Jaggar S I, Hasnie F S, Sellaturay S, Rice A S
Department of Anaesthetics, Imperial College School of Medicine, St. Mary's Hospital, London, UK.
Pain. 1998 May;76(1-2):189-99. doi: 10.1016/s0304-3959(98)00041-4.
This study assessed the effects of two N-acylethanolamides in established rat models of visceral and somatic inflammatory pain. (1) The therapeutic effects of the cannabinoid anandamide and the putative CB2 agonist palmitoylethanolamide were tested in a model of persistent visceral pain (turpentine inflammation of the urinary bladder). Both anandamide (at a dose of 25 mg/kg) and palmitoylethanolamide (at doses of 10-30 mg/kg) were able to attenuate the viscero-visceral hyper-reflexia (VVH) induced by inflammation of the urinary bladder. (2) The effects of the same compounds on the behavioural response to subcutaneous formalin injection were assessed. The characteristic biphasic response was observed in control animals. Anandamide (dose range 5-25 mg/kg) and palmitoylethanolamide (dose range 5-10 mg/kg) both reduced the second phase of the response. The results confirm the analgesic potential of endogenous ligands at cannabinoid receptor sites. The anti-nociceptive effect of the putative CB2 receptor agonist, palmitoylethanolamide, is particularly interesting since it is believed to be a peripherally mediated effect. This observation might be exploited to separate central psychotropic effects from peripheral analgesic actions of the cannabinoids, under inflammatory conditions.
本研究评估了两种N-酰基乙醇胺在已建立的大鼠内脏和躯体炎性疼痛模型中的作用。（1）在持续性内脏疼痛（膀胱松节油炎症）模型中测试了大麻素花生四烯乙醇胺和假定的CB2激动剂棕榈酰乙醇胺的治疗效果。花生四烯乙醇胺（剂量为25 mg/kg）和棕榈酰乙醇胺（剂量为10 - 30 mg/kg）均能够减轻膀胱炎症诱导的内脏-内脏反射亢进（VVH）。（2）评估了相同化合物对皮下注射福尔马林行为反应的影响。在对照动物中观察到典型的双相反应。花生四烯乙醇胺（剂量范围5 - 25 mg/kg）和棕榈酰乙醇胺（剂量范围5 - 10 mg/kg）均降低了反应的第二阶段。结果证实了内源性配体在大麻素受体位点的镇痛潜力。假定的CB2受体激动剂棕榈酰乙醇胺的抗伤害感受作用尤其有趣，因为它被认为是一种外周介导的作用。这一观察结果可能有助于在炎症条件下将大麻素的中枢精神作用与外周镇痛作用区分开来。
