Effects of dehydroepiandrosterone and alprazolam on hypothalamic-pituitary responses to exercise.

Author(s): Deuster PA, Faraday MM, Chrousos GP, Poth MA

Affiliation(s): MPH, Department of Military and Emergency Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA. pdeuster@usuhs.mil

Publication date & source: 2005-08, J Clin Endocrinol Metab., 90(8):4777-83. Epub 2005 May 31.

Publication type: Clinical Trial; Randomized Controlled Trial

CONTEXT: The hypothalamic-pituitary-adrenal axis (HPA) is restrained by activation of gamma-amino-butyric acid receptors. Alprazolam (APZ) and dehydroepiandrosterone (DHEA) are purported to be gamma-amino-butyric acid agonists and antagonists, respectively. OBJECTIVE: Our objective was to examine the effects of APZ and DHEA alone and in combination on HPA axis activity. DESIGN: This was a double-blind, crossover, placebo-controlled study. SETTING: The study setting was the general community. PARTICIPANTS: Subjects consisted of 15 men (age, 20-45 yr) with a body mass index of 20-25 kg/m2. INTERVENTIONS: DHEA (100 mg/d) or placebo was given for 4 wk, followed by a 2-wk washout; participants ingested 0.5 mg APZ or placebo 10 and 2 h before high-intensity exercise. OUTCOME MEASURES: We measured basal and exercise-induced ACTH, arginine vasopressin (AVP), cortisol, DHEA, and GH responses. It was hypothesized that DHEA would enhance and APZ would blunt exercise-induced ACTH and cortisol release. Results: DHEA significantly increased the AVP response to exercise (P < 0.01). APZ treatment significantly increased basal GH and blunted plasma cortisol, ACTH, AVP, and DHEA responses to exercise (P < 0.05). DHEA and APZ in combination significantly increased the GH response to exercise (P < 0.01). CONCLUSIONS: DHEA may alter a subset of receptors involved in AVP release. Together DHEA and APZ may up-regulate GH during exercise by blunting a suppressive (HPA axis) and potentiating an excitatory (glutamate receptor) system.