Modification of brain acetylcholine release by morphine and its antagonists in normal and morphine-dependent rats.
1 The spontaneous release of acetylcholine (ACh) from the cerebral cortex of control and morphine-dependent rats was investigated. The rate of resting output of ACh in morphine-dependent animals was lower than that in the control animals.2 Administration of naloxone and nalorphine to morphine-dependent rats was followed by a significant rise in the release of cortical ACh. In control rats no such increase in the release of ACh occurred after similar injections of narcotic antagonists.3 Injections of morphine produced a consistent decrease in the rate of spontaneous release of cortical ACh in the control rats, but similar injections in the dependent rats did not produce a decrease in the rate of cortical ACh release.4 The relevance of these results with regard to development of the narcotic abstinence syndrome is discussed.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009021:Morphine Dependence / Q000378:metabolism*; D009269:Nalorphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D051381:Rats
D009270:Naloxone; D009020:Morphine; D000109:Acetylcholine; D009269:Nalorphine