CHARACTERIZATION OF HUMAN LIVER MICROSOMAL UDP-GLYCOSYLTRANSFERASES USING PHOTOAFFINITY ANALOGS

NARCIS (Netherlands)

LITTLE, JM; DRAKE, RR; VONK, R; KUIPERS, F; LESTER, R; RADOMINSKA, A

The photoaffinity analogs [beta-P-32]5-azido-UDP-glucuronic acid ([P-32]5N3UDP-GlcUA) and [beta-P-32]5-azido-UDP-glucose ([P-32]5N(3)UDP-Glc) were used to characterize UDP-glycosyl-transferases of microsomes prepared from human liver. Photoincorporation of both probes into proteins in the 50- to

The effects of gender, age, ethnicity, and liver cirrhosis on cytochrome P450 enzyme activity in human liver microsomes and inducibility in cultured human hepatocytes

International Nuclear Information System (INIS)

Parkinson, Andrew; Mudra, Daniel R.; Johnson, Cory; Dwyer, Anne; Carroll, Kathleen M.

2004-01-01

We have measured cytochrome P450 (CYP) activity in nearly 150 samples of human liver microsomes and 64 samples of cryopreserved human hepatocytes, and we have performed induction studies in over 90 preparations of cultured human hepatocytes. We have analyzed these data to examine whether the expression of CYP enzyme activity in liver microsomes and isolated hepatocytes or the inducibility of CYP enzymes in cultured hepatocytes is influenced by the gender, age, or ethnicity of the donor (the latter being limited to Caucasians, African Americans, and Hispanics due to a paucity of livers from Asian donors). In human liver microsomes, there were no statistically significant differences (P > 0.05) in CYP activity as a function of age, gender, or ethnicity with one exception. 7-Ethoxyresorufin O-dealkylase (CYP1A2) activity was greater in males than females, which is consistent with clinical observation. Liver microsomal testosterone 6β-hydroxylase (CYP3A4) activity was slightly greater in females than males, but the difference was not significant. However, in cryopreserved human hepatocytes, the gender difference in CYP3A4 activity (females = twice males) did reach statistical significance, which supports the clinical observation that females metabolize certain CYP3A4 substrates faster than do males. Compared with those from Caucasians and African Americans, liver microsomes from Hispanics had about twice the average activity of CYP2A6, CYP2B6, and CYP2C8 and half the activity of CYP1A2, although this apparent ethnic difference may be a consequence of the relatively low number of Hispanic donors. Primary cultures of hepatocytes were treated with β-naphthoflavone, an inducer of CYP1A2, phenobarbital or rifampin, both of which induce CYP2B6, CYP2C9, CYP2C19, and CYP3A4, albeit it to different extents. Induction of these CYP enzymes in freshly cultured hepatocytes did not appear to be influenced by the gender or age of the donor. Furthermore, CYP3A4 induction in

Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis

OpenAIRE

Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F

1998-01-01

Background—Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). 
Aims—Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. 
Patients—Twenty one patients with type 2 AIH were studied. 
Methods—A...

Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study

Energy Technology Data Exchange (ETDEWEB)

Buc-Calderon, P.; Roberfroid, M. (Universite Catholique de Louvain, Brussels (Belgium))

1989-09-01

Captodative substituted olefins are radical scavengers which react with free radicals to form stabilized radical adducts. One of those compounds, N-(paramethoxyphenylacetyl)dehydroalanine (AD-5), may react and scavenge both superoxide anion (O-2) and alk-oxyl radicals (RO.), and in this way prevent the appearance of their mediated biological effects. Nitrofurantoin and tert-butyl hydroperoxide were used as model compounds to stimulate free radical production and their mediated lipid peroxidation in rat liver microsomes. In addition, lipid peroxidation was also initiated by exposure of rat liver microsomal suspensions to ionizing radiation (gamma rays). The microsomal lipid peroxidation induced by these chemicals and physical agents was inhibited by the addition of AD-5. These effects were dose-dependent in a millimolar range of concentration. In addition, AD-5 has no effect on microsomal electron transport, showing that NADPH-cytochrome P450 reductase activity was not modified. These data, together with the comparisons of the effects of AD-5 and some antioxidant molecules such as superoxide dismutase, uric acid, and mannitol, support the conclusion that inhibition of lipid peroxidation by AD-5 is the result of its free radical scavenger activity. In addition, the inhibitory effect of AD-5 on microsomal lipid peroxidation was dependent of the nature of the free radical species involved in the initiation of the process, suggesting that O-2 is scavenged more efficiently than RO.

Identification of a tryptanthrin metabolite in rat liver microsomes by liquid chromatography/electrospray ionization-tandem mass spectrometry.

Science.gov (United States)

Lee, Sang Kyu; Kim, Ghee Hwan; Kim, Dong Hyeon; Kim, Dong Hyun; Jahng, Yurngdong; Jeong, Tae Cheon

2007-10-01

Tryptanthrin originally isolated from Isatis tinctoria L. has been characterized to have anti-inflammatory activities through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase mediated prostaglandin and leukotriene syntheses. To characterize phase I metabolite(s), tryptanthrin was incubated with rat liver microsomes in the presence of NADPH-generating system. One metabolite was identified by liquid chromatography/electrospray ionization-tandem mass spectrometry. M1 could be identified as a metabolite mono-hydroxylated on the aromatic ring of indole moiety from the MS(2) spectra of protonated tryptanthrin and M1. The structure of metabolite was confirmed as 8-hydroxytryptanthrin with a chemically synthesized authentic standard. The formation of M1 was NADPH-dependent and was inhibited by SKF-525A, a general CYP-inhibitor, indicating the cytochrome P450 (CYP)-mediated reaction. In addition, it was proposed that M1 might be formed by CYP 1A in rat liver microsomes from the experiments with enriched rat liver microsomes.

Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yoko, E-mail: y-watanabe@nichiyaku.ac.jp [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Kojima, Hiroyuki; Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Uramaru, Naoto [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Sanoh, Seigo [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Sugihara, Kazumi [Faculty of Pharmaceutical Science, Hiroshima International University, Koshingai 5-1-1, Kure, Hiroshima 737-0112 (Japan); Kitamura, Shigeyuki [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Ohta, Shigeru [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

2015-01-15

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. - Highlights: • Metabolic modification of the endocrine-disrupting activity of BP-3 was examined. • 2,4,5-TriOH BP and 3-OH BP-3 were identified as new BP-3 metabolites. • 2,4-DiOH BP and 2,3,4-triOH BP exhibited high or similar estrogenic activities. • Estrogenic activity of BP-3 was enhanced by incubation with rat liver

Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis.

Science.gov (United States)

Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F B

1998-05-01

Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. Twenty one patients with type 2 AIH were studied. All sera were tested by indirect immunofluorescence, counterimmunoelectrophoresis, and immunoblotting visualised by enhanced chemiluminescence. To evaluate LKM1 and LC1 levels, the 50 kDa microsomal reactivity (corresponding to CYP2D6) and the 58 kDa cytosolic reactivity were quantified by densitometric analysis. Seven patients were positive for LKM1, nine for LC1, and five for both. Serial serum samples at onset and during immunosuppressive treatment were analysed in 13 patients (four positive for LKM1, six positive for LC1 and three positive for both). During remission, LKM1 concentration remained essentially unchanged in six of seven patients, and decreased in only one. Conversely, in two of nine patients, LC1 was completely lost, and, in the remaining seven, LC1 concentration was reduced by more than 50%. After immunosuppression tapering or withdrawal, flare ups of liver necrosis ensued with increasing LC1 concentration, but not LKM1. LC1 concentration, at variance with that of LKM1, parallels liver disease activity, and its participation in the pathogenic mechanisms of liver injury can be hypothesised.

Non-invasive evaluation of liver stiffness after splenectomy in rabbits with CCl4-induced liver fibrosis

OpenAIRE

Wang, Ming-Jun; Ling, Wen-Wu; Wang, Hong; Meng, Ling-Wei; Cai, He; Peng, Bing

2016-01-01

AIM To investigate the diagnostic performance of liver stiffness measurement (LSM) by elastography point quantification (ElastPQ) in animal models and determine the longitudinal changes in liver stiffness by ElastPQ after splenectomy at different stages of fibrosis. METHODS Liver stiffness was measured in sixty-eight rabbits with CCl4-induced liver fibrosis at different stages and eight healthy control rabbits by ElastPQ. Liver biopsies and blood samples were obtained at scheduled time points...

Metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy LSD (O-H-LSD) in human liver microsomes and cryopreserved human hepatocytes.

Science.gov (United States)

Klette, K L; Anderson, C J; Poch, G K; Nimrod, A C; ElSohly, M A

2000-10-01

The metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD) was investigated in liver microsomes and cyropreserved hepatocytes from humans. Previous studies have demonstrated that O-H-LSD is present in human urine at concentrations 16-43 times greater than LSD, the parent compound. Additionally, these studies have determined that O-H-LSD is not generated during the specimen extraction and analytical processes or due to parent compound degradation in aqueous urine samples. However, these studies have not been conclusive in demonstrating that O-H-LSD is uniquely produced during in vivo metabolism. Phase I drug metabolism was investigated by incubating human liver microsomes and cryopreserved human hepatocytes with LSD. The reaction was quenched at various time points, and the aliquots were extracted using liquid partitioning and analyzed by liquid chromatography-mass spectrometry. O-H-LSD was positively identified in all human liver microsomal and human hepatocyte fractions incubated with LSD. In addition, O-H-LSD was not detected in any microsomal or hepatocyte fraction not treated with LSD nor in LSD specimens devoid of microsomes or hepatocytes. This study provides definitive evidence that O-H-LSD is produced as a metabolic product following incubation of human liver microsomes and hepatocytes with LSD.

[Comparative metabolism of three amide alkaloids from Piper longum in five different species of liver microsomes].

Science.gov (United States)

He, Huan; Guo, Wei-Wei; Chen, Xiao-Qing; Zhao, Hai-Yu; Wu, Xia

2016-08-01

Piperine, piperlonguminine and pellitorine are three major amide alkaloids from Piper longum, showing a variety of pharmacological activities. In order to investigate the different metabolism pathways of these compounds in five species of liver microsomes in vitro, the data of full mass spectrum, and MS2, MS3 spectra of these three alkaloids were collected and analyzed by using ultra-high-performance liquid chromatography coupled with a LTQ-orbitrap mass spectrometer (UHPLC-LTQ-Orbitrap MS); gragment ion information was collected and combined with fragmentation regularities of mass spectra and accurate mass spectrometry data of metabolites, to compare the metabolism difference of three amide alkaloids in liver microsomes of human, rhesus monkey, Beagle dogs, rats and mice. 3 metabolites of piperine, 2 metabolites of piperlonguminine and 1 metabolite of pellitorine were identified quickly. The results showed that the major metabolic pathways of these amide alkaloids in liver microsomes were methylenedioxy group demethylation and oxidation reaction, and metabolic rates were different between species. This study provides basis for further research on in vivo metabolism of piperine analogues from Piper longum. Copyright© by the Chinese Pharmaceutical Association.

Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.

Science.gov (United States)

Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M P; Albano, E; Bianchi, F B

2000-04-01

Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.

Development of vitamin D3 25-hydroxylase activity in rat liver microsomes

International Nuclear Information System (INIS)

Thierry-Palmer, M.; Cullins, S.; Rashada, S.; Gray, T.K.; Free, A.

1986-01-01

The authors have determined the ontogeny of vitamin D 3 25-hydroxylase activity in rat liver microsomes. Microsomes from fetuses, neonates, and their mothers were incubated with 44 nM 3 H-vitamin D 3 in the presence of an NADPH generating system, oxygen, KCl, and MgCl 2 . Lipid extracts of the incubation samples were partially purified by thin-layer chromatography. Tritiated 25-hydroxy vitamin D 3 (250HD 3 ) was analyzed by high-pressure liquid chromatography using 94/6 hexane/isopropanol. Production rate for 250HD 3 in the mothers ranged from 0.22 to 0.30 pmol/mg protein/hr. Activities in the fetuses and neonates were 2.1, 12.9, 32.0, 35.8, and 71.0% of that of their mothers at -3, 0, 2, 7, and 15 days of age. The cytosolic fraction protected the substrate from degradation, stimulated the vitamin D 3 25-hydroxylase reaction in neonates and mothers (1.4 to 1.7 fold increase), and was absolutely required for 25-hydroxylase activity in fetuses. These data suggest that microsomal vitamin D 3 25-hydroxylase activity develops slowly and approaches full activity near the weaning stage. A cytosolic factor present as early as -3 days of age stimulates the activity of the microsomal vitamin D 3 25-hydroxylase

Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

Energy Technology Data Exchange (ETDEWEB)

Reed, James R., E-mail: rreed@lsuhsc.edu [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Cawley, George F.; Ardoin, Taylor G. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Backes, Wayne L. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States)

2014-06-01

Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

International Nuclear Information System (INIS)

Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

2014-01-01

Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

[Peroxide modification of membranes and isomorphic composition of cytochrome P-450 of rat liver microsomes during antioxidant deficiency].

Science.gov (United States)

Gubskiy, Iu I; Paramonova, G I; Boldeskul, A E; Primak, R G; Bogdanova, L A; Zadorina, O V; Litvinova, N V

1992-01-01

Lipid peroxidation (LPO), physico-chemical properties of the membranes and isoformic composition of microsomal cytochrome P-450 from the rat liver were studied under conditions of antioxidant insufficiency (AOI) which was modelled by exclusion of alpha-tocopherol from the animals' ration. An insignificant accumulation of microsomal diene conjugates and schiff bases against a sharp increase of the ability to the prooxidant stimulated LPO in vitro took place. A significant decrease of membrane lipid microviscosity and a change in surface properties of microsomal membranes of rats with AOI was determined. Absence of alpha-tocopherol in the ration was accompanied by a significant change in the content of separate isoforms of cytochrome P-450 exhibited in growth of a polypeptide with m. w. 54 kDa and the lowering of proteins with m. w. 48 and 50 kDa. Less intensive quenching of tryptophan fluorescence by acrylamide was also revealed, which testified to a lower accessibility of the quencher to membrane proteins or their fluorophore sites. Modification of lipid composition and of physicochemical properties of the rat liver membrane microsomes which was observed at AOI was significantly correlated by pretreatment with the antioxidant 4-methyl-2,6-ditretbutylphenol (ionol).

Quantitative evaluation of fatty liver by computed tomography in rabbits

International Nuclear Information System (INIS)

Kawata, R.; Sakata, K.; Kunieda, T.; Saji, S.; Doi, H.; Nozawa, Y.

1984-01-01

Biochemical, histologic, and computed tomographic (CT) examinations of the liver were performed in 32 rabbits in which fatty liver was induced by prolonged intravenous fat infusion. In two groups of rabbits, in which 2 and 4 g/kg/day of fat emulsion was administered, respectively, posttreatment reduction in CT value of mild degree was observed. In the group that received 8 g/kg/day of fat emulsion, posttreatment change in CT value was sufficient for a diagnosis of fatty liver of moderate degree. Reduction in CT value in fatty liver might be due largely to accumulation of triglyceride and cholesterol in the liver cells. Significant correlation was found between changes in CT value of the liver and degrees of histological fat accumulation in the liver cells. Consecutive measurement of CT values of the liver during prolonged intravenous hyperalimentation is a nonagressive method of diagnosing fatty liver

Trapping of cis-2-butene-1,4-dial to measure furan metabolism in human liver microsomes by cytochrome P450 enzymes.

