RESUMO
The antiamnesic effects of prolyl-leucyl-glycinamide (PLG) and analogues of this tripeptide were investigated in rats. Retrograde amnesia was induced by electroconvulsive shock treatment and the degree of amnesia was characterized by the attenuation of one-trial learning passive avoidance response. PLG resulted in dose-dependent attenuation of retrograde amnesia. Structural modifications included N-terminal protection, substitution of the C-terminal NH2 group, replacement of the N-terminal amino acid, and replacement of the second amino acid of the tripeptide. Some tripeptides, all of them containing D-pipecolic acid instead of the N-terminal proline, were more effective than PLG. Therefore, D-pipecolic acid, D-pipecolamide and their N-terminally protected analogues were also investigated, and were found to have powerful antiamnesic effects.
Assuntos
Amnésia Retrógrada/tratamento farmacológico , Amnésia/tratamento farmacológico , Aprendizagem da Esquiva/efeitos dos fármacos , Hormônio Inibidor da Liberação de MSH/análogos & derivados , Ácidos Pipecólicos/farmacologia , Amnésia Retrógrada/etiologia , Animais , Relação Dose-Resposta a Droga , Eletrochoque/efeitos adversos , Hormônio Inibidor da Liberação de MSH/farmacologia , Masculino , Ratos , Ratos Endogâmicos , Tempo de Reação/efeitos dos fármacosRESUMO
The effect of the presence of 500 micrograms ethyl epovincaminate (Cavinton) on the aerobic metabolism of 14C-labelled glucoses was studied in vitro. The drug tested increased the metabolism of [1-14C]-D-glucose first of all, which indicated a significant activation of pentose-phosphate shunt.