STUDIES ON THE PROLACTIN-LIKE SUBSTANCE IN HUMAN PLACENTA II

Abstract

A prolactin-like substance was isolated from the human placenta by the method of extraction with alkaline water of pH 8.6-8.8 and the fractional precipitation with ammonium sulfate. The substance possesses the crop-glandstimulating activity similar to the anterior pituitary lactogenic hormone. The activity is concentrated in a precipitate at the concentration of 10-25% of ammonium sulfate from the pH 5.4-precipitate. This fraction causes proliferation of the mucous membrane of the crop-gland, production of the crop milk and increase of the granules of the fat in the crop milk.