The effect of diazepam on indices of 5-HT function in man

The effects of acute and chronic diazepam administration on L-tryptophan induced prolactin release was studied in seven male volunteers. Acute diazepam diminished the prolactin neuroendocrine response to L-tryptophan. On chronic administration this effect was lost, suggesting tolerance had developed. The sedative effects of L-tryptophan were unaltered by either acute or chronic diazepam administration. A possible explanation for the tolerance development to the neuroendocrine effects may be the observed reduction in platelet 3H-imipramine binding that was observed.