Search results for "hepatocyte"
showing 10 items of 369 documents
Potential hepatoprotective effects of new Cuban natural products in rat hepatocytes culture.
2008
The protective effects of five Cuban natural products (Mangifera indica L. (MSBE), Erythroxylum minutifolium, Erythroxylum confusum, Thalassia testudinum and Dictyota pinnatifida extracts and mangiferin) on the oxidative damage induced by model toxicants in rat hepatocyte cultures were studied. Cells were pre-incubated with the natural products (5-200 microg/mL) for 24 h. Then hepatotoxins (tert-butyl hydroperoxide, ethanol, carbon tetrachloride and lipopolysaccharide) were individually added and post-incubated for another 24 h. After treatments, cell viability was determined using the MTT assay. Mangiferin and MSBE exhibited the highest cytoprotective potential (EC50 between 50 and 125 mic…
Cellular damage to human hepatocytes through repeated application of 5-aminolevulinic acid.
2003
Abstract Background/Aims : 5-Aminolevulinic acid (ALA), a precursor of porphyrins is used for photodynamic diagnosis and therapy within topical or systemic applications. A potential toxic effect on the human liver is of major interest and therefore we investigated the impact of a repeated application of ALA without illumination on cultures of human hepatocytes. Methods : After ALA treatment of hepatocytes in vitro the porphyrin synthesis, albumin secretion, liver-specific enzyme release, and malondialdehyde levels were determined. In order to reduce levels of reactive oxygen substances, mannitol and the antioxidant enzymes superoxide dismutase and catalase were supplemented. Results : Porph…
Effects of Mangifera indica L. aqueous extract (Vimang) on primary culture of rat hepatocytes.
2007
Abstract Vimang is an aqueous extract from stem bark of Mangifera indica L. (Mango) with pharmacological properties. It is a mixture of polyphenols (as main components), terpenoids, steroids, fatty acids and microelements. In the present work we studied the cytotoxic effects of Vimang on rat hepatocytes, possible interactions of the extract with drug-metabolizing enzymes and its effects on GSH levels and lipid peroxidation. No cytotoxic effects were observed after 24 h exposure to Vimang of up to 1000 μg/mL, while a moderate cytotoxicity was observed after 48 and 72 h of exposure at higher concentrations (500 and 1000 μg/mL). The effect of the extract (50–400 μg/mL) on several P450 isozymes…
The Major Virus-Producing Cell Type during Murine Cytomegalovirus Infection, the Hepatocyte, Is Not the Source of Virus Dissemination in the Host
2008
SummaryThe course of systemic viral infections is determined by the virus productivity of infected cell types and the efficiency of virus dissemination throughout the host. Here, we used a cell-type-specific virus labeling system to quantitatively track virus progeny during murine cytomegalovirus infection. We infected mice that expressed Cre recombinase selectively in vascular endothelial cells or hepatocytes with a murine cytomegalovirus for which Cre-mediated recombination would generate a fluorescently labeled virus. We showed that endothelial cells and hepatocytes produced virus after direct infection. However, in the liver, the main contributor to viral load in the mouse, most viruses…
In vivo formation of aflatoxin B1-DNA adducts in parenchymal and non-parenchymal cells of rat liver
1992
The induction of hepatocellular carcinoma from liver parenchymal cells in laboratory animals by aflatoxin B1 (AFB1) is well documented. In contrast no tumours arising from the sinusoidal cell population have been reported after exposure to AFB1. The apparent resistance of the latter cell type was investigated at the level of DNA adduct formation in vivo in male Sprague-Dawley rats. Liver parenchymal and non-parenchymal cell populations were isolated from rats at 20 min and 1, 24 and 72 h after administration of 240 microCi (0.6 mg) [G-3H]AFB1/kg. AFB1-DNA binding was observed in both liver cell subpopulations and was 3- to 5-fold higher in parenchymal cells than in non-parenchymal cells. Th…
