Substances tested

Raises the peroxisome volume fraction in hepatocytes from 1.05 percent to 6.26 percent and the mitochondrial volume fraction from 22 percent to 29.5 percent. Also protected the animals against the toxic, hypoglycaemic and hypothermic effects of hypoglycin and pent-4-enoate, and completely prevented the ultrastructural damage hypoglycin caused.

Doubles the mitochondrial volume fraction in hepatocytes, from 22 percent to 44 percent, and cuts the peroxisome volume fraction from 1.05 percent to 0.26 percent. Hypoglycaemic and hypothermic.

Increases hepatocyte size: the average volume of the largest sedimenting cell fraction rose to 16,725 um3 from 10,500 um3 previously reported in untreated animals, and the number of cells in the fast-sedimenting fractions also increased. Cytochrome P-450 was raised, and a gradient of P-450 concentration across cell sizes persisted, with a 6.8-fold range in cytochrome per cell. Density fell in cells of all sizes.

Unlike phenobarbital, caused no significant increase in the size or number of cells in the fast-sedimenting fractions, but made the discontinuity in density and volume characteristics markedly more pronounced. The P-450 gradient across cell sizes was less steep, 4.62-fold against phenobarbital's 6.8-fold.

Concentration-dependent inhibition of CYP3A4-mediated luciferin-isopropyl acetal metabolism in human hepatocytes, with more than 50 percent inhibition already at the lowest concentration evaluated.

Concentration-dependent inhibition of the same CYP3A4 reaction, more than 50 percent at the lowest concentration evaluated. Used here as the non-selective comparator that establishes the reaction is P450-dependent.

Induced CYP3A activity 2.8-fold in cryopreserved human hepatocytes, from 57.2 to 157.7 pmol per well per minute, against 2.3-fold in non-frozen cells, from 115.8 to 269.1. Note the basal activity in cryopreserved cells is about half that of fresh cells, so the larger fold-change starts from a lower floor.

Covalent binding was confined to the centrilobular hepatocytes, which is the area of the ensuing necrosis. The zonal restriction of the binding, not the binding alone, is what matches the injury pattern: the regioisomer 3'-hydroxyacetanilide binds proteins at similar levels without causing toxicity.

Scrambles the hepatocyte's membrane domains. The antigen A39 moved from the sinusoidal membrane to the lateral and canalicular membranes while B10 was displaced from the canalicular to the sinusoidal and lateral, ending in almost equal labelling of all three domains with both antibodies. Evidence that the hepatocyte's three-domain polarity is maintained by microtubule-dependent traffic rather than being structurally fixed.

Studied alongside colchicine in the same work as the second drug known to interfere with hepatocyte secretory processes, to separate microtubule-dependent from actin-dependent maintenance of membrane domain identity.

Caused a significant depletion of cellular GSH content and lipid peroxidation in isolated rat hepatocytes. The dose selected for cytoprotection experiments with calcium channel blockers was 300 mM. Calcium channel blockers (verapamil, diltiazem) partially restored GSH and reduced lipid peroxidation.

Inhibited cholesterol synthesis in primary human hepatocytes with IC50 of 23 nM, compared to 105 nM for pravastatin. In HepG2 (lacking the hepatic uptake transporter), simvastatin IC50 was 34 nM vs. pravastatin 1900 nM. The greater potency difference in HepG2 than in primary hepatocytes reflects a missing transporter in the cell line.

Activates AMPK in hepatocytes; as a result, acetyl-CoA carboxylase (ACC) activity is reduced, fatty acid oxidation is induced, and expression of lipogenic enzymes is suppressed. Using a novel AMPK inhibitor, AMPK activation was found to be required for metformin's inhibitory effect on glucose production by hepatocytes.

Insulin at 10 nM stimulated net glycogen accumulation in primary cultures of rat hepatocytes from fasted animals. Effects were linear at physiological (5 to 10 mM) and supraphysiological (20 to 30 mM) glucose concentrations over 2 hours.

