Affordable Access

Effects of nor-binaltorphimine on the development of analgesic tolerance to and physical dependence on morphine.

Authors
  • Suzuki, T
  • Narita, M
  • Takahashi, Y
  • Misawa, M
  • Nagase, H
Type
Published Article
Journal
European Journal of Pharmacology
Publisher
Elsevier
Publication Date
Mar 17, 1992
Volume
213
Issue
1
Pages
91–97
Identifiers
PMID: 1499660
Source
Medline
License
Unknown

Abstract

The effects of a highly selective kappa antagonist, nor-binaltorphimine (nor-BNI), on the development of tolerance to morphine analgesia and physical dependence on morphine were examined. Pretreatment with nor-BNI (5 mg/kg s.c.) 2 h prior to injection of morphine or a selective kappa agonist, U-50,488H, significantly antagonized the analgesic effect of U-50,488H, but not morphine analgesia in mice. The development of tolerance to morphine analgesia was significantly potentiated by pretreatment of mice with nor-BNI 2 h prior to morphine treatment during chronic morphine treatment for 5 days. Additionally, the pretreatment with nor-BNI during chronic treatment with the high dose of morphine for 5 days significantly potentiated the naloxone-induced body weight loss in morphine-dependent mice and rats. These findings suggest that inactivation of the kappa opioid system may potentiate the development of tolerance to morphine analgesia in mice and may aggravate the naloxone-precipitated body weight loss in morphine-dependent mice and rats.

Report this publication

Statistics

Seen <100 times