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Titolo:
FLOW-GENERATING CAPABILITY OF THE ISOLATED SKELETAL-MUSCLE PUMP
Autore:
SHERIFF DD; VANBIBBER R;
Indirizzi:
USAF,RES LAB,HEPM,FLIGHT MOT EFFECTS BRANCH,2504 GILLINGHAM DR BROOKSAFB TX 78235 UNIV WASHINGTON,SCH MED,DEPT PHYSIOL & BIOPHYS SEATTLE WA 98195 USAF,RES LAB,HEPM,FLIGHT MOT EFFECTS BRANCH BROOKS AFB TX 78235
Titolo Testata:
American journal of physiology. Heart and circulatory physiology
fascicolo: 5, volume: 43, anno: 1998,
pagine: 1502 - 1508
SICI:
0363-6135(1998)43:5<1502:FCOTIS>2.0.ZU;2-X
Fonte:
ISI
Lingua:
ENG
Soggetto:
HEAVY RHYTHMIC EXERCISE; BLOOD-FLOW; DYNAMIC EXERCISE; CARDIAC-OUTPUT; CALF MUSCLE; CAPACITY; PRESSURE; VOLUME; ONSET;
Keywords:
MUSCLE BLOOD FLOW; SKELETAL MUSCLE VEINS; MUSCLE VASCULAR CONDUCTANCE; MUSCLE VASCULAR RESISTANCE; METABOLIC VASODILATION; FUNCTIONAL HYPEREMIA; MUSCLE VENOUS PUMP; VENOUS RETURN; VENOUS FUNCTION; VENOUS PHYSIOLOGY; VASCULAR CAPACITANCE; BLOOD PRESSURE; MUSCLE CONTRACTION; EXERCISE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
21
Recensione:
Indirizzi per estratti:
Citazione:
D.D. Sheriff e R. Vanbibber, "FLOW-GENERATING CAPABILITY OF THE ISOLATED SKELETAL-MUSCLE PUMP", American journal of physiology. Heart and circulatory physiology, 43(5), 1998, pp. 1502-1508

Abstract

We sought to test directly whether the mechanical forces produced during rhythmic muscle contraction and relaxation act on the muscle vasculature in a manner sufficient to initiate and sustain blood flow To accomplish this goal, we evaluated the mechanical performance of the isolated skeletal muscle pump. The hindlimb skeletal muscle pump was isolated by reversibly connecting the inferior vena cava and terminal aorta with extracorporeal tubing in 15- to 20-kg anesthetized pigs (n = 5). During electrically evoked contractions (1/s), hindlimb muscles weremade to perfuse themselves by diverting the venous blood propelled out of the muscles into the shunt tubing, which had been prefilled with fresh arterial blood. This caused arterial blood to be pushed into thedistal aorta and then through the muscles (shunt open, proximal aortaand vena cava clamped). In essence, the muscles perfused themselves for brief periods by driving blood around a ''short-circuit'' that isolates muscle from the remainder of the circulation, analogous to isolated heart-lung preparations. Because the large, short shunt offers a negligible resistance to flow, the arterial-venous pressure difference across the limbs was continuously zero, and thus the energy to drive flow through muscle could come only from the muscle pump. The increase in blood flow during normal heart-perfused contractions (with only the shunt tubing clamped) was compared with shunt perfused contractions inwhich the large veins were preloaded with extra blood volume. Muscle blood flow increased by 87 +/- 11 and 110 +/- 21 (SE) ml/min in the first few seconds after the onset of shunt-perfused and heart-perfused contractions, respectively (P > 0.4). We conclude that the mechanical forces produced by muscle contraction and relaxation act on the muscle vasculature in a manner sufficient to generate a significant flow of blood.

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Documento generato il 02/07/20 alle ore 18:01:31