Science.gov (United States)

Gates, Leah A; Lu, Ding; Peterson, Lisa A

2012-03-01

Furan is a liver toxicant and carcinogen in rodents. It is classified as a possible human carcinogen, but the human health effects of furan exposure remain unknown. The oxidation of furan by cytochrome P450 (P450) enzymes is necessary for furan toxicity. The product of this reaction is the reactive α,β-unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). To determine whether human liver microsomes metabolize furan to BDA, a liquid chromatography/tandem mass spectrometry method was developed to detect and quantify BDA by trapping this reactive metabolite with N-acetyl-l-cysteine (NAC) and N-acetyl-l-lysine (NAL). Reaction of NAC and NAL with BDA generates N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine (NAC-BDA-NAL). Formation of NAC-BDA-NAL was quantified in 21 different human liver microsomal preparations. The levels of metabolism were comparable to that observed in F-344 rat and B6C3F1 mouse liver microsomes, two species known to be sensitive to furan-induced toxicity. Studies with recombinant human liver P450s indicated that CYP2E1 is the most active human liver furan oxidase. The activity of CYP2E1 as measured by p-nitrophenol hydroxylase activity was correlated to the extent of NAC-BDA-NAL formation in human liver microsomes. The formation of NAC-BDA-NAL was blocked by CYP2E1 inhibitors but not other P450 inhibitors. These results suggest that humans are capable of oxidizing furan to its toxic metabolite, BDA, at rates comparable to those of species sensitive to furan exposure. Therefore, humans may be susceptible to furan's toxic effects.

Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

Science.gov (United States)

Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

2004-03-07

The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

Hepatitis C virus infection associated with liver-kidney microsomal antibody type 1 (LKM1) autoantibodies in children.

Science.gov (United States)

Bortolotti, Flavia; Muratori, Luigi; Jara, Paloma; Hierro, Loreto; Verucchi, Gabriella; Giacchino, Raffaella; Barbera, Cristiana; Zancan, Lucia; Guido, Maria; Resti, Massimo; Pedditzi, Sabrina; Bianchi, Francesco; Gatta, Angelo

2003-02-01

To evaluate the clinical pattern and evolution of chronic hepatitis C in children with liver/kidney microsomal antibody type 1 autoantibodies (LKM1). A multicenter, retrospective study, including the following groups of children with hepatitis C virus infection: (1). 21 consecutive LKM1-positive patients, (2). 42 age- and sex- matched LKM1-negative patients, and (3). 4 interferon-induced LKM1-positive cases. LKM1 reactivity to human microsomes and recombinant cytochrome P450IID6 (CYP2D6) was assayed by immunoblotting. Clinical and biochemical features overlapped in LKM1-positive and LKM1-negative children, but a fibrosis score >3 (range 0-6) was significantly more frequent (P =.04) in the former. Reactivity to microsomal protein and CYP2D6 was significantly (P =.02) associated with LKM1 titers >or=1:320 and was found in 39% of patients, including severe cases and both children (of 4 treated) who achieved a sustained alanine aminotransferase (ALT) normalization after steroid treatment. Five of 7 LKM1-positive children treated with interferon had an ALT exacerbation. LKM1-positive hepatitis C in children is characterized by a wide spectrum of biochemical, serologic, and histologic features. Whether autoimmunity may contribute to liver damage in a subgroup of patients with more severe liver disease, high LKM1 titers, and reactivity to CYP2D6 is a question deserving further investigation.

Biotransformation of a novel antimitotic agent, I-387, by mouse, rat, dog, monkey, and human liver microsomes and in vivo pharmacokinetics in mice.

Science.gov (United States)

Ahn, Sunjoo; Kearbey, Jeffrey D; Li, Chien-Ming; Duke, Charles B; Miller, Duane D; Dalton, James T

2011-04-01

3-(1H-Indol-2-yl)phenyl)(3,4,5-trimethoxyphenyl)methanone (I-387) is a novel indole compound with antitubulin action and potent antitumor activity in various preclinical models. I-387 avoids drug resistance mediated by P-glycoprotein and showed less neurotoxicity than vinca alkaloids during in vivo studies. We examined the pharmacokinetics and metabolism of I-387 in mice as a component of our preclinical development of this compound and continued interest in structure-activity relationships for antitubulin agents. After a 1 mg/kg intravenous dose, noncompartmental pharmacokinetic analysis in plasma showed that clearance (CL), volume of distribution at steady state (Vd(ss)), and terminal half-life (t(1/2)) of I-387 were 27 ml per min/kg, 5.3 l/kg, and 7 h, respectively. In the in vitro metabolic stability study, half-lives of I-387 were between 10 and 54 min by mouse, rat, dog, monkey, and human liver microsomes in the presence of NADPH, demonstrating interspecies variability. I-387 was most stable in rat liver microsomes and degraded quickly in monkey liver microsomes. Liquid chromatography-tandem mass spectrometry was used to identify phase I metabolites. Hydroxylation, reduction of a ketone group, and O-demethylation were the major metabolites formed by the liver microsomes of the five species. The carbonyl group of I-387 was reduced and identified as the most labile site in human liver microsomes. The results of these drug metabolism and pharmacokinetic studies provide the foundation for future structural modification of this pharmacophore to improve stability of drugs with potent anticancer effects in cancer patients.

Lichen planus, liver kidney microsomal (LKM1) antibodies and hepatitis C virus antibodies.

Science.gov (United States)

Divano, M C; Parodi, A; Rebora, A

1992-01-01

No anti-liver kidney microsomal (LKM1) antibodies were detected in 46 patients with LP, 16 of whom had also a chronic liver disease (CLD). In contrast, anti-hepatitis C virus (HCV) antibodies were found in 10% of patients with LP and in 50% of those with LP and CLD. Anti-HCV antibodies may be considered as a false-positive reaction in 56% of cases, especially when anti-LKM1 antibodies are present. Our findings do not support such a hypothesis, but suggest that CLD in LP patients is, at least in Italy, mostly a postviral chronic active hepatitis.

Effect of cholesterol feeding on tissue lipid perioxidation, glutathione peroxidase activity and liver microsomal functions in rats and guinea pigs

NARCIS (Netherlands)

TSAI, A. C.; THIE, G. M.; Lin, C. R.

1977-01-01

The effect of cholesterol feeding on liver and aortic nonenzymatic lipid peroxidation and glutathione peroxidase activities, and on liver microsomal NADPH-dependent lipid peroxidation, codeine hydroxylation and cytochrome P-450 levels was examined in rats and guinea pigs. One percent cholesterol was

Roles of different forms of cytochrome P450 in the activation of the promutagen 6-aminochrysene to genotoxic metabolites in human liver microsomes.

Science.gov (United States)

Yamazaki, H; Mimura, M; Oda, Y; Inui, Y; Shiraga, T; Iwasaki, K; Guengerich, F P; Shimada, T

1993-07-01

We reported previously that the potent mutagen 6-aminochrysene is catalyzed principally by rat liver microsomal P4501A and P4502B enzymes to reactive metabolites that induce umu gene expression in O-acetyltransferase-over-expressing strain Salmonella typhimurium NM2009; the proposal was made that there are different mechanisms in the formation of reactive N-hydroxylated and diolepoxide metabolites by P450 enzymes (Yamazaki, H. and Shimada, T., Biochem. Pharmacol., 44, 913-920, 1992). Here we further examined the roles of human liver P450 enzymes and the mechanism of activation of 6-aminochrysene by rat and human P450 enzymes in the Salmonella tester strains. Liver microsomes from 18 different human samples catalyzed activation of 6-aminochrysene more efficiently in S. typhimurium NM2009 than in the original strain of S. typhimurium TA1535/pSK1002. The rates of 6-aminochrysene activation in 18 human liver samples showed good correlation to the contents of P4502B6 as well as contents of P4503A4 and the respective mono-oxygenase activities catalyzed by P4503A4. Among purified P450 enzymes examined, P4501A2 as well as P4503A4 were highly active in transforming 6-amino-chrysene to reactive metabolites, suggesting the involvement of different human P450 enzymes in the reaction. Four human samples that contained relatively high levels of particular P450 enzymes in their microsomes were selected and used for further characterization. Liver microsomes from human samples HL-13 and HL-4 that contained the highest levels of P4502B6 and P4503A4 respectively, were sensitive to the respective antibodies raised against monkey P4502B and human P4503A4; the activity in sample HL-16 having the highest level of P4501A2 was inhibited by anti-P4501A2 IgG. alpha-Naphthoflavone enhanced the activation of 6-aminochrysene very significantly in human liver microsomes enriched in P4503A4 and P4502B6 enzymes. Pentachlorophenol, an inhibitor of acetyltransferase activity, suppressed the

Characterization of anti-liver-kidney microsome antibody (anti-LKM1) from hepatitis C virus-positive and -negative sera.

Science.gov (United States)

Yamamoto, A M; Cresteil, D; Homberg, J C; Alvarez, F

1993-06-01

Hepatitis C virus-related antibodies were found in sera positive for antibodies to liver/kidney microsome antibody, usually considered a marker of autoimmune hepatitis. The aim of this study was to analyze the specificity of this autoantibody in sera from patients with and without hepatitis C virus infection. Fifteen anti-hepatitis C virus- and anti-liver kidney microsome-positive sera were compared with 11 sera from patients with autoimmune hepatitis, for reactivity against rat and human liver microsomal proteins, P450IID6 recombinant proteins, and various synthetic peptides spanning the 241-429 amino acids sequence of the P450IID6. Ten of 11 sera from patients with autoimmune hepatitis bound to recombinant proteins spanning the P450IID6 region between amino acids 72 and 458. These sera bound to the 254-271 peptide, and some also recognized the 321-351, 373-389 and 410-429 peptides. Four of 15 antihepatitis C virus recognized the fusion protein coded by the full-length P450IID6 complementary DNA; 3 of them also reacted with the P450IID6 region between amino acids 72-456. Only 1 sera recognized the 321-351 peptide. P450IID6 antigenic sites recognized by anti-hepatitis C virus-positive sera were different from those recognized by sera from patients with autoimmune hepatitis.

Role of metabolic activation by cytochrome P-450 in covalent binding of VP 16-213 to rat liver and HeLa cell microsomal proteins

Energy Technology Data Exchange (ETDEWEB)

van Maanen, J.M.; de Ruiter, C.; de Vries, J.; Kootstra, P.R.; Gobas, F.; Pinedo, H.M.

1985-09-01

Covalent binding of /sup 3/H-labeled VP 16-213 to rat liver and HeLa cell microsomal proteins was studied in vitro. Metabolic activation by cytochrome P-450 was found to play a role in the covalent binding of VP 16-213 to rat liver microsomal proteins, as shown by the need of NADPH cofactor, the increased binding after phenobarbital pretreatment and the inhibition by SFK-525A. Addition of ascorbic acid or alpha-phenyl-N-tert. butylnitrone to the incubation mixture depressed covalent binding by about 85%, suggesting that formation of a reactive metabolite from the phenolic structure may be involved in the binding process. VP 16-213 did not inhibit aminopyrine N-demethylase at the concentration used in the binding experiments (17 microM), indicating that metabolism of its methylenedioxy group does not play a role in binding to microsomal proteins. HeLa cell microsomes were found to possess aminopyrine N-demethylase activity. Covalent binding of radiolabeled VP 16-213 to HeLa cell microsomes decreased by about 64% if NADPH was omitted.

Microsomal metabolism of trenbolone acetate metabolites ...

Science.gov (United States)

Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

Rat liver microsomal cytochrome P450-dependent oxidation of 3,5-disubstituted analogues of paracetamol

NARCIS (Netherlands)

Bessems, J.G.M.; Koppele, J.M. te; Dijk, P.A. van; Stee, L.L.P. van; Commandeur, J.N.M.; Vermeulen, N.P.E.

1996-01-01

1. The cytochrome P450-dependent binding of paracetamol and a series of 3,5-disubstituted paracetamol analogues (R = -F, -Cl, -Br, -I, -C(H)3, -C2H5, -iC3H7) have been determined with β-naphthoflavone (βNF)-induced rat liver microsomes and produced reverse type I spectral changes. K(s,app) varied

Whole-liver MR perfusion imaging in rabbit liver VX2 tumors: early findings of coagulative necrosis after percutaneous ethanol injection therapy

International Nuclear Information System (INIS)

Zhang Wanshi; Wang Dong; Meng Limin; Shi Huiping; Song Yunlong; Wu Bing

2007-01-01

Objective: To investigate the value of whole-liver MR perfusion imaging (MRPI) for early detection of coagulative necrosis after percutaneous ethanol injection (PEI) in rabbit liver VX 2 tumors. Methods: VX 2 tumor cell suspension was inoculated into rabbit liver and liver VX 2 tumors [diameter of (2.6 ± 0.6) cm] were induced in 10 male rabbits. MR T 1 WI and T 2 WI were performed to monitor the development of the liver tumor on the 2 nd and 3 rd week after inoculation. Whole-liver MRPI was performed in the 10 rabbits with liver VX 2 tumors before and 6 days after PEI therapy (1.0 ml ethanol was injected into the most enhanced tumor region under CT guiding). Signal intensity (SI) values of untreated tumor parts and treated areas 6 days after PEI were recorded respectively. The steepest slope (SS) and bolus arrival time (T0) of SI-time curves were measured. The t-Student test was used in statistical analysis of the data. Results: There was significant difference in MRPI data between untreated tumor parts [T0: (16.0 ± 1.2) s and SS: 38.9 ± 2.2] and treated areas [T0: (50.8 ± 5.9) s and SS: 6.0 ± 1.2] 6 days after PEI(t was 15.8 and -39.6 respectively, P 1 WI and T 2 WI could not show any differences between untreated tumor parts and treated areas. Conclusion: Whole-liver MRPI could detect coagulative necrosis of rabbit liver VX 2 tumors after PEI early. Disappearance of early enhancement can be a potential marker for efficacy of PEI. (authors)

An integrated study for the utilization of anthraquinone compounds extract “Heshouwu” In vivo and their comparative metabolism in liver microsomes using UPLC-ESI-Q-TOF/MSn

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Sha Chen

2018-01-01

Full Text Available Objective: Anthraquinone (AQ, a major bioactive component of the traditional Chinese medicine HeShouWu, has widespread applications in industry and medicine. The objective of the current study is to explore the differences in the bioavailability of anthraquinones in vivo and the metabolism in liver microsomes. Materials and Methods: In vivo, we used a reliable UPLC-ESI-QqQ-MS/MS method to measure seven AQ compounds in the jugular vein plasma of rats following oral administration of HeShouWu. Furthermore, in order to quantify the bioavailability of AQs in vivo and to further understand the metabolism of these compounds, we compared the in vitro metabolism of AQ in different species with respect to metabolic profiles, the enzymes involved, and catalytic efficiency using liver microsomes from human (HLM, mouse (MLM, rat (RLM, and beagle dog (DLM. Results: We identified two metabolic pathways, including the hydroxylation and glucuronidation of AQ, in the liver microsomes of humans and other species using UPLC-ESI-Q-TOF. We found that substitutions on the AQ ring were crucial to the activity and regioselectivity of its hydroxylation. In general, hydroxylation activity decreased greatly with β-COOH (rhein and enhanced dramatically with β-OH (emodin. We also found that glucuronidation of the compound emodin-8-O-β-D-glucoside acts as the main isoform in AQ hydroxylation in HLM and DLM. Total microsomal intrinsic clearance values for AQ were greatest in mouse microsomes, followed by those in dog, human, and rat microsomes. Conclusion: The absorption of different anthrquinone compounds varied based on the compound structure, the metabolism types and products of anthraquinones in liver microsomes were different in different species. These findings provide vital information for a deeper unuunderstanding of the metabolism of AQs.

