SLC22A8 and pulmonary arterial hypertension: Furthermore, leptomeninges containing arachnoid epithelial cells express Oat1 and Oat3 proteins; 2.73 ± 0.07 (fmol/μg protein) and 6.65 ± 0.20 (fmol/μg protein), respectively (48), and the elimination clearance of PAH was inhibited completely by ceftriaxone, an inhibitor of Oat1, and by 17% with cephalothin, an inhibitor of Oat3 (48, 66).