Organic anion transporting polypeptides (OATPs/Oatps) are important transporters for uptake of bile acids, thyroid hormones, and clinical drugs into cells. However, expression and function of OATPs/Oatps in skeletal muscles have been unknown. Anti-hyperlipidemic statins adversely affect skeletal muscles. The risk of hydrophilic statins to induce muscular injury has been believed to be less than that of lipophilic statins. However, clinical data revealed that hydrophilic statins cause myopathy as frequently as did lipophilic statins in patients. In this study, we herein compared the toxic effect of hydrophilic pravastatin and the expression of Oatps between myofibers and two types of mononuclear cells (fibroblasts and L6 skeletal myoblasts). In myofibers, the median value of the concentration-viability curve of pravastatin was 8.6 μM. Conversely, the other mononuclear cells were insensitive to pravastatin. Using RT-PCR, we examined the mRNA expression levels of the transporters reported for pravastatins; Oatp1a4 and Oatp2b1. Both transporters were expressed in the myofibers but not in the mononuclear cells. The pretreatment of myofibers with estrone sulfate, a substrate of Oatp attenuated the effect of pravastatin. Our results indicate that hydrophilic statins are transported into myofibers and could therefore cause toxicity, but not in mononuclear cells, because these mononuclear cells do not express Oatps for statins. [J Physiol Sci. 2008;58 Suppl:S70]