Locomotor activity and contracture of isolated ileum precipitated by naloxone following treatment of guinea-pigs with a single dose of morphine.
Guinea-pigs treated with a single dose of morphine, 15 mg kg-1 s.c., exhibited an increase in locomotor activity 2 h later on injection of naloxone, 4 mg kg-1 i.p. At the same time, contracture of ileal preparations isolated from morphine-treated guinea-pigs occurred on addition of naloxone 1 microM. Contracture of the ileum was inhibited by the tachykinin antagonist, spantide, and was therefore presumably mediated by a substance P-like agent. This study has established a useful model for the parallel investigation of central and enteric nervous system mechanisms of opiate dependence.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013375:Substance Withdrawal Syndrome / Q000139:chemically induced*
D013373:Substance P; D009270:Naloxone; D009020:Morphine; D001285:Atropine; C042867:spantide