Mouse utricle expresses Oat1 and Oatps. A mRNA expression levels of four Oatps, including Oatp1b2, which mediates phalloidin uptake in rodent hepatocytes, and Oat1 in the neonatal mouse sensory epithelium, stroma, liver, and kidneys (n = 3). B Probenecid treatments decreased fluorescence by 33.9 %.