HYPOTHALAMIC SECRETORY FACTOR FOR ADRENOCORTICOTROPIC HORMONE (SF-ACTH).

The purpose of this research is to purify the hypothalamic hormone responsible for the increased biosynthesis and secretion of ACTH in stress. Because the only feasible guide to yield and specific activity of hormone during purification steps is a complicated biological assay system, we also are engaged in studies of ways to improve and simplify the biological assay. The principal and perhaps only suitable methods of biological assay for the hypothalamic secretory factor for ACTH are based on our original finding that in the rat anesthetized with pentobarbital, morphine inhibits ACTH secretion to nonspecific stimuli without interfering with the action of the hypothalamic factor on the anterior pituitary gland. One of the difficulties in the method is that the combination of the two drugs in adequate doses, pentobarbital and morphine, is rather toxic to the rat. By pretreating the rats several hours before use with cortisol or a synthetic analogue like dexamethasone, it has been found by other investigators that either may be substituted for pentobarbital as the anesthetic. This should be an advantage, because the ethermorphine combination is relatively nontoxic to rats. Author