title: Effects of dexamethasone on the metabolic responses to mental stress in humans.
abstract: The haemodynamic effects of the sympathetic nervous system (SNS) activations elicited by hypoglycaemia, acute alcohol administration, or insulin can be prevented by a pretreatment with dexamethasone in humans. This suggests a possible role of central corticotropin releasing hormone (GRIT) release. Mental stress activates the SNS, and decreases systemic vascular resistances though a beta-adrenergic-mediated vasodilation thought to involve vascular nitric oxide release. It also increases insulin-mediated glucose disposal, an effect presumably related to vasodilation. In order to evaluate whether activation of SNS by mental stress is glucocorticoid-sensitive, we monitored the haemodynamic and metabolic effects of mental stress during hyperinsulinaemia in healthy humans with and without a 2-day treatment with 8 mg day(-1) dexamethasone. Mental stress decreased systemic vascular resistances by 21.9% and increased insulin-mediated glucose disposal by 2 8.4% without dexamethasone pretreatment. After 2 days of dexamethasone treatment, whole body insulin-mediated glucose disposal was decreased by 40.8%. The haemodynainic effects of mental stress were however, not affected. Mental stress acutely increased insulin-mediated glucose disposal by 28.0%. This indicates that mental stress elicits a stimulation of SNS through dexamethasone-insensitive pathway, distinct of those activated by insulin, alcohol, or hyperglycaemia.
authors: Institute of Physiology, University of Lausanne, Switzerland.
authors: G
authors: G
authors: Seematter
authors: P
authors: P
authors: Battilana
authors: L
authors: L
authors: Tappy
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D002302:Cardiac Output; D003907:Dexamethasone / Q000008:administration & dosage*; D004734:Energy Metabolism / Q000187:drug effects*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D006339:Heart Rate; D006801:Humans; D007328:Insulin / Q000097:blood; D009638:Norepinephrine / Q000097:blood; D013315:Stress, Psychological / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000378:metabolism; D014655:Vascular Resistance; D014664:Vasodilation / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D005938:Glucocorticoids; D007328:Insulin; D003907:Dexamethasone; D009638:Norepinephrine