Pressor Polypeptides Formed in Vivo and in Vitro as Mediators of Renal Hypertension

Abstract
During the purification of hypertensin formed in vitro, evidence of heterogeneity of the pressor activity was obtained by counter current distribution. Pepsitensin shows a similar heterogeneity. These facts lead to the hypothesis that other proteolytic enzymes may also be present in the tissues and may hydrolyze hypertensinogen with the formation of pressor polypeptides of the hypertensin or pepsitensin type. Thus, substances similar to hypertensin may be formed in the organism by the action of proteolytic enzymes other than renin and may, if produced locally, exert a vasoconstrictor action or, if they enter the circulation, cause an increase in blood pressure.