Search results for "trains"
showing 10 items of 600 documents
The rat liver foci bioassay: I. Age-dependence of induction by vinyl chloride of ATPase-deficient foci
1985
The age-dependence of the induction of pre-neoplastic enzyme-altered hepatic foci was investigated. Rats were exposed (8 h/day, 7 days/week) to 2000 p.p.m. vinyl chloride (VC) either 'transplacentally' (exposure of pregnant females), or immediately after birth for different time intervals (5, 11, 17, 47, 83 days) or from an age of 7 or 21 days onwards. The animals were then kept without further treatment; livers were evaluated for ATPase-deficient foci at the age of 4 months. 'Transplacental' exposure and exposure from day 1 through 5 caused no increase over controls in ATPase-deficient foci, probably due to the lack of hepatocellular proliferation and the low rate of VC metabolism at this …
l-glutamine: a major substrate for tumor cells in vivo?
1987
From 65 human breast cancer xenografts investigated, a net glutamine uptake was found in 13 tumors (mean +/- SE: 15.7 +/- 4.5 nmol/g per min) whereas a net release (22.5 +/- 3.3 nmol/g per min) was observed in 40 tumors. In 12 tumors neither a significant net uptake nor a net release was obvious. There is experimental evidence that glutamine is taken up by cancer cells only at arterial concentrations greater than 0.5 mM. Another parameter determining glutamine utilization by tumor cells may be the tissue oxygenation. In hypoxic or anoxic tumor areas, glutamine oxidation is unlikely since oxygen is required for the reoxidation of coenzymes which are reduced in the course of this metabolic pa…
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…
Induction of hepatic heme oxygenase-1 by diclofenac in rodents: role of oxidative stress and cytochrome P-450 activity
2003
Abstract Background/Aims : The role of oxidative stress in diclofenac hepatotoxicity is still not clear. This study examined whether the drug induced heme oxygenase-1 (HO-1), a stress protein. Methods : HO-1 mRNA and HO activity were measured in mouse liver and in rat hepatocytes after treatment with diclofenac parallel to release of serum alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) as a marker of hepatic damage. Results : HO-1 was transcriptionally and dose-dependently induced by diclofenac in mouse liver and rat hepatocytes. HO-1 mRNA, ALT and SDH peaked at the same time. Mechanistic studies revealed that the drug synergized with buthionine sulfoximine (BSO) in lowerin…
Effect of metal ion catalyzed oxidation of rifamycin SV on cell viability and metabolic performance of isolated rat hepatocytes.
1991
The effect of rifamycin SV on metabolic performance and cell viability was studied using isolated hepatocytes from fed, starved and glutathione (GSH) depleted rats. The relationships between GSH depletion, nutritional status of the cells, glucose metabolism, lactate dehydrogenase (LDH) leakage and malondialdehyde (MDA) production in the presence of rifamycin SV and transition metal ions was investigated. Glucose metabolism was impaired in isolated hepatocytes from both fed and starved animals, the effect is dependent on the rifamycin SV concentration and is enhanced by copper (II). Oxygen consumption by isolated hepatocytes from starved rats was also increased by copper (II) and a partial i…
Neuroprotective properties of mildronate, a mitochondria-targeted small molecule.
2010
Mildronate, a representative of the aza-butyrobetaine class of drugs with proven cardioprotective efficacy, was recently found to prevent dysfunction of complex I in rat liver mitochondria. The present study demonstrates that mildronate also acts as a neuroprotective agent. In a mouse model of azidothymidine (anti-HIV drug) neurotoxicity, mildronate reduced the azidothymidine-induced alterations in mouse brain tissue: it normalized the increase in caspase-3, cellular apoptosis susceptibility protein (CAS) and iNOS expression assessed by quantitative and semi-quantitative analysis. Mildronate also normalized the changes in cytochrome c oxidase (COX) expression, reduced the expression of glia…
The distribution, induction and isoenzyme profile of glutathione S-transferase and glutathione peroxidase in isolated rat liver parenchymal, Kupffer …
1989
The distribution and inducibility of cytosolic glutathione S-transferase (EC 2.5.1.18) and glutathione peroxidase (EC 1.11.1.19) activities in rat liver parenchymal, Kupffer and endothelial cells were studied. In untreated rats glutathione S-transferase activity with 1-chloro-2,4-dinitrobenzene and 4-hydroxynon-2-trans-enal as substrates was 1.7-2.2-fold higher in parenchymal cells than in Kupffer and endothelial cells, whereas total, selenium-dependent and non-selenium-dependent glutathione peroxidase activities were similar in all three cell types. Glutathione S-transferase isoenzymes in parenchymal and non-parenchymal cells isolated from untreated rats were separated by chromatofocusing …
A population of prenatally generated cells in the rat paleocortex maintains an immature neuronal phenotype into adulthood.
2008
New neurons in the adult brain transiently express molecules related to neuronal development, such as the polysialylated form of neural cell adhesion molecule, or doublecortin (DCX). These molecules are also expressed by a cell population in the rat paleocortex layer II, whose origin, phenotype, and function are not clearly understood. We have classified most of these cells as a new cell type termed tangled cell. Some cells with the morphology of semilunar-pyramidal transitional neurons were also found among this population, as well as some scarce cells resembling semilunar, pyramidal. and fusiform neurons. We have found that none of these cells in layer II express markers of glial cells, m…
Increased helper cell activity of NZB mice against H-2-identical allogeneic cells.
1988
The T cells of NZB mice become hyperreactive after stimulation with minor histocompatibility (MIH) antigens. This hyperreactivity has previously been demonstrated only for cytotoxic T cells of NZB, although there was some evidence for an increase of their T-helper cell activity facilitating the response. Here we report a quantitative analysis of T-cell help and help of T-cell subpopulations against autologous, MIH, and H-2 antigens in a limiting dilution assay. After stimulation of NZB T cells with autologous and H-2 antigens, the T-helper cell frequencies did not differ from that of normal mice. After stimulation with MIH antigens however, Lyt 1<sup>+</sup>2<sup>+</sup…
N-acetyl-L-glutamate in brain: assay, levels, and regional and subcellular distribution.
1991
N-Acetyl-L-glutamate (NAG), the activator of mitochondrial carbamoyl phosphate synthetase (CPS), is demonstrated by several methods, including a new HPLC assay, in the brain of mammals and of chicken. The brain levels of NAG are 200-300 times lower than the levels of N-acetyl-L-aspartate (NAA), and are similar to the levels of NAG in rat liver. The NAG levels in chicken liver are very low. Although NAG is mitochondrial in the liver, it is cytosolic in brain. Using enzyme activity and immuno assays we did not detect CPS in brain (detection limit, 12.5 micrograms/g brain), excluding that brain NAG is involved in citrullinogenesis. The regional distribution of brain NAG differs from that of NA…