Kamerling S, Wood T, DeQuick D, Weckman T J, Tai C, Blake J W, Tobin T
Department of Veterinary Physiology, College of Veterinary Medicine, Louisiana State University, Baton Rouge.
Equine Vet J. 1989 Jan;21(1):4-12. doi: 10.1111/j.2042-3306.1989.tb02081.x.
Narcotic analgesics produce pharmacological effects by interacting with specific opiate receptors. At least five major types of opiate receptors have been recognised. These include mu (morphine) and kappa (ethylketazocine) receptor types. Narcotic analgesics which interact with mu receptors produce locomotor and autonomic stimulation at doses that produce little or no analgesia. Therefore, use of these drugs as analgesics in equine medicine has not been very satisfactory. Theoretical considerations suggested that the role of kappa agonists in equine analgesia be investigated. Using a pure kappa agonist, U-50, 488H, good analgesia was produced in the horse with little or no locomotor stimulation or autonomic effects. These data suggest that kappa agonists may be superior analgesics for clinical use in the horse. On the other hand, the locomotor stimulant effects of mu agonist analgesics enable their use as illegal medications. Specifically, these agents produce a good running response, signs of central nervous stimulation and analgesia, all potentially useful effects in a racehorse. Regulatory control of most narcotic analgesics can be obtained by high performance thin layer chromatographic screening. However, effective screening for the fentanyls and small doses of etorphine can only be achieved by use of immunoassay.
麻醉性镇痛药通过与特定的阿片受体相互作用产生药理效应。已识别出至少五种主要类型的阿片受体。这些包括μ（吗啡）和κ（乙基酮唑辛）受体类型。与μ受体相互作用的麻醉性镇痛药在产生很少或不产生镇痛作用的剂量下会产生运动和自主神经刺激。因此，在马医学中使用这些药物作为镇痛药并不十分令人满意。理论上的考虑表明，应研究κ激动剂在马镇痛中的作用。使用纯κ激动剂U-50,488H，在马中产生了良好的镇痛效果，几乎没有运动刺激或自主神经效应。这些数据表明，κ激动剂可能是马临床使用中更优的镇痛药。另一方面，μ激动剂镇痛药的运动刺激作用使其可被用作非法药物。具体而言，这些药物会产生良好的奔跑反应、中枢神经刺激迹象和镇痛作用，所有这些在赛马中都可能是有用的效果。大多数麻醉性镇痛药的监管控制可通过高效薄层色谱筛查实现。然而，对芬太尼和小剂量埃托啡的有效筛查只能通过免疫测定来实现。
