Qualitative and quantitative status of cytochrome P450s after the administration of a liposomal platelet substitute in rat liver.

In the process of the drug development, studies on the cytochrome P450 (CYP) profiles after its administration provided fundamental information regarding drug interactions with concomitantly administered drugs. Here, we evaluated the influence of the administration of H12-(ADP)-liposomes, a platelet substitute, on the mRNA and protein expression, and metabolic activity of CYPs, with focus on the CYP1A2, CYP2C11 and CYP3A2, in rat liver.At 24 h after administering saline or H12-(ADP)-liposomes (10 mg of lipids/kg), a quantitative RT-PCR and western blot analysis revealed that the mRNA and proteins expression of all of the target hepatic CYP isoforms were not different between the saline and H12-(ADP)-liposome groups. Furthermore, an ex vivo CYP metabolic activity assay showed that hepatic CYP metabolic activities in the H12-(ADP)-liposome group were comparable to the corresponding saline group. On the other hand, the area under the blood concentration-time curve for substitutes for CYP1A2 and CYP2C11 was higher in H12-(ADP)-liposome group than in saline group, but the degree of elevations was negligible levels.At a minimum, based on these results, we conclude that H12-(ADP)-liposomes have no quantitative and qualitative effect on the hepatic CYP isoforms, indicating that the drug interactions of H12-(ADP)-liposomes with CYP-metabolizing drugs would be negligible.