These studies are designed to examine the effects of hormones on the metabolism of monoamine neurotransmitters (norepinephrine, dopamine, and serotonin), and hormones (epinephrine) in the brain and adrenal medulla, and the participation of these monoamines in the control of secretion from the anterior and posterior pituitary glands. Five specific research programs, some of which are currently in progress, are projected: 1) The effects of adrenocortical hormones on the synthesis of adrenomedullary catecholamines and proteins; the dual control of medullary chromaffin cells by neural and endocrine inputs. 2) Effects of natural and experimentally-induced alterations in plasma gonadotropin and gonadal steroid concentrations on the metabolism of brain catecholamines; 3) An attempt to assay previously-reported hypothalamic enzymes thought to catalyze the biosynthesis of TRF from its amino acid constituents; the effects on these enzymes of experimental manipulations in brain monoamine metabolism; 4) Effects of hormonal peptides and their behaviorally-active analogs on the metabolism of brain monoamines; and, 5) Effects of diet-induced manipulations in brain serotonin on the spontaneous and evoked secretion of vasopressin and LH.