In vivo and in vitro effect of imipramine and fluoxetine on Na+, K+-ATPase activity in synaptic plasma membranes from the cerebral cortex of rats
Braz. j. med. biol. res
; 34(10): 1265-1269, Oct. 2001. graf
Artigo
em Inglês
| LILACS
| ID: lil-299841
Biblioteca responsável:
BR1.1
RESUMO
The effects of in vivo chronic treatment and in vitro addition of imipramine, a tricyclic antidepressant, or fluoxetine, a selective serotonin reuptake inhibitor, on the cortical membrane-bound Na+,K+-ATPase activity were studied. Adult Wistar rats received daily intraperitoneal injections of 10 mg/kg of imipramine or fluoxetine for 14 days. Twelve hours after the last injection rats were decapitated and synaptic plasma membranes (SPM) from cerebral cortex were prepared to determine Na+,K+-ATPase activity. There was a significant decrease (10 percent) in enzyme activity after imipramine but fluoxetine treatment caused a significant increase (27 percent) in Na+,K+-ATPase activity compared to control (P<0.05, ANOVA; N = 7 for each group). When assayed in vitro, the addition of both drugs to SPM of naive rats caused a dose-dependent decrease in enzyme activity, with the maximal inhibition (60-80 percent) occurring at 0.5 mM. We suggest that a) imipramine might decrease Na+,K+-ATPase activity by altering membrane fluidity, as previously proposed, and b) stimulation of this enzyme might contribute to the therapeutic efficacy of fluoxetine, since brain Na+,K+-ATPase activity is decreased in bipolar patients
Texto completo:
Disponível
Coleções:
Bases de dados internacionais
Base de dados:
LILACS
Assunto principal:
Membranas Sinápticas
/
Córtex Cerebral
/
Fluoxetina
/
ATPase Trocadora de Sódio-Potássio
/
Imipramina
/
Antidepressivos
Limite:
Animais
Idioma:
Inglês
Revista:
Braz. j. med. biol. res
Assunto da revista:
Biologia
/
Medicina
Ano de publicação:
2001
Tipo de documento:
Artigo
País de afiliação:
Brasil
Instituição/País de afiliação:
Fundaçäo Universidade do Rio Grande/BR
/
Universidade Federal do Rio Grande do Sul/BR