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Differential contribution of ACh-muscarinic and β-adrenergic receptors to vasodilatation in noncontracting muscle during voluntary one-legged exercise.

Ishii K, Matsukawa K, Liang N, Endo K, Idesako M, Hamada H, Kataoka T, Ueno K, Watanabe T, Takahashi M - Physiol Rep (2014)

Bottom Line: Propranolol also failed to affect the initial increases in femoral blood flow and vascular conductance of nonexercising leg but significantly attenuated (P < 0.05) their later increases during exercise.Subsequent atropine (10-15 μg/kg iv) abolished the initial increases in Oxy-Hb of both VL muscles.It is likely that the rapid cholinergic and delayed β-adrenergic vasodilator mechanisms cooperate to increase muscle blood flow during exercise.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

No MeSH data available.


Related in: MedlinePlus

(A) The time courses of the changes in heart rate (HR), and mean arterial blood pressure (MAP), and signal of oxygenated hemoglobin (Oxy‐Hb) of noncontracting and contracting vastus lateralis (VL) muscle during voluntary one‐legged cycling at 35% of maximal voluntary effort (MVE) in the control (○, CON), propranolol (, PROP), and atropine and propranolol (●, ATR+PROP) conditions (n = 10 subjects). The relative percent changes in Oxy‐Hb were determined by identifying the zero level with muscle ischemia. Each variable was sequentially calculated every 1 s. Vertical dotted lines indicate the onset and end of one‐legged exercise. Yellow areas indicate the early (5–20 s) and later period (45–60 s) of the exercise. A square bar indicates the duration of exercise. (B) The initial and later changes in HR, MAP, and Oxy‐Hb of noncontracting and contracting VL muscle during one‐legged cycling in the CON (□), PROP () and ATR+PROP (■) (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) among the conditions (CON vs. PROP vs. ATR+PROP). N.S., not significant.
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fig01: (A) The time courses of the changes in heart rate (HR), and mean arterial blood pressure (MAP), and signal of oxygenated hemoglobin (Oxy‐Hb) of noncontracting and contracting vastus lateralis (VL) muscle during voluntary one‐legged cycling at 35% of maximal voluntary effort (MVE) in the control (○, CON), propranolol (, PROP), and atropine and propranolol (●, ATR+PROP) conditions (n = 10 subjects). The relative percent changes in Oxy‐Hb were determined by identifying the zero level with muscle ischemia. Each variable was sequentially calculated every 1 s. Vertical dotted lines indicate the onset and end of one‐legged exercise. Yellow areas indicate the early (5–20 s) and later period (45–60 s) of the exercise. A square bar indicates the duration of exercise. (B) The initial and later changes in HR, MAP, and Oxy‐Hb of noncontracting and contracting VL muscle during one‐legged cycling in the CON (□), PROP () and ATR+PROP (■) (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) among the conditions (CON vs. PROP vs. ATR+PROP). N.S., not significant.

Mentions: The Oxy‐Hb of each of noncontracting and contracting VL muscle increased at the early period (5–20 s) of one‐legged cycling without any drugs as shown in Fig. 1A. It is noted that the initial increases in the Oxy‐Hb appeared simultaneously with tachycardia but were unrelated to the MAP response and that they tended to persist after propranolol but disappeared following subsequent atropine and propranolol. Figure 1B summarizes the effects of propranolol on the initial responses in HR, MAP, and the Oxy‐Hb of the noncontracting and contracting VL muscles. The initial increase in HR was blunted (P <0.05) by propranolol and further by subsequent atropine and propranolol. A slight rise in MAP was observed in the control and propranolol conditions, although the MAP changes were not statistically significant (P >0.05). The initial increase of 5 ± 1% in Oxy‐Hb of the noncontracting muscle was slightly attenuated by propranolol (P <0.05). The initial increase in Oxy‐Hb was abolished by subsequent atropine and propranolol and turned out to be a decreased response. In the contracting muscle, the initial increase in Oxy‐Hb was not affected by propranolol but abolished by subsequent atropine and propranolol. On the whole, the initial Oxy‐Hb of both muscles tended to respond similarly in all conditions.


