The phenotype pantoprazole-C breath test (Ptz-BT) was used to evaluate the extent of phenoconversion of CYP2C19 enzyme activity caused by commonly prescribed proton pump inhibitors (PPI) omeprazole and esomprazole. The Ptz-BT was administered to 26 healthy volunteers and 8 stable cardiovascular patients twice at baseline and after 28 days of PPI therapy to evaluate reproducibility of the Ptz-BT...

The phenotype pantoprazole-(13)C breath test (Ptz-BT) was used to evaluate the extent of phenoconversion of CYP2C19 enzyme activity caused by commonly prescribed proton pump inhibitors (PPI) omeprazole and esomprazole. The Ptz-BT was administered to 26 healthy volunteers and 8 stable cardiovascular patients twice at baseline and after 28 days of PPI therapy to evaluate reproducibility of the Pt...

Upon characterization of baculovirus-expressed cytochrome P-450 (CYP) 2C19, it was observed that this enzyme metabolized (+/-) bufuralol to 1'hydroxybufuralol, a reaction previously understood to be selectively catalyzed by CYP2D6. The apparent K(m) for this reaction was 36 microM with recombinant CYP2C19, approximately 7-fold higher than for recombinant CYP2D6. The intrinsic clearance for this...

CYP2C19 is an important enzyme for human drug metabolism, and it also participates in the metabolism of endogenous substrates, whereas the CYP2C18 enzyme is not expressed in human liver despite high mRNA expression. Mice transgenic for the human CYP2C18 and CYP2C19 genes were generated. Quantitative mRNA analysis showed CYP2C18 and CYP2C19 transcripts in liver, kidneys, and heart to be expresse...

Upon characterization of baculovirus-expressed cytochrome P-450 (CYP) 2C19, it was observed that this enzyme metabolized (1/2) bufuralol to 1*hydroxybufuralol, a reaction previously understood to be selectively catalyzed by CYP2D6. The apparent Km for this reaction was 36 mM with recombinant CYP2C19, approximately 7-fold higher than for recombinant CYP2D6. The intrinsic clearance for this react...

Background: Clopidogrel is a standout amongst the most ordinarily recommended medications to avoid ischemic occasions taking after coronary disorder or stant position. However, impaired responses the therapy as well as resistance to the therapy have also been reported. Genetic variants play an important role in clopidogrel biotransformation of its active metabolite that may subsequently influen...

Cytochrome P450 2C19 (CYP2C19) plays an important role in the metabolism and elimination of a wide range of medications. The polymorphisms of this enzyme give rise to substantial inter-individual and interethnic variability in drug excretion rates and final serum concentrations. For this reason, therapeutic responses and adverse drug reactions may vary from one person to another. In this study ...

Inherited variation in the function of the drug metabolizing enzyme CYP2C19 was first observed 40 years ago. The SNP variants which underpin loss of CYP2C19 function have been elucidated and extensively studied in healthy populations. However, there has been relatively meagre translation of this information into the clinic. The presence of genotype-phenotype discordance in certain patients sugg...

It has been previously reported that omeprazole (OP) oxidation is mediated by CYP2C19 and CYP3A4 in human livers. In this study, we assessed their relative contributions with human liver microsomal fractions from Chinese populations that were genotyped by CYP2C19 and recruited from two ethnic groups, Han and Zhuang. The kinetics of 5-hydroxyomeprazole (5-OH-OP) formation was best described by t...