Glucuronidation of trans-resveratrol by human liver and intestinal microsomes and UGT isoforms.

Science.gov (United States)

Brill, Shirley S; Furimsky, Anna M; Ho, Mark N; Furniss, Michael J; Li, Yi; Green, Adam G; Bradford, Wallace W; Green, Carol E; Kapetanovic, Izet M; Iyer, Lalitha V

2006-04-01

Resveratrol (trans-resveratrol, trans-3,5,4'-trihydroxystilbene) is a naturally occurring stilbene analogue found in high concentrations in red wine. There is considerable research interest to determine the therapeutic potential of resveratrol, as it has been shown to have tumour inhibitory and antioxidant properties. This study was performed to investigate the glucuronidation of resveratrol and possible drug interactions via glucuronidation. Two glucuronide conjugates, resveratrol 3-O-glucuronide and resveratrol 4'-O-glucuronide, were formed by human liver and intestinal microsomes. UGT1A1 and UGT1A9 were predominantly responsible for the formation of the 3-O-glucuronide (Km = 149 microM) and 4'-O-glucuronide (Km = 365 microM), respectively. The glucuronide conjugates were formed at higher levels (up to 10-fold) by intestinal rather than liver microsomes. Resveratrol was co-incubated with substrates of UGT1A1 (bilirubin and 7-ethyl-10-hydroxycamptothecin (SN-38)) and UGT1A9 (7-hydroxytrifluoromethyl coumarin (7-HFC)). No major changes were noted in bilirubin glucuronidation in the presence of resveratrol. Resveratrol significantly inhibited the glucuronidation of SN-38 (Ki = 6.2 +/- 2.1 microM) and 7-HFC (Ki = 0.6 +/- 0.2 microM). Hence, resveratrol has the potential to inhibit the glucuronidation of concomitantly administered therapeutic drugs or dietary components that are substrates of UGT1A1 and UGT1A9.

Age dependent in vitro metabolism of bifenthrin in rat and human hepatic microsomes.

Science.gov (United States)

Nallani, Gopinath C; Chandrasekaran, Appavu; Kassahun, Kelem; Shen, Li; ElNaggar, Shaaban F; Liu, Zhiwei

2018-01-01

Bifenthrin, a pyrethroid insecticide, undergoes oxidative metabolism leading to the formation of 4'-hydroxy-bifenthrin (4'-OH-BIF) and hydrolysis leading to the formation of TFP acid in rat and human hepatic microsomes. In this study, age-dependent metabolism of bifenthrin in rats and humans were determined via the rates of formation of 4'-OH-BIF and TFP acid following incubation of bifenthrin in juvenile and adult rat (PND 15 and PND 90) and human (18years) liver microsomes. Furthermore, in vitro hepatic intrinsic clearance (CL int ) of bifenthrin was determined by substrate consumption method in a separate experiment. The mean V max (±SD) for the formation of 4'-OH-BIF in juvenile rat hepatic microsomes was 25.0±1.5pmol/min/mg which was significantly lower (pbifenthrin occurs primarily via oxidative pathway with relatively lesser contribution (~30%) from hydrolytic pathway in both rat and human liver microsomes. The CL int values for bifenthrin, determined by monitoring the consumption of substrate, in juvenile and adult rat liver microsomes fortified with NADPH were 42.0±7.2 and 166.7±20.5μl/min/mg, respectively, and the corresponding values for human liver microsomes were 76.0±4.0 and 21.3±1.2μl/min/mg, respectively. The data suggest a major species difference in the age dependent metabolism of bifenthrin. In human liver microsomes, bifenthrin is metabolized at a much higher rate in juveniles than in adults, while the opposite appears to be true in rat liver microsomes. Copyright © 2017 Elsevier Inc. All rights reserved.

Hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, T.; Hirai, Y.; Koga, N.; Tomokuni, K.

1983-01-01

The hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/ was investigated with specific reference to the oxygen utilization of liver slices. In control rats, the major oxygen utilization of the liver slices was attributed to mitochondrial particles. Since the mitochondrial oxygen utilization was inhibited by cyanide, the microsomal oxygen utilization was induced by NADPH and phenobarbital (a substrate for microsomal mixed function oxidase). Changes in oxygen utilization were observed in the recovery course of rats intoxicated with CCl/sub 4/, and the recovery of mitochondria was found to be faster than that of microsomes. A sex difference was present in the recovery mechanism of the microsomes.

Metabolism of ginger component [6]-shogaol in liver microsomes from mouse, rat, dog, monkey, and human.

Science.gov (United States)

Chen, Huadong; Soroka, Dominique; Zhu, Yingdong; Sang, Shengmin

2013-05-01

There are limited data on the metabolism of [6]-shogaol (6S), a major bioactive component of ginger. This study demonstrates metabolism of 6S in liver microsomes from mouse, rat, dog, monkey, and human. The in vitro metabolism of 6S was compared among five species using liver microsomes from mouse, rat, dog, monkey, and human. Following incubations with 6S, three major reductive metabolites 1-(4'-hydroxy-3'-methoxyphenyl)-4-decen-3-ol (M6), 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9), and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11), as well as two new oxidative metabolites (1E,4E)-1-(4'-hydroxy-3'-methoxyphenyl)-deca-1,4-dien-3-one (M14) and (E)-1-(4'-hydroxy-3'-methoxyphenyl)-dec-1-en-3-one (M15) were found in all species. The kinetic parameters of M6 in liver microsomes from each respective species were quantified using Michaelis-Menten theory. A broad CYP-450 inhibitor, 1-aminobenzotriazole, precluded the formation of oxidative metabolites, M14 and M15, and 18β-glycyrrhetinic acid, an aldo-keto reductase inhibitor, eradicated the formation of the reductive metabolites M6, M9, and M11 in all species. Metabolites M14 and M15 were tested for cancer cell growth inhibition and induction of apoptosis and both showed substantial activity, with M14 displaying greater potency than 6S. We conclude that 6S is metabolized extensively in mammalian species mouse, rat, dog, monkey, and human, and that there are significant interspecies differences to consider when planning preclinical trials toward 6S chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

OpenAIRE

Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

2000-01-01

BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confo...

Influence of acute and chronic administration of methadone hydrochloride on NADPH-cytochrome c reductase and cytochrome P-450 of mouse liver microsomes.

Science.gov (United States)

Datta, R K; Johnson, E A; Bhattacharjee, G; Stenger, R J

1976-03-01

Administration of a single acute dose (20 mg/kg body weight) of methadone hydrochloride to both male and female mice increased the specific activity of NADPH-cytochrome c reductase and did not change much the content of cytochrome P-450 of their liver microsomes. Administration of multiple acute doses of methadone in male mice increased the specific activity of cytochrome c reductase and the content of cytochrome P-450 of their liver microsomes. Chronic administration of progressively increasing doses of methadone (up to 40 mg/kg body weight) to male mice increased the specific activity of c reductase. Similar chronic administration of methadone up to 28 mg/kg body weight also increased the microsomal content of P-450, but with higher doses of methadone, the content of P-450 declined and finally dropped slightly below control levels. The levels of c reductase activity and P-450 content returned to normal about two weeks after discontinuation of methadone administration.

Inhibitory Effects of Dimethyllirioresinol, Epimagnolin A, Eudesmin, Fargesin, and Magnolin on Cytochrome P450 Enzyme Activities in Human Liver Microsomes

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Ju-Hyun Kim

2017-05-01

Full Text Available Magnolin, epimagnolin A, dimethyllirioresinol, eudesmin, and fargesin are pharmacologically active tetrahydrofurofuranoid lignans found in Flos Magnoliae. The inhibitory potentials of dimethyllirioresinol, epimagnolin A, eudesmin, fargesin, and magnolin on eight major human cytochrome P450 (CYP enzyme activities in human liver microsomes were evaluated using liquid chromatography–tandem mass spectrometry to determine the inhibition mechanisms and inhibition potency. Fargesin inhibited CYP2C9-catalyzed diclofenac 4’-hydroxylation with a Ki value of 16.3 μM, and it exhibited mechanism-based inhibition of CYP2C19-catalyzed [S]-mephenytoin 4’-hydroxylation (Ki, 3.7 μM; kinact, 0.102 min−1, CYP2C8-catalyzed amodiaquine N-deethylation (Ki, 10.7 μM; kinact, 0.082 min−1, and CYP3A4-catalyzed midazolam 1’-hydroxylation (Ki, 23.0 μM; kinact, 0.050 min−1 in human liver microsomes. Fargesin negligibly inhibited CYP1A2-catalyzed phenacetin O-deethylation, CYP2A6-catalyzed coumarin 7-hydroxylation, CYP2B6-catalyzed bupropion hydroxylation, and CYP2D6-catalyzed bufuralol 1’-hydroxylation at 100 μM in human liver microsomes. Dimethyllirioresinol weakly inhibited CYP2C19 and CYP2C8 with IC50 values of 55.1 and 85.0 μM, respectively, without inhibition of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, and CYP3A4 activities at 100 μM. Epimagnolin A, eudesmin, and magnolin showed no the reversible and time-dependent inhibition of eight major CYP activities at 100 μM in human liver microsomes. These in vitro results suggest that it is necessary to investigate the potentials of in vivo fargesin-drug interaction with CYP2C8, CYP2C9, CYP2C19, and CYP3A4 substrates.

EX VIVO STUDY OF QUANTITATIVE ULTRASOUND PARAMETERS IN FATTY RABBIT LIVERS

Science.gov (United States)

Ghoshal, Goutam; Lavarello, Roberto J.; Kemmerer, Jeremy P.; Miller, Rita J.; Oelze, Michael L.

2012-01-01

Nonalcoholic fatty liver disease (NAFLD) affects more than 30% of Americans, and with increasing problems of obesity in the United States, NAFLD is poised to become an even more serious medical concern. At present, accurate classification of steatosis (fatty liver) represents a significant challenge. In this study, the use of high-frequency (8 to 25 MHz) quantitative ultrasound (QUS) imaging to quantify fatty liver was explored. QUS is an imaging technique that can be used to quantify properties of tissue giving rise to scattered ultrasound. The changes in the ultrasound properties of livers in rabbits undergoing atherogenic diets of varying durations were investigated using QUS. Rabbits were placed on a special fatty diet for 0, 3, or 6 weeks. The fattiness of the livers was quantified by estimating the total lipid content of the livers. Ultrasonic properties, such as speed of sound, attenuation, and backscatter coefficients, were estimated in ex vivo rabbit liver samples from animals that had been on the diet for varying periods. Two QUS parameters were estimated based on the backscatter coefficient: effective scatterer diameter (ESD) and effective acoustic concentration (EAC), using a spherical Gaussian scattering model. Two parameters were estimated based on the backscattered envelope statistics (the k parameter and the μ parameter) according to the homodyned K distribution. The speed of sound decreased from 1574 to 1565 m/s and the attenuation coefficient increased from 0.71 to 1.27 dB/cm/MHz, respectively, with increasing fat content in the liver. The ESD decreased from 31 to 17 μm and the EAC increased from 38 to 63 dB/cm3 with increasing fat content in the liver. A significant increase in the μ parameter from 0.18 to 0.93 scatterers/mm3 was observed with increasing fat content in the liver samples. The results of this study indicate that QUS parameters are sensitive to fat content in the liver. PMID:23062376

Analysis of growth hormone and lactogenic binding sites cross-linked to iodinated human growth hormone

International Nuclear Information System (INIS)

Hughes, J.P.; Simpson, J.S.; Friesen, H.G.

1983-01-01

GH (GHR) and lactogenic receptors were analyzed after use of the cross-linking reagent ethylene glycol bis-(succinimidyl succinate) to attach covalently iodinated human GH (hGH) to binding proteins 1) on intact IM-9 lymphocytes, 2) in a partially purified GHR preparation from rabbit liver, and 3) in crude microsomal fractions from rabbit liver, rabbit mammary gland, and rat liver. The latter two microsomal preparations contain primarily lactogenic receptors, whereas in IM-9 lymphocytes and the rabbit liver preparations, GHR predominate. Cross-linked [125I]hGH-receptor complexes were solubilized, reduced, and separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Analysis of proteins cross-linked to [125I]hGH in the microsomal fraction from rabbit liver showed a specifically labeled complex with an estimated molecular weight (mol wt) of 75K. A slightly lower mol wt (71K) was determined for the complex labeled in the purified GHR preparation. In contrast to the relatively low mol wt complexes in rabbit liver, a complex that migrated with an apparent mol wt of 130K was identified in IM-9 lymphocytes. Labeled complexes were identified at 66K from rat liver and 61K from rabbit mammary gland. If it is assumed that hGH contributes 21K to the mol wt of the radiolabeled complexes, then the approximate mol wts of hGH-binding sites are 50-54K from rabbit liver, 109K from IM-9 lymphocytes, 45K from rat liver, and 40K from rabbit mammary gland

Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs

DEFF Research Database (Denmark)

Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent

2006-01-01

Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, an...... 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid...

ROLE OF LEPTIN ON CYTOCHROME P-450 AND SOME LIVER MICROSOMAL ENZYMES ACTIVITIES IN THE OBESE AND LEAN MICE

International Nuclear Information System (INIS)

HEBEISHY, M.I.A.; MAZEN, G.M.A.; SHAHIN, M.I

2008-01-01

Leptin is a hormone that is secreted by adipocytes and regulates body weight through its effect on satiety and energy metabolism. The obese mouse is deficient in this protein and is characterized by obesity and other metabolic disorders. This study investigated the alterations of several hepatic cytochrome P 4 -5 0 (CYP), conjugation and antioxidant enzymes in lean and obese mice and the role of leptin in the modulation of these enzymes. Lean and obese male mice were injected with leptin (100 μg / rat) for 15 days. The obtained results revealed that administration of leptin to lean mice caused a significant elevation in the level of blood glucose, serum insulin, 6α, 6β, 16α- hydroxylation of testosterone, the activity of CYP 1 A 1 , CYP 4 A and GSH reductase in liver microsomes while serum corticosterone and the activity of total GSH were significantly decreased when compared to lean control mice. Moreover, obese mice treated with leptin recorded significant reduction in body weight, blood glucose concentration, serum levels of insulin and corticosterone, 7α and 16α- hydroxylation of testosterone, the activity of CYP 1A 1, CYP 2 B 1 and CYP 4 A and GST in liver microsomes. On the other hand, 6α, 6β-hydroxylation of testosterone, the activity of CYP 2 E 1 and GSH reductase in liver microsome were significantly increased when compared to obese control mice. The mechanism for the observed alterations may be due to direct leptin effects or via indirect alterations in insulin, corticosterone and/or growth hormone

Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

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Menéndez R.

