Naslov
Muscle blood flow response to contraction: influence of venous pressure

Autori
Valić, Zoran ; Buckwalter, B. John ; Clifford S. Philip

Izvornik
Journal of Applied Physiology (8750-7587) 98 (2005), 1; 72-76

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
exercise; hyperemia; muscle pump; vasodilation; dog

Sažetak
The skeletal muscle pump is thought to be at least partially responsible for the immediate muscle hyperemia seen with exercise. We hypothesized that increases in venous pressure within the muscle would enhance the effectiveness of the muscle pump and yield greater postcontraction hyperemia. In nine anesthetized beagle dogs, arterial inflow and venous outflow of a single hindlimb were measured with ultrasonic transit-time flowprobes in response to 1 sec tetanic contractions evoked by electrical stimulation of the sciatic nerve. Venous pressure in the hindlimb was manipulated by tilting the upright dogs to a 30° angle in the headup or headdown positions. The volume of venous blood expelled during contractions was 2.2± ; ; 0.2, 1.6± ; ; 0.2, and 1.4± ; ; 0.2 ml with the head up, horizontal, and head down positions, respectively. Although altering hindlimb venous pressure influenced venous expulsion during contraction, the increase in arterial inflow was similar regardless of position. Moreover, the volume of blood expelled was a small fraction of the cumulative arterial volume following the contraction. These results suggest that the muscle pump is not a major contributor to the hyperemic response to skeletal muscle contraction.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA