title: Quantification of statin effects on hepatic cholesterol synthesis by transient (13)C-flux analysis.
abstract: The present work is the first to deal with the determination of cholesterol synthesis rates in primary rat hepatocytes using transient (13)C-flux analysis. The effects of statins on cholesterol biosynthesis and central carbon fluxes were quantified at a therapeutic concentration of 50 nM atorvastatin using carbon-labeled glutamine. The flux through the cholesterol pathway decreased from 0.27 to 0.08 mmol/l(cv)h in response to the administration of the hypolipidemic drug. Isotopic steady state was reached within 4h in the central carbon metabolism but not in the cholesterol pathway, regardless of whether atorvastatin was administered or not. Marked channeling was observed for the symmetrical tricarboxylic acid cycle intermediates, succinate and fumarate. Non-stationary (13)C-based flux identification delivers both intracellular fluxes and intermediate levels, which was for the first time utilized for investigating systems-level effects of the administered drug by quantifying the flux control of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase.
authors: Institute of Biochemical Engineering, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
authors: Klaus
authors: K
authors: Maier
authors: Ute
authors: U
authors: Hofmann
authors: Alexander
authors: A
authors: Bauer
authors: Anja
authors: A
authors: Niebel
authors: Gabriele
authors: G
authors: Vacun
authors: Matthias
authors: M
authors: Reuss
authors: Klaus
authors: K
authors: Mauch
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002247:Carbon Isotopes / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000096:biosynthesis*; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D007553:Isotope Labeling; D007700:Kinetics; D008099:Liver / Q000201:enzymology* / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000924:Anticholesteremic Agents; D002247:Carbon Isotopes; D002244:Carbon; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases