Abstract
Static exercise increases arterial pressure, heart rate, and ventilation, effects which are believed in part to arise reflexly from a metabolic stimulus in the working muscle. In anesthetized cats, we tested the hypothesis that intra-arterial injections of lactic and hydrochloric acid, which created levels of these substances in muscle similar to those seen during contraction, reflexly increased cardiovascular and ventilatory function. Hydrochloric acid (32 and 57 mM; 1 ml) injected into the arterial supply of the triceps surae decreased intramuscular pH from 7.26 ± 0.05 to 7.17 ± 0.05 (P < 0.01) and reflexly increased arterial pressure (23 ± 7 mmHg; P < 0.01), heart rate (11 ± 2 beats/min; P < 0.001), and ventilation (187 ± 72 ml/min; P < 0.05). Static contraction of the triceps surae decreased intramuscular pH from 7.28 ± 0.06 to 7.13 ± 0.06 (P < 0.01). Lactic acid was more potent in causing reflexes than was equimolar HCl. For example, lactic acid containing 4 mM lactate and 0.87 mM H+ reflexly increased arterial pressure, heart rate, and ventilation, whereas 0.87 mM HCl did not. Intra-arterial sodium lactate (13 and 33 mM) at a neutral pH had no effect on these variables. We conclude that contraction-induced accumulation of H+, especially that arising from lactic acid, might provide a metabolic stimulus to evoke reflex autonomic effects.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 256-263 |
| Number of pages | 8 |
| Journal | Journal of Applied Physiology |
| Volume | 67 |
| Issue number | 1 |
| State | Published - 1989 |
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ASJC Scopus subject areas
- Endocrinology
- Physiology
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Reflex cardiovascular and ventilatory responses to increasing H+ activity in cat hindlimb muscle. / Rotto, D. M.; Stebbins, Charles L; Kaufman, Marc P.
In: Journal of Applied Physiology, Vol. 67, No. 1, 1989, p. 256-263.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Reflex cardiovascular and ventilatory responses to increasing H+ activity in cat hindlimb muscle
AU - Rotto, D. M.
AU - Stebbins, Charles L
AU - Kaufman, Marc P
PY - 1989
Y1 - 1989
N2 - Static exercise increases arterial pressure, heart rate, and ventilation, effects which are believed in part to arise reflexly from a metabolic stimulus in the working muscle. In anesthetized cats, we tested the hypothesis that intra-arterial injections of lactic and hydrochloric acid, which created levels of these substances in muscle similar to those seen during contraction, reflexly increased cardiovascular and ventilatory function. Hydrochloric acid (32 and 57 mM; 1 ml) injected into the arterial supply of the triceps surae decreased intramuscular pH from 7.26 ± 0.05 to 7.17 ± 0.05 (P < 0.01) and reflexly increased arterial pressure (23 ± 7 mmHg; P < 0.01), heart rate (11 ± 2 beats/min; P < 0.001), and ventilation (187 ± 72 ml/min; P < 0.05). Static contraction of the triceps surae decreased intramuscular pH from 7.28 ± 0.06 to 7.13 ± 0.06 (P < 0.01). Lactic acid was more potent in causing reflexes than was equimolar HCl. For example, lactic acid containing 4 mM lactate and 0.87 mM H+ reflexly increased arterial pressure, heart rate, and ventilation, whereas 0.87 mM HCl did not. Intra-arterial sodium lactate (13 and 33 mM) at a neutral pH had no effect on these variables. We conclude that contraction-induced accumulation of H+, especially that arising from lactic acid, might provide a metabolic stimulus to evoke reflex autonomic effects.
AB - Static exercise increases arterial pressure, heart rate, and ventilation, effects which are believed in part to arise reflexly from a metabolic stimulus in the working muscle. In anesthetized cats, we tested the hypothesis that intra-arterial injections of lactic and hydrochloric acid, which created levels of these substances in muscle similar to those seen during contraction, reflexly increased cardiovascular and ventilatory function. Hydrochloric acid (32 and 57 mM; 1 ml) injected into the arterial supply of the triceps surae decreased intramuscular pH from 7.26 ± 0.05 to 7.17 ± 0.05 (P < 0.01) and reflexly increased arterial pressure (23 ± 7 mmHg; P < 0.01), heart rate (11 ± 2 beats/min; P < 0.001), and ventilation (187 ± 72 ml/min; P < 0.05). Static contraction of the triceps surae decreased intramuscular pH from 7.28 ± 0.06 to 7.13 ± 0.06 (P < 0.01). Lactic acid was more potent in causing reflexes than was equimolar HCl. For example, lactic acid containing 4 mM lactate and 0.87 mM H+ reflexly increased arterial pressure, heart rate, and ventilation, whereas 0.87 mM HCl did not. Intra-arterial sodium lactate (13 and 33 mM) at a neutral pH had no effect on these variables. We conclude that contraction-induced accumulation of H+, especially that arising from lactic acid, might provide a metabolic stimulus to evoke reflex autonomic effects.
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UR - http://www.scopus.com/inward/citedby.url?scp=0024363135&partnerID=8YFLogxK
M3 - Article
C2 - 2759951
AN - SCOPUS:0024363135
VL - 67
SP - 256
EP - 263
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 1
ER -