Kappa opioid receptor stimulation decreases amphetamine-induced behavior and neuropeptide mRNA expression in the striatum.
The purpose of this study was to investigate the role that kappa opioid receptor stimulation has upon stimulant-induced behavior and neuropeptide gene expression in the striatum. Acute administration of amphetamine (2.5 mg/kg i.p.) caused an increase in behavioral activity and preprodynorphin, substance P, and preproenkephalin mRNA expression. When amphetamine-treated rats were pretreated with U69593, a kappa agonist (0.16 or 0.32 mg/kg s.c.), there was a significant decrease in behavioral activity. Quantitative in situ hybridization histochemistry revealed that 0.32 mg/kg U69593 significantly decreased amphetamine-induced mRNA expression of all three neuropeptides; however, only the induction of preproenkephalin mRNA was decreased by 0.16 mg/kg. These data suggest that stimulation of kappa receptors decreases acute amphetamine-induced behavior and mRNA expression of neuropeptides in the rat striatum.
Tzaferis
J A
JA
Department of Physiology and Neuroscience, Medical University of South Carolina, 173 Ashley Avenue, BSB 403, Charleston, SC 29425, USA.
McGinty
J F
JF
D000661:Amphetamine / Q000494:pharmacology*; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D044482:Benzeneacetamides; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D004399:Dynorphins / Q000235:genetics; D004745:Enkephalins / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D017403:In Situ Hybridization; D008297:Male; D009479:Neuropeptides / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics; D011759:Pyrrolidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017473:Receptors, Opioid, kappa / Q000378:metabolism*; D013268:Stimulation, Chemical; D013373:Substance P / Q000235:genetics
D000700:Analgesics; D044482:Benzeneacetamides; D000697:Central Nervous System Stimulants; D004745:Enkephalins; D009479:Neuropeptides; D011498:Protein Precursors; D011759:Pyrrolidines; D012333:RNA, Messenger; D017473:Receptors, Opioid, kappa; C036448:pre-prodynorphin; D013373:Substance P; D004399:Dynorphins; C033660:preproenkephalin; D000661:Amphetamine; C045444:U 69593