【Objective】 To explore the effects and mechanism of sphingosine 1-phosphate (S1P) on differentiation of skeletal myoblast cells into mature myocytes and consequent formation of myotubes in rats. 【Methods】 Primary skeletal myoblast cells in rats were separated and cultured

here we described the roles of S1P in the regulation of differentiation by observing alteration of their appearance under phase contrast microscope and detected for the expression change of muscle-associated gene- myosine and myogenin by immunocytochemistry. Sphingosine kinase inhibitors were used to during S1P on differentiation of myoblast cells. 【Results】 S1P remarkably promoted myotude formation of myoblasts. Induced with S1P for 2-3 days

myotubes started to form. Later on

more and more myotubes appeared

and at the peak on 6-7 days. S1P induced myogenin positive nucleis higher with concentration-dependent form compare with control (P < 0.01). But SphK inhibitors reduce S1P effect on differentiation of myoblast cells(P < 0.01).【Conclusion】 S1P may through sphingosine kinase promote differentiation of skeletal myoblast cells into mature myocytes and formation of myotube.