Effects of chronic nicotine and haloperidol administration on muscarinic receptor-mediated phosphoinositide turnover in rat brain slices.
Muscarinic receptor-mediated phosphoinositide (PI) turnover in rat brain slices was assessed after chronic administration of nicotine (12 mg/kg/day) or haloperidol decanoate (1.5 mg/kg/day), either alone or in combination, for 6 weeks. Nicotine alone did not significantly alter carbachol-induced inositol monophosphate (IP1) accumulation in the frontal cortex, but did result in a significant increase in the hippocampus, and in a decrease in the striatum. Haloperidol alone attenuated carbachol-stimulated IP1 accumulation in all three brain regions. Chronic treatment with combined nicotine and haloperidol resulted in no significant change in carbachol-sensitive IP1 accumulation in either the frontal cortex or hippocampus but did result in a decrease in the striatum. The results suggest significant cross-talk between cholinergic and dopaminergic systems in affecting PI metabolism.
Neuropsychiatry Branch, National Institute of Mental Health, Neuroscience Center at Saint Elizabeths, Washington, DC 20032.
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Li
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Wing
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Kirch
R J
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Wyatt
D M
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Chuang
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002217:Carbachol / Q000494:pharmacology; D005625:Frontal Lobe / Q000187:drug effects / Q000378:metabolism; D006220:Haloperidol / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D010716:Phosphatidylinositols / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011976:Receptors, Muscarinic / Q000187:drug effects*
D010716:Phosphatidylinositols; D011976:Receptors, Muscarinic; D009538:Nicotine; D002217:Carbachol; D006220:Haloperidol