Journal of Molecular Neuroscience

, Volume 30, Issue 3, pp 341–347

Effects of prolonged treatment with the opiate tramadol on prodynorphin gene expression in rat CNS

  • Sanzio Candeletti
  • Giuseppe Lopetuso
  • Rosalia Cannarsa
  • Chiara Cavina
  • Patrizia Romualdi
Original Article

DOI: 10.1385/JMN:30:3:341

Cite this article as:
Candeletti, S., Lopetuso, G., Cannarsa, R. et al. J Mol Neurosci (2006) 30: 341. doi:10.1385/JMN:30:3:341

Abstract

A low abuse liability is reported for tramadol, an analgesic drug centrally acting through either opioid or nonopioid mechanisms. In this paper, we evaluated the effects of the repeated administration (7 d) of different doses of tramadol (10, 20, and 80 mg/kg, intraperitoneally) on the opioid precursor prodynorphin biosynthesis, in comparison with morphine (10 mg/kg, intraperitoneally), in the rat central nervous system (CNS). Northern analysis showed that morphine and tramadol produced different effects. While morphine caused a down-regulation of prodynorphin mRNA levels in all investigated areas (hypothalamus, hippocampus, and striatum), tramadol did not cause any significant change in the striatum, and did not decrease prodynorphin biosynthesis in the hypothalamus and in the hippocampus, at nontoxic doses (10 and 20 mg/kg). The highest dose of tramadol (80 mg/kg) decreased prodynorphin mRNA levels in the hypothalamus and the hippocampus but not in the striatum. These data give some information on tramadol effects at molecular level in the CNS. They indicate that the alterations of prodynorphin gene expression caused by tramadol and morphine show a different pattern that may be related to the different abuse potential of the two analgesic drugs.

Index Entries

Tramadol opiates morphine prodynorphin gene expression rat 

Copyright information

© Humana Press Inc 2006

Authors and Affiliations

  • Sanzio Candeletti
    • 1
  • Giuseppe Lopetuso
    • 1
  • Rosalia Cannarsa
    • 1
  • Chiara Cavina
    • 1
  • Patrizia Romualdi
    • 1
  1. 1.Department of PharmacologyUniversity of BolognaBolognaItaly

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