Effects of Reserpine and Guanethidine on Venous Reflexes

Abstract

The effects of reserpine and guanethidine on reflex venoconstriction were studied in a group of open-chest anesthetized dogs by the major vessel occlusion technique described by Bartelstone. Guanethidine (10 mg./Kg. intravenously) blocked reflex venous constriction following carotid occlusion and central vagal stimulation within, five minutes after injection in five dogs. Reserpine (0.5 mg./Kg. intravenously) required 50 to 110 minutes to abolish these venopressor reflexes in five animals. Pretreatment with either reserpine (0.5 mg./Kg. intraperitoneally on two consecutive days in four dogs) or guanethidine (10 mg./Kg. intravenously on two days in four dogs) also abolished reflex venoconstriction. These results indicate that reserpine and guanethidine are capable of blocking reflex venoconstriction, and it is suggested that this action may contribute to their effects in the treatment of hypertension.