Psychotropic drugs and human 5-HT neuroendocrinology
Studies on the effects of psychotropic drugs on brain 5-HT function have been stimulated by the discovery of important subdivisions of 5-HT receptors in the mammalian nervous system. Ligand binding investigations suggest that 5-HT receptor subtypes also occur in the human brain, but testing brain 5-HT function in humans in vivo presents certain difficulties. The release of prolactin in humans is partly controlled by brain 5-HT pathways and there is increasing evidence that the elevation in plasma prolactin following infusion of the 5-HT precursor, l-tryptophan, can be used to determine certain aspects of brain 5-HT function. Psychotropic drugs produce striking changes in this 5-HT-mediated neuroendocrine response, usually in directions predicted by animal investigations. Philip Cowen examines the value of 5-HT neuroendocrine tests for assessing the potential clinical effects of novel ligands for 5-HT receptors as well as helping to elucidate the actions of conventional psychotropic agents. © 1987.