2000-01-01

Full Text Available The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS. When D002 (5-100 mg/kg body weight was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46% occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40% and brain (28-44% microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

In vitro modulatory effects of Terminalia arjuna, arjunic acid, arjunetin and arjungenin on CYP3A4, CYP2D6 and CYP2C9 enzyme activity in human liver microsomes

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Alice Varghese

2015-01-01

Full Text Available Terminalia arjuna is a tree having an extensive medicinal potential in cardiovascular disorders. Triterpenoids are mainly responsible for cardiovascular properties. Alcoholic and aqueous bark extracts of T. arjuna, arjunic acid, arjunetin and arjungenin were evaluated for their potential to inhibit CYP3A4, CYP2D6 and CYP2C9 enzymes in human liver microsomes. We have demonstrated that alcoholic and aqueous bark extract of T. arjuna showed potent inhibition of all three enzymes in human liver microsomes with IC50 values less than 50 μg/mL. Arjunic acid, arjunetin and arjungenin did not show significant inhibition of CYP enzymes in human liver microsomes. Enzyme kinetics studies suggested that the extracts of arjuna showed reversible non-competitive inhibition of all the three enzymes in human liver microsomes. Our findings suggest strongly that arjuna extracts significantly inhibit the activity of CYP3A4, CYP2D6 and CYP2C9 enzymes, which is likely to cause clinically significant drug–drug interactions mediated via inhibition of the major CYP isozymes.

Hepatic microsomal metabolism of BDE-47 and BDE-99 by lesser snow geese and Japanese quail.

Science.gov (United States)

Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

2017-09-01

In the present study, we investigated the oxidative biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) by liver microsomes from wild lesser snow geese (Chen caerulescens caerulescens) and domesticated Japanese quail (Coturnix japonica). Formation of hydroxy-metabolites was analyzed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with avian liver microsomes produced sixteen hydroxy-metabolites, eight of which were identified using authentic standards. The major metabolites formed by liver microsomes from individual lesser snow geese were 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), and 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether (4'-OH-BDE-49). By comparison, 4-OH-BDE-42 and 4'-OH-BDE-49, but not 3-OH-BDE-47, were major metabolites of Japanese quail liver microsomes. Unidentified metabolites included monohydroxy- and dihydroxy-tetrabromodiphenyl ethers. Incubation of BDE-99 with avian liver microsomes produced seventeen hydroxy-metabolites, twelve of which were identified using authentic standards. The major metabolites formed by lesser snow goose liver microsomes were 2,4,5-tribromophenol, 3-OH-BDE-47, 4'-OH-BDE-49, 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90), and 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99). By comparison, the major metabolites produced by liver microsomes from Japanese quail included 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) and 2-hydroxy-2',3,4,4',5-pentabromodiphenyl ether (2-OH-BDE-123), but not 3-OH-BDE-47. Unidentified metabolites consisted of monohydroxy-pentabromodiphenyl ethers, monohydroxy-tetrabromodiphenyl ethers and dihydroxy-tetrabromodiphenyl ethers. Another difference between the two species was that formation rates of BDE-47 and BDE-99 metabolites were greater with liver

Pregnancy-induced insulin resistance in liver and skeletal muscles of the conscious rabbit

International Nuclear Information System (INIS)

Hauguel, S.; Gilbert, M.; Girard, J.

1987-01-01

Insulin sensitivity of maternal nonuterine tissues (liver and skeletal muscles) has been investigated in the conscious rabbit during late gestation (24 and 30 days). The specific effect of insulin on glucose production and utilization was evaluated with the hyperinsulinemic euglycemic clamp technique using two types of labelled microspheres ( 57 Co and 113 Sn). The net balance of glucose across the hindlimb muscles was studied by means of the Fick principle in basal and insulin stimulated conditions (clamp study). The results show that an insulin-resistant state developed between days 24 and 30 of gestation in the rabbit and involves both glucose producing (liver) and utilizing (muscles) tissues. On day 30 of gestation, muscle glucose uptake was not significantly stimulated at a plasma insulin concentration of 700 μU/ml determined by radioimmunoassay, whereas it was stimulated by 30-40% in nonpregnant and 24 day pregnant rabbits. At similar plasma insulin concentration, endogenous glucose production was suppressed by 85% in both nonpregnant and 24 day pregnant rabbits, whereas it was decreased by only 30% in 30 day pregnant rabbits. The present data suggest that hindlimb muscles of late pregnant rabbits are able to reduce their insulin-induced glucose utilization. This could contribute to meet the glucose requirements of pregnant uterus in late gestation

Dietary saturated and monounsaturated fats protect against acute acetaminophen hepatotoxicity by altering fatty acid composition of liver microsomal membrane in rats

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Shim Eugene

2011-10-01

Full Text Available Abstract Background Dietary polyunsaturated fats increase liver injury in response to ethanol feeding. We evaluated the effect of dietary corn oil (CO, olive oil (OO, and beef tallow (BT on fatty acid composition of liver microsomal membrane and acute acetaminophen hepatotoxicity. Methods Male Sprague-Dawley rats were fed 15% (wt/wt CO, OO or BT for 6 weeks. After treatment with acetaminophen (600 mg/kg, samples of plasma and liver were taken for analyses of the fatty acid composition and toxicity. Results Treatment with acetaminophen significantly elevated levels of plasma GOT and GPT as well as hepatic TBARS but reduced hepatic GSH levels in CO compared to OO and BT groups. Acetaminophen significantly induced protein expression of cytochrome P450 2E1 in the CO group. In comparison with the CO diet, lower levels of linoleic acid, higher levels of oleic acids and therefore much lower ratios of linoleic to oleic acid were detected in rats fed OO and BT diets. Conclusions Dietary OO and BT produces similar liver microsomal fatty acid composition and may account for less severe liver injury after acetaminophen treatment compared to animals fed diets with CO rich in linoleic acid. These findings imply that types of dietary fat may be important in the nutritional management of drug-induced hepatotoxicity.

The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

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Feng Li

2018-05-01

Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

In vitro metabolism of the anti-androgenic fungicide vinclozolin by rat liver microsomes.

Science.gov (United States)

Sierra-Santoyo, Adolfo; Angeles-Soto, Esperanza; de Lourdes López-González, Ma; Harrison, Randy A; Hughes, Michael F

2012-03-01

Vinclozolin (V) is a fungicide used in agricultural settings. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1 and M2 have antiandrogenic properties by interacting with the androgen receptor. Data on V, M1 and M2 biotransformation are limited. Our objective was to characterize V metabolism by rat liver microsomes. V was incubated with non-treated adult male Long-Evans rat liver microsomes and NADPH. Several metabolites were detected following the extraction of incubate with acetonitrile and analysis by HPLC/DAD/MSD. One metabolite was identified as [3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3-oxazolidine-2,4-dione] (M4), which was gradually converted to 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (M5). Both co-eluted in the same HPLC peak. Another metabolite ([M7]) was detected by UV but was unstable for mass spectral analysis. The K(M app) for co-eluted M4/M5 and [M7] was 53.7 and 135.4 μM, the V(max app) was 0.812 and 0.669 nmoles/min/mg protein, and CL(int) was 15.1 and 4.9 ml/min/g protein, respectively. Pilocarpine, orphenadrine and proadifen and anti-rat cytochrome P450 (CYP)2A, 2B and 3A antibodies inhibited M4/M5 and [M7] formation. These results indicate that V is efficiently metabolized by CYP. Determination of the metabolites of V will provide further insight into the relationship between toxicity and tissue dose of V and its metabolites.

Radiofrequency ablation of rabbit liver in vivo: effect of the Pringle maneuver on pathologic changes in liver surrounding the ablation zone

International Nuclear Information System (INIS)

Kim, Seung Kwon; Lim, Hyo K; Ryu, Jeong Ah

2004-01-01

We wished to evaluate the effect of the Pringle maneuver (occlusion of both the hepatic artery and portal vein) on the pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone in rabbit livers. Radiofrequency (RF) ablation zones were created in the livers of 24 rabbits in vivo by using a 50-W, 480-kHz monopolar RF generator and a 15-gauge expandable electrode with four sharp prongs for 7 mins. The tips of the electrodes were placed in the liver parenchyma near the porta hepatis with the distal 1 cm of their prongs deployed. Radiofrequency ablation was performed in the groups with (n=12 rabbits) and without (n=12 rabbits) the Pringle maneuver. Three animals of each group were sacrificed immediately, three days (the acute phase), seven days (the early subacute phase) and two weeks (the late subacute phase) after RF ablation. The ablation zones were excised and serial pathologic changes in the hepatic vessels, bile ducts and liver parenchyma surrounding the ablation zone were evaluated. With the Pringle maneuver, portal vein thrombosis was found in three cases (in the immediate [n=2] and acute phase [n=1]), bile duct dilatation adjacent to the ablation zone was found in one case (in the late subacute phase [n=1]), infarction adjacent to the ablation zone was found in three cases (in the early subacute [n=2] and late subacute [n=1] phases). None of the above changes was found in the livers ablated without the Pringle maneuver. On the microscopic findings, centrilobular congestion, sinusoidal congestion, sinusoidal platelet and neutrophilic adhesion, and hepatocyte vacuolar and ballooning changes in liver ablated with Pringle maneuver showed more significant changes than in those livers ablated without the Pringle maneuver (ρ < 0.05). Radiofrequency ablation with the Pringle maneuver created more severe pathologic changes in the portal vein, bile ducts and liver parenchyma surrounding the ablation zone compared with RF

Influence of whole body irradiation on induction of the hepatic microsomal system metabolizing drugs

International Nuclear Information System (INIS)

Szyszko, A.; Bitny-Szlachto, S.

1977-01-01

Effects of whole body irradiation (600 R) on rat liver aminophenazone demethylase activities of the liver homogenate 10,000 X g supernatant and its microsomal fraction were compared. Either activities were found to be decreased by irradiation by some 35%. The phenobarbital treatment (3 x 100 mg/kg i.p.) has turned out to provide higher relative augmentation of the liver demethylase activity in irradiated than in unirradiated rats. The cytoplasmic activity was found to be augmented by phenobarbital treatment 2,21-fold in unirradiated, and 3,20-fold in irradiated rats, and the microsomal activity increased 3,28-fold and 3,77-fold, respectively. Microsomal levels of cytochrome P-450 were found to be not affected by irradiation. (author)

Flumazenil does not improve hepatic encephalopathy associated with acute ischemic liver failure in the rabbit

NARCIS (Netherlands)

C.C.D. van der Rijt (Carin); R.J. de Knegt (Robert); S.W. Schalm (Solko); O.T. Terpstra (Onno); K. Mechelse (Karel)

1990-01-01

textabstractThe effect of flumazenil, a benzodiazepine antagonist, on hepatic encephalopathy was studied in rabbits with acute hepatic failure induced by a two-stage liver devascularization procedure. The rabbits were randomized for treatment with 5 mg/kg of flumazenil or the placebo. The drug was

Preparation of a three-dimensional extracellular matrix by decellularization of rabbit livers

OpenAIRE

Nari, Gustavo A.; Cid, Mariana; Comín, Romina; Reyna, Laura; Juri, Gustavo; Taborda, Ricardo; Salvatierra, Nancy A.

2013-01-01

Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrix. Methods: a combination of physical, chemica...

MnDPDP enhancement in rabbit liver after intravenous bolus injection and slow infusion

International Nuclear Information System (INIS)

Thorstensen, Oe.; Isberg, B.; Jorulf, H.; Westman, L.; Svahn, U.; Venizelos, N.

1997-01-01

Purpose: To investigate the MR-enhancing effect of mangafodipir trisodium (MnDPDP, Teslascan) in the rabbit liver in relation to dose, mode of administration and imaging window. Material and Methods: MnDPDP was administered to 18 rabbits at a dose of 10 μmol/kg or 20 μmol/kg, as a bolus injection or infusion. MR imaging of the liver was performed at different time intervals. Results: Peak liver enhancement was typically observed 10-30 min after administration and the enhancement declined with a half-time of about 5 h. This pattern was observed in all sequences (SE 400/15, FLASH, and SE 132/10), with both doses and with both rates of administration. The peak enhancement was greater, though not significantly so after 20 μmol/kg than after 10 μmol/kg. A higher relative peak signal was observed with SE 132/10 than with FLASH or SE 400/15. (orig./AJ)

Experimental microangiographic study in normal rabbit liver

International Nuclear Information System (INIS)

Kim, Yoon Gyoo; Park, Jong Yeon; Han, Kook Sang; Moon, Ki Ho; Choi, Chang Ho; Han, Koon Taek; Lee, Suck Hong; Kim, Byung Soo

1994-01-01

Microangiography is an experimental radiologic technique for evaluation of the morphology and the function of small vessels. The purpose of this study is to introduce a good microangiographic technique and to present the microangiographic appearance of normal hepatic vascular pattern. Five white rabbits weighing 2.5-2.9Kg were objected. Polyethylene catheters were inserted in portal vein and then in IVC. Heparin mixed normal saline (2cc/1000cc) was infused through portal vein and blood was drained to IVC. Barium suspension was infused via the catheter placed in portal vein until the liver surface showed satisfactory finding in barium filling. The liver was removed and this preparation was fixed in 10% formaline for 7 days. After fixation, the liver was sectioned on 1-2mm thickness. The slices were radiographed on high resolution plate using Faxitron. H-E staining of liver tissue was also done. The microbrium was well distributed in all small vessels without filling defect. And we could find the hexagonal shaped classic liver lobule, in which the central vein was located at central portion and portal vein at periphery. The enlargement was showed numerous sinusoids, but there was less dye in the central portion of lobule, but the central vein was well filled by microbarium. The peripheral portion of lobule was well filled with microbarium. So, we could find diamond shaped liver acinus, in which central vein was located at priperal portion and the center of liver acinus was terminal portal vein that growed out from a small portal space. The three acini made the complex acinus and acinar agglomerate was composed of three or four complex acini. It is considered that the liver acinus pattern of Rapparport is more acceptable on microangiography than the classic concept of hepatic lobule

Comparative Study of the Liver Anatomy in the Rat, Rabbit, Guinea Pig and Chinchilla

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Florin Gheorghe STAN

2018-05-01

Based on detailed study of the macroscopic anatomy of rat, rabbit, guinea pig and chinchilla a proper experimental model in liver research, could be assessed. In this regard, the vascular anatomy of the liver in the mentioned species is of a great importance and it is subject of another report.

Identification of metabolites of the tryptase inhibitor CRA-9249: observation of a metabolite derived from an unexpected hydroxylation pathway.

Science.gov (United States)

Yu, Walter; Dener, Jeffrey M; Dickman, Daniel A; Grothaus, Paul; Ling, Yun; Liu, Liang; Havel, Chris; Malesky, Kimberly; Mahajan, Tania; O'Brian, Colin; Shelton, Emma J; Sperandio, David; Tong, Zhiwei; Yee, Robert; Mordenti, Joyce J

2006-08-01

The metabolites of the tryptase inhibitor CRA-9249 were identified after exposure to liver microsomes. CRA-9249 was found to be degraded rapidly in liver microsomes from rabbit, dog, cynomolgus monkey, and human, and less rapidly in microsomes from rat. The key metabolites included cleavage of an aryl ether, in addition to an unexpected hydroxylation of the amide side chain adjacent to the amide nitrogen. The chemical structures of both metabolites were confirmed by synthesis and comparison to material isolated from the liver microsomes. Several suspected hydroxylated metabolites were also synthesized and analyzed as part of the structure identification process.

A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1.

Science.gov (United States)

Kerkar, N; Ma, Y; Hussain, M; Muratori, L; Targett, C; Williams, R; Bianchi, F B; Mieli-Vergani, G; Vergani, D

1999-03-04

Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.

Experimental study on quantitative analysis of fatty liver by computed tomography in rabbit

Energy Technology Data Exchange (ETDEWEB)

Park, Choong Ki; Hahm, Chang Kok; Kim, Chung Jin [Hanyang University College of Medicine, Seoul (Korea, Republic of); Yoon, Jong Sup [Hallym College, Seoul (Korea, Republic of)

1985-10-15

For the study of correlation of CT number and fatty contact of the liver, total 35 rabbit were used. The rabbits were divided into one control and three experimental groups according to the amount of carbon tetrachloride, administered 1 ml, 2 ml, and 3 ml per kg of body weight respectively. The carbon tetrachloride was administered via intragastric route. CT was performed 72 hours following administration of carbon tetrachloride, and immediately prior to CT scan each rabbit was anesthetized by means of IM injection of ketamine and IV injection of succinylcholine to stop motion and respiration. CT numbers were measured and histological study for the deposition of fat in the liver tissue was done. Also biochemical analysis of lipid in the blood and in the extraction of liver tissue was performed. Comparison of CT number with biochemical and histological data was done. The result was as follows: 1. In each experimental group, the degree of accumulation of fat in the liver was proportional to the amount of carbon tetrachloride. 2. Degree of decreasing CT number was correlated with the increase in the accumulation of fat in the liver. 3. In the control and experimental (1, 2, 3) groups, when the amount of carbon tetrachloride increased, the amount of total lipid, cholesterol and triglyceride on biochemical analysis of the liver increased. Also increase in the amount of plasma lipids on biochemical analysis and great degree of increase in accumulation of fat in the liver on histological examination were seen. But no changes in the amount of phospholipid and protein on biochemical analysis of the liver were noticed. 4. Increase in the amount of total lipid could make a change in the CT number of the liver remarkably (r=-0.63). As the amount of cholesterol and triglyceride increased, the CT number of the liver decreased (r=-0.61 and r=-0.76 respectively). But there was no significant correlation between the amount of protein and phospholipid and the degree of decrease in

Experimental study on quantitative analysis of fatty liver by computed tomography in rabbit

International Nuclear Information System (INIS)

Park, Choong Ki; Hahm, Chang Kok; Kim, Chung Jin; Yoon, Jong Sup

1985-01-01

For the study of correlation of CT number and fatty contact of the liver, total 35 rabbit were used. The rabbits were divided into one control and three experimental groups according to the amount of carbon tetrachloride, administered 1 ml, 2 ml, and 3 ml per kg of body weight respectively. The carbon tetrachloride was administered via intragastric route. CT was performed 72 hours following administration of carbon tetrachloride, and immediately prior to CT scan each rabbit was anesthetized by means of IM injection of ketamine and IV injection of succinylcholine to stop motion and respiration. CT numbers were measured and histological study for the deposition of fat in the liver tissue was done. Also biochemical analysis of lipid in the blood and in the extraction of liver tissue was performed. Comparison of CT number with biochemical and histological data was done. The result was as follows: 1. In each experimental group, the degree of accumulation of fat in the liver was proportional to the amount of carbon tetrachloride. 2. Degree of decreasing CT number was correlated with the increase in the accumulation of fat in the liver. 3. In the control and experimental (1, 2, 3) groups, when the amount of carbon tetrachloride increased, the amount of total lipid, cholesterol and triglyceride on biochemical analysis of the liver increased. Also increase in the amount of plasma lipids on biochemical analysis and great degree of increase in accumulation of fat in the liver on histological examination were seen. But no changes in the amount of phospholipid and protein on biochemical analysis of the liver were noticed. 4. Increase in the amount of total lipid could make a change in the CT number of the liver remarkably (r=-0.63). As the amount of cholesterol and triglyceride increased, the CT number of the liver decreased (r=-0.61 and r=-0.76 respectively). But there was no significant correlation between the amount of protein and phospholipid and the degree of decrease in

Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

Science.gov (United States)

Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

1989-03-15

Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

Effects of Loud Noise on Oxidation and Lipid peroxidation Variations of Liver Tissue of Rabbit

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Mirzaei Ramazan

2009-06-01

Full Text Available Background: In today's world, noise is one of the major physical pollutants. The exact mechanism leading to tissue damage in loud noise is not clear. There are increasing evidences that show damage to cochlear tissue by noise is linked to cell injury induced by free radical species. The aim of this study was to investigate the relationship between change in liver tissue glutathione (anti- oxidant and malondialdehyde (one metabolite of lipid oxidation levels that occur in rabbits which were exposed to continuous loud noise.Materials and Methods: This experimental study was performed on 12 white Newzeland male rabbits in Tarbiat Modarres University in 2004. The rabbits were assigned to the following two groups: control, and exposed to continuous loud noise for 96 hours (8 h/day for 12 days, SPL=110dBA and 250Hz to 20 KHz. The concentration of malondialdehyde (MDA and glutathione (GSH in liver tissue samples were measured in rabbits after exposure to noise. Thiobarbituric acid reacting substance, Ellman's reagent and spectrophotometry techniques were used for this measurement. The data were statically analyzed by SPSS software and 2 groups were compared by t-test. Differences at the level of P<0.05 were considered statistically significant.Results: Comparison of the biochemical parameters of GSH and MDA measured in treated group with control indicated that antioxidant and lipid peroxidants parameters were suppressed in treated group compared to control group (p<0.05.Conclusion: Possible similarities between rabbit and human biological system indicate the possible role of noise in causation of oxidative stress in context with liver tissue impairm

Age dependence of rat liver function measurements

DEFF Research Database (Denmark)

Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

1989-01-01

Changes in the galactose elimination capacity, the capacity of urea-N synthesis and antipyrine clearance were studied in male Wistar rats at the age of 8, 20 and 44 weeks. Further, liver tissue concentrations of microsomal cytochrome P-450, microsomal protein and glutathione were measured. All...... liver function measurements increased from the age of 8 to 44 weeks when expressed in absolute values. In relation to body weight, these function measurements were unchanged or reduced from week 8 to week 20. At week 44, galactose elimination capacity and capacity of urea-N synthesis related to body...... weight were increased by 10% and 36%, respectively, and antipyrine plasma clearance was reduced to 50%. Liver tissue concentrations of microsomal cytochrome P-450 and microsomal protein increased with age when expressed in absolute values, but were unchanged per g liver, i.e., closely related to liver...

Regulation of rat liver cytochrome P450j, a high affinity N-nitrosodimethylamine demethylase (NDMAD)

International Nuclear Information System (INIS)

Thomas, P.E.; Bandiera, S.; Maines, S.L.; Ryan, D.E.; Levin, W.

1987-01-01

Purified IgG from sera of rabbits immunized with homogeneous P450j was absorbed to produce monospecific anti-P450j. Results using anti-P450j in ELISA show that rat liver microsomal P450j content decreases between 3 and 6 wks of age in both sexes. Several xenobiotics (Aroclor 1254, mirex and 3-methylcholanthrene) repressed P450j levels when administered to male rats. In contrast, hepatic levels of P450j were induced by isoniazid, dimethylsulfoxide, pyrazole, 4-methylpyrazole, ethanol and chemically-induced diabetes. P450j levels were measurable in kidney, whereas this isozyme was barely detectable in lung, ovaries and testes; however, extra-hepatic P450j was inducible by isoniazid. Between 80-90% of microsomal NDMAD was inhibited by anti-P450j whether the microsomes were isolated from untreated rats or animals administered inducers or repressors of P450j. Results obtained with the reconstituted system suggest that the remaining microsomal NDMAD resistant to antibody inhibition is the result of the inaccessibility of a certain proportion of P450j due to interference by NADPH-P450 reductase. P450j content and NDMAD activity correlated well in microsomes from rats of all treatment groups. The evidence indicates that P450j is the primary, and possibly only, microsomal catalyst of NDMAD at substrate concentrations relevant to hepatocarcinogenesis induced by NDMA

Comparison of epoxide and free-radical mechanisms for activation of benzo[a]pyrene by Sprague-Dawley rat liver microsomes

International Nuclear Information System (INIS)

Selkirk, J.K.

1980-01-01

Coincubation of [6- 3 H]benzo[a]pyrene ([6- 3 H]BP) and [ 14 C]BP with SD rat liver microsomes produced metabolic profiles that showed that the C-6 of BP was not affected by formation of 4,5-dihydro-4,5-dihydroxy-BP, 7,8-dihydro-7,8-dihydroxy-BP, and 9,10-dihydro-9,10-dihydroxy-BP nor the 3- and 9-phenols of BP. Complete retention of tritium at C-6, except in the three quinones, confirmed the radical-cation model for formation of the 6-oxo-radical followed by oxidation to quinone. Epoxide formation at the carcinogenically active regions of BP appeared to biochemically isolate from 6-position activation and suggested that the microsomal epoxide pathway is unrelated to the radicalcation scheme. These molar ratios derived from double-label experiments reinforced the current literature that indicates the epoxide mechanism as the major pathway toward carcinogenic forms of BP

Metabolism of indole alkaloid tumor promoter, (-)-indolactam V, which has the fundamental structure of teleocidins, by rat liver microsomes

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, N.; Irie, K.; Tokuda, H.; Koshimizu, K.

1987-07-01

Metabolic activation and/or deactivation of indole alkaloid tumor promoter, (-)-indolactam V (ILV), was examined using rat liver microsomes. Reaction of ILV with the microsomes supplemented with NADPH and MgCl/sub 2/ gave three major metabolites, which were identified as (-)-N13-desmethylindolactam V and two diastereomers of (-)-2-oxyindolactam V at C-3. The tumor-promoting activities of these metabolites were evaluated by induction of Epstein-Barr virus early antigen and inhibition of specific binding of (/sup 3/H)-12-O-tetradecanoylphorbol-13-acetate to a mouse epidermal particulate fraction, and proved to be conspicuously lower than that of ILV. These results demonstrate that the metabolism of ILV results in detoxification, and that it itself is the tumor-promoting entity. Studies on the enzymes concerned with this metabolism suggested the involvement of cytochrome P-450-containing mixed-function oxidases. Similar deactivation seems to be possible by skin, where the mixed-function oxidases are known to exist.

Determination of the 4-monohydroxy metabolites of perhexiline in human plasma, urine and liver microsomes by liquid chromatography.

Science.gov (United States)

Davies, Benjamin J; Herbert, Megan K; Coller, Janet K; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

2006-11-07

The use of perhexiline (PHX) is limited by hepatic and neurological toxicity associated with elevated concentrations in plasma that are the result of polymorphism of the cytochrome P450 2D6 isoform (CYP2D6). PHX is cleared by hepatic oxidation that produces three 4-monohydroxy metabolites: cis-OH-PHX, trans1-OH-PHX and trans2-OH-PHX. The current study describes an HPLC-fluorescent method utilising pre-column derivatization with dansyl chloride. Following derivatization, the metabolites were resolved on a C18 column with a gradient elution using a mobile phase composed of methanol and water. The method described is suitable for the quantification of the metabolites in human plasma and urine following clinical doses and for kinetic studies using human liver microsomes. The method demonstrates sufficient sensitivity, accuracy and precision between 5.0 and 0.01, 50.0 and 0.2 and 1.0 and 0.005 mg/l in human plasma, urine and liver microsomes, respectively, with intra-assay coefficients of variation and bias D6 extensive metaboliser (EM) patients at steady state with respect to PHX dosing determined that the mean (+/-S.D.) renal clearances of trans1-OH-PHX and cis-OH-PHX were 1.58+/-0.35 and 0.16+/-0.06l/h, respectively. The mean (+/-S.D.) dose recovered in urine as free and glucuronidated 4-monohydroxy PHX metabolites was 20.6+/-11.6%.

Metabolic activation of 2-methylfuran by rat microsomal systems

International Nuclear Information System (INIS)

Ravindranath, V.; Boyd, M.R.

1985-01-01

2-Methylfuran (2-MF), a constituent of cigarette smoke and coffee, causes necrosis of liver, lungs, and kidneys in rodents. 2-MF is metabolically activated by mixed-function oxidases to acetylacrolein, a reactive metabolite that binds covalently to microsomal protein. The hepatic microsomal metabolism of 2-MF to reactive metabolite required the presence of NADPH and oxygen and was dependent on incubation time and substrate concentration. The microsomal metabolism of 2-MF was inducible by pretreatment of rats with phenobarbital and was inhibited by piperonyl butoxide and N-octyl imidazole, which indicates that the metabolism of 2-MF may be mediated by cytochrome P-450. Acetylacrolein was a potent inhibitor of mixed-function oxidase and completely inhibited the microsomal metabolism of 2-MF, indicating that 2-MF is a suicide substrate for the enzyme. The sulfhydryl nucleophile cysteine was a better trapping agent of the reactive metabolite of 2-MF than N-acetylcysteine or glutathione. Lysine decreased the covalent binding of 2-MF metabolites, presumably by reacting with the aldehyde group of acetylacrolein. In addition, in the presence of NADPH, 2-MF was bioactivated by both pulmonary and renal cortical microsomes to reactive metabolites that were covalently bound to microsomal proteins

LP-THAE induced tumor cell apoptosis of rabbit VX2 liver carcinoma

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Chen Shengli; Quan Yi; Huang Zicheng; Chen Guodong; Zhu Dongliang

2007-01-01

Objective: To research tumor cell apoptosis induced by Lp-THAE of rabbit VX2 liver implanted tumor. Methods: 27 New Zealand white rabbits implanted with VX2 tumor at left middle lobe of the liver divided into three groups: Group A(n= 9) Lp-THAE: treated through transhepatic artery catheterization; Group B(n=9) THAI and Group C(n=9) as control. The rabbits were executed at second to fifth day after treatment. HE dye microscopy was taken for counting the typical apoptosis cells and calculating apoptosis index (ApI). FITC-AnnexinV/PI assay was used for measuring apoptosis by flow cytometry. Results: The ApI of tumor central area and marginal area were (17.769±2.417)%, (4.129±1.172)%, P<0.01. The percentages of tumor cell apoptosis and tumor cell necrosis were (16.483±1.404)%, (9.478±0.964)%, P<0.01 and (43.559±5.053)%, (33.460±1.840)%, P=0.093. The total percentages of tumor cell apoptosis and necrosis were (60.042±13.979)%, (42.938±8.979)%, P< 0.01, at tumor center and marginal area in THAE group respectively. The ApI, percentages of tumor cell apoptosis and necrosis in THAE group were significantly higher than those of THAI group (P<0.01). The percentages of tumor cell apoptosis at tumor center area in THAE group were significantly higher than those of tumor marginal area(P<0.01). Conclusion: Induced tumor cell apoptosis and necrosis are two mechanisms of action for Lp-THAE treatment of liver carcinoma. (authors)

Distinct ontogenic patterns of overt and latent DGAT activities of rat liver microsomes.

