Abstract
We examined the effects of exercise conditioning on muscle sympathetic nerve activity (MSNA) during handgrip and post-handgrip circulatory arrest (PHG-CA). Two conditioning stimuli were studied: forearm dominance and bodybuilding. Static handgrip at 30% maximal voluntary contraction followed by PHG-CA led to a rise in MSNA smaller in dominant than in nondominant forearms (99% vs. 222%; P < 0.02) and in body builders than in normal volunteers (28% vs. 244%; P < 0.01). Separate 31P NMR experiments showed no effect of dominance on forearm pH but a pH in bodybuilders higher (6.88) than in normal volunteers (6.79; P < 0.02) during PHG-CA. Our second goal was to determine if factors besides attenuated [H+] contribute to this conditioning effect. If differences in MSNA during exercise were noted at the same pH, then other mechanisms must contribute to the training effect. We measured MSNA during ischemic fatiguing handgrip. No dominance or bodybuilding effect on pH was noted. However, we noted increases in MSNA smaller in dominant than nondominant forearms (212% vs. 322%; P < 0.02) and in bodybuilders than in normal volunteers (161% vs. 334%; P < 0.01). In summary, MSNA responses were less during exercise of conditioned limbs. Factors aside from a lessening of muscle acidosis contribute to this effect.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1875-1884 |
| Number of pages | 10 |
| Journal | Journal of Clinical Investigation |
| Volume | 89 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jan 1 1992 |
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- Medicine(all)
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Hydrogen ion concentration is not the sole determinant of muscle metaboreceptor responses in humans. / Sinoway, Lawrence; Rea, R. F.; Mosher, Timothy; Smith, M. B.; Mark, A. L.
In: Journal of Clinical Investigation, Vol. 89, No. 6, 01.01.1992, p. 1875-1884.Research output: Contribution to journal › Article
TY - JOUR
T1 - Hydrogen ion concentration is not the sole determinant of muscle metaboreceptor responses in humans
AU - Sinoway, Lawrence
AU - Rea, R. F.
AU - Mosher, Timothy
AU - Smith, M. B.
AU - Mark, A. L.
PY - 1992/1/1
Y1 - 1992/1/1
N2 - We examined the effects of exercise conditioning on muscle sympathetic nerve activity (MSNA) during handgrip and post-handgrip circulatory arrest (PHG-CA). Two conditioning stimuli were studied: forearm dominance and bodybuilding. Static handgrip at 30% maximal voluntary contraction followed by PHG-CA led to a rise in MSNA smaller in dominant than in nondominant forearms (99% vs. 222%; P < 0.02) and in body builders than in normal volunteers (28% vs. 244%; P < 0.01). Separate 31P NMR experiments showed no effect of dominance on forearm pH but a pH in bodybuilders higher (6.88) than in normal volunteers (6.79; P < 0.02) during PHG-CA. Our second goal was to determine if factors besides attenuated [H+] contribute to this conditioning effect. If differences in MSNA during exercise were noted at the same pH, then other mechanisms must contribute to the training effect. We measured MSNA during ischemic fatiguing handgrip. No dominance or bodybuilding effect on pH was noted. However, we noted increases in MSNA smaller in dominant than nondominant forearms (212% vs. 322%; P < 0.02) and in bodybuilders than in normal volunteers (161% vs. 334%; P < 0.01). In summary, MSNA responses were less during exercise of conditioned limbs. Factors aside from a lessening of muscle acidosis contribute to this effect.
AB - We examined the effects of exercise conditioning on muscle sympathetic nerve activity (MSNA) during handgrip and post-handgrip circulatory arrest (PHG-CA). Two conditioning stimuli were studied: forearm dominance and bodybuilding. Static handgrip at 30% maximal voluntary contraction followed by PHG-CA led to a rise in MSNA smaller in dominant than in nondominant forearms (99% vs. 222%; P < 0.02) and in body builders than in normal volunteers (28% vs. 244%; P < 0.01). Separate 31P NMR experiments showed no effect of dominance on forearm pH but a pH in bodybuilders higher (6.88) than in normal volunteers (6.79; P < 0.02) during PHG-CA. Our second goal was to determine if factors besides attenuated [H+] contribute to this conditioning effect. If differences in MSNA during exercise were noted at the same pH, then other mechanisms must contribute to the training effect. We measured MSNA during ischemic fatiguing handgrip. No dominance or bodybuilding effect on pH was noted. However, we noted increases in MSNA smaller in dominant than nondominant forearms (212% vs. 322%; P < 0.02) and in bodybuilders than in normal volunteers (161% vs. 334%; P < 0.01). In summary, MSNA responses were less during exercise of conditioned limbs. Factors aside from a lessening of muscle acidosis contribute to this effect.
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U2 - 10.1172/JCI115792
DO - 10.1172/JCI115792
M3 - Article
VL - 89
SP - 1875
EP - 1884
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
SN - 0021-9738
IS - 6
ER -