Inhibition of protein and lipid synthesis in muscle by 2,4-dinitrofluorobenzene, an inhibitor of creatine phosphokinase.

The incorporation of [3H]-valine into protein and [14C]-acetate into lipid was measured in rat diaphragm and hepatocytes after pretreatment of the tissue with 2,4-dinitrofluorobenzene (FDNB), an inhibitor of creatine phosphokinase (CPK) (EC2.7.3.2). The activity of CPK was also measured. Increasing concentrations of FDNB inhibited protein and lipid synthesis in muscle in parallel with the inhibition of CPK activity. In hepatocytes, which have little CPK activity, similar concentrations of FDNB had no effect on protein synthesis and little effect on lipid synthesis. The possible role of CPK and the creatine phosphate shuttle in muscle metabolism is discussed.