title: Sympathetic nonnoradrenergic cutaneous vasoconstriction in women is associated with reproductive hormone status.
abstract: We tested whether a nonnoradrenergic component of reflex vasoconstriction of skin blood flow (SkBF) is sensitive to female reproductive hormones. Six women taking oral contraceptives underwent whole-body cooling during high-hormone (HH) and low-hormone (LH) phases of oral contraceptive use. SkBF was monitored by laser Doppler flowmetry (LDF) at sites treated by intradermal injection of yohimbine-propranolol (5 mM and 1 mM; YOPR) to block the effects of norepinephrine (NE) or at saline (Sal) control sites. Mean arterial pressure (MAP) was measured with the use of the Penaz method. Cutaneous vascular conductance (CVC = LDF/mean arterial pressure) was expressed as a percentage of baseline. Whole body skin temperature was decreased from 34 to 31 degrees C in HH and LH. In both HH and LH, CVC at Sal-treated sites was reduced during cooling (CVC = 53.1 +/- 8.6% and 54.4 +/- 4.2%, both P < 0.05). In HH, CVC at YOPR sites was reduced during cooling (78.8 +/- 3.6%, P < 0.05). In contrast, CVC at YOPR sites was not reduced significantly during cooling in LH (CVC = 95.9 +/- 2.8%, P > 0.05). Across phases, CVC at YOPR sites during cooling was significantly different (P < 0.05). After cooling, the effects of NE at YOPR sites were completely blocked. These data indicate that a nonnoradrenergic mechanism of reflex cutaneous vasoconstriction is present in women and is associated with reproductive hormone status.
authors.affiliation: Department of Physiology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 78229-3900, USA.
authors.forename: Dan P
authors.initials: DP
authors.lastname: Stephens
authors.forename: Lee Ann T
authors.initials: LA
authors.lastname: Bennett
authors.forename: Ken
authors.initials: K
authors.lastname: Aoki
authors.forename: Wojciech A
authors.initials: WA
authors.lastname: Kosiba
authors.forename: Nisha
authors.initials: N
authors.lastname: Charkoudian
authors.forename: John M
authors.initials: JM
authors.lastname: Johnson
mesh_terms: D000328:Adult; D001794:Blood Pressure; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D005260:Female; D006801:Humans; D011433:Propranolol / Q000494:pharmacology; D012039:Regional Blood Flow / Q000502:physiology*; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature / Q000187:drug effects / Q000502:physiology*; D016683:Supine Position; D014661:Vasoconstriction / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D003277:Contraceptives, Oral, Combined; D015016:Yohimbine; D011433:Propranolol