The Effects of Ēthrane on Arterial Pressure, Preganglionic Sympathetic Activity, and Barostatic Reflexes
The effects of Ēthrane on cervical preganglionic sympathetic nervous activity and on the responses of this activity to electrical stimulation of the aortic depressor nerve have been examined. Mean arterial blood pressure was also measured. Subjects of the experiments were cats anesthetized with nitrous oxide and immobilized with gallaminc. Both ambient efferent sympathetic activity and mean arterial blood pressure declined as the concentration of Ēthrane increased; however, both still responded with further decreases when the central end of the left aortic depressor nerve was stimulated electrically. The authors postulate that Ēthrane, like halothane and the barbiturates, acts predominantly on the pressor elements of the medullary vasomotor center. The actions of this group of agents are compared with those of agents which cause sympathetic nervous activation (eg., diethyl ether).