Oxytocin blocks the development of heroin-enkephalin cross-tolerance in mice

Márta Kriván, Gyula Szabó, Zoltán Sarnyai, Gábor L. Kovács, Gyula Telegdy

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9 Citations (Scopus)


The development of cross-tolerance to an analgesic effect has been observed between a μ-receptor agonist, heroin, and a δ-receptor agonist, Met2-Pro5-enkephalinamide. Repeated treatments with heroin twice a day for 4 days resulted in a decreased nociceptive effect to enkephalin on day 5. The enkephalin dose-response line was shifted to the right, considered a sign of the development of cross-tolerance. Peripheral treatment with oxytocin blocked the development of heroin-enkephalin cross-tolerance. A similar effect was observed after intracerebroventricular administration oxytocin, supportinng our assumption that oxytocin blocks the development of heroin-enkephalin cross-tolerance via CNS mechanisms.

Original languageEnglish
Pages (from-to)187-192
Number of pages6
JournalPharmacology, Biochemistry and Behavior
Issue number1
Publication statusPublished - Sep 1992



  • Analgesic effect
  • Cross-tolerance
  • Enkephalin
  • Heroin
  • Met-Pro-enkephalinamide
  • Opiate receptor
  • Oxytocin

ASJC Scopus subject areas

  • Biochemistry
  • Toxicology
  • Pharmacology
  • Clinical Biochemistry
  • Biological Psychiatry
  • Behavioral Neuroscience

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