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Waterman, Ian J; Price, Nigel T; Zammit, Victor A

2002-09-01

We have studied the ontogeny of the two functional diacylglycerol acyltransferase (DGAT) activities (overt and latent) during postnatal development in rat liver. We find that the ontogenic patterns of the two are highly distinct. Overt DGAT shows a transient rise in activity up to day 4 postnatally, after which it declines until weaning; thereafter, it increases steadily to reach high adult values that may contribute to the high rates of turnover of cytosolic triacylglycerol (TAG). By contrast, latent DGAT activity increases continuously during the suckling period but falls sharply upon weaning onto chow but not onto a high-fat diet. Rates of TAG secretion by hepatocytes are higher than in the adult during the first 7 days after birth, and are largely dependent on the mobilization of the abundant intrahepatocyte TAG as a source of acyl moieties. When the hepatic steatosis is cleared (after day 7) the TAG secretion rate declines by 80% to reach adult values. Quantification of the content of mRNA for the DGAT1 and DGAT2 genes does not show correlation with either of the DGAT activities. We conclude that post-translational modification may play an important role in the overt and latent distribution of DGAT activity in the liver microsomal membrane.

Microsomal lipid peroxidation as a mechanism of cellular damage. [Dissertation

Energy Technology Data Exchange (ETDEWEB)

Kornbrust, D.J.

1979-01-01

The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to be dependent on the presence of free ferrous ion and maintains iron in the reduced Fe/sup 2 +/ state. Chelation of iron by EDTA inhibited peroxidation. Addition of iron, after preincubation of microsomes in the absence of iron, did not enhance the rate of peroxidation suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of pre-formed hydroperoxides. Liposomes also underwent peroxidation in the presence of ferrous iron at a rate comparable to intact microsomes and was stimulated by ascorbate. Carbon tetrachloride initiated lipid peroxidation in the absence of free metal ions. Rates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely between different tissues and species. The effects of paraquat on lipid peroxidation was also studied. (DC)

The Dynamics of Glutathione Species and Ophthalmate Concentrations in Plasma from the VX2 Rabbit Model of Secondary Liver Tumors

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R. Abbas

2011-01-01

Full Text Available Purpose. Available tumor markers have low sensitivity/specificity for the diagnosis of liver tumors. The present study was designed to evaluate the oxidoreductive status of the liver as surrogates of tumor subsistence and growth. Methods. Glutathione species (GSH:GSSG, ophthalmate (OA concentrations, and their turnover were measured in plasma of rabbits (n=6 in their healthy state and in the state of tumor growth after implantation of the VX2 carcinoma in their liver. Tumors were allowed to grow for a period of 14 days when rabbits were sacrificed. Livers were removed and cysteine concentration was measured in liver tissue. Results. Tumor growth was found in 100% of the rabbits. Concentration and labeling of GSH/GSSG were similar in experimental animals before and after tumor implantation and to sham animals. In contrast, OA concentration increased significantly in experimental animals after tumor implantation when compared to same animals prior to tumor implantation and to sham animals (P<.05. The concentration of cysteine, a precursor of GSH, was found to be significantly lower in the liver tissue adjacent to the tumor (P<.05. Conclusion. Disturbances in the oxidoreductive state of livers appear to be a surrogate of early tumor growth.

Effect of interventional treatment with p53 on the invasion and metastasis of VX2 liver tumor in experimental rabbits

International Nuclear Information System (INIS)

Li Caixia; Feng Yan; Gu Tao; Li Chunmei

2010-01-01

Objective: To investigate the effect of interventional treatment with p53 on the invasion and metastasis of VX2 liver tumor in experimental rabbits. Methods: VX2 carcinoma cells were surgically implanted into the left hepatic lobe in 48 New Zealand white rabbits, and the rabbit hepatic carcinoma models were thus established. The rabbits were randomly divided into 4 groups with 12 rabbits in each group. After hepatic arterial catheterization was completed physiological saline (control group), Lipiodol (Group A), Ad-p53 (Group B) and Lipiodol+Ad-p53 (Group C) were respectively infused into the rabbits of four groups via common hepatic artery. One week after the procedure the rabbits were sacrificed and the livers were removed for the determination of matrix metalloprotein-2 (MMP-2), proliferating cell nuclear antigen (PCNA) and vascular endothelial growth factor (VEGF) of the tumor with immunohistochemistry technique. Results: The tumor growth in study groups (group A, B and C) was markedly suppressed, which was significantly different in comparison with that in control group (P 0.05). The positive rates of MMP-2, PCNA and VEGF in group B and C were significantly lower than those in control group (P < 0.05). The positive rates of MMP-2, PCNA and VEGF of the rabbits with metastasis were markedly higher than those without metastasis(P < 0.05). MMP-2 bore a certain relationship with VEGF and PCNA (P < 0.05). Conclusion: The increase of the positive rates of MMP-2, PCNA and VEGF indicates that the tumor possesses higher possibility for developing metastasis, proliferation and vascular formation. The interventional treatment with Adp53 or Lipiodol+Ad-p53 can inhibit the growth, metastasis and vascular formation of VX2 liver tumor in experimental rabbits. (J Intervent Radiol, 2010, 19 : 800-804) (authors)

Effects of thiol antioxidants on the atropselective oxidation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) by rat liver microsomes.

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Wu, Xianai; Lehmler, Hans-Joachim

2016-02-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0-10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol), 4-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.

Influence of sex hormones on relative quantities of multiple species of cytochrome P-450 in rat liver microsomes

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Fujita, S.; Peisach, J.; Chevion, M.; Hebrew Univ., Jerusalem

1981-01-01

EPR spectra of rat liver microsomes from male, female and hormonally-treated castrated hepatectomized rats were studied. The spectra, especially in the region of gsub(max) suggested a heterogeneity of local environments of the low spin ferric heme indicative of multiple structures for cytochrome P-450. Certain features in the spectrum correlated with sexual differences. It is suggested that the changes in the relative amplitudes of the EPR features represent differences in the relative abundance of the individual proteins in the mixture that, in turn, are related to the sexual differences of metabolic patterns for reactions catalyzed by cytochrome P-450. (author)

Application of the relative activity factor approach in scaling from heterologously expressed cytochromes p450 to human liver microsomes: studies on amitriptyline as a model substrate.

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Venkatakrishnan, K; von Moltke, L L; Greenblatt, D J

2001-04-01

The relative activity factor (RAF) approach is being increasingly used in the quantitative phenotyping of multienzyme drug biotransformations. Using lymphoblast-expressed cytochromes P450 (CYPs) and the tricyclic antidepressant amitriptyline as a model substrate, we have tested the hypothesis that the human liver microsomal rates of a biotransformation mediated by multiple CYP isoforms can be mathematically reconstructed from the rates of the biotransformation catalyzed by individual recombinant CYPs using the RAF approach, and that the RAF approach can be used for the in vitro-in vivo scaling of pharmacokinetic clearance from in vitro intrinsic clearance measurements in heterologous expression systems. In addition, we have compared the results of two widely used methods of quantitative reaction phenotyping, namely, chemical inhibition studies and the prediction of relative contributions of individual CYP isoforms using the RAF approach. For the pathways of N-demethylation (mediated by CYPs 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4) and E-10 hydroxylation (mediated by CYPs 2B6, 2D6, and 3A4), the model-predicted biotransformation rates in microsomes from a panel of 12 human livers determined from enzyme kinetic parameters of the recombinant CYPs were similar to, and correlated with the observed rates. The model-predicted clearance via N-demethylation was 53% lower than the previously reported in vivo pharmacokinetic estimates. Model-predicted relative contributions of individual CYP isoforms to the net biotransformation rate were similar to, and correlated with the fractional decrement in human liver microsomal reaction rates by chemical inhibitors of the respective CYPs, provided the chemical inhibitors used were specific to their target CYP isoforms.

Characterization of in vitro glucuronidation clearance of a range of drugs in human kidney microsomes: comparison with liver and intestinal glucuronidation and impact of albumin.

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Gill, Katherine L; Houston, J Brian; Galetin, Aleksandra

2012-04-01

Previous studies have shown the importance of the addition of albumin for characterization of hepatic glucuronidation in vitro; however, no reports exist on the effects of albumin on renal or intestinal microsomal glucuronidation assays. This study characterized glucuronidation clearance (CL(int, UGT)) in human kidney, liver, and intestinal microsomes in the presence and absence of bovine serum albumin (BSA) for seven drugs with differential UDP-glucuronosyltransferase (UGT) 1A9 and UGT2B7 specificity, namely, diclofenac, ezetimibe, gemfibrozil, mycophenolic acid, naloxone, propofol, and telmisartan. The impact of renal CL(int, UGT) on accuracy of in vitro-in vivo extrapolation (IVIVE) of glucuronidation clearance was investigated. Inclusion of 1% BSA for acidic drugs and 2% for bases/neutral drugs in incubations was found to be suitable for characterization of CL(int, UGT) in different tissues. Although BSA increased CL(int, UGT) in all tissues, the extent was tissue- and drug-dependent. Scaled CL(int, UGT) in the presence of BSA ranged from 2.22 to 207, 0.439 to 24.4, and 0.292 to 23.8 ml · min(-1) · g tissue(-1) in liver, kidney, and intestinal microsomes. Renal CL(int, UGT) (per gram of tissue) was up to 2-fold higher in comparison with that for liver for UGT1A9 substrates; in contrast, CL(int, UGT) for UGT2B7 substrates represented approximately one-third of hepatic estimates. Scaled renal CL(int, UGT) (in the presence of BSA) was up to 30-fold higher than intestinal glucuronidation for the drugs investigated. Use of in vitro data obtained in the presence of BSA and inclusion of renal clearance improved the IVIVE of glucuronidation clearance, with 50% of drugs predicted within 2-fold of observed values. Characterization and consideration of kidney CL(int, UGT) is particularly important for UGT1A9 substrates.

Hepatic microsomal phospholipids in rats exposed intratracheally to coal fly ash

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Srivastava, P.K.; Chauhan, S.S.; Misra, U.K.

1986-01-01

The effects of intratracheal administration of fly ash (50 mg/kg body weight, daily for 7 days) on hepatic microsomal phospholipid metabolism has been studied in rats using various phospholipid precursors, viz NaH 2 32 PO 4 , (methyl- 14 C)-choline, and (methyl- 14 C)-methionine. Fly ash administration significantly increased microsomal phosphatidylcholine (PC), and lysophosphatidylcholine (LPC). The incorporation of NaH 2 32 PO 4 into total liver phospholipids, PC and Phosphatidyl ethanolamine (PE) was significantly increased in fly ash-treated rats as compared to the control. Fly ash administration also increased the incorporation of (methyl- 14 C)-choline into microsomal PC. Incorporation of (methyl- 14 C)-methionine into microsomal PC was not affected. Fly ash administration decreased the per cent distribution of arachidonic acid in PC and PE and increased that of oleic acid in PC and of linoleic acid in PE. (orig.)

Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

International Nuclear Information System (INIS)

Zhang, Long Jiang; Wu, Shengyong; Wang, Mei; Lu, Li; Chen, Bo; Jin, Lixin; Wang, Jiandong; Larson, Andrew C.; Lu, Guang Ming

2012-01-01

Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

Preparation of a three-dimensional extracellular matrix by decellularization of rabbit livers

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Gustavo A. Nari

2013-03-01

Full Text Available Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrix. Methods: a combination of physical, chemical (Triton X-100 and SDS and enzymatic agents to decellularize rabbit livers was used. After 68 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy and scanning electron microscopy and biochemical (DNA quantification studies. Results: the decellularization process was verified by macroscopic observation of the organ using macroscopic staining, which revealed a correct conservation of bile and vascular trees. A microscopic observation corroborated these macroscopic results, with the hematoxylin-eosin staining showing no cells or nuclear material and the presence of a portal triad. Wilde's staining demonstrated the conservation of reticulin fibers in the decellularized matrix. In addition, scanning electron microscopy revealed a preserved Glisson's capsule and a decellularized matrix, with the DNA quantification being less than 10 % in the decellularized liver compared to control. Finally, the time taken to develop the decellularization protocol was less than 96 hours. Conclusions: the proposed decellularization protocol was correct, and was verified by an absence of cells. The hepatic matrix had preserved vascular and bile ducts with a suitable three-dimensional architecture permitting further cell seeding.

A reliable radiochromatographic assay technique for hepatic microsomal 16α-hydroxylase activity towards oestrone 3-sulphate

International Nuclear Information System (INIS)

Tsoutsoulis, C.J.; Hobkirk, R.

1980-01-01

A reliable procedure for the assay of liver microsomal 16α-hydroxylation of oestrone 3-sulphate has been developed for the guinea pig. It is based on the rapid, quantitative separation of oestradiol and oestriol by Sephadex LH-20 columns after the chemical reduction and enzymic hydrolysis of the incubation products. Microsomal preparations and incubation conditions that optimized 16α-hydroxylation of oestrone 3-sulphate were employed. Under these circumstances, reduction of the substrate at C-17 and hydrolysis of the sulphate were minimized. Conditions were established that yielded reaction linearity with respect to time and microsomal concentration. This hydroxylation had an absolute requirement for NADPH, which could not be satisfied by NADH. Apparent Ksub(m) values for oestrone 3-sulphate and NADPH, under the conditions used, were 14μM and 0.17mM respectively. 16α-hydroxylase activity was present in the liver microsomal fraction from heavily pigmented, female English Shorthaired guinea pigs. Much lower activity was detected in mature pigmented males and albino females. No activity could be demonstrated in mature, albino males. (author)

The establishment of implanted VX2 liver tumor model in rabbits and discussion on superselective left hepatic arterial catheterization with micro-catheter technique via femoral artery

International Nuclear Information System (INIS)

Jiang Xiongying; Luo Rongguang; Huang Jinhua; Miao Bijian; Wang Yan

2011-01-01

Objective: To establish the implanted VX2 liver tumor model in rabbits and to discuss the feasibility and technical features of superselective left hepatic arterial catheterization by using micro-catheter through the femoral artery catheter sheath. Methods: Forty New Zealand white rabbits were inoculated with fragments of VX2 tumor into the medial left lobe of liver by using a 16G lumbar puncture needle through laparotomy route. Two weeks later, all the rabbits were proved to be successfully inoculated with liver neoplasm on CT scanning. Then, the catheter sheath was inserted into one of the femoral arteries, which was followed by celiac artery angiography and left hepatic artery catheterization with a micro-catheter under DSA guidance in order to evaluate the main branches of celiac artery and the imaging manifestations of VX2 liver tumor. After that, some scheduled interventional experiments were carried out. Results: Imaging examination and histopathologic study showed that the successful rate of implanted rabbit VX2 liver tumor was 100% (40/40). And the successful rate of the catheter sheath inserted to femoral artery was 97.5% (39/40). The successful rate of celiac artery, gastro-hepatic artery, common hepatic artery, proper hepatic artery and left hepatic artery catheterizations was 100% (39/39), 100% (39/39), 100% (39/39), 94.9% (37/39) and 71.2% (28/39) respectively. Conclusion: To implant tumor tissue mass through laparotomy is a stable and reliable method to establish rabbit VX2 liver tumor model. The insertion of micro-catheter through rabbit femoral catheter sheath approach is a convenient and simple technique to be carried out for the left hepatic artery catheterization and it can efficiently solve the technical difficulties when performing the interventional treatment of the rabbit VX2 hepatic tumor via left hepatic artery approach. (authors)

Detection of liver kidney microsomal type 1 antibody using molecularly based immunoassays.

