title: Effects of acute vasodilation on the hemodynamic response to muscle metaboreflex.
abstract: The aim of the present study was to test the contribution of stroke volume (SV) in hemodynamic response to muscle metaboreflex activation in healthy individuals. We hypothesized that an acute decrease in cardiac afterload and preload due to the administration of a vasodilating agent could reduce postexercise muscle ischemia (PEMI)-induced SV response. Ten healthy males (age 33.6 ± 1.3 yr) were enrolled and randomly assigned to the following study protocol: 1) PEMI session, 2) control exercise recovery (CER) session, 3) PEMI after sublingual administration of 5 mg of isosorbide dinitrate (ISDN), and 4) CER after ISDN. Central hemodynamics were evaluated by means of impedance cardiography. The main findings were a blunted SV response during metaboreflex following acute arterial and venous vasodilation, associated with a reduction in cardiac diastolic time and filling, and a decrement of systemic vascular resistance. These hemodynamic changes restrain blood pressure response during metaboreflex activation. Our results indicate that hemodynamic response to metaboreflex activation is a highly integrated phenomenon encompassing complex interplay between heart rate, cardiac performance, preload, and afterload and that impairment of one or more of these parameters leads to altered hemodynamic response to metaboreflex.
authors.affiliation: Department of Medical Sciences, Sports Physiology Laboratory, University of Cagliari, Cagliari, Italy;
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Marongiu
authors.forename: Massimo
authors.initials: M
authors.lastname: Piepoli
authors.forename: Raffaele
authors.initials: R
authors.lastname: Milia
authors.forename: Luca
authors.initials: L
authors.lastname: Angius
authors.forename: Marco
authors.initials: M
authors.lastname: Pinna
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Bassareo
authors.forename: Silvana
authors.initials: S
authors.lastname: Roberto
authors.forename: Filippo
authors.initials: F
authors.lastname: Tocco
authors.forename: Alberto
authors.initials: A
authors.lastname: Concu
authors.forename: Antonio
authors.initials: A
authors.lastname: Crisafulli
mesh_terms: D000222:Adaptation, Physiological; D000286:Administration, Sublingual; D000328:Adult; D000704:Analysis of Variance; D062186:Arterial Pressure; D015444:Exercise; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D007548:Isosorbide Dinitrate / Q000008:administration & dosage; D007558:Italy; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000294:innervation* / Q000378:metabolism*; D009200:Myocardial Contraction; D020127:Recovery of Function; D012018:Reflex; D013318:Stroke Volume / Q000187:drug effects; D013997:Time Factors; D014655:Vascular Resistance; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate
keywords: blood pressure; cardiac preload; myocardial contractility; stroke volume; venous return