Differential contribution of ACh-muscarinic and β-adrenergic receptors to vasodilatation in noncontracting muscle during voluntary one-legged exercise.

Ishii K, Matsukawa K, Liang N, Endo K, Idesako M, Hamada H, Kataoka T, Ueno K, Watanabe T, Takahashi M - Physiol Rep (2014)

(A) The time courses of the changes in heart rate (HR), and mean arterial blood pressure (MAP), and signal of oxygenated hemoglobin (Oxy‐Hb) of noncontracting and contracting vastus lateralis (VL) muscle during voluntary one‐legged cycling at 35% of maximal voluntary effort (MVE) in the control (○, CON), propranolol (, PROP), and atropine and propranolol (●, ATR+PROP) conditions (n = 10 subjects). The relative percent changes in Oxy‐Hb were determined by identifying the zero level with muscle ischemia. Each variable was sequentially calculated every 1 s. Vertical dotted lines indicate the onset and end of one‐legged exercise. Yellow areas indicate the early (5–20 s) and later period (45–60 s) of the exercise. A square bar indicates the duration of exercise. (B) The initial and later changes in HR, MAP, and Oxy‐Hb of noncontracting and contracting VL muscle during one‐legged cycling in the CON (□), PROP () and ATR+PROP (■) (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) among the conditions (CON vs. PROP vs. ATR+PROP). N.S., not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4255809&req=5

fig01: (A) The time courses of the changes in heart rate (HR), and mean arterial blood pressure (MAP), and signal of oxygenated hemoglobin (Oxy‐Hb) of noncontracting and contracting vastus lateralis (VL) muscle during voluntary one‐legged cycling at 35% of maximal voluntary effort (MVE) in the control (○, CON), propranolol (, PROP), and atropine and propranolol (●, ATR+PROP) conditions (n = 10 subjects). The relative percent changes in Oxy‐Hb were determined by identifying the zero level with muscle ischemia. Each variable was sequentially calculated every 1 s. Vertical dotted lines indicate the onset and end of one‐legged exercise. Yellow areas indicate the early (5–20 s) and later period (45–60 s) of the exercise. A square bar indicates the duration of exercise. (B) The initial and later changes in HR, MAP, and Oxy‐Hb of noncontracting and contracting VL muscle during one‐legged cycling in the CON (□), PROP () and ATR+PROP (■) (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) among the conditions (CON vs. PROP vs. ATR+PROP). N.S., not significant.
Mentions: The Oxy‐Hb of each of noncontracting and contracting VL muscle increased at the early period (5–20 s) of one‐legged cycling without any drugs as shown in Fig. 1A. It is noted that the initial increases in the Oxy‐Hb appeared simultaneously with tachycardia but were unrelated to the MAP response and that they tended to persist after propranolol but disappeared following subsequent atropine and propranolol. Figure 1B summarizes the effects of propranolol on the initial responses in HR, MAP, and the Oxy‐Hb of the noncontracting and contracting VL muscles. The initial increase in HR was blunted (P <0.05) by propranolol and further by subsequent atropine and propranolol. A slight rise in MAP was observed in the control and propranolol conditions, although the MAP changes were not statistically significant (P >0.05). The initial increase of 5 ± 1% in Oxy‐Hb of the noncontracting muscle was slightly attenuated by propranolol (P <0.05). The initial increase in Oxy‐Hb was abolished by subsequent atropine and propranolol and turned out to be a decreased response. In the contracting muscle, the initial increase in Oxy‐Hb was not affected by propranolol but abolished by subsequent atropine and propranolol. On the whole, the initial Oxy‐Hb of both muscles tended to respond similarly in all conditions.

Bottom Line: Propranolol also failed to affect the initial increases in femoral blood flow and vascular conductance of nonexercising leg but significantly attenuated (P < 0.05) their later increases during exercise.Subsequent atropine (10-15 μg/kg iv) abolished the initial increases in Oxy-Hb of both VL muscles.It is likely that the rapid cholinergic and delayed β-adrenergic vasodilator mechanisms cooperate to increase muscle blood flow during exercise.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

No MeSH data available.


Related in: MedlinePlus