title: Role of nitric oxide and prostanoids in the regulation of leg blood flow and blood pressure in humans with essential hypertension: effect of high-intensity aerobic training.
abstract: We examined the role of nitric oxide (NO) and prostanoids in the regulation of leg blood flow and systemic blood pressure before and after 8 weeks of aerobic high-intensity training in individuals with essential hypertension (n = 10) and matched healthy control subjects (n = 11). Hypertensive subjects were found to have a lower (P < 0.05) blood flow to the exercising leg than normotensive subjects (30 W: 2.92 ± 0.16 vs. 3.39 ± 0.37 l min(−1)). Despite the lower exercise hyperaemia, pharmacological inhibition of the NO and prostanoid systems reduced leg blood flow to a similar extent during exercise in the two groups and vascular relaxation to the NO-dependent vasodilator acetylcholine was also similar between groups. High-intensity aerobic training lowered (P < 0.05) resting systolic (∼9 mmHg) and diastolic (∼12 mmHg) blood pressure in subjects with essential hypertension, but this effect of training was abolished when the NO and prostanoid systems were inhibited. Skeletal muscle vascular endothelial NO synthase uncoupling, expression and phosphorylation status were similar in the two groups before and after training. These data demonstrate that a reduction in exercise hyperaemia in hypertensive subjects is not associated with a reduced capacity of the NO and prostanoid systems to induce vasodilatation or with altered acetylcholine-induced response. However, our data suggest that the observed reduction in blood pressure is related to a training-induced change in the tonic effect of NO and/or prostanoids on vascular tone.
authors.affiliation: Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark. mnyberg@ifi.ku.dk
authors.forename: Michael
authors.initials: M
authors.lastname: Nyberg
authors.forename: Lasse G
authors.initials: LG
authors.lastname: Jensen
authors.forename: Pia
authors.initials: P
authors.lastname: Thaning
authors.forename: Ylva
authors.initials: Y
authors.lastname: Hellsten
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Mortensen
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007213:Indomethacin / Q000494:pharmacology; D007866:Leg / Q000098:blood supply / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology; D009569:Nitric Oxide / Q000097:blood / Q000502:physiology*; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000502:physiology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000502:physiology; D011453:Prostaglandins / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology*; D014664:Vasodilation; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D011453:Prostaglandins; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; D000109:Acetylcholine; D007213:Indomethacin