The most significant abnormal feature of arterial hypertension, in the light of present knowledge, is the increased peripheral arteriolar resistance. Weiss and Ellis,1 in 1930, attempted to measure the peripheral resistance quantitatively, and found that the average resistance of the arteriolar system of the greater circulation in a group of patients with hypertension was twice as great as in the normal control subjects. The factors, however, that are responsible for this increase in arteriolar resistance were not established.
The work of a number of investigators, such as Billigheimer,2 Kraus and Zondek,3 Zondek,4 Kylin5 and Spiro,6 indicated that the increased peripheral constriction of the vascular system is due to a disturbance of the vegetative nervous system. This altered function of the autonomic nervous system, according to these investigators, is accompanied by a change in the equilibrium of the blood through two powerful physiologic agents, potassium and calcium,