Abstract
Dynorphin (DYN) fragments are the members of the endogenous opioid system and postulated ligands for the opioid receptors. Infusion of DYN(1-17) fragment into the rat dorsal striatum caused a significant increase in acetylcholine and decrease in dopamine overflow. Contrary to this, infusions of DYN(2-17) fragment into the rat dorsal striatum caused a significant increase in dopamine and decrease in acetylcholine overflow. Intrastriatal infusions of different doses of the acetylcholinesterase blocker, neostigmine, augmented acetylcholine and inhibited dopamine overflow in a dose-dependent manner. The opposing responses of the DYN fragments suggest that the N-terminal residue plays a key role in presynaptic neuromodulation.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Acetylcholine / metabolism*
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Animals
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Brain Chemistry / drug effects*
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Cholinesterase Inhibitors / pharmacology
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Chromatography, High Pressure Liquid
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Dopamine / metabolism*
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Dynorphins / administration & dosage
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Dynorphins / pharmacology*
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Electrochemistry
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Male
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Microdialysis
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Microinjections
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Neostigmine / pharmacology
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Neostriatum / anatomy & histology
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Neostriatum / physiology*
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Peptide Fragments / administration & dosage
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Peptide Fragments / pharmacology
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Rats
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Rats, Sprague-Dawley
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Receptors, Presynaptic / drug effects
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Synaptic Transmission / drug effects
Substances
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Cholinesterase Inhibitors
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Peptide Fragments
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Receptors, Presynaptic
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Neostigmine
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Dynorphins
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Acetylcholine
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Dopamine