Isolation of melanocyte-stimulating hormone from hog pituitary gland.

The present communication is concerned with two substances possessing melanocyte-stimulating hormone (MSH) activity, ar-MSH and /3-MSH, found in hog pituitary gland. The main component, o(-MSH, was isolated by a four-step process consisting of solvent extraction and fractional precipitation, oxycellulose adsorption, counter-current distribution, and paper electrophoresis. a-MSH has been found to be homogeneous with respect to counter-current distribution and to paper electrophoresis at different pH values. A preliminary report on the isolation of CK-MSH appeared elsewhere (1). These hormones, which are produced in the intermediate lobe of the pituitary gland (a), previously were called the melanophore hormone, melanophore-expanding hormone, or intermedin. It has been known for several years that the skin of aquatic animals could be darkened by injections of these hormones (3). Recently, a similar effect was observed in human beings (4).