Relation of Potency of Anterior Pituitary-Like Hormone to Hydrogen ion Concentration

Abstract

ConclusionsFrom the foregoing results, conclusions are drawn that the urine of pregnant women is most potent in anterior pituitary-like action at a pH of 6.1 to 7.3. Potency is defined as the smallest amount of urine causing the graafian follicles to rupture in 3 out of 5 test animals. The hormone may be protein-like in nature, or carried down with the foreign protein at the isoelectric point of 6.1.Potency is little affected by acid, but varies with the alkali content, sometimes being greatly reduced, as when sodium hydroxide is added, and again showing less change after 3 months in the icebox at an alkaline pH which has developed on standing.These observations in no way affect the Friedman modification of the Aschheim-Zondek test,4 since larger amounts varying from 5 to 10 cc. are always used in the latter.