Fractionation of Rat Pituitary Extract by Starch Gel Electrophoresis and Identification of Growth Hormone and Prolactin

Abstract

Vertical starch gel electrophoresis of alkaline extract of rat anterior pituitary gland at pH 8.5 reveals multiple anionic components. Many of these components are comprised of serum proteins which are removed from the glands by incubation in buffered saline before electrophoresis. When incubated anterior lobes are used, only 2 major components are present after electrophoresis. The slower moving of these bands has been shown to be growth hormone, and the rapidly moving component has been shown to be prolactin. The prolactin band is much more prominent in the female, while growth hormone appears to be slightly more prominent in the male. Lactation in the female and estrogen treatment in the male are associated with a marked increase in the prolactin band, while castration causes this band to disappear. (Endocrinology76: 678, 1965)