RESUMO
This study was designed to investigate whether calcium-channel blocker, nitrendipine affects memory of rats in three-panel runway test. Nitrendipine (2-4 mg kg(-1), intra peritoneally (i.p.)) neither enhanced nor impaired reference and working memory performances of young adult rats. However, it improved impairment in reference memory induced by anticholinergic drug scopolamine (3 mg kg(-1), i.p.) while it had no effects on impairment in working memory induced by the same drug. The results suggest that nitrendipine may be of benefit in the treatment of memory disturbances resulted from cholinergic deficit.
Assuntos
Memória/efeitos dos fármacos , Nitrendipino/farmacologia , Animais , Masculino , Memória/fisiologia , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologiaRESUMO
In this study, the effects of losartan, an angiotensin II receptor antagonist, on heart rate variability and the changes of plasma corticosterone levels caused by immobilization stress were investigated. Losartan (3 mg/kg, p.o.) significantly prevented increases in plasma corticosterone levels in both losartan+acute stress and losartan+chronic stress groups. But, losartan did not prevent the diminution of the power of heart rate variability caused by stress. Our results supported the idea that the renin-angiotensin system is also involved in the stress- induced cardiovascular response, besides the autonomic nervous system. But, the effects of losartan on heart rate variability remained controversial.
