![]() |
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona (A.J.L., C.D.F., L.M.Au., D.G.B., N.J.C.); Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, Storrs, Connecticut (L.M.Al., J.E.M.); and Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Rhode Island (A.L.S.).
Efflux transporters are responsible for the excretion of numerous xenobiotics and endobiotics and thus play an essential role in proper liver and kidney function. Nonalcoholic fatty liver diseases (NAFLDs) comprise a spectrum of disorders that range from simple fatty liver (SFL) to nonalcoholic steatohepatitis (NASH). Although the precise events leading to NAFLD are unclear, even less is known about the effects on efflux transporter expression and drug disposition. The purpose of this study was to determine the effect of NAFLD on efflux transporter expression in rat liver as well as on acetaminophen (APAP) metabolite excretion. To simulate SFL and NASH, rats were fed either a high-fat (HF) or a methionine- and choline-deficient (MCD) diet for 8 weeks. In the livers of MCD rats, there were striking increases in both mRNA and protein levels of multidrug resistance-associated protein (Mrp) 3, Mrp4, and breast cancer resistance protein, as well as increased Mrp2 protein. After administration of a nontoxic dose of APAP, biliary concentrations of APAP-sulfate, APAP-glucuronide (APAP-GLUC), and APAP-glutathione were reduced in MCD rats. The effects of the HF diet on both transporter expression and APAP disposition were by comparison far less dramatic than the MCD diet-induced alterations. Whereas APAP-sulfate levels were also decreased in MCD rat plasma, the levels of the Mrp3 substrate APAP-GLUC were elevated. Urinary elimination of APAP metabolites was identical between groups, except for APAP-GLUC, the concentration of which was 80% higher in MCD rats. These studies correlate increased hepatic Mrp3 protein in the MCD model of NASH with increased urinary elimination of APAP-GLUC. Furthermore, the proportional shift in elimination of APAP metabolites from bile to urine indicates that MCD-induced alterations in efflux transporter expression can affect the route of drug elimination.
This article has been cited by other articles:
![]() |
J. K. Lee, K. Abe, A. S. Bridges, N. J. Patel, T. J. Raub, G. M. Pollack, and K. L. R. Brouwer Sex-Dependent Disposition of Acetaminophen Sulfate and Glucuronide in the in Situ Perfused Mouse Liver Drug Metab. Dispos., September 1, 2009; 37(9): 1916 - 1921. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. J. Schrieber, Z. Wen, M. Vourvahis, P. C. Smith, M. W. Fried, A. D. M. Kashuba, and R. L. Hawke The Pharmacokinetics of Silymarin Is Altered in Patients with Hepatitis C Virus and Nonalcoholic Fatty Liver Disease and Correlates with Plasma Caspase-3/7 Activity Drug Metab. Dispos., September 1, 2008; 36(9): 1909 - 1916. [Abstract] [Full Text] [PDF] |
||||