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Kerkar, N; Ma, Y; Davies, E T; Cheeseman, P; Mieli-Vergani, G; Vergani, D

2002-12-01

To assess the diagnostic value of two commercial molecularly based immunoassays detecting liver kidney microsomal type 1 antibody (LKM1). The performance of Varelisa and LKM1 enzyme linked immunosorbent assay (ELISA) was compared with immunofluorescence, and two validated research techniques-an in house ELISA and a radioligand assay measuring antibodies to P4502D6. Thirty serum samples from three patients with autoimmune hepatitis type 2 covering immunofluorescence titres of 1/10 to 1/10 240 and 55 LKM1 negative controls were tested. All 30 sera that were LKM1 positive by immunofluorescence were positive by the in house ELISA, the radioligand assay, and LKM1-ELISA, and 29 were also positive by Varelisa. None of the 55 sera negative for LKM1 by immunofluorescence was positive by the in house ELISA and radioligand assay, but one was positive by Varelisa and 14 were positive using the LKM1-ELISA. Agreement between immunofluorescence, the in house ELISA, the radioligand assay, and Varelisa was high (kappa > 0.8), and agreement between immunofluorescence and LKM1-ELISA was moderate (kappa = 0.63). The assay kit marketed as Varelisa allows accurate detection of LKM1.

Morphometric alterations, steatosis, fibrosis and active caspase-3 detection in carbamate bendiocarb treated rabbit liver

Czech Academy of Sciences Publication Activity Database

Petrovová, E.; Purzyc, H.; Mazenský, D.; Luptáková, L.; Torma, N.; Sopoliga, I.; Sedmera, David

2015-01-01

Roč. 30, č. 2 (2015), s. 212-222 ISSN 1520-4081 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : bendiocarb * caspase-3 activity * fibrosis * toxicity * rabbit * liver Subject RIV: EA - Cell Biology Impact factor: 2.868, year: 2015

Evidence of a genetic basis for the different geographic occurrences of liver/kidney microsomal antibody type 1 in hepatitis C.

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Muratori, Paolo; Czaja, Albert J; Muratori, Luigi; Granito, Alessandro; Guidi, Marcello; Ferri, Silvia; Volta, Umberto; Mantovani, Wilma; Pappas, Georgios; Cassani, Fabio; Lenzi, Marco; Bianchi, Francesco B

2007-01-01

Antibodies to liver/kidney microsome type 1 occur in Italian patients with hepatitis C, but rarely develop in North American patients. Our goals were to compare the frequencies of the HLA markers associated with autoimmune expression in Italian and North American patients with chronic hepatitis C and to determine genetic bases for regional differences in antibody production. HLA B8, DR3, DR4, DR7, DR11, DR13, DQ2, and the B8-DR3-DQ2 haplotype were determined by microlymphocytotoxicity and polymerase chain reaction in 105 Italian patients (50 with microsomal antibodies), 100 North American patients (none with microsomal antibodies), and Italian and North American healthy control subjects. Italian patients with microsomal antibodies differed from North American patients without these antibodies by having a higher frequency of HLA DR7 (54% vs. 27%, P=0.002). HLA DR7 occurred more frequently in seropositive Italian patients than in seronegative counterparts (54% vs. 11% P < 0.0001), Italian healthy control subjects (54% vs. 29%, P=0.0009), and North American healthy control subjects (54% vs. 19%, P < 0.0001). The frequency of HLA DR7 was similar in North American patients and controls (27% vs. 19%, P=0.2), but it was lower than in Italian controls (19% vs. 29%, P=0.059). Seropositive Italian patients had a lower frequency of HLA DR11 than seronegative Italian patients and Italian controls (18% vs. 34%, P=0.07, and 18% vs. 35%, P=0.02, respectively). In contrast to seropositive Italian patients, North American patients had HLA DR4 (30% vs. 12%, P=0.02), HLA DR13 (29% vs. 10%, P=0.01), and the B8-DR3-DQ2 haplotype (23% vs. 6%, P=0.01) more often. Similarly, HLA DR4 and the B8-DR3-DQ2 phenotype were more frequent in North American patients than in Italian controls (30% vs. 16%, P=0.005, and 23% vs. 7%, P=0.00002, respectively). HLA DR7 is associated with the development of microsomal antibodies in Italian patients with chronic hepatitis C. The lower frequency of HLA DR7

Hepatic and intestinal glucuronidation of mono(2-ethylhexyl) phthalate, an active metabolite of di(2-ethylhexyl) phthalate, in humans, dogs, rats, and mice: an in vitro analysis using microsomal fractions.

Science.gov (United States)

Hanioka, Nobumitsu; Isobe, Takashi; Kinashi, Yu; Tanaka-Kagawa, Toshiko; Jinno, Hideto

2016-07-01

Mono(2-ethylhexyl) phthalate (MEHP) is an active metabolite of di(2-ethylhexyl) phthalate (DEHP) and has endocrine-disrupting effects. MEHP is metabolized into glucuronide by UDP-glucuronosyltransferase (UGT) enzymes in mammals. In the present study, the hepatic and intestinal glucuronidation of MEHP in humans, dogs, rats, and mice was examined in an in vitro system using microsomal fractions. The kinetics of MEHP glucuronidation by liver microsomes followed the Michaelis-Menten model for humans and dogs, and the biphasic model for rats and mice. The K m and V max values of human liver microsomes were 110 µM and 5.8 nmol/min/mg protein, respectively. The kinetics of intestinal microsomes followed the biphasic model for humans, dogs, and mice, and the Michaelis-Menten model for rats. The K m and V max values of human intestinal microsomes were 5.6 µM and 0.40 nmol/min/mg protein, respectively, for the high-affinity phase, and 430 µM and 0.70 nmol/min/mg protein, respectively, for the low-affinity phase. The relative levels of V max estimated by Eadie-Hofstee plots were dogs (2.0) > mice (1.4) > rats (1.0) ≈ humans (1.0) for liver microsomes, and mice (8.5) > dogs (4.1) > rats (3.1) > humans (1.0) for intestinal microsomes. The percentages of the V max values of intestinal microsomes to liver microsomes were mice (120 %) > rats (57 %) > dogs (39 %) > humans (19 %). These results suggest that the metabolic abilities of UGT enzymes expressed in the liver and intestine toward MEHP markedly differed among species, and imply that these species differences are strongly associated with the toxicity of DEHP.

Obtaining liver tridimensional scaffold through the decellularization of rabbit whole liver in 24 hours

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Federico, Schliamser; Ayelen, Rinaldi; Romina, Comin; Alba Nelly, Borchert; Adrian, Nari Gustavo; Alicia, Salvatierra Nancy; Mariana Paula, Cid

2016-04-01

In the present work, we development a new protocol for liver decellularization in which the hole decellularization was reached over 24 h. Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrixin which the time period involved didn't pass 24 h. Methods: The decellularization is obtained through the use of water and SDS (0,1-0,3 %), after freezing at -80 degrees, is the best alternative of different physical and/or chemical mechanisms to break down organ cells and leave only the extracellular matriz. After 24 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy) and biochemical (DNA quantification) studies. Results: the decellularization process was verified by macroscopic observation of the organ using microscopic observation corroborated the macroscopic results, with the hematoxylin-eosin and Masson staining showing no cells or nuclear material. In addition, the DNA quantification was less than 10% in the decellularized liver compared to control. Finally,the time taken to develop the decellularization protocol was less than 24 hours.

Obtaining liver tridimensional scaffold through the decellularization of rabbit whole liver in 24 hours

International Nuclear Information System (INIS)

Federico, Schliamser; Ayelen, Rinaldi; Romina, Comin; Alicia, Salvatierra Nancy; Paula, Cid Mariana; Nelly, Borchert Alba; Adrian, Nari Gustavo

2016-01-01

In the present work, we development a new protocol for liver decellularization in which the hole decellularization was reached over 24 h. Introduction: the availability of transplantable livers is not sufficient to fulfill the current demand for grafts, with the search for therapeutic alternatives having generated different lines of research, one of which is the use of decellularized three-dimensional biological matrices and subsequent cell seeding to obtain a functional organ. Objective: to produce a decellularization protocol from rabbit liver to generate a three-dimensional matrixin which the time period involved didn't pass 24 h. Methods: The decellularization is obtained through the use of water and SDS (0,1-0,3 %), after freezing at -80 degrees, is the best alternative of different physical and/or chemical mechanisms to break down organ cells and leave only the extracellular matriz. After 24 h of retrograde perfusion, a decellularized translucent matrix was generated. To evaluate if the decellularization protocol was successful, with the extracellular matrix being preserved, we carried out histological (light microscopy) and biochemical (DNA quantification) studies. Results: the decellularization process was verified by macroscopic observation of the organ using microscopic observation corroborated the macroscopic results, with the hematoxylin-eosin and Masson staining showing no cells or nuclear material. In addition, the DNA quantification was less than 10% in the decellularized liver compared to control. Finally,the time taken to develop the decellularization protocol was less than 24 hours. (paper)

Oxidation of N-alkyl and N-aryl azaheterocycles by free and immobilized rabbit liver aldehyde oxidase

NARCIS (Netherlands)

Angelino, S.A.G.F.

1984-01-01

Aldehyde oxidase isolated from rabbit liver is studied in this thesis with regard to its application in organic synthesis. The enzyme has a broad substrate specificity towards azaheterocycles and therefore offers great potential for profitable use.

The oxidation of

Subchronic exposure to deoxynivalenol exerts slight effect on the immune system and liver morphology of growing rabbits

Directory of Open Access Journals (Sweden)

Mariam Kachlek

2017-01-01

Full Text Available As the most common grain contaminant worldwide, deoxynivalenol is of high importance despite its low toxicity compared to other trichothecene mycotoxins. Data on the effects of deoxynivalenol in rabbits are scarce. Thus, the aim of this study was to investigate the effects of dietary deoxynivalenol fed at a high level (10 mg/kg of feed on the productive performance, blood indices, immunological variables, histopathological changes, and genotoxicity in rabbits. Forty-eight Pannon White rabbits were exposed to contaminated diets for three weeks. Despite its high concentration, deoxynivalenol did not affect the feed intake, body weight, and body weight gain. Liver and kidney function was not affected, as shown by the clinical chemistry indices. Conversely, in two rabbits the toxin caused mild fibrosis of the liver, without degenerative changes of the hepatocytes. No genotoxicity could be observed either. Gut cytokines and the phagocytic activity of the macrophages did not differ significantly. The percentage of neutrophils was significantly lower, whereas that of eosinophils was significantly higher in the toxin-fed group. Deoxynivalenol did not cause significant changes in gut and villus morphology. In 4 out of the 6 deoxynivalenol-treated animals, the ratio of lymphoblast proliferation and simultaneous apoptosis shifted towards apoptosis in the gut-associated lymphoid tissue. In the central part of the lymphoid follicles of the spleen, lymphocyte depletion and follicular atrophy could be detected. It can be concluded that rabbits are less sensitive to deoxynivalenol, but the findings confirm that this Fusarium toxin is capable of modulating the immune response.

Interaction of rocuronium with human liver cytochromes P450

OpenAIRE

Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

2015-01-01

Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver micro...

Radioprotection of liver lipids of whole-body gamma-irradiated female rats by cystamine

International Nuclear Information System (INIS)

Ramanathan, R.; Misra, U.K.

1976-01-01

The effect of administration of cystamine (5 mg/100 g body weight) before 1,200 R whole-body gamma irradiation has been studied on irradiation-induced changes in liver and its subcellular fractions'lipids of fasted female rats. Cystamine prevented the irradiation-induced increase in liver triglycerides and liver mitochondrial total phospholipids, but it decreased microsomal total phospholipids and proteins. Cystamine prevented the radiation-induced increased 32 P-radioactivity (counts/min/μmole phospholipid phosphorus) of microsomal phosphatidyl choline. Cystamine prevented the radiation-induced increased uptake of NaH 2 32 PO 4 (counts/min/g liver) in liver microsomal phosphatidyl ethanolamine and supernatant phosphatidyl choline; but in microsomal phosphatidyl choline, cystamine did not do so, but on the other hand it itself increased the uptake in control rats. Cystamine did not prevent the irradiation-induced decreased incorporation of (U- 14 C)glucose into liver triglycerides, total phospholipids and phosphatidyl choline. Cystamine itself decreased the incorporation of (U- 14 C)glucose into liver triglycerides and phosphoglycerides of control rats. (orig.) [de

Triglycerides produced in the livers of fasting rabbits are predominantly stored as opposed to secreted into the plasma

Science.gov (United States)

Tuvdendorj, Demidmaa; Zhang, Xiao-jun; Chinkes, David L.; Wang, Lijian; Wu, Zhanpin; Rodriguez, Noe A.; Herndon, David N.; Wolfe, Robert R.

2015-01-01

Objective The liver plays a central role in regulating fat metabolism; however, it is not clear how the liver distributes the synthesized triglycerides (TGs) to storage and to the plasma. Materials and Methods We have measured the relative distribution of TGs produced in the liver to storage and the plasma by means of U-13C16-palmitate infusion in anesthetized rabbits after an overnight fast. Results The fractional synthesis rates of TGs stored in the liver and secreted into the plasma were not significantly different (Stored vs. Secreted: 31.9 ± 0.8 vs. 27.7 ± 2.6 %•h−1, p > 0.05. However, the absolute synthesis rates of hepatic stored and secreted TGs were 543 ± 158 and 27 ± 7 nmol·kg−1·min−1 respectively, indicating that in fasting rabbits the TGs produced in the liver were predominately stored (92±3%) rather than secreted (8±3%) into the plasma. This large difference was mainly due to the larger pool size of the hepatic TGs which was 21±9-fold that of plasma TGs. Plasma free fatty acids (FFAs) contributed 47±1% of the FA precursor for hepatic TG synthesis, and the remaining 53±1% was derived from hepatic lipid breakdown and possibly plasma TGs depending on the activity of hepatic lipase. Plasma palmitate concentration significantly correlated with hepatic palmitoyl-CoA and TG synthesis. Conclusion In rabbits, after an overnight fast, the absolute synthesis rate of hepatic stored TGs was significantly higher than that of secreted due to the larger pool size of hepatic TGs. The net synthesis rate of TG was approximately half the absolute rate. Plasma FFA is a major determinant of hepatic TG synthesis, and therefore hepatic TG storage. PMID:25682063

Activation and detoxification metabolism of urban air pollutants 2-nitrobenzanthrone and carcinogenic 3-nitrobenzanthrone by rat and mouse hepatic microsomes.

