Neuroendocrinological Effects of L-Threo-3, 4-Dihydroxyphenylserine (DOPS), a Putative Norepinephrine Precursor, on Healthy Volunteers

Abstract: The effect of L-threo-3, 4-dihydroxyphenylserine (DOPS) on plasma Cortisol, prolactin, thyrotropin-stimulating hormone (TSH) and growth hormone concentrations was studied in nine healthy male volunteers. The drug was administered orally (300 mg or 600 mg DOPS) using a multiple crossover placebo-controlled study design. Plasma hormone concentrations were measured at 30 minute intervals for 3 hours after dosing. Plasma DOPS peak concentrations were observed between 2 and 3 hours after dosing. DOPS, however, had no effect on plasma hormone concentrations and this may be attributed to the known low brain permeability of DOPS in healthy subjects.