Optimization of Culture Conditions for Determining Protein Synthesis in Myoblasts Using Extracts of Adult Bovine Muscle Treated with Muscle Enhancing Compounds1

The objective of this study was to optimize a methodology in which muscle extracts from cattle are added to growth media and then applied to muscle cultures to determine effects of treating cattle on indirect cellular protein uptake and synthesis. Experiments were designed as 2 × 2 × 2 × 2 factorial arrangement of cell type (C2C12 myoblasts vs. primary bovine muscle cell cultures), growth medium [Dulbecco's Modified Eagle's Medium (DMEM) vs. skeletal muscle cell basal medium), muscle extract buffer (potassium phosphate buffer vs. prerigor extraction), and β-adrenergic agonist treatment of bovine (control vs. treated) to determine differences in protein accretion. Cell type affected amino acid uptake and protein synthesis (P = 0.03); C2C12 myoblasts had a greater 14Camino acid uptake than bovine muscle cell cultures, and bovine muscle cell cultures had greater protein synthesis compared to C2C12 myoblasts (P < 0.05). There was a cell type × β-adrenergic agonist interaction (P = 0.01) for amino acid uptake. Treatment increased amino acid uptake in C2C12 myoblasts compared to control myoblasts (P < 0.05), although uptake was not affected (P > 0.05) by treatment of bovine muscle cell cultures. There was a media × β-adrenergic agonist interaction (P = 0.03) for amino acid uptake. Cells treated with the DMEM β-adrenergic agonist media had a greater amino acid uptake than cells in control DMEM (P < 0.05), whereas there were no differences when placed in skeletal muscle cell basal medium. The use of DMEM with C2C12 myoblasts proved to be the most effective methodology.