相互作用对水肿有显著影响，这与CA和纳洛酮的作用有关。我们的研究结果表明，EOS参与了对局部损伤的生理反应，调节炎症组织中的微血管渗漏。
