Effects of molsidomine on scopolamine-induced amnesia and hypermotility in the rat.
Nitric oxide (NO) is hypothesized to be a novel intracellular messenger in the central nervous system. Recently, NO involvement in learning and memory processes has been proposed. Compounds that inhibit nitric oxide synthase, the key synthesizing enzyme, may block cognition, while NO donors may facilitate it. The aim of this study was to assess in the rat the effects of the NO donor molsidomine (2 and 4 mg/kg, i.p.) on memory deficits caused by scopolamine. For this purpose, the object recognition task and the step-through passive avoidance procedure were chosen. In addition, the effects of molsidomine in antagonizing the scopolamine-induced hypermotility were also examined. Scopolamine at 0.2 mg/kg (object recognition) and 0.75 mg/kg (passive avoidance) disrupted acquisition in both the tasks and induced locomotor hyperactivity at the dose of 0.2 mg/kg. Molsidomine at either dose reversed the scopolamine-induced deficits in the object recognition paradigm but did not counteract the hypermotility and the deficits occurred in the passive avoidance test. These results suggest that to some extent, the NO donor molsidomine is involved in memory processing.
Pitsikas
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N
Department of Medical Pharmacology, Faculty of Medicine, University of Milan, via Vanvitelli 32, 20129 Milan, Italy. nikpit@yahoo.it
Rigamonti
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AE
Cella
S G
SG
Locatelli
V
V
Sala
M
M
Muller
E E
EE
D000647:Amnesia / Q000139:chemically induced / Q000517:prevention & control*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D008568:Memory / Q000187:drug effects; D008981:Molsidomine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D019832:N-Methylscopolamine / Q000494:pharmacology; D051381:Rats; D012601:Scopolamine / Q000494:pharmacology*; D013997:Time Factors; D014665:Vasodilator Agents / Q000494:pharmacology*
D018727:Muscarinic Antagonists; D014665:Vasodilator Agents; D008981:Molsidomine; D012601:Scopolamine; D019832:N-Methylscopolamine