Prolactin of normal and dwarf mice.

Abstract

Prolactin and albumin of the mouse, when analyzed either as a mixture of the two purified proteins or as constituents of a pituitary homogenate, were not well separated from each other by disc-electrophoresis at pH 9.5 unless the concentration of acrylamide exceeded 7.5%. By using a gel made with 10% acrylamide, a maximum resolution of all the major components of the electrophoretic pattern was obtained, and the procedure then could be used to demonstrate differences in the amount of protein in the prolactin band in the pituitary gland of the mouse under various conditions. Both the greater amount of this band in the pituitary gland of the female mouse as compared to the male, and its increase in the pituitary of the male after administration of estradiol were detected easily. The band designated as prolactin in the electrophoretic pattern was isolated by preparative electrophoresis and identified as having prolactin activity by the pigeon crop sac assay. A molecular weight of 23,000 ± 1000 was found for ...