title: [Effects of intragastric administration of thenorphine on morphine-induced behavioral sensitization in mice].
abstract: OBJECTIVE
  To investigate the effects of intragastric administration of thenorphine (Then) on behavioral sensitization to morphine (Mor) in mice.
  
  
  METHODS
  Locomotor activity was detected after intragastric administration of thenorphine or co-administration of thenorphine with Mor in mice. Mice were induced to be behaviorally sensitive to Mor, and were given the combination of Mor and thenorphine to observe the effects of thenorphine on the development, transfer and expression of Mor-induced behavioral sensitization.
  
  
  RESULTS
  A single intragastric administration of thenorphine (1.25 - 5.0 mg x kg(-1)) dose-dependently inhibited the locomotor activity in mice (P < 0.01) and the effects of thenorphine on locomotor activity developed tolerance after repeated administration. Co-administration of thenorphine effectively inhibited Mor-induced hyperactivity (P < 0.05) and the development, transfer, expression of Mor-induced behavioral sensitization in mice (P < 0.05 or P < 0.01).
  
  
  CONCLUSIONS
  Thenorphine was shown to suppress the central nervous system and may be effective against the abuse and addiction to opioids.
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100083, China.
authors.forename: Wen-li
authors.initials: WL
authors.lastname: Zhao
authors.forename: Jian-hui
authors.initials: JH
authors.lastname: Liang
authors.forename: Ze-hui
authors.initials: ZH
authors.lastname: Gong
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002047:Buprenorphine / Q000031:analogs & derivatives* / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D005260:Female; D008297:Male; D051379:Mice; D009020:Morphine / Q000037:antagonists & inhibitors*; D009043:Motor Activity / Q000187:drug effects; D011897:Random Allocation
chemical_list: D002492:Central Nervous System Depressants; C497654:thenorphine; D002047:Buprenorphine; D009020:Morphine