title: Functional sympatholysis during exercise in patients with type 2 diabetes with intact response to acetylcholine.
abstract: OBJECTIVE
  Sympathetic vasoconstriction is blunted in contracting human skeletal muscles (functional sympatholysis). In young subjects, infusion of adenosine and ATP increases blood flow, and the latter compound also attenuates α-adrenergic vasoconstriction. In patients with type 2 diabetes and age-matched healthy subjects, we tested 1) the sympatholytic capacity during one-legged exercise, 2) the vasodilatory capacity of adenosine and ATP, and 3) the ability to blunt α-adrenergic vasoconstriction during ATP infusion.
  
  
  METHODS
  In 10 control subjects and 10 patients with diabetes and normal endothelial function, determined by leg blood flow (LBF) response to acetylcholine infusion, we measured LBF and venous NA, with and without tyramine-induced sympathetic vasoconstriction, during adenosine-, ATP-, and exercise-induced hyperemia.
  
  
  RESULTS
  LBF during acetylcholine did not differ significantly. LBF increased ninefold during exercise and during adenosine- and ATP-induced hyperemia. Infusion of tyramine during exercise did not reduce LBF in either the control or the patient group. During combined ATP and tyramine infusions, LBF decreased by 30% in both groups. Adenosine had no sympatholytic effect.
  
  
  CONCLUSIONS
  In patients with type 2 diabetes and normal endothelial function, functional sympatholysis was intact during moderate exercise. The vasodilatory response for adenosine and ATP did not differ between the patients with diabetes and the control subjects; however, the vasodilatory effect of adenosine and ATP and the sympatholytic effect of ATP seem to decline with age.
authors: The Copenhagen Muscle Research Centre, Rigshospitalet, Copenhagen, Denmark. piathaning@gmail.com
authors: Pia
authors: P
authors: Thaning
authors: Laurids T
authors: LT
authors: Bune
authors: Morten
authors: M
authors: Zaar
authors: Bengt
authors: B
authors: Saltin
authors: Jaya B
authors: JB
authors: Rosenmeier
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000241:Adenosine / Q000008:administration & dosage / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000494:pharmacology; D000367:Age Factors; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D015444:Exercise; D005260:Female; D006801:Humans; D006940:Hyperemia / Q000139:chemically induced / Q000209:etiology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D000255:Adenosine Triphosphate; D000241:Adenosine; D000109:Acetylcholine