Effect of naloxone-precipitated morphine withdrawal on noradrenaline release in rat hippocampus in vivo.
Here we investigated the effect of naloxone-precipitated morphine withdrawal on the release of noradrenaline in hippocampus of the anaesthetised rat. Naloxone (1 mg/kg i.p.) injected 3 and 24 h, but not 3 weeks, after eight daily injections of morphine, induced an immediate increase in hippocampal noradrenaline release. This striking effect of naloxone was markedly attenuated by pretreatment with clonidine (0.1 mg/kg s.c.). These findings provide direct evidence for a marked release of noradrenaline in hippocampus during opiate withdrawal in vivo.
Done
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MRC Unit, Radcliffe Infirmary, Oxford, UK.
Silverstone
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Sharp
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T
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003000:Clonidine / Q000494:pharmacology; D003956:Dialysis; D004563:Electrochemistry; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008125:Locus Coeruleus / Q000187:drug effects; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D019966:Substance-Related Disorders / Q000378:metabolism
D009270:Naloxone; D009020:Morphine; D003000:Clonidine; D009638:Norepinephrine