Characterization of sphingosine 1-phoshate-induced actions and its signaling pathways in rat hepatocytes

The effects of sphingosine 1-phosphate (S-1-P) and lysophosphatidic acid (LPA) on glycogen phosphorylase stimulation were analyzed in freshly prepared and primary cultured hepatocytes isolated from adult rats. The presence of S-1-P and LPA in primary cultured rat hepatocytes induced the stimulation of glycogen phosphorylase which was mediated by phospholipase C activation and elevations in [Ca2+]i. Furthermore, S-1-P attenuated adenosine 3',5'-cyclic monophosphate accumulation in rat hepatocytes.