Dynorphin A-(1-13) and (2-13) improve beta-amyloid peptide-induced amnesia in mice.
The anti-amnesic effects of dynorphins on beta-amyloid peptide-(25-35)-induced impairment of learning and/or memory in mice were investigated using a Y-maze task and a passive avoidance test. Administration of beta-amyloid peptide-(25-35) (betaAP(25-35); 8.2 nmol, i.c.v.) 7 and 14 days before behavioral tests induced a decrease in both alternation behavior and latency in passive avoidance tests. Dynorphin A-(1-13) and A-(2-13) (0.5 and/or 1.5 nmol, i.c.v.) 30 min before behavioral tests improved the beta-amyloid peptide-(25-35)-induced impairment of alternation performance and shortened the step-down latency. Nor-binaltorphimine (4.9 nmol, i.c.v.) partially blocked the effects of dynorphin A-(1-13), but not A-(2-13). These results indicate that dynorphin A-(1-13) and A-(2-13) improve amnesia induced by betaAP-(25-35) via not only kappa opioid receptors, but also by non-opioid mechanisms.
Hiramatsu
M
M
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya, Japan.
Inoue
K
K
Kameyama
T
T
D000647:Amnesia / Q000139:chemically induced* / Q000523:psychology*; D016229:Amyloid beta-Peptides; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects; D004399:Dynorphins / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011930:Reaction Time / Q000187:drug effects
D016229:Amyloid beta-Peptides; D009292:Narcotic Antagonists; D009294:Narcotics; D010446:Peptide Fragments; C113041:amyloid beta-protein (35-25); C051844:norbinaltorphimine; D009271:Naltrexone; C026843:dynorphin (1-13); D004399:Dynorphins; C036730:dynorphin A, desTyr(1)-desTrp(14)-desAsp(15)-desAsn(16)-desGlu(17)-