Abstract: | Spontaneously hypertensive rats (SHR) have basal levels of plasma renin activity (PRA) lower than the ones observed in normal Sprague Dawley rats. Three beta blocking agents are orally administered to unanesthetized spontaneously hypertensive and normotensive rats. Propranolol and S 464 reduce PRA in spontaneously hypertensive and normotensive control rats. Pindolol do not lower PRA in normotensive rats but increases levels of PRA in spontaneously hypertensive rats. These results are discussed. |