Expression of L- and M2-pyruvate kinases in proliferating oval cells and cholangiocellular lesions developing in the livers of rats fed a methyl-defi…
1994
Male outbred Sprague-Dawley rats were fed a choline-deficient diet containing 0.1% w/w DL-ethionine (CDE) for up to 22 weeks. The expression of the pyruvate kinase isoenzymes L (L-PK) and M2 (M2-PK) was immunohistochemically analyzed in liver slices from rats killed 4, 10, 14 and 22 weeks after starting the treatment. M2-PK was detected in bile duct epithelial cells of untreated rats and in proliferating oval cells, cholangiofibroses and cholangiofibromas of CDE-fed animals. Thus, M2-PK can be viewed as a positive marker of the bile duct epithelial/oval cell compartment. L-PK, a parenchymal cell-specific protein in untreated rat liver, was not present in proliferating oval cells, but was co…
cAMP-dependent phosphorylation of CYP2B1 as a functional switch for cyclophosphamide activation and its hormonal controlin vitro andin vivo
2001
An important feature of cytochrome P450 (CYP) 2B1 is its high ability to convert the prodrug cyclophosphamide (CPA) to therapeutically cytotoxic metabolites, resulting in interstrand DNA-cross-linking and cell death. We have examined whether and how the phosphorylation of CYP2B1 influences CPA metabolic activation in vitro and in vivo. We found first that only part of the total CYP2B1 pool undergoes phosphorylation. This part is fully inactivated. Second, phosphorylation of CYP2B1 in intact hepatocytes reduced by up to 75% toxification of CPA to mutagenic metabolites (totally dependent on the same preferentially CYP2B-catalyzed 4-hydroxylation of CPA as is the generation of highly cytotoxic…
Enzyme histochemical and immunohistochemical characterization of oval and parenchymal cells proliferating in livers of rats fed a choline-deficient/D…
1991
Male outbred Sprague-Dawley rats were fed a choline-deficient diet containing 0.10% DL-ethionine for up to 30 weeks. Liver slices from rats killed 4, 6, 10, 14, 22 and 30 weeks after starting the treatment were histochemically analyzed for the following parameters: basophilia, expression of cytokeratin 19 (which in the liver is bile duct epithelial cell-specific), glycogen content and activities of glycogen synthetase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6PASE), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerin-3-phosphate dehydrogenase (G3PDH), 'malic enzyme' (MDH), alkaline phosphatase (ALKPASE) and gamma-glutamyl…
Adipose stem cell niche reprograms the colorectal cancer stem cell metastatic machinery.
2021
Obesity is a strong risk factor for cancer progression, posing obesity-related cancer as one of the leading causes of death. Nevertheless, the molecular mechanisms that endow cancer cells with metastatic properties in patients affected by obesity remain unexplored. Here, we show that IL-6 and HGF, secreted by tumor neighboring visceral adipose stromal cells (V-ASCs), expand the metastatic colorectal (CR) cancer cell compartment (CD44v6 + ), which in turn secretes neurotrophins such as NGF and NT-3, and recruits adipose stem cells within tumor mass. Visceral adipose-derived factors promote vasculogenesis and the onset of metastatic dissemination by activation of STAT3, which inhibits miR-200…
Effects of peroxisome proliferator-activated receptor alpha activation on pathways contributing to cholesterol homeostasis in rat hepatocytes
2004
International audience; Peroxisome proliferator-activated receptor alpha (PPARa) activation by fibrates controls expression of several genes involved in hepatic cholesterol metabolism. Other genes could be indirectly controlled in response to changes in cellular cholesterol availability. To further understand how fibrates may affect cholesterol synthesis, we investigated in parallel the changes in the metabolic pathways contributing to cholesterol homeostasis in liver. Ciprofibrate increased HMG-CoA reductase and FPP synthase mRNA levels in rat hepatocytes, together with cholesterogenesis from [14C] acetate and [3H] mevalonate. The up-regulation observed in fenofibrate- and WY-14,643-treate…