Exercise-induced increase in interstitial bradykinin and adenosine concentrations in skeletal muscle and peritendinous tissue in humans

TY - JOUR

T1 - Exercise-induced increase in interstitial bradykinin and adenosine concentrations in skeletal muscle and peritendinous tissue in humans

AU - Langberg, H

AU - Bjørn, C

AU - Boushel, Robert Christopher

AU - Hellsten, Y

AU - Kjaer, M

N1 - PUF 2002 5200 091

PY - 2002/8/1

Y1 - 2002/8/1

N2 - Bradykinin is known to cause vasodilatation in resistance vessels and may, together with adenosine, be an important regulator of tissue blood flow during exercise. Whether tissue concentrations of bradykinin change with exercise in skeletal muscle and tendon-related connective tissue has not yet been established. Microdialysis (molecular mass cut-off 5 kDa) was performed simultaneously in calf muscle and peritendinous Achilles tissue at rest and during 10 min periods of incremental (0.75 W, 2 W, 3.5 W and 4.75 W) dynamic plantar flexion exercise in 10 healthy individuals (mean age 27 years, range 22-33 years). Interstitial bradykinin and adenosine concentrations were determined using an internal reference to determine relative recovery ([2,3,prolyl-3,4-(3)H(N)]-bradykinin and [2-(3)H]-adenosine). Bradykinin and adenosine recovery were closely related and in the range of 30-50 %. The interstitial concentration of bradykinin rose in response to exercise both in skeletal muscle (from 23.1 +/- 4.9 nmol l(-1) to 110.5 +/- 37.9 nmol l(-1); P <0.05) and in the peritendinous tissue (from 27.7 +/- 7.8 nmol l(-1) to 105.0 +/- 37.9 nmol l(-1); P <0.05). In parallel, the adenosine concentration increased both in muscle (from 0.48 +/- 0.07 micromol l(-1) to 1.59 +/- 0.35 micromol l(-1); P <0.05) and around the tendon (from 0.33 +/- 0.03 micromol l(-1) to 0.86 +/- 0.16 micromol l(-1); P <0.05). In conclusion, the data show that muscular activity increases the interstitial concentrations of bradykinin and adenosine in both skeletal muscle and the connective tissue around its adjacent tendon. These findings support a role for bradykinin and adenosine in exercise-induced hyperaemia in skeletal muscle and suggest that bradykinin and adenosine are potential regulators of blood flow in peritendinous tissue.

AB - Bradykinin is known to cause vasodilatation in resistance vessels and may, together with adenosine, be an important regulator of tissue blood flow during exercise. Whether tissue concentrations of bradykinin change with exercise in skeletal muscle and tendon-related connective tissue has not yet been established. Microdialysis (molecular mass cut-off 5 kDa) was performed simultaneously in calf muscle and peritendinous Achilles tissue at rest and during 10 min periods of incremental (0.75 W, 2 W, 3.5 W and 4.75 W) dynamic plantar flexion exercise in 10 healthy individuals (mean age 27 years, range 22-33 years). Interstitial bradykinin and adenosine concentrations were determined using an internal reference to determine relative recovery ([2,3,prolyl-3,4-(3)H(N)]-bradykinin and [2-(3)H]-adenosine). Bradykinin and adenosine recovery were closely related and in the range of 30-50 %. The interstitial concentration of bradykinin rose in response to exercise both in skeletal muscle (from 23.1 +/- 4.9 nmol l(-1) to 110.5 +/- 37.9 nmol l(-1); P <0.05) and in the peritendinous tissue (from 27.7 +/- 7.8 nmol l(-1) to 105.0 +/- 37.9 nmol l(-1); P <0.05). In parallel, the adenosine concentration increased both in muscle (from 0.48 +/- 0.07 micromol l(-1) to 1.59 +/- 0.35 micromol l(-1); P <0.05) and around the tendon (from 0.33 +/- 0.03 micromol l(-1) to 0.86 +/- 0.16 micromol l(-1); P <0.05). In conclusion, the data show that muscular activity increases the interstitial concentrations of bradykinin and adenosine in both skeletal muscle and the connective tissue around its adjacent tendon. These findings support a role for bradykinin and adenosine in exercise-induced hyperaemia in skeletal muscle and suggest that bradykinin and adenosine are potential regulators of blood flow in peritendinous tissue.

KW - Achilles Tendon

KW - Adenosine

KW - Adult

KW - Bradykinin

KW - Connective Tissue

KW - Exercise

KW - Extracellular Space

KW - Female

KW - Humans

KW - Male

KW - Muscle, Skeletal

KW - Osmolar Concentration

U2 - 10.1113/jphysiol.2002.018077

DO - 10.1113/jphysiol.2002.018077

M3 - Journal article

C2 - 12154194

SN - 0022-3751

VL - 542

SP - 977

EP - 983

JO - The Journal of Physiology

JF - The Journal of Physiology

IS - 3

ER -