Nitric oxide is involved in the memory facilitation induced by spermidine in rats.
BACKGROUND
Spermidine (SPD) is an endogenous polyamine that modulates N-methyl-D: -aspartate receptor functions, which has been reported to facilitate memory formation.


OBJECTIVE
In the current study, we investigated the involvement of nitric oxide in the facilitatory effect of SPD on the memory of adult male Wistar rats in the inhibitory avoidance task.


RESULTS
The coadministration of the nonspecific NOS inhibitor N (G) nitro-L: -arginine methyl ester (L: -NAME) (0.1 nmol, intrahippocampus) with spermidine (0.2 nmol), immediately after training, prevented the memory improvement caused by spermidine in the avoidance inhibitory task. Spermidine increased nitrite and nitrate levels (NO(X)) in the hippocampus 30 min after its administration, and L: -NAME coinjection prevented the stimulatory effect of spermidine on NO(X) levels. The systemic injection of 7-nitroindazole (30 mg/kg, i.p.), 30 min before training, impaired memory and did not prevent spermidine-induced increase of NO(X) levels in the hippocampus.


CONCLUSIONS
These results suggest that memory enhancement by spermidine is prevented by the nonspecific nitric oxide synthase inhibitor L: -NAME.
Guerra
Gustavo Petri
GP
Departamento de Química, Centro de Ciências Naturais e Exatas, Laboratório de Neurotoxicidade e Psicofarmacologia, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil, marubin@smail.ufsm.br
Mello
Carlos Fernando
CF
Sauzem
Patricia Dutra
PD
Berlese
Daiane Bolzan
DB
Furian
Ana Flávia
AF
Tabarelli
Zuleica
Z
Rubin
Maribel Antonello
MA
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013095:Spermidine / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D007191:Indazoles; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D013095:Spermidine; C080122:7-nitroindazole; D019331:NG-Nitroarginine Methyl Ester