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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 and C) The time courses of the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP (taken as the propranolol‐ (○) or atropine and propranolol‐ (●) sensitive component of the Oxy‐Hb responses) of noncontracting (A) and contracting VL muscle (C) during voluntary one‐legged cycling at 35% MVE (n = 10 subjects). Dashed gray lines indicate the ΔOxy‐HbATR (taken as the atropine‐sensitive component of the Oxy‐Hb responses) obtained from Ishii et al. (2013). Solid gray lines indicate the summation of ΔOxy‐HbPROP and ΔOxy‐HbATR. (B and D) The initial and later changes in ΔOxy‐HbPROP (□) and ΔOxy‐HbATR+PROP (■) of noncontracting (B) and contracting VL muscle (D) during one‐legged cycling (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) between ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP.
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fig02: (A and C) The time courses of the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP (taken as the propranolol‐ (○) or atropine and propranolol‐ (●) sensitive component of the Oxy‐Hb responses) of noncontracting (A) and contracting VL muscle (C) during voluntary one‐legged cycling at 35% MVE (n = 10 subjects). Dashed gray lines indicate the ΔOxy‐HbATR (taken as the atropine‐sensitive component of the Oxy‐Hb responses) obtained from Ishii et al. (2013). Solid gray lines indicate the summation of ΔOxy‐HbPROP and ΔOxy‐HbATR. (B and D) The initial and later changes in ΔOxy‐HbPROP (□) and ΔOxy‐HbATR+PROP (■) of noncontracting (B) and contracting VL muscle (D) during one‐legged cycling (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) between ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP.

Mentions: The time courses of the ΔOxy‐HbPROP (defined as the propranolol‐sensitive component) and ΔOxy‐HbATR+PROP (defined as the atropine and propranolol‐sensitive component) during one‐legged cycling are shown in Fig. 2. The ΔOxy‐HbPROP of the noncontracting VL muscle increased gradually during the later period of the exercise, whereas the ΔOxy‐HbATR+PROP of the muscle started to increase from the early period of the exercise and continued to increase until the end of the exercise (Fig. 2A). In the contracting VL muscle (Fig. 2C), the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP also increased with the similar time courses and magnitudes as those observed in the noncontracting muscle. It was of interest that the ΔOxy‐HbATR+PROP response matched an algebraic summation of ΔOxy‐HbPROP and ΔOxy‐HbATR [= (ΔCON‐Oxy‐Hb) − (ΔATR‐Oxy‐Hb), cited from Ishii et al. (2013)] in either VL muscle (Fig. 2A and C). Figure 2B and D summarize the initial and later changes in the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP of the noncontracting and contracting muscles. The initial and later responses in the ΔOxy‐HbPROP were not different (P >0.05) between the noncontracting and contracting muscles: the ΔOxy‐HbPROP did not change significantly (P >0.05) from the baseline at the early period of exercise, whereas the ΔOxy‐HbPROP increased by 5–6% (P <0.05) during the later period. The initial and later increases in the ΔOxy‐HbATR+PROP were much greater (P <0.05) than the ΔOxy‐HbPROP responses and were identical between both muscles (Fig. 2B and D).


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 and C) The time courses of the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP (taken as the propranolol‐ (○) or atropine and propranolol‐ (●) sensitive component of the Oxy‐Hb responses) of noncontracting (A) and contracting VL muscle (C) during voluntary one‐legged cycling at 35% MVE (n = 10 subjects). Dashed gray lines indicate the ΔOxy‐HbATR (taken as the atropine‐sensitive component of the Oxy‐Hb responses) obtained from Ishii et al. (2013). Solid gray lines indicate the summation of ΔOxy‐HbPROP and ΔOxy‐HbATR. (B and D) The initial and later changes in ΔOxy‐HbPROP (□) and ΔOxy‐HbATR+PROP (■) of noncontracting (B) and contracting VL muscle (D) during one‐legged cycling (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) between ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
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fig02: (A and C) The time courses of the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP (taken as the propranolol‐ (○) or atropine and propranolol‐ (●) sensitive component of the Oxy‐Hb responses) of noncontracting (A) and contracting VL muscle (C) during voluntary one‐legged cycling at 35% MVE (n = 10 subjects). Dashed gray lines indicate the ΔOxy‐HbATR (taken as the atropine‐sensitive component of the Oxy‐Hb responses) obtained from Ishii et al. (2013). Solid gray lines indicate the summation of ΔOxy‐HbPROP and ΔOxy‐HbATR. (B and D) The initial and later changes in ΔOxy‐HbPROP (□) and ΔOxy‐HbATR+PROP (■) of noncontracting (B) and contracting VL muscle (D) during one‐legged cycling (n = 10 subjects). *Significant difference (P <0.05) from the baseline. †Significant difference (P <0.05) between ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP.
Mentions: The time courses of the ΔOxy‐HbPROP (defined as the propranolol‐sensitive component) and ΔOxy‐HbATR+PROP (defined as the atropine and propranolol‐sensitive component) during one‐legged cycling are shown in Fig. 2. The ΔOxy‐HbPROP of the noncontracting VL muscle increased gradually during the later period of the exercise, whereas the ΔOxy‐HbATR+PROP of the muscle started to increase from the early period of the exercise and continued to increase until the end of the exercise (Fig. 2A). In the contracting VL muscle (Fig. 2C), the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP also increased with the similar time courses and magnitudes as those observed in the noncontracting muscle. It was of interest that the ΔOxy‐HbATR+PROP response matched an algebraic summation of ΔOxy‐HbPROP and ΔOxy‐HbATR [= (ΔCON‐Oxy‐Hb) − (ΔATR‐Oxy‐Hb), cited from Ishii et al. (2013)] in either VL muscle (Fig. 2A and C). Figure 2B and D summarize the initial and later changes in the ΔOxy‐HbPROP and ΔOxy‐HbATR+PROP of the noncontracting and contracting muscles. The initial and later responses in the ΔOxy‐HbPROP were not different (P >0.05) between the noncontracting and contracting muscles: the ΔOxy‐HbPROP did not change significantly (P >0.05) from the baseline at the early period of exercise, whereas the ΔOxy‐HbPROP increased by 5–6% (P <0.05) during the later period. The initial and later increases in the ΔOxy‐HbATR+PROP were much greater (P <0.05) than the ΔOxy‐HbPROP responses and were identical between both muscles (Fig. 2B and D).

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