The Neurogenic Component in Hypertension

Abstract

The magnitude of the blood pressure falls, in the horizontal posture, following intravenous hexamethonium, shows that an important part of the blood pressure elevation is neurogenically maintained in essential hypertension. When the blood pressure is first raised by angiotonin or by other pressor agents, the subsequent response to hexamethonium is much reduced. Similar responses are observed in normotensive and hypertensive subjects. This is due to the reaction of the regulating centers which compensate for the effect of the pressor agent by reducing the neurogenic component. The resulting decrease in the neurogenically maintained fraction of the blood pressure diminishes the response to hexamethonium. It is suggested that, in the course of time, long exposure to pressor stimuli induces the vasomotor centers to exercise their regulating function at a higher than normal level.