Communication Magnesium deficiency stimulated mRNA expression of tumor necrosis factor-a in skeletal muscle of rats

Tumor necrosis factor-a (TNF-a) has been known to induce insulin resistance in adipose tissue and skeletal muscle as a local and systemic factor. The objective of this study was to determine the effect of magnesium deficiency on mRNA expression of TNF-a in the tissues related to hypoglycemic action of insulin, such as skeletal muscle, adipose tissue, and liver, and on plasma TNF-a concentration. Twelve male rats were divided into 2 groups and given a magnesium-deficient diet or control diet for 4 weeks. Although magnesium deficiency did not affect the expression of TNF-a mRNA in liver and adipose tissue, magnesium deficiency increased TNF-a mRNA expression in skeletal muscle. Plasma TNF-a was higher in the magnesium-deficient diet group than in the control group, but the circulating TNF-a level was unlikely to be sufficient for causing insulin resistance in the magnesium-deficient rat. This study suggests that magnesium deficiency stimulates TNF-a production in skeletal muscle, which may cause local insulin resistance in rats.