Science.gov (United States)

Stiborova, Marie; Cechova, Tereza; Borek-Dohalska, Lucie; Moserova, Michaela; Frei, Eva; Schmeiser, Heinz H; Paca, Jan; Arlt, Volker M

2012-01-01

2-Nitrobenzanthrone (2-NBA) has recently been detected in ambient air particulate matter. Its isomer 3-nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust. Understanding which enzymes are involved in metabolism of these toxicants is important in the assessment of individual susceptibility. Here, metabolism of 2-NBA and 3-NBA by rat and mouse hepatic microsomes containing cytochromes P450 (CYPs), their reductase (NADPH:CYP reductase), and NADH:cytochrome b5 reductase was investigated under anaerobic and aerobic conditions. In addition, using the same microsomal systems, 2-NBA and 3-NBA were evaluated to be enzymatically activated under anaerobic conditions to species generating 2-NBA- and 3-NBA-derived DNA adducts. High performance liquid chromatography (HPLC) with ultraviolet (UV) detection was employed for the separation and characterization of 2-NBA and 3-NBA metabolites formed by hepatic microsomes of rats and mice under the anaerobic and aerobic conditions. Microsomal systems isolated from the liver of the control (untreated) rats and rats pretreated with Sudan I, β-naphthoflavone (β-NF), phenobarbital (PB), ethanol and pregnenolon 16α-carbonitrile (PCN), the inducers of cytochromes P450 (CYP) 1A1, 1A1/2, 2B, 2E1 and 3A, respectively, were used in this study. Microsomes of mouse models, a control mouse line (wild-type, WT) and Hepatic Cytochrome P450 Reductase Null (HRN) mice with deleted gene of NADPH:CYP reductase in the liver, thus absenting this enzyme in their livers, were also employed. To detect and quantify the 2-NBA- and 3-NBA-derived DNA adducts, the 32P postlabeling technique was used. Both reductive metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), found to be formed predominantly under the anaerobic conditions, and two 3-NBA oxidative metabolites, whose structures have not yet been investigated, were formed by several microsomal systems used in the study. Whereas a 3-NBA reductive metabolite

Combined treatment of radiofrequency ablation and acetic acid injection: an in vivo feasibility study in rabbit liver

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong Min; Kim, Se Hyung; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, 28, Yongon-Dong, Chongno-Gu, 110-744, Seoul (Korea); Lee, Young Hwan [Department of Diagnostic Radiology, Wonkwang University Hospital, Iksan (Korea); Kim, Young Kon; Kim, Sang Won [Department of Diagnostic Radiology, Chonbuk National University Hospital, Chonju (Korea)

2004-07-01

The aim of this study was to compare the effects of percutaneous radiofrequency ablation (RFA) combined with percutaneous acetic acid injection (PAI) and either therapy alone for their effects on in vivo rabbit liver tissue. Thirty New Zealand white rabbits were included in this study and were allocated to three groups: group A, conventional RFA (n=10); group B, PAI (n=10); and group C, combined RFA and PAI (n=10). Under US guidance, 1 ml of 50% acetic acid was injected into the target area of the liver parenchyma through a 21-G Chiba needle before performing RFA. The RFA was then performed using a 17-G internally cooled electrode with 1-cm active tip, and RF energy (30 W) was applied for 3 min with or without acetic acid injection. After RFA or PAI, contrast-enhanced CT and CT pathologic correlation were performed. The maximum diameters of the thermal lesions in each group were compared. All procedures were technically successful, and a total of 30 lesions (10 lesions for each group) were produced. The mean maximum diameter of the coagulation necrosis in the rabbits of group C (25{+-}9 mm) was significantly larger than the diameters of the other groups: 12.2{+-}1 mm (group A) and 14.3{+-}3 mm (group B; p=0.001). On contrast-enhanced CT scanning, the lesions of group B (7 of 10, 70%) appeared frequently irregular compared with those of groups A (2 of 10, 20%) and C (4 of 10, 40%; p=0.08). There were seven complications (23.3%): a localized hematoma in a group-A rabbit; two hematomas and one chemical peritonitis in group-B rabbits; and a hematoma, a chemical peritonitis, and a burn injury to the stomach in group-C rabbits. Compared with the group-A rabbits (1 of 10, 10%), the group-B (3 of 10, 30%) and group-C rabbits (3 of 10, 30%) showed a tendency toward complications, but the difference was not significant (p=0.48). Under the present experimental condition, combined RFA and PAI was able to increase the diameter of coagulation necrosis up to 2.5 cm without

Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

Science.gov (United States)

Kukiełka, E; Cederbaum, A I

1995-04-15

Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid DNA into the relaxed open circular state. The plasmid used was pBluescript II KS(-), and the forms of DNA were separated by agarose-gel electrophoresis. Incubation of rat liver microsomes with plasmid plus NADH plus ferric-ATP caused DNA strand cleavage. The addition of rifamycin SV produced a time- and concentration-dependent increase in DNA-strand cleavage. No stimulation by rifamycin SV occurred in the absence of microsomes, NADH or ferric-ATP. Stimulation occurred with other ferric complexes besides ferric-ATP, e.g. ferric-histidine, ferric-citrate, ferric-EDTA, and ferric-(NH4)2SO4. Rifamycin SV did not significantly increase the high rates of DNA strand cleavage found with NADPH as the microsomal reductant. The stimulation of NADH-dependent microsomal DNA strand cleavage was completely blocked by catalase, superoxide dismutase, GSH and a variety of hydroxyl-radical-scavenging agents, but not by anti-oxidants that prevent microsomal lipid peroxidation. Redox cycling agents, such as menadione and paraquat, in contrast with rifamycin SV, stimulated the NADPH-dependent reaction; menadione and rifamycin SV were superior to paraquat in stimulating the NADH-dependent reaction. These results indicate that rifamycin SV can, in the presence of an iron catalyst, increase microsomal production of reactive oxygen species which can cause DNA-strand cleavage. In contrast with other redox cycling agents, the stimulation by rifamycin SV is more pronounced with NADH than with NADPH as the

Effect of ethionine on hepatic mitochondrial and microsomal calcium uptake

International Nuclear Information System (INIS)

Agarwal, A.K.; Zinermon, W.D.; Latoni, L.

1988-01-01

Ethionine, an ethyl analog of methionine, produces a variety of physiological and pathological effects in animals. These range from acute effects in the liver, kidney, pancreas, and other organs to liver carcinogenesis. Female rats when injected with ethionine exhibit a rapid decrease in hepatic adenosine triphosphate levels followed by a marked inhibition of RNA and protein synthesis and accumulation of triglycerides. Since calcium transport in mitochondria and microsomes is ATP dependent, it becomes interesting to find out if ethionine administration has any effect on subcellular calcium transport. Calcium has recently gained an increased controversy regarding its role in chemical induced lethal cell damage. Certain groups believe that influx of extracellular calcium across the damaged plasma membrane might actually mediate the irreversible damage to the cell, whereas according to other, entry of calcium into the cell is secondary to the damage. The present study was carried out to investigate the calcium [ 45 Ca] transport in mitochondria and microsomes following ethionine administration. The effect of carbon tetrachloride on calcium uptake in ethionine treated rats was also studied

EFFECTS OF THIOL ANTIOXIDANTS ON THE ATROPSELECTIVE OXIDATION OF 2,2′,3,3′,6,6′-HEXACHLOROBIPHENYL (PCB 136) BY RAT LIVER MICROSOMES

Science.gov (United States)

Wu, Xianai; Lehmler, Hans-Joachim

2015-01-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol) and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136 and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo. PMID:26155892

Sex-related difference in the inductions by perfluoro-octanoic acid of peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase in rat liver.

Science.gov (United States)

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

Inductions by perfluoro-octanoic acid (PFOA) of hepatomegaly, peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase were compared in liver between male and female rats. Marked inductions of these four parameters were seen concurrently in liver of male rats, whereas the inductions in liver of female rats were far less pronounced. The sex-related difference in the response of rat liver to PFOA was much more marked than that seen with p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). Hormonal manipulations revealed that this sex-related difference in the inductions is strongly dependent on sex hormones, namely that testosterone is necessary for the inductions, whereas oestradiol prevented the inductions by PFOA. PMID:2570571

VX2 Carcinoma in rabbit liver: Different radiologic features according to innoculation methods

International Nuclear Information System (INIS)

Lee, Joon Woo; Chung, Jin Wook; Choi, Guk Myeong; Kim, Chong Jai; Kim, Se Hyung; Choi, Joon Il; Lee, Kyoung Ho; Kim, Seung Hyup; Park, Jae Hyung

2000-01-01

To investigate radiologic features about hepatic VX2 carcinoma induced by two methods, direct intraparenchymal innoculation vs transpotal approach, focus on enhancement pattern and comparison of each imaging modalities and innoculation methods. VX2 carcinomas were induced in 11 rabbit livers by direct inoculation (n=7) or infusion into mesenteric vein (n=4). After two weeks, spiral CT, digital subtraction angiography (DSA), intravenous contrast-enhanced power Doppler sonography, intraarterial CO 2 sonography were done. The enhancement patterns were assessed independently and correlated with histopathologic features. With direct intraprenchymal innoculation, localized hepatic VX2 tumors were developed. Considering all imaging modalities, six of 7 tumors appeared peripheral hypervascularity, one hypovascularity. On pathologic and radiologic correlations, the enhancing portions of 4 tumors corresponded to viable tumor and pseudo-capsule portion, the other enhancing portions of 2 tumors corresponded to sinusoidal vascular spaces. With the transportal approaches, diffuse hepatic tumors were developed. Spiral CT and DSA revealed these tumors as marked peripheral hypervascular tumors with multiple A-P shunts. On pathologic findings, multiple thin walled sinusoidal spaces were seen at periphery of nodule. Spiral CT was superior to the other modalities in evaluation of enhancement characteristics. VX2 carcinomas in rabbit livers showed different radiologic and histopathologic features according to the innoculation methods.

Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo

International Nuclear Information System (INIS)

Chung, Dong Jin; Cho, Se Hyun; Lee, Jae Mun; Hahn, Seong-Tae

2012-01-01

Objective: To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver. Materials and methods: HIFU ablations (intensity of 400 W/cm 2 for 4 s, six times, with a 5 s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8 ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test. Results: The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P < 0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P < 0.05). Conclusion: HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.

Identification of AKB-48 and 5F-AKB-48 Metabolites in Authentic Human Urine Samples Using Human Liver Microsomes and Time of Flight Mass Spectrometry

OpenAIRE

Vikingsson, Svante; Josefsson, Martin; Green, Henrik

2015-01-01

The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 3...

Comparison of lesion conspicuity of radiofrequency ablation zones among MR sequences according to time in the normal rabbit liver

International Nuclear Information System (INIS)

Ku, Myong Seo; Kim, Seung Kwon; Hong, Hyun Pyo; Kwag, Hyon Joo

2007-01-01

To compare the lesion conspicuity of radiofrequency ablation (RFA) zones among MR sequences according to time in the normal rabbit liver. RFA zones were created in 12 rabbit livers with a 17-gauge internally cooled electrode (1-cm active tip, 30 Watts, 3 minutes). Three rabbits were sacrificed immediately, three days, two weeks, and six weeks after the RFA procedure, respectively. Before sacrifice, T1-, T2-weighted images (WI), and gadolinium-enhanced (GE)-T1WI images were obtained. The lesion conspicuity of the RAF zone and the contrast-to-noise ratio (CNR) of the RFA zone to the liver parenchyma were analyzed and compared among the MR sequences according to time. On T1WI, the RFA zones were only clearly seen on acute phase. On T2WI, the RFA zones were clearly seen on all phases except the hyperacute phase. On GE T1WI, the RFA zones were clearly seen on all phases. The CNRs of the RFA zone to the liver parenchyma of GE-T1WI (8.1-12.4) were significantly higher than the CNRs of TIWI (1.6-2.7) and T2WI (1.7-6.3) on all phases (ρ < 0.05), but the visual lesion conspicuity between GE T1WI and T2WI were similar. On hyperacute phase, GE T1WI showed better lesion conspicuity of the RFA zone than T1WI and T2WI. On other phases, GE T1WI and T2WI showed similar lesion conspicuity

Strategy for Hepatotoxicity Prediction Induced by Drug Reactive Metabolites Using Human Liver Microsome and Online 2D-Nano-LC-MS Analysis.

Science.gov (United States)

Zhuo, Yue; Wu, Jian-Lin; Yan, Xiaojing; Guo, Ming-Quan; Liu, Ning; Zhou, Hua; Liu, Liang; Li, Na

2017-12-19

Hepatotoxicity is a leading cause of drug withdrawal from the market; thus, the assessment of potential drug induced liver injury (DILI) in preclinical trials is necessary. More and more research has shown that the covalent modification of drug reactive metabolites (RMs) for cellular proteins is a possible reason for DILI. Unfortunately, so far no appropriate method can be employed to evaluate this kind of DILI due to the low abundance of RM-protein adducts in complex biological samples. In this study, we proposed a mechanism-based strategy to solve this problem using human liver microsomes (HLMs) and online 2D nano-LC-MS analysis. First, RM modification patterns and potential modified AA residues are determined using HLM and model amino acids (AAs) by UHPLC-Q-TOF-MS. Then, a new online 2D-nano-LC-Q-TOF-MS method is established and applied to separate the digested modified microsomal peptides from high abundance peptides followed by identification of RM-modified proteins using Mascot, in which RM modification patterns on specific AA residues are added. Finally, the functions and relationship with hepatotoxicity of the RM-modified proteins are investigated using ingenuity pathway analysis (IPA) to predict the possible DILI. Using this strategy, 21 proteins were found to be modified by RMs of toosendanin, a hepatotoxic drug with complex structure, and some of them have been reported to be associated with hepatotoxicity. This strategy emphasizes the identification of drug RM-modified proteins in complex biological samples, and no pretreatment is required for the drugs. Consequently, it may serve as a valuable method to predict potential DILI, especially for complex compounds.

Effect of rat whole-body irradiation on oxidase chain and glucose-6-phosphatase of liver microsome: influence of cysteamine

International Nuclear Information System (INIS)

Bernard, Pierre.

1979-11-01

Three enzymatic systems of the male rat liver endoplasmic reticulum were studied by biochemical methods. Two means of investigation were used: - whole-body irradiation of the animal, - administration of cysteamine. The results obtained are discussed, in view of the functioning of these enzymatic systems, from two viewpoints: - the study of enzymatic radiolesions in relation to the radiobiological effect on the animal, the organ and the sub-cellular organite, - the study of chemical radioprotection. After a 900 R whole-body gamma irradiation a severe drop was observed in the enzymatic activity of two essential elements of the microsome oxydase chain: NADPH cytochrome P450 reductase and ethylmorphine N-demethylation. Glucose 6 phosphatase is also impaired by irradiation. Here it seems that the microsomal protein fraction could be responsible for the change in the enzyme activity. The irradiation effect is therefore not specific to one enzyme. The changes in these enzymatic activities correspond