Olmesartan-d6 is intended for use as an internal standard for the quantification of olmesartan by GC- or LC-MS. Olmesartan is a non-peptide angiotensin II receptor 1 (AT1) antagonist (IC50 = 0.0077 µM for the bovine adrenal cortex receptor) and an active metabolite of olmesartan medoxomil .1 It is formed from olmesartan medoxomil by paraoxonase 1 (PON1) in human plasma.2 Olmesartan is selective for AT1 over AT2 (IC50 = >100 µM for the bovine cerebellar receptor). It reduces contraction of isolated guinea pig aorta induced by angiotensin II but not phenylephrine or potassium chloride. Olmesartan (0.01 and 0.03 mg/kg, i.v.) reduces the angiotensin II-induced pressor response in conscious normotensive rats.
1.Mizuno, M., Sada, T., Ikeda, M., et al.Pharmacology of CS-866, a novel nonpeptide angiotensin II receptor antagonistEur. J. Pharmacol.285(2)181-188(1995) 2.Ishizuka, T., Fujimori, I., Nishida, A., et al.Paraoxonase 1 as a major bioactivating hydrolase for olmesartan medoxomil in human blood circulation: Molecular identification and contribution to plasma metabolismDrug Metab. Dispos.40(2)374-380(2012)