![]() |
|
|
School of Pharmacy and Pharmaceutical Sciences, University of Manchester, Manchester, United Kingdom
Freshly isolated hepatocytes are currently regarded as the most superior in vitro model for use in prediction studies, in particular to provide estimates of in vivo intrinsic clearance (CLint). However, due to their loss of viability within 4 h and a decrease in cytochrome P450-dependent metabolism upon culture, newer cellular models are being developed. Cryopreserved hepatocytes have several potential advantages, but to date evaluation of the utility of this model for estimating in vitro CLint has been limited to the substrate depletion approach. We have incubated eight compounds with suspensions of freshly isolated and cryopreserved rat hepatocytes and obtained in vitro CLint via metabolite formation kinetics (for 14 pathways). A substantial range of in vitro CLint values (0.198 µl/min/106cells) was obtained in both models, and the freshly isolated suspension data were in good agreement with the literature. Cryopreserved suspensions were able to give a comparable estimation (within 2-fold) of in vitro CLint to fresh cells for six pathways, namely tolbutamide, three diazepam metabolites, propranolol, and 7-hydroxylation of warfarin. A higher estimation of in vitro CLint was obtained for the three other metabolites of warfarin due to a decrease in the KM values. Lower estimations of in vitro CLint were observed for four compounds (six pathways), and this was particularly pronounced (416%) for pathways showing atypical Michaelis-Menten kinetic profiles (dextromethorphan, nordiazepam) but less so (2545%) for pathways showing biphasic Michaelis-Menten kinetics (7-ethoxycoumarin and phenytoin).
This article has been cited by other articles:
![]() |
A. P. Li Evaluation of Luciferin-Isopropyl Acetal as a CYP3A4 Substrate for Human Hepatocytes: Effects of Organic Solvents, Cytochrome P450 (P450) Inhibitors, and P450 Inducers Drug Metab. Dispos., August 1, 2009; 37(8): 1598 - 1603. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. S. Brown, A. Chadwick, and J. B. Houston Use of Isolated Hepatocyte Preparations for Cytochrome P450 Inhibition Studies: Comparison with Microsomes for Ki Determination Drug Metab. Dispos., November 1, 2007; 35(11): 2119 - 2126. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. S. Brown, M. Griffin, and J. B. Houston Evaluation of Cryopreserved Human Hepatocytes as an Alternative in Vitro System to Microsomes for the Prediction of Metabolic Clearance Drug Metab. Dispos., February 1, 2007; 35(2): 293 - 301. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Lu, P. Li, R. Gallegos, V. Uttamsingh, C. Q. Xia, G. T. Miwa, S. K. Balani, and L.-S. Gan Comparison of Intrinsic Clearance in Liver Microsomes and Hepatocytes from Rats and Humans: Evaluation of Free Fraction and Uptake in Hepatocytes Drug Metab. Dispos., September 1, 2006; 34(9): 1600 - 1605. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Hallifax, H. C. Rawden, N. Hakooz, and J. B. Houston PREDICTION OF METABOLIC CLEARANCE USING CRYOPRESERVED HUMAN HEPATOCYTES: KINETIC CHARACTERISTICS FOR FIVE BENZODIAZEPINES Drug Metab. Dispos., December 1, 2005; 33(12): 1852 - 1858. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Treijtel, H. van Helvoort, A. Barendregt, B. J. Blaauboer, and J. C. H. van Eijkeren THE USE OF SANDWICH-CULTURED RAT HEPATOCYTES TO DETERMINE THE INTRINSIC CLEARANCE OF COMPOUNDS WITH DIFFERENT EXTRACTION RATIOS: 7-ETHOXYCOUMARIN AND WARFARIN Drug Metab. Dispos., September 1, 2005; 33(9): 1325 - 1332. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Komura and M. Iwaki NONLINEAR PHARMACOKINETICS OF PROPAFENONE IN RATS AND HUMANS: APPLICATION OF A SUBSTRATE DEPLETION ASSAY USING HEPATOCYTES FOR ASSESSMENT OF NONLINEARITY Drug Metab. Dispos., June 1, 2005; 33(6): 726 - 732. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. J. Griffin and J. B. Houston PREDICTION OF IN VITRO INTRINSIC CLEARANCE FROM HEPATOCYTES: COMPARISON OF SUSPENSIONS AND MONOLAYER CULTURES Drug Metab. Dispos., January 1, 2005; 33(1): 115 - 120. [Abstract] [Full Text] [PDF] |
||||