title: The roles of the Na+/K+-ATPase, NKCC, and K+ channels in regulating local sweating and cutaneous blood flow during exercise in humans in vivo.
abstract: Na+/K+-ATPase has been shown to regulate the sweating and cutaneous vascular responses during exercise; however, similar studies have not been conducted to assess the roles of the Na-K-2Cl co-transporter (NKCC) and K+channels. Additionally, it remains to be determined if these mechanisms underpinning the heat loss responses differ with exercise intensity. Eleven young (24 ± 4 years) males performed three 30-min semirecumbent cycling bouts at low (30% VO2peak), moderate (50% VO2peak), and high (70% VO2peak) intensity, respectively, each separated by 20-min recovery periods. Using intradermal microdialysis, four forearm skin sites were continuously perfused with either: (1) lactated Ringer solution (Control); (2) 6 mmol·L-1ouabain (Na+/K+-ATPase inhibitor); (3) 10 mmol·L-1bumetanide (NKCC inhibitor); or (4) 50 mmol·L-1BaCl2(nonspecific K+channel inhibitor); sites at which we assessed local sweat rate (LSR) and cutaneous vascular conductance (CVC). Inhibition of Na+/K+-ATPase attenuated LSR compared to Control during the moderate and high-intensity exercise bouts (both P ˂ 0.01), whereas attenuations with NKCC and K+channel inhibition were only apparent during the high-intensity exercise bout (both P ≤ 0.05). Na+/K+-ATPase inhibition augmented CVC during all exercise intensities (all P ˂ 0.01), whereas CVC was greater with NKCC inhibition during the low-intensity exercise only (P ˂ 0.01) and attenuated with K+channel inhibition during the moderate and high-intensity exercise conditions (both P ˂ 0.01). We show that Na+/K+-ATPase, NKCC and K+channels all contribute to the regulation of sweating and cutaneous blood flow but their influence is dependent on the intensity of dynamic exercise.
authors.affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Louie
authors.affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Naoto
authors.initials: N
authors.lastname: Fujii
authors.affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Meade
authors.affiliation: Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, ON, Canada gkenny@uottawa.ca.
authors.forename: Glen P
authors.initials: GP
authors.lastname: Kenny
mesh_terms: D000328:Adult; D017609:Barium Compounds / Q000008:administration & dosage / Q000494:pharmacology; D001833:Body Temperature Regulation; D002034:Bumetanide / Q000008:administration & dosage / Q000494:pharmacology; D002712:Chlorides / Q000008:administration & dosage / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007271:Injections, Intradermal / Q000379:methods; D008297:Male; D010042:Ouabain / Q000008:administration & dosage / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects* / Q000502:physiology; D012867:Skin / Q000098:blood supply* / Q000187:drug effects / Q000294:innervation; D012879:Skin Physiological Phenomena / Q000187:drug effects; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism / Q000502:physiology*; D013545:Sweat Glands / Q000187:drug effects; D013546:Sweating / Q000187:drug effects* / Q000502:physiology; D014664:Vasodilation / Q000502:physiology; D055815:Young Adult
chemical_list: D017609:Barium Compounds; D002712:Chlorides; D004791:Enzyme Inhibitors; D015221:Potassium Channels; D049994:Sodium Potassium Chloride Symporter Inhibitors; D028021:Sodium-Potassium-Chloride Symporters; C024986:barium chloride; D002034:Bumetanide; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase
keywords: 
  NKCC
  ; Exercise; K+ channels; Na+/K+‐ATPase; heat loss; microcirculation; sweat gland