TY - JOUR
T1 - Interaction between muscle chemoreflex and muscle mechanoreflex modulation of baroreflex sensitivity during and after human exercise
AU - Carrington, Charlotte
AU - Ubolsakka, Chulee
AU - White, Michael
PY - 2003/1/1
Y1 - 2003/1/1
N2 - The effect of external calf compression on baroreflex sensitivity (BRS) during electrically evoked plantar flexion and postexercise circulatory occlusion (PECO) was studied. Subjects took part in two experimental trials: control and compression. In both trials, electrically evoked isometric plantarflexion (Stim) was performed at 30% maximum voluntary contraction force for 2 min. During compression, a cuff (inflated to 250 mmHg) was applied to the active calf during exercise and PECO. Sequence analysis carried out on the systolic blood pressure responses, and R-wave-R-wave intervals revealed a rightward shift of the regression line along the pressure axis during Stim in both trials. In the control experiment, BRS was significantly (P <0.01) increased from 10.37 +/- 1.87 ms/mmHg during Stim to 12.79 +/- 1.62 ms/ mmHg during PECO. With external compression, BRS was unaltered between Stim (10.84 +/- 1.86 ms/mmHg) and PECO (11.40 +/- 1.54 ms/ mmHg). Because the metabolic conditions were the same in both experiments, the results may best be explained by reactivation of muscle mechanoreceptor activity by external compression during PECO.
AB - The effect of external calf compression on baroreflex sensitivity (BRS) during electrically evoked plantar flexion and postexercise circulatory occlusion (PECO) was studied. Subjects took part in two experimental trials: control and compression. In both trials, electrically evoked isometric plantarflexion (Stim) was performed at 30% maximum voluntary contraction force for 2 min. During compression, a cuff (inflated to 250 mmHg) was applied to the active calf during exercise and PECO. Sequence analysis carried out on the systolic blood pressure responses, and R-wave-R-wave intervals revealed a rightward shift of the regression line along the pressure axis during Stim in both trials. In the control experiment, BRS was significantly (P <0.01) increased from 10.37 +/- 1.87 ms/mmHg during Stim to 12.79 +/- 1.62 ms/ mmHg during PECO. With external compression, BRS was unaltered between Stim (10.84 +/- 1.86 ms/mmHg) and PECO (11.40 +/- 1.54 ms/ mmHg). Because the metabolic conditions were the same in both experiments, the results may best be explained by reactivation of muscle mechanoreceptor activity by external compression during PECO.
KW - cardiovascular control
KW - muscle afferents
KW - isometric exercise
U2 - 10.1152/japplphysiol.00895.2002
DO - 10.1152/japplphysiol.00895.2002
M3 - Article
C2 - 12547840
SN - 1522-1601
VL - 95
SP - 43
EP - 48
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
ER -