FIGURE 3.

Mechanical stimulation increases DAG and membrane DGK activity. Mouse EDL muscles were held at Lo in an ex vivo organ culture system and treated as follows. A, prelabeled with [³H]myristic acid for 2 h and then subjected to 15 or 90 min of a stretch (Stretch +) or control condition (Stretch −). The concentration of ³H-labeled DAG was measured and expressed as a percentage of values obtained in the control samples. B, subjected to 15 min of the stretch or control conditions and then separated into cytosolic (Cyt) and membrane (Memb) fractions. The different fractions were then subjected to Western blot analysis for Na⁺/K⁺-ATPase and LDH. C and D, subjected to 5–90 min of the stretch or control conditions, and then DGK activity (³²P-PA) in the membrane fraction (C) and whole lysates (D) was measured and expressed as a percentage of the values obtained in the time-matched control samples. All values are presented as the mean ± S.E. (n = 3–4 per group). *, Significantly different from the time-matched control group; p ≤ 0.05.