title: Effect of systemic α1-adrenergic receptor blockade on central blood pressure response during exercise.
abstract: The aortic pulse pressure (PP), which consists mainly of the incident wave and the reflected wave, has emerged as an important property of systemic blood vessels underlying the pathophysiology of cardiovascular disease. To determine the role of sympathetic nerve activity on the aortic PP response during dynamic exercise, we evaluated aortic hemodynamics during the right-leg knee-extension (40 and 60 % of maximal voluntary contraction) in six young adults with and without the systemic α1-adrenergic receptor blockade using prazosin (1 mg/20 kg body weight). The use of prazosin attenuated the exercise-induced increase in aortic PP (P < 0.05) but not in radial arterial PP. The amplitude of the reflected waves (via augmentation index) significantly decreased with the exercise and decreased more with the use of prazosin. These results suggest that during dynamic exercise the α1-adrenergic-mediated vasoconstrictor tone of the peripheral resistance vessels is manifestly involved in the magnitude of the reflected wave and the modulation of the aortic PP responses.
authors.affiliation: Human Technology Research Institute, National Institute of Advanced Industrial Science and Technology AIST, 1-1-1 Higashi, Tsukuba 305-8566, Japan. jun.sugawara@aist.go.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Sugawara
authors.forename: R Matthew
authors.initials: RM
authors.lastname: Brothers
authors.forename: Peter B
authors.initials: PB
authors.lastname: Raven
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Okazaki
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Ogoh
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology*; D000328:Adult; D001011:Aorta / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D011224:Prazosin / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D018340:Receptors, Adrenergic, alpha-1; D014662:Vasoconstrictor Agents; D011224:Prazosin