Mama K R, Pascoe P J, Steffey E P
Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis 95616.
Can J Vet Res. 1993 Apr;57(2):106-9.
This study was designed to determine the interactive effects of mu and kappa opioid agonists on locomotor behavior in the horse. Three doses of a mu agonist, fentanyl (5, 10, 20 micrograms/kg) and a kappa agonist U50,488H (30, 60, 120 micrograms/kg) were administered in a random order to six horses. Locomotor activity was measured using a two minute footstep count. Each dose of U50,488H was then combined with 20 micrograms/kg of fentanyl to determine the interactive effects of the drugs on locomotor activity. A significant increase in locomotor activity was seen with 20 micrograms/kg of fentanyl and all the drug combinations. The combination of U50,488H with fentanyl resulted in an earlier onset of locomotor activity. At the highest doses of the combination (U50,488H 120 micrograms/kg, fentanyl 20 micrograms/kg), the duration of locomotor activity was significantly increased when compared to the other doses. We conclude that locomotor activity is maintained or enhanced in horses when a receptor specific kappa agonist is combined with a mu receptor agonist.
本研究旨在确定μ和κ阿片类激动剂对马匹运动行为的交互作用。将三种剂量的μ激动剂芬太尼（5、10、20微克/千克）和κ激动剂U50,488H（30、60、120微克/千克）以随机顺序给予6匹马。使用两分钟的步数计数来测量运动活性。然后将每种剂量的U50,488H与20微克/千克的芬太尼联合使用，以确定药物对运动活性的交互作用。在给予20微克/千克芬太尼以及所有药物组合后，观察到运动活性显著增加。U50,488H与芬太尼联合使用导致运动活性更早出现。在联合使用的最高剂量（U50,488H 120微克/千克，芬太尼20微克/千克）下，与其他剂量相比，运动活性的持续时间显著增加。我们得出结论，当受体特异性κ激动剂与μ受体激动剂联合使用时，马匹的运动活性得以维持或增强。
