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This Article Full Text Full Text (PDF) All Versions of this Article: 287/6/E1064    most recent 00364.2003v1 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 Morita, N. Articles by Kawaguchi, H. Search for Related Content PubMed PubMed Citation Articles by Morita, N. Articles by Kawaguchi, H.

Exposure to pressure stimulus enhances succinate dehydrogenase activity in L6 myoblasts

Departments of ¹Laboratory Medicine and ²Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo 060-8638; ³Health Sciences University of Hokkaido, Toubetsu 061-0293; and ⁴Faculty of Pharmaceutical Sciences, Aomori University, Aomori 030-0943, Japan

Submitted 13 August 2003 ; accepted in final form 27 July 2004

Contraction of skeletal muscle generates pressure stimuli to intramuscular tissues. However, the effects of pressure stimuli, other than those created by electricity or nerve impulse, on physiological and biochemical responses in skeletal muscles are unknown. The purpose of this study is to examine the effects of a pure pressure stimulus on metabolic responses in a skeletal muscle cell line. Atmospheric pressure was applied to L6 myoblasts using an original apparatus. Succinate dehydrogenase (SDH) activity was evaluated by colorimetric assay using tetrazolium monosodium salt. The amounts of 2-deoxy-[³H]glucose uptake and lactate release were measured. SDH activity was 2.6- to 2.9-fold higher in pressurized L6 cells than in nonpressurized L6 cells (P < 0.01), and 2-deoxy-[³H]glucose uptake was 2.2-fold higher (P < 0.001). In addition, the amount of released lactate decreased from 6.8 to 3.7 µmol/dish when pressure was applied (P < 0.001). In contrast, the intracellular lactate contents of the pressurized cells were higher than those of nonpressurized cells (P < 0.01). However, the total amount of released lactate and intracellular lactate was lower in the pressurized cells than in nonpressurized cells. These findings demonstrate that a pure pressure stimulus enhances aerobic metabolism in L6 skeletal muscle cells and raise the possibility that elevated intramuscular pressure during muscle activity may be an important factor in stimulating oxidative metabolic responses in skeletal muscles.

mechanical pressure; aerobic metabolism; lactate; glucose uptake