Changes in blood flow in conduit artery and veins of the upper arm during leg exercise in humans

Abstract

This study investigated changes in blood flow in the conduit artery, superficial vein, and deep vein of the upper arm during increase in internal temperature due to leg cycling. Additionally, we sought to demonstrate the contributions of blood velocity and vessel diameter on blood flow responses. Fourteen subjects performed supine cycling exercise at 60-69% maximal oxygen uptake for 30 min at an ambient temperature of 28 degrees C and relative humidity of 50%. Blood velocity and diameter in the brachial artery, basilic vein (superficial vein), and brachial vein (deep vein) were measured using ultrasound Doppler, and blood flow was calculated. Blood flow in the artery and superficial vein increased linearly with rising oesophageal temperature (DeltaT (oes)) after DeltaT (oes) was about 0.3 degrees C (within threshold), as well as cutaneous vascular conductance on the forearm. Changes in blood velocity in these vessels were similar to those in blood flow. Conversely, the brachial artery and superficial vein diameter did not affect the blood flow response. Blood flow variables in the deep vein did not change remarkably with rising DeltaT (oes). These results suggest that blood flow response, by an increase in velocity, in the conduit artery with rising DeltaT (oes) during exercise is similar to that in the superficial vein, but not deep vein. Also, it is indicated that these increases in blood flow relate to the increase in skin blood flow on the forearm with the rise in body temperature during exercise.

Compliance in the deep and superficial conduit veins of the nonexercising arm is unaffected by short-term exercise

“…The reduction in CSA during dynamic and static exercise was similarly observed in our previous studies using the same ultrasonography technique to assess a basilic vein during cycling exercise (Ooue et al. ) and static exercise (Ooue et al. , ).…”

Effect of cold water immersion on repeated cycling performance and limb blood flow

“…Arm and leg blood flows were measured in an attempt to differentiate the local effects of exercise, which would be greatest in the legs, from the effects of temperature, which would have a similar influence on blood flow in the arms and legs 29 30. Indeed, resting blood flow was initially elevated in both the arms and legs above normal resting levels (fig 3).…”

Vascular Effects of Exercise: Endothelial Adaptations Beyond Active Muscle Beds

“…It is now established that, at the onset of lower-limb dynamic exercise (i.e., first ~10 min), the brachial artery is exposed to a marked increase in retrograde and oscillatory shear (63, 64, 66, 181, 194) likely as a result of the increase in downstream resistance (181). As exercise continues, blood flow to the forearm is increased and primarily directed to the skin to serve thermoregulatory needs (97, 152) (see Cutaneous Circulation ). Cutaneous vasodilation (and the subsequent decrease in forearm vascular resistance) observed during prolonged exercise results in a significant augmentation of shear stress in the upstream conduit arteries (i.e., brachial and radial) (153, 181, 188, 196) and the partial removal of the initial increase in retrograde and oscillatory shear (181) (FIGURE 1).…”