Abstract
Catecholamines were infused intravenously for 45 min into pentobarbital sodium-anesthetized rabbits. Physiologically low-dose epinephrine (0.125 μg.min-1.kg-1) decreased medial gastrocnemius (MG) surface pH (SpH) 0.16 ± 0.03 (SD) (P < 0.001) to a low of 7.25 ± 0.11 and soleus (S) SpH 0.09 ± 0.04 (P < 0.01) to a low of 7.33 ± 0.08 without changing blood pressure significantly. Surface temperature measurements suggested a statistically insignificant small increase in local blood flow in both muscles. With 1.25 μg.min-1.kg-1 epinephrine, MG SpH decreased 0.22 ± 0.05 (P < 0.001) to a low of 7.17 ± 0.06 and S SpH decreased 0.10 ± 0.05 (P < 0.02) to a low of 7.26 ± 0.04. The MG SpH decrease exceeded the S SpH decrease in each experiment for both epinephrine infusion levels, and the incremental difference was significantly greater (P < 0.02) with the higher dose, demonstrating a dose-response effect more pronounced for glycolytic compared with oxidative fibers. Norepinephrine infusions of 1.25 and 2.5 μg.min-1.kg-1 did not change SpH of either muscle significantly, despite increases in blood pressure of 10 ± 3 (P < 0.002) and 19 ± 10 mmHg (P < 0.02), respectively.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1667-1672 |
| Number of pages | 6 |
| Journal | Journal of Applied Physiology Respiratory Environmental and Exercise Physiology |
| Volume | 54 |
| Issue number | 6 |
| State | Published - 1983 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Endocrinology
- Physiology
Cite this
Surface pH responses of muscles of different fiber-type composition to catecholamines. / Kost, Gerald J.
In: Journal of Applied Physiology Respiratory Environmental and Exercise Physiology, Vol. 54, No. 6, 1983, p. 1667-1672.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Surface pH responses of muscles of different fiber-type composition to catecholamines
AU - Kost, Gerald J
PY - 1983
Y1 - 1983
N2 - Catecholamines were infused intravenously for 45 min into pentobarbital sodium-anesthetized rabbits. Physiologically low-dose epinephrine (0.125 μg.min-1.kg-1) decreased medial gastrocnemius (MG) surface pH (SpH) 0.16 ± 0.03 (SD) (P < 0.001) to a low of 7.25 ± 0.11 and soleus (S) SpH 0.09 ± 0.04 (P < 0.01) to a low of 7.33 ± 0.08 without changing blood pressure significantly. Surface temperature measurements suggested a statistically insignificant small increase in local blood flow in both muscles. With 1.25 μg.min-1.kg-1 epinephrine, MG SpH decreased 0.22 ± 0.05 (P < 0.001) to a low of 7.17 ± 0.06 and S SpH decreased 0.10 ± 0.05 (P < 0.02) to a low of 7.26 ± 0.04. The MG SpH decrease exceeded the S SpH decrease in each experiment for both epinephrine infusion levels, and the incremental difference was significantly greater (P < 0.02) with the higher dose, demonstrating a dose-response effect more pronounced for glycolytic compared with oxidative fibers. Norepinephrine infusions of 1.25 and 2.5 μg.min-1.kg-1 did not change SpH of either muscle significantly, despite increases in blood pressure of 10 ± 3 (P < 0.002) and 19 ± 10 mmHg (P < 0.02), respectively.
AB - Catecholamines were infused intravenously for 45 min into pentobarbital sodium-anesthetized rabbits. Physiologically low-dose epinephrine (0.125 μg.min-1.kg-1) decreased medial gastrocnemius (MG) surface pH (SpH) 0.16 ± 0.03 (SD) (P < 0.001) to a low of 7.25 ± 0.11 and soleus (S) SpH 0.09 ± 0.04 (P < 0.01) to a low of 7.33 ± 0.08 without changing blood pressure significantly. Surface temperature measurements suggested a statistically insignificant small increase in local blood flow in both muscles. With 1.25 μg.min-1.kg-1 epinephrine, MG SpH decreased 0.22 ± 0.05 (P < 0.001) to a low of 7.17 ± 0.06 and S SpH decreased 0.10 ± 0.05 (P < 0.02) to a low of 7.26 ± 0.04. The MG SpH decrease exceeded the S SpH decrease in each experiment for both epinephrine infusion levels, and the incremental difference was significantly greater (P < 0.02) with the higher dose, demonstrating a dose-response effect more pronounced for glycolytic compared with oxidative fibers. Norepinephrine infusions of 1.25 and 2.5 μg.min-1.kg-1 did not change SpH of either muscle significantly, despite increases in blood pressure of 10 ± 3 (P < 0.002) and 19 ± 10 mmHg (P < 0.02), respectively.
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M3 - Article
VL - 54
SP - 1667
EP - 1672
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 6
ER -