Search results for "3005 Toxicology"
showing 7 items of 7 documents
A time-course investigation of vitamin A levels and drug metabolizing enzyme activities in rats following a single treatment with prototypic polychlo…
1987
Xenobiotics previously characterized as selective inducers of drug-metabolizing enzymes were chosen to probe possible relationships between enzyme induction and vitamin A metabolism. Liver, kidney and serum retinol and retinyl palmitate levels were investigated in male Sprague--Dawley rats receiving a single i.p. injection of the polychlorinated biphenyls (PCBs), 2,2',5,5'-tetrachlorobiphenyl, 3,3',4,4'-tetrachlorobiphenyl or 2,2',4,4',5,5'-hexachlorobiphenyl (300 mumol/kg) or 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)-ethane (DDT) (150 mumol/kg). While 2,2',5,5'-tetrachlorobiphenyl, a weak or non-inducer, and 2,2',4,4',5,5'-hexaclorobiphenyl and DDT, phenobarbital-type inducers of cytochrome…
People with Alcohol Use Disorders in Specialized Care in Eight Different European Countries
2015
Aim: To provide a description of patients receiving alcohol treatment in eight different European countries, including the level of comorbidities and functional limitations. Methods: Drinking behaviours, DSM-IV alcohol use disorder (AUD), mental and somatic comorbidities, disability and health services utilization of 1767 patients from various specialized treatment settings were assessed as representative for regions of eight European countries. Severity of alcohol dependence (AD) in terms of drinking level was compared with a large representative US sample. Alcohol and Alcoholism, 2015, 1–9 doi: 10.1093/alcalc/agv009 Article © The Author 2015. Medical Council on Alcohol and Oxford Universi…
cis- and trans-1,2-diphenylaziridines: induction of xenobiotic-metabolizing enzymes in rat liver and mutagenicity in Salmonella typhimurium.
1986
trans-Stilbene imine (trans-1,2-diphenylaziridine) is the nitrogen analog of trans-stilbene oxide, a potent inducer of several microsomal and cytosolic xenobiotic-metabolizing enzymes. Although the acute toxicity of cis- and trans-stilbene imines prevents their application at the usual dose for trans-stilbene oxide (400 mg/kg/day), it is apparent that the imines nevertheless potently induce several xenobiotic-metabolizing enzymes in rat liver. The IP administration of trans-stilbene imine resulted in statistically significant increases in the activities of aminopyrine N-demethylase, microsomal epoxide hydrolase, glutathione transferase (toward 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nit…
Metabolic detoxification: implications for thresholds.
2000
The fact that chemical carcinogenesis involves single, isolated, essentially irreversible molecular events as discrete steps, several of which must occur in a row to finally culminate in the development of a malignancy, rather suggests that an absolute threshold for chemical carcinogens may not exist. However, practical thresholds may exist due to saturable pathways involved in the metabolic processing, especially in the metabolic inactivation, of such compounds. An important example for such a pathway is the enzymatic hydrolysis of epoxides via epoxide hydrolases, a group of enzymes for which the catalytic mechanism has recently been established. These enzymes convert their substrates via…
Xenobiotic-metabolizing enzyme activities in hybrid cell lines established by fusion of primary rat liver parenchymal cells with hepatoma cells
1992
1. The activities of xenobiotic-metabolizing enzymes were determined in hybrid cell lines (hepatocytoma, HPCT) which have been established by fusion of liver parenchymal cells from adult rat (PC) with cells from a Reuber hepatoma cell line (FAO). 2. Cytochrome P450 was not measurable spectrophotometrically in FAO and HPCT. P450-dependent conversion of testosterone was below the detection limit in FAO and only marginally present in HPCT. 3. Microsomal and cytosolic epoxide hydrolase, glutathione S-transferase and phenol sulphotranserase were low or even below detection limit in FAO. These enzyme activities were significantly higher in HPCT and correspond to about 1-10% the activities measure…
Xenobiotic metabolizing enzyme activities and viability are well preserved in EDTA-isolated rat liver parenchymal cells after cryopreservation
1995
Rat liver parenchymal cells (PC) were isolated by EDTA perfusion and were purified by a subsequent Percoll centrifugation. The isolated PC had a viability of 95%, as judged by trypan blue exclusion. Freshly isolated PC were cryopreserved with an optimized protocol in a computer-controlled freezer. After thawing, the PC still retained a viability of 89%. The activities of representative xenobiotic metabolizing enzymes were compared between freshly isolated and cryopreserved PC after thawing. The cytochrome P450 content and the cytochrome P450 2C11 isoenzyme activity, determined by hydroxylation of testosterone in intact cells, were not affected by the cryopreservation. The following phase II…
Escitalopram causes fewer seizures in human overdose than citalopram
2010
Seizures are a recognized complication of acute overdose with the racemic (1:1 ratio of R- and S-enantiomers) selective serotonin reuptake inhibitor antidepressant citalopram.We tested the hypothesis that escitalopram (the therapeutically active S-enantiomer of citalopram) causes fewer seizures in overdose than citalopram at comparable doses of the S-enantiomer.Multicenter retrospective review of cases with citalopram and escitalopram overdose reported to German, Austrian, and Swiss Poisons Centers between 1997 and 2006.316 citalopram and 63 escitalopram cases were analyzed. Somnolence, nausea, vomiting, tachycardia, QT prolongation, and tremor occurred with similar frequency in both groups…