Influence of intrastriatal infusion of dynorphin fragments on overflow of acetylcholine and dopamine in the rat brain.
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.
Pani
Amar K
AK
Department of Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, USA. amar.pani@stjude.org
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism*; D004399:Dynorphins / Q000008:administration & dosage / Q000494:pharmacology*; D004563:Electrochemistry; D008297:Male; D017551:Microdialysis; D008845:Microinjections; D009388:Neostigmine / Q000494:pharmacology; D017072:Neostriatum / Q000033:anatomy & histology / Q000502:physiology*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017661:Receptors, Presynaptic / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects
D002800:Cholinesterase Inhibitors; D010446:Peptide Fragments; D017661:Receptors, Presynaptic; D009388:Neostigmine; D004399:Dynorphins; D000109:Acetylcholine; D004298:Dopamine