Muscle samples (about 50 mg) were incubated (Dubnoff incubator) at 25 °C with constant shaking for 60 min in 500 μL of SFC pH 7.8, equilibrated with O2:CO2 (95:5, v/v) in the presence of 0.2 μCi of 1-[14C]-methyl aminoisobutyric acid (60 mCi/mol, Du Pont). Following incubation, the tissue fractions were removed from the medium, rinsed twice in cold incubation buffer (without radiolabeled products), blotted on filter paper and immediately transferred to screw cap tubes containing 1 mL of distilled water, and alternately frozen and boiled three times ( Schein et al., 2005).