Evaluation of the interaction of mu and kappa opioid agonists on locomotor behavior in the horse

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....

Full description

Saved in:
Bibliographic Details
Published in:Canadian journal of veterinary research 1993-04, Vol.57 (2), p.106-109
Main Authors: Mama, K R, Pascoe, P J, Steffey, E P
Format: Article
Language:English
Subjects:
3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
Analgesics - pharmacology
Animals
Drug Interactions
Fentanyl - pharmacology
Horses - physiology
Motor Activity - drug effects
Pyrrolidines - pharmacology
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0830-9000