TY - JOUR
T1 - Differential effects of lower body negative pressure on forearm and calf blood flow
AU - Essandoh, L. K.
AU - Houston, D. S.
AU - Vanhoutte, P. M.
AU - Shepherd, J. T.
PY - 1986
Y1 - 1986
N2 - Modest degrees of lower body negative pressure (<20 mmHg) cause a reflex constriction of forearm resistance vessels attributable to a decrease in activity of cardiopulmonary mechanoreceptors. In the present study, we sought to determine whether the calf vessels respond similarly. Left forearm and right calf blood flows were measured simultaneously by strain-gauge plethysmography in 10 healthy volunteers. Forearm flows decreased significantly from control during negative pressures of 10, 15, or 20 mmHg, whereas calf flows did not increase significantly until 20 mmHg; at 10, 15, and 20 mmHg, decreases in forearm flow were significantly greater than those of the calf. Similar results were obtained in a second series of experiments in which venous pooling in the right leg during lower body negative pressure was prevented by enclosing it in a boot. At 40 mmHg, or after a Valsalva maneuver, both forearm and calf vessels constricted markedly and to the same degree. It appears that the reflex reduction in blood flow to the skeletal muscles of the limbs resulting from deactivation of the low-pressure intrathoracic mechanoreceptors is directed primarily to the arm.
AB - Modest degrees of lower body negative pressure (<20 mmHg) cause a reflex constriction of forearm resistance vessels attributable to a decrease in activity of cardiopulmonary mechanoreceptors. In the present study, we sought to determine whether the calf vessels respond similarly. Left forearm and right calf blood flows were measured simultaneously by strain-gauge plethysmography in 10 healthy volunteers. Forearm flows decreased significantly from control during negative pressures of 10, 15, or 20 mmHg, whereas calf flows did not increase significantly until 20 mmHg; at 10, 15, and 20 mmHg, decreases in forearm flow were significantly greater than those of the calf. Similar results were obtained in a second series of experiments in which venous pooling in the right leg during lower body negative pressure was prevented by enclosing it in a boot. At 40 mmHg, or after a Valsalva maneuver, both forearm and calf vessels constricted markedly and to the same degree. It appears that the reflex reduction in blood flow to the skeletal muscles of the limbs resulting from deactivation of the low-pressure intrathoracic mechanoreceptors is directed primarily to the arm.
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U2 - 10.1152/jappl.1986.61.3.994
DO - 10.1152/jappl.1986.61.3.994
M3 - Article
C2 - 3759785
AN - SCOPUS:0022522899
SN - 8750-7587
VL - 61
SP - 994
EP - 998
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 3
ER -