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This Article Full Text Full Text (PDF) All Versions of this Article: 291/6/E1250    most recent 00060.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Derave, W. Articles by Hespel, P. Search for Related Content PubMed PubMed Citation Articles by Derave, W. Articles by Hespel, P.

Electrolysis stimulates creatine transport and transporter cell surface expression in incubated mouse skeletal muscle: potential role of ROS

¹Research Centre for Exercise and Health, Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, Katholieke Universiteit Leuven, Leuven, Belgium; and ²Institute of Cell Biology, ETH Zürich, Zurich, Switzerland

Submitted 7 February 2006 ; accepted in final form 30 June 2006

Electrical field stimulation of isolated, incubated rodent skeletal muscles is a frequently used model to study the effects of contractions on muscle metabolism. In this study, this model was used to investigate the effects of electrically stimulated contractions on creatine transport. Soleus and extensor digitorum longus muscles of male NMRI mice (35–50 g) were incubated in an oxygenated Krebs buffer between platinum electrodes. Muscles were exposed to [¹⁴C]creatine for 30 min after either 12 min of repeated tetanic isometric contractions (contractions) or electrical stimulation of only the buffer before incubation of the muscle (electrolysis). Electrolysis was also investigated in the presence of the reactive oxygen species (ROS) scavenging enzymes superoxide dismutase (SOD) and catalase. Both contractions and (to a lesser degree) electrolysis stimulated creatine transport severalfold over basal. The amount of electrolysis, but not contractile activity, induced (determined) creatine transport stimulation. Incubation with SOD and catalase at 100 and 200 U/ml decreased electrolysis-induced creatine transport by 50 and 100%, respectively. The electrolysis effects on creatine uptake were completely inhibited by -guanidino propionic acid, a competitive inhibitor of (creatine for) the creatine transporter (CRT), and were accompanied by increased cell surface expression of CRT. Muscle glucose transport was not affected by electrolysis. The present results indicate that electrical field stimulation of incubated mouse muscles, independently of contractions per se, stimulates creatine transport by a mechanism that depends on electrolysis-induced formation of ROS in the incubation buffer. The increased creatine uptake is paralleled by an increased cell surface expression of the creatine transporter.

reactive oxygen species; exercise; oxidative stress; glucose transport