In isolated rat hepatocytes under batch incubation, the EC50 for glucagon-induced glycogenolysis was 1 nM (10^-9 mol/L). By contrast, the perfused liver required only 0.05 nM (5 x 10^-11 mol/L) to produce the same effect. The rightward shift in isolated hepatocytes was attributed to an inhibitory substance released by hepatocytes in batch culture.

Treatment of palmitic acid-exposed hepatocytes with 10 uM empagliflozin or dapagliflozin reduced hepatic lipid accumulation and inflammation by inhibiting CD36 and suppressing ER stress-induced pro-inflammatory cytokine expression, slowing NAFLD progression in vitro.

Bile acids are physiological ligands for the nuclear receptor FXR. When bound to bile acids, FXR represses transcription of CYP7A1, the rate-limiting enzyme in bile acid synthesis, and activates intestinal bile acid-binding protein. This identified FXR as the receptor mediating the feedback suppression of bile acid synthesis.

Cells exposed to 2.5 mM acetaminophen for 90 min showed substantial depletion of glutathione, to 19 percent of control values. Dithiothreitol reversed subsequent cell death without restoring GSH, implicating oxidised protein thiols rather than GSH depletion alone as the lethal lesion.

Three weeks of the Lieber-DeCarli ethanol diet in male rats caused a 7-fold increase in CYP2E1 protein content in hepatocytes (as well as in Kupffer cells). The induced CYP2E1 was catalytically active (p-nitrophenol hydroxylation) and was inhibited by anti-CYP2E1 IgG, confirming identity.

Phenobarbital at 0.5 mM for 96 hours induced CYP2B protein 5.2-fold in precision-cut rat liver slices maintained in defined medium. This preparation also supported simultaneous induction monitoring of CYP2E1 and other enzymes and is used as a hepatocyte-rich surrogate for primary hepatocyte induction studies.

Rifampicin activates hPAR (the human ortholog of rodent PXR/SXR), which binds to a conserved regulatory sequence in human CYP3A gene promoters and trans-activates CYP3A expression. This identifies PXR as the nuclear receptor mediating human-selective CYP3A induction by rifampicin and explains why rodent models do not recapitulate the human induction response.

Cyclosporine A caused the highest intracellular taurocholate (TC) accumulation among cholestatic drugs tested in primary human hepatocytes (sandwich culture). In human hepatocytes TC is normally eliminated via canalicular (34.4%) and basolateral (34.8%) routes in roughly equal proportions; cyclosporine A blocked both routes. Rat hepatocytes, which show dominant basolateral efflux (71.7% of total), were partially protected, explaining the species difference in susceptibility to cyclosporine-induced cholestasis.

Valproate exposure in human hepatocytes caused a sustained 15% increase in lipogenesis followed by mitochondrial stress; TC50 = 2.5 mM. Metabolic flux disruption was detectable before cytotoxicity (onset 15 to 20 hours post-exposure). Steatosis induction was confirmed in both 2D and 3D hepatocyte cultures, establishing the sequence: lipogenesis increase → mitochondrial stress → steatosis.

Repeat exposure to amiodarone produced dose-dependent induction of triglycerides and lipid droplet accumulation in HepaRG cells. In addition to vesicular steatosis, amiodarone created intracytoplasmic vesicles appearing as lamellar bodies (phospholipidosis). Lipogenic genes were upregulated. The pattern of gene induction differed from oleic acid-induced steatosis, indicating a distinct drug-specific mechanism.

Repeat exposure to tetracycline produced dose-dependent induction of triglycerides and vesicular steatosis (lipid droplet accumulation) in HepaRG cells, with upregulation of lipogenesis-related and lipid-droplet-formation genes. Unlike amiodarone in the same model, tetracycline did not produce lamellar bodies (phospholipidosis), demonstrating a mechanistic distinction between the two drugs despite similar steatotic outcomes.

In rat hepatocytes exposed to 1 uM 6-ECDCA, SHP and bsep mRNA were induced 3- to 5-fold and bile acid synthesis enzyme expression was reduced 70 to 80%. In vivo administration restored bile flow and altered bile acid secretion patterns in an estrogen-induced cholestasis model. FXR ligand GW4064 produced similar effects, confirming the mechanism is FXR-mediated.