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Titolo:
Alteration of humoral and peripheral vascular responses during graded exercise in heart failure
Autore:
Hammond, RL; Augustyniak, RA; Rossi, NF; Lapanowski, K; Dunbar, JC; OLeary, DS;
Indirizzi:
Wayne State Univ, Sch Med, Dept Physiol, Detroit, MI 48201 USA Wayne StateUniv Detroit MI USA 48201 Dept Physiol, Detroit, MI 48201 USA John D Dingell Vet Affairs Med Ctr, Dept Med, Detroit, MI 48201 USA John DDingell Vet Affairs Med Ctr Detroit MI USA 48201 oit, MI 48201 USA
Titolo Testata:
JOURNAL OF APPLIED PHYSIOLOGY
fascicolo: 1, volume: 90, anno: 2001,
pagine: 55 - 61
SICI:
8750-7587(200101)90:1<55:AOHAPV>2.0.ZU;2-C
Fonte:
ISI
Lingua:
ENG
Soggetto:
CONSCIOUS DOGS; VASOPRESSIN; RENIN; MECHANISM; OUTPUT; FLOW;
Keywords:
cardiac output; regional blood flow; sympathetic nervous system; congestive heart failure;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
28
Recensione:
Indirizzi per estratti:
Indirizzo: O'Leary, DS Wayne State Univ, Sch Med, Dept Physiol, 540 E Canfield Ave, Detroit, MI 48201 USA Wayne State Univ 540 E Canfield Ave Detroit MI USA 48201 1 USA
Citazione:
R.L. Hammond et al., "Alteration of humoral and peripheral vascular responses during graded exercise in heart failure", J APP PHYSL, 90(1), 2001, pp. 55-61

Abstract

We hypothesized that performance of exercise during heart failure (HF) would lead to hypoperfusion of active skeletal muscles, causing sympathoactivation at lower workloads and alteration of the normal hemodynamic and hormonal responses. We measured cardiac output, mean aortic and right atrial pressures, hindlimb and renal blood flow (RBF), arterial plasma norepinephrine (NE), plasma renin activity (PRA), and plasma arginine vasopressin (AVP) inseven dogs during graded treadmill exercises and at rest. In control experiments, sympathetic activation at the higher workloads resulted in increased cardiac performance that matched the increased muscle vascular conductance. There were also increases in NE, PRA, and AVP. Renal vascular conductance decreased during exercise, such that RBF remained at resting levels. After control experiments, HF was induced by rapid ventricular pacing, and the exercise protocols were repeated. At rest in HF, cardiac performance was significantly depressed and caused lower mean arterial pressure, despite increased HR. Neurohumoral activation was evidenced by renal and hindlimb vasoconstriction and by elevated NE, PRA, and AVP levels, but it did not increase at the mildest workload. Beyond mild exercise, sympathoactivation increased, accompanied by progressive renal vasaconstriction, a fall in RBF, and very large increases of NE, PRA, and AVP. As exercise intensity increased, peripheral vasoconstriction increased, causing arterial pressure to rise to near normal levels, despite depressed cardiac output. However, combined with redirection of RBF, this did not correct the perfusion deficit to the hindlimbs. We conclude that, in dogs with HF, the elevated sympathetic activity observed at rest is not exacerbated by mild exercise. However, with heavier workloads, sympathoactivation begins at lower workloads and becomes progressively exaggerated at higher workloads, thus altering distribution of blood flow.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 00:39:41