Role of Pressor Substances in Etiology of Arterial Hypertension

Abstract

The theory that circulating substances play an etiological role in arterial hypertension has been revived recently by a series of studies carried on by Bohn and his associates. 1 ,²,³ These investigators of the Volhard clinic have reported the finding of increased amounts of pressor substances in the urine and in the blood of patients with “pale hypertension” (Volhard). In view of the important implications of Bonn's conclusions, we have reinvestigated this problem.

Because of the fact that several hormones and chemical substances are present in greater concentration in the urine than in the blood, and because large amounts of urine are readily obtainable for maximum chemical concentration, we have studied particularly extracts of urine. Blood and chest, abdominal and cerebrospinal fluids were also tested, both before and after extraction. In order to ascertain the efficacy of the alcohol-acetone fractionation of pressor and depressor substances, we have tested biologically not only the alcohol but also the acetone fraction, whereas Bohn utilized only the former. Twenty-one subjects were studied, 8 of whom were normal, 7 had malignant hypertension, 2 benign hypertension, and 4 chronic glomerulonephritis with hypertension. Extraction of a number of 24-hour urine specimens on each subject was performed. A total of 120 extracts were repeatedly tested on 55 cats. Dial and amytal given intraperitoneally were used as anesthetics, but comparative observations were also made of the effect of identical extracts on animals anesthetized with ether, chloral hydrate and urethane. Care was taken to test the same extracts in different animals, as well as to test different extracts obtained from the same subject in the same animal.