Extraction and Assay of Lactogenic Hormone in Postpartum Urine12

Abstract

Two methods are described for preparing fresh post-partum urine for the assay of lactogenic hormone. The first requires 9 volumes of alcohol at a pH of 5.4-5.7 for the precipitation of the active principle. By the other method the urine is merely dialyzed, evaporated, and injected as such. The urinary lactogen is assayed by the very sensitive "micro" pigeon test. In a study of 10 lactating [female][female] during the first 2 wks. post-partum, a daily excretion of urinary lactogen was found of from 4.05 to 12.50 I.U. of hormone. From 0.8 cc. to 3 cc. of urine were required for a unit response in the case of normal lactators. In 3 cases of definite or suspected hypogalactia less lactogen was found in the urine than in the case of normal lactators, while the 3 best lactators excreted the highest avg. amts. of urinary lactogen. Pregnancy urine contained only l/8th to l/16th the amt. of lactogen present in post-partum urine. A very probable relationship evidently exists between the amt. of urinary lactogen and the level of milk secretion, and it is believed that an assay of urinary lactogen would reveal whether or not this hormone is the factor responsible for cases of hypogalactia.