Oxytocin mediates the inhibitory action of acute lithium on the morphine dependence in rats

• Published in: Neuroscience research 2001-10, Vol.41 (2), p.143-150
• Main Authors: You, Zhen Dong, Li, Jian Hong, Song, Chao You, Lu, Chang Lin, He, Cheng
• Format: Article
• Language: English
• Subjects: Analgesia; Analgesics, Opioid - pharmacology; Animals; Antimanic Agents - pharmacology; Behavior, Animal - drug effects; Behavior, Animal - physiology; Conditioned place preference; Conditioning (Psychology) - drug effects; Conditioning (Psychology) - physiology; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Interactions - physiology; Hypothalamo-Hypophyseal System - drug effects; Hypothalamo-Hypophyseal System - metabolism; Hypothalamo-Hypophyseal System - secretion; Hypothalamus, Anterior - drug effects; Hypothalamus, Anterior - metabolism; Hypothalamus, Anterior - secretion; Lithium; Lithium Chloride - pharmacology; Male; Morphine - pharmacology; Morphine dependence; Morphine Dependence - drug therapy; Morphine Dependence - metabolism; Morphine Dependence - physiopathology; Morphine tolerance; Naloxone - pharmacology; Narcotic Antagonists - pharmacology; Neurosecretion - drug effects; Neurosecretion - physiology; Oxytocin; Oxytocin - analogs & derivatives; Oxytocin - antagonists & inhibitors; Oxytocin - metabolism; Oxytocin - pharmacology; Oxytocin - secretion; Pain Measurement - drug effects; Pain Threshold - drug effects; Pain Threshold - physiology; Rats; Rats, Sprague-Dawley; Substance Withdrawal Syndrome - drug therapy; Substance Withdrawal Syndrome - metabolism; Substance Withdrawal Syndrome - physiopathology; Withdrawal syndrome
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/S0168-0102(01)00272-3

The role of central oxytocin in inhibitory action of lithium on the development of morphine dependence was behavioral investigated in rats. Acute lithium could enhance the morphine-induced analgesia in rats with or without chronic morphine treatment; this effect could be inhibited by intraventricular injection of oxytocin antagonist d (CH 2) 5-Tyr (Me)-[Orn 8]-Vasotocin (OVT). Lithium could attenuate naloxone-precipitated withdrawal signs in morphine dependent rats. The reduction of the expression of naloxone-precipitated withdrawal signs by lithium was reversed by ICV of OVT. The lithium significantly inhibited the conditioned place preference (CPP) induced by morphine, which inhibitory action of lithium could also reverse by ICV injection of OVT. These results suggested that lithium might inhibit the physical dependence on morphine as well as psychological dependence in rats, and that this inhibitory effect of lithium on the development of morphine dependence might be associated with oxytocin systems in the central nervous system.