Intracellular β2-adrenergic receptor signaling specificity in mouse skeletal muscle in response to single-dose β2-agonist clenbuterol treatment and acute exercise

Shogo Sato,Daisuke Inoue,Kaoru Tachiyashiki,Ryosuke Mitsuhashi,Takako Kizaki,Kazuhiko Imaizumi,Hideki Ohno,Ken Shirato

doi:10.1007/s12576-013-0253-z

Shogo Sato, Daisuke Inoue + Show 6 more

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https://doi.org/10.1007/s12576-013-0253-z

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Abstract

The aim of this study was to clarify the intracellular β2-adrenergic receptor signaling specificity in mouse slow-twitch soleus and fast-twitch tibialis anterior (TA) muscles, resulting from single-dose β2-agonist clenbuterol treatment and acute exercise. At 1, 4, and 24 h after single-dose treatment with clenbuterol or after acute running exercise, the soleus and TA muscles were isolated and subjected to analysis. The phosphorylation of p38 mitogen-activated protein kinase (MAPK) increased after single-dose clenbuterol treatment and acute exercise in the soleus muscle but not in the TA muscle. Although there was no change in the phosphorylation of Akt after acute exercise in either muscle, phosphorylation of Akt in the soleus muscle increased after single-dose clenbuterol treatment, whereas that in the TA muscle remained unchanged. These results suggest that p38 MAPK and Akt pathways play a functional role in the adaptation to clenbuterol treatment and exercise, particularly in slow-twitch muscles.

Highlights

The aim of this study was to clarify the intracellular b2-adrenergic receptor signaling specificity in mouse slow-twitch soleus and fast-twitch tibialis anterior (TA) muscles, resulting from single-dose b2-agonist clenbuterol treatment and acute exercise
We first investigated whether the phosphorylation of cAMP response element binding protein (CREB) in skeletal muscles is changed by single-dose clenbuterol treatment and acute exercise, but there was no change in the phosphorylation of CREB in the soleus and TA muscles at 1–24 h after singledose clenbuterol treatment and acute exercise
6-week clenbuterol treatment increased the weight of TA muscle, to 115 %, and 6-week voluntary exercise increased the weight of soleus muscle, to 129 %, there was no change in the phosphorylation of p38 mitogenactivated protein kinase (MAPK) and Akt in the soleus or TA muscle

Summary

Introduction

The aim of this study was to clarify the intracellular b2-adrenergic receptor signaling specificity in mouse slow-twitch soleus and fast-twitch tibialis anterior (TA) muscles, resulting from single-dose b2-agonist clenbuterol treatment and acute exercise. There was no change in the phosphorylation of Akt after acute exercise in either muscle, phosphorylation of Akt in the soleus muscle increased after single-dose clenbuterol treatment, whereas that in the TA muscle remained unchanged These results suggest that p38 MAPK and Akt pathways play a functional role in the adaptation to clenbuterol treatment and exercise, in slow-twitch muscles. In the present study, we investigated the acute effects of clenbuterol treatment and exercise on the phosphorylation of CREB, p38 MAPK and Akt in mouse skeletal muscles to clarify the intracellular signaling specificity in the typical slow-twitch soleus and fast-twitch tibialis anterior (TA) muscles

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