Description_x000D_ Packaging_x000D_ 5, 25 mg in glass bottle_x000D_ Biochem/physiol Actions_x000D_ Sitaxentan (Sitaxsentan) is a potent and selective endothelin ET(A) receptor antagonist once used in the treatment of pulmonary arterial hypertension (PAH), but removed from the market because of hepatotoxicity. It is over 6000-fold selective for the the ETA receptor subtype with an IC50 of 1 nM for ETA versus an IC50 of 9800 nM for ETB._x000D_ Sitaxsentan prevents shunt mediated elevation of pulmonary vascular resistance (PVR). Sitaxsentan effectively inhibits basolateral Na+-taurocholate cotransporting polypeptide (NTCP), organic anion-transporting polypeptides (OATPs) and bile salt export pump (BSEP)._x000D_ Other Notes_x000D_ This compound was developed by Pfizer for Neuroscience research. To learn more about Sigma′s partnership with Pfizer and view other authentic, high-quality Pfizer compounds, visit sigma.com/bsm-pfizer._x000D_ To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here._x000D_ Legal Information_x000D_ Sold for research purposes under agreement from Pfizer Inc._x000D_ Pfizer is a registered trademark of Pfizer, Inc.