Prolactin Activity of Homogeneous Primate Growth Hormone Preparations

Abstract
Three preparations of primate [human and simian] pituitary growth hormone, each appearing homogeneous by several physicochemical criteria and having similar growth hormone potencies in the tibia test, were assayed for prolactin activity by the pigeon crop-sac method. The apparent homogeneity of these preparations and the demonstration that all of them possess small but similar pigeon crop-sac-stimulating potencies support the view that prolactin activity may be an intrinsic characteristic of human and simian growth hormone.