Aim. The purpose of present study was to study the effect of 8 weeks resistance training on plasma Sphingosine-1-phosphate (S1P) level and gene expression of S1P receptors in skeletal muscles of male Wistar rat. Methods. In this study 24 (8 week-old) male Wistar rats (190-250 gr) were divided randomly to a control (N.=12) and a training (N.=12) group. Resistance ladder was 1 meter height with 2 cm grid ladder. The content of plasma S1P and relative mRNA expression of S1P receptors were determined by high pressure liquid chromatography (HPLC) and Real-time PCR, respectively. Results. Resistance training increased the content of plasma S1P of exercised group compared to control group (P=0.001). Furthermore, Resistance exercise training increased the gene expression of S1P1 (P=0.001), S1P2 (P=0.000) and S1P3 receptors (P=0.021) in exercised flexor hallucis longus (FHL) compared to control group. In soleus (SOL) muscle, resistance training increased the gene expression of S1P1 (P=0.000), S1P2 (P=0.603) and S1P3 receptors (P=0.009). Conclusion. The key conclusion is that resistance training strongly caused to increase in plasma SIP content and its receptors in skeletal muscles of rat that might indicate to the involvement of S1P signalling in the molecular events controlling adaptations of resistance trained muscles which needs to be elucidated in future studies
