Lipid storage and lipolytic capacity.

(A) Cultured myotubes were incubated with 100 µM [1-14C] oleate for 3 h, then the cells were harvested and total lipid extracted. Total lipid synthesis was measured as incorporation of radiolabel into total cellular lipids. (B) Lipid intermediates species such as phospholipids (PL), diacylglycerol (DAG), and triacylglycerol (TAG) rates of synthesis were measured by thin-layer chromatography. (C) Lipolysis measured as glycerol release was determined by subtracting baseline values to values during the stimulation with 1 µM of isoproterenol (a non-selective β-adrenergic agonist). The graph represents the changes in lipolysis at baseline in response to isoproterenol in control and PFI conditions. Data are expressed as mean ± SEM of 4 separate experiments. * p<0.05, ** p<0.01 versus control.