Changes in blood flow in a conduit artery and superficial vein of the upper arm during passive heating in humans

Abstract

The purposes of this study were (1) to evaluate changes in blood flow in the brachial artery and basilic vein of the upper arm with a rise in internal temperature during passive heating; and (2) to investigate the contributions of blood velocity and anteroposterior vessel diameter to these blood flow changes. Ten subjects rested in the supine position between a pair of tube-lined sheets. Thermoneutral water was circulated through the tubes to keep a mean skin temperature (Tsk) of 34-35 degrees C, and then hot water was circulated to maintain Tsk of 37-38 degrees C. The blood velocity and diameter in the brachial artery and basilic vein were continuously monitored by Doppler ultrasound technique and used to calculate blood flow. Blood flow in the brachial artery and basilic vein increased linearly as the oral temperature (T(or)) rose by < or =0.6 degrees C. The magnitude of the change in blood flow did not differ significantly between the two vessels. In addition, plots of DeltaT(or) versus blood flow yielded slopes that did not differ significantly between the brachial artery and the basilic vein. As T (or) increased, blood velocity, but not diameter, also increased. In conclusion, blood flow in the brachial artery and the basilic vein increased linearly as the internal temperature variable T (or) increased < or =0.6 degrees C. In both vessels, the passive heating-induced increases in blood flow resulted primarily from a change in blood velocity, rather than from a change in diameter.

Mechanisms for the control of local tissue blood flow during thermal interventions: influence of temperature‐dependent ATP release from human blood and endothelial cells

“…1947; Ooue et al . 2007). A common factor in the whole‐body heating studies is that the internal temperature was increased significantly.…”

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

“…During these procedures, the probe was fixed in the middle of the upper arm (Ooue et al 2007). D artery , D sup vein , and D deep vein were measured using Bmode ultrasound with a mean transmission frequency of 8.7 MHz.…”

“…BF is calculated by measuring blood velocity (V) and vessel diameter (D). D in the artery and veins does not change during passive heating and exercise, although BF increases (Abraham et al 1994a, b, c;Gaenzer et al 2001;Green et al 2002a;Joannides et al 2002;Ooue et al 2007;Rådegran and Saltin 2000;Van Beekvelt et al 2001).…”

“…Furthermore, when internal temperatures are elevated, BF mainly returns to the superficial vein to promote heat loss (Rowell 1986). BF in the conduit artery and superficial vein of the upper arm increases linearly with a rise in internal temperature during passive heating (Ooue et al 2007), and BF in the superficial vein of the forearm increases, without changes in BF in the deep vein, during lower leg immersion (Roddie et al 1956). Although changes in BF of the brachial artery and the superficial and deep veins of the forearm have been investigated during incremental exercise or brief leg exercise (Bevegård and Shepherd 1966;Green et al 2002aGreen et al , b, 2005Tanaka et al 2006), it is not known how changes in BF of these vessels manifest with an increase in internal temperature during leg exercise.…”

“…Since SkBF increases and muscle BF decreases in the inactive limb during internal temperature elevation with prolonged exercise (Johnson and Rowell 1975), it is hypothesized that BF in the conduit artery and superficial vein of the upper arm increases, but that BF in the deep vein does not change, with a rise in internal temperature during leg exercise. Furthermore, we considered that changes in BF would be related to those in V rather than in D (Ooue et al 2007). …”