BEHAVIORAL AND NEUROENDOCRINE EFFECTS OF THE PARTIAL NMDA AGONIST D-CYCLOSERINE IN HEALTHY-SUBJECTS

The effects of D-cycloserine, ct partial agonist of the N-Methyl-D-Asp artate (NMDA) receptor, were assessed in a (neuroendocrine) challenge paradigm to examine NMDA systems in male healthy volunteers, using a d ouble-blind, placebo-controlled crossover design. Oral D-cycloserine ( 15, 50, and 150 mg) teas readily absorbed and its plasma concentration increased dose-dependently. Behavioral and hormonal responses were me asured for 240 minutes after administration of the drug. D-cycloserine tons well tolerated and did not induce side-effects according to the Visual Analog Scales (VAS), the Brief Psychiatric Rating Scale (BPRS) and the Adverse Events Checklist (AEC) & codes. D-cycloserine failed t o elicit a neuroendocrine response as evaluated by cortisol, prolactin , and luteinizing hormone (LH) plasma levels. The present result sugge sts that D-cycloserine can readily be administered to healthy voluntee rs but that, in the dosages used, neuroendocrine secretion fails to se rve as a model for testing NMDA receptor function in humans. (C) 1997 American College of Neuropsychopharmacology.