Preprothyrotropin-releasing hormone mRNA in the rat central gray is strongly and persistently induced during morphine withdrawal.
In vivo evidence strongly implicates the central gray in expression of the physical symptoms of opiate withdrawal. Preprothyrotropin-releasing hormone (ppTRH) mRNA is highly expressed in the central gray. Furthermore, systemic administration of thyrotropin-releasing hormone (TRH) inhibits the development of opiate dependence in rats. To elucidate the link between TRH and opiate withdrawal, we examined the regulation of ppTRH mRNA in the central gray of rats made dependent on morphine, and during opiate withdrawal, using quantitative in situ hybridization. In the ventrolateral central gray, a significant increase in ppTRH mRNA was observed 3 h after precipitation of withdrawal, and this increase persisted for 36 h. Upregulation of ppTRH mRNA was not seen with chronic morphine or acute naltrexone treatment alone and was specific for the ventrolateral central gray. These findings support a role for TRH or other ppTRH-derived peptides in the central gray during morphine withdrawal.
Gahn
L G
LG
Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
Sevarino
K A
KA
D000701:Analgesics, Opioid / Q000633:toxicity*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D008636:Mesencephalon / Q000648:ultrastructure; D009020:Morphine / Q000633:toxicity*; D009271:Naltrexone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011498:Protein Precursors / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D013788:Thalamus / Q000648:ultrastructure; D013973:Thyrotropin-Releasing Hormone / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics*; D015854:Up-Regulation
D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D011498:Protein Precursors; D012333:RNA, Messenger; C063596:prepro-thyrotropin-releasing hormone; D009271:Naltrexone; D013973:Thyrotropin-Releasing Hormone; D009020:Morphine