TY - JOUR

T1 - Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

AU - Boushel, Robert Christopher

AU - Langberg, H

AU - Green, Sara Marie Ehrenreich

AU - Skovgaard, D

AU - Bulow, J

AU - Kjaer, M

PY - 2000/4/1

Y1 - 2000/4/1

N2 - 1. Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise, and (2) whether blood flow is coupled to oxidative metabolism. 2. Seven individuals performed dynamic plantar flexion from 1 to 9 W. Radial artery and popliteal venous blood were sampled for O2, peritendinous blood flow was determined by 133Xe-washout, calf blood flow by plethysmography, cardiac output by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). 3. Calf blood flow rose 20-fold with exercise, reaching 44 +/- 7 ml (100 g)-1 min-1 (mean +/- s.e.m. ) at 9 W, while Achilles' peritendinous flow increased (7-fold) to 14 +/- 4 ml (100 g)-1 min-1, which was 18 % of the maximal flow established during reactive hyperaemia. SRS-O2 saturation fell both in muscle (from 66 +/- 2 % at rest to 57 +/- 3 %, P <0.05) and in peritendinous regions (58 +/- 4 to 52 +/- 4 %, P <0.05) during exercise along with a rise in leg vascular conductance and microvascular haemoglobin volume, despite elevated systemic vascular resistance. 4. The parallel rise in calf muscle and peritendinous blood flow and fall in O2 saturation during exercise indicate that blood flow is coupled to oxidative metabolism in both tissue regions. Increased leg vascular conductance accompanied by elevated microvascular haemoglobin volume reflect vasodilatation in both muscle and peritendinous regions. However, peak exercise peritendinous blood flow reaches only approximately 20 % of its maximal blood flow capacity.

AB - 1. Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise, and (2) whether blood flow is coupled to oxidative metabolism. 2. Seven individuals performed dynamic plantar flexion from 1 to 9 W. Radial artery and popliteal venous blood were sampled for O2, peritendinous blood flow was determined by 133Xe-washout, calf blood flow by plethysmography, cardiac output by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). 3. Calf blood flow rose 20-fold with exercise, reaching 44 +/- 7 ml (100 g)-1 min-1 (mean +/- s.e.m. ) at 9 W, while Achilles' peritendinous flow increased (7-fold) to 14 +/- 4 ml (100 g)-1 min-1, which was 18 % of the maximal flow established during reactive hyperaemia. SRS-O2 saturation fell both in muscle (from 66 +/- 2 % at rest to 57 +/- 3 %, P <0.05) and in peritendinous regions (58 +/- 4 to 52 +/- 4 %, P <0.05) during exercise along with a rise in leg vascular conductance and microvascular haemoglobin volume, despite elevated systemic vascular resistance. 4. The parallel rise in calf muscle and peritendinous blood flow and fall in O2 saturation during exercise indicate that blood flow is coupled to oxidative metabolism in both tissue regions. Increased leg vascular conductance accompanied by elevated microvascular haemoglobin volume reflect vasodilatation in both muscle and peritendinous regions. However, peak exercise peritendinous blood flow reaches only approximately 20 % of its maximal blood flow capacity.

KW - Achilles Tendon

KW - Adult

KW - Blood Pressure

KW - Cardiac Output

KW - Exercise

KW - Hemodynamics

KW - Hemoglobins

KW - Humans

KW - Leg

KW - Motor Activity

KW - Muscle, Skeletal

KW - Oxygen Consumption

KW - Oxyhemoglobins

KW - Regional Blood Flow

KW - Vascular Resistance

M3 - Journal article

C2 - 10747200

VL - 524 Pt 1

SP - 305

EP - 313

JO - The Journal of Physiology

JF - The Journal of Physiology

SN - 0022-3751

ER -