PREPARATION AND CHEMISTRY OF ANTERIOR PITUITARY HORMONES

The past ten years have witnessed the isolation of six hormones from anterior pituitary tissue. Each of these has been prepared in a pure or a relatively pure form. Although there may exist in the secretion of the anterior pituitary addi-tional hormonal principles whose physiological effects are as yet undescribed, the specific chemical substances which have been isolated account for most of the recognized hormonal roles assigned to the anterior pituitary. The elucidation of these hormonal functions has come from observations of 1, the physiological effects of extirpation of the anterior pituitary gland; 2, the ameliorative effects resulting from injection of anterior pituitary tissue extracts into hypophysecto-mized animals; 3, the results produced by injections of excess of the gland’s secretions, in the form of extracts, into the normal animal. The application of these methods of research has disclosed the diverse types of physiological activity which are under hormonal control of the anterior pituitary gland. The isolation of six individual chemical substances has been a develop-ment of the physiological studies, and it has been demonstrated that each of th