RESUMO
The effects of three models of stress upon blood pressure and central responsiveness to angiotensin II (AII) and noradrenaline (NA) were assessed in rats. Considering general parameters of stress efficacy, all models were effective to induce stress but hypertension only occurred in animals submitted to rapid eye movement sleep deprivation (REM-sd) and electric shock (ES). An increased central pressor effect of AII and NA was observed in these groups. On the other hand, restriction (R) did not increase blood pressure or central responsiveness to AII or NA. Instead of hypertension, R induced gastric ulcers and testis atrophy. Thus, hypertension occurs only in some models of stress and may be due to increased central responsiveness to AII and NA.