PT - JOURNAL ARTICLE AU - Veronica Krogstad AU - Alexandra Peric AU - Ida Robertsen AU - Marianne K. Kringen AU - Christine Wegler AU - Philip Carlo Angeles AU - Jøran Hjelmesæth AU - Cecilia Karlsson AU - Shalini Andersson AU - Per Artursson AU - Anders Åsberg AU - Tommy B. Andersson AU - Hege Christensen TI - A Comparative Analysis of Cytochrome P450 Activities in Paired Liver and Small Intestinal Samples from Patients with Obesity AID - 10.1124/dmd.119.087940 DP - 2020 Jan 01 TA - Drug Metabolism and Disposition PG - 8--17 VI - 48 IP - 1 4099 - http://dmd.aspetjournals.org/content/48/1/8.short 4100 - http://dmd.aspetjournals.org/content/48/1/8.full SO - Drug Metab Dispos2020 Jan 01; 48 AB - The liver and small intestine restrict oral bioavailability of drugs and constitute the main sites of pharmacokinetic drug-drug interactions. Hence, detailed data on hepatic and intestinal activities of drug metabolizing enzymes is important for modeling drug disposition and optimizing pharmacotherapy in different patient populations. The aim of this study was to determine the activities of seven cytochrome P450 (P450) enzymes in paired liver and small intestinal samples from patients with obesity. Biopsies were obtained from 20 patients who underwent Roux-en-Y gastric bypass surgery following a 3-week low-energy diet. Individual hepatic and intestinal microsomes were prepared and specific probe substrates in combined incubations were used for determination of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A activities. The activities of CYP2C8, CYP2C9, CYP2D6, and CYP3A were quantified in both human liver microsomes (HLM) and human intestinal microsomes (HIM), while the activities of CYP1A2, CYP2B6, and CYP2C19 were only quantifiable in HLM. Considerable interindividual variability was present in both HLM (9- to 23-fold) and HIM (5- to 55-fold). The median metabolic HLM/HIM ratios varied from 1.5 for CYP3A to 252 for CYP2C8. The activities of CYP2C9 in paired HLM and HIM were positively correlated (r = 0.74, P < 0.001), while no interorgan correlations were found for activities of CYP2C8, CYP2D6, and CYP3A (P > 0.05). Small intestinal CYP3A activities were higher in females compared with males (P < 0.05). Hepatic CYP2B6 activity correlated negatively with body mass index (r = −0.72, P < 0.001). These data may be useful for further in vitro-in vivo predictions of drug disposition in patients with obesity.SIGNIFICANCE STATEMENT Hepatic and intestinal drug metabolism is the key determinant of oral drug bioavailability. In this study, paired liver and jejunum samples were obtained from 20 patients with obesity undergoing gastric bypass surgery following a 3-week low-energy diet. We determined the hepatic and small intestinal activities of clinically important P450 enzymes and provide detailed enzyme kinetic data relevant for predicting in vivo disposition of P450 substrates in this patient population.