title: Mental stress impairs endothelial vasodilatory function by a beta-adrenergic mechanism.
abstract: Mental stress has been shown to impair endothelium-dependent vasodilation (EDV) in the human forearm. The aim of this study was to investigate if this response could be blunted by local infusions of beta-blockade (propranolol), alpha-blockade (phentolamine), or neurogenic blockade. Thirty-one young healthy volunteers underwent forearm blood flow (FBF) measurements, using venous occlusion plethysmography, during local intra-arterial infusions of metacholine (MCh; inducing EDV) and sodium nitroprussid (SNP; inducing endothelial-independent vasodilation [EIDV]), respectively. These measurements were repeated during a 5-min mental arithmetic stress test without (n = 8) or with concomitant local infusion of propranolol (n = 7) or phentolamine (n = 8) in the forearm or during axillary plexus blockade (n = 8). An index of endothelial vasodilatory function (EFI) was calculated as the EDV to EIDV ratio. Mental stress impaired EDV significantly (p < .05), and as a result, EFI was significantly reduced (p = .02). This effect on EFI could be blocked by propranolol and neurogenic blockade but not by phentolamine (p < .05). Thus, impairment of endothelial vasodilatory function induced by mental stress could be blocked by beta-adrenergic, but not alpha-adrenergic, receptor blockade.
authors.affiliation: Department of Anaesthesiology and Intensive Care, Uppsala University Hospital, Uppsala, Sweden. Mats.Eriksson@surgsci.uu.se
authors.forename: M
authors.initials: M
authors.lastname: Eriksson
authors.forename: K
authors.initials: K
authors.lastname: Johansson
authors.forename: M
authors.initials: M
authors.lastname: Sarabi
authors.forename: L
authors.initials: L
authors.lastname: Lind
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage*; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009599:Nitroprusside / Q000008:administration & dosage*; D010646:Phentolamine / Q000008:administration & dosage*; D011433:Propranolol / Q000008:administration & dosage*; D013312:Stress, Physiological / Q000503:physiopathology*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000008:administration & dosage*
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D014665:Vasodilator Agents; D009599:Nitroprusside; D011433:Propranolol; D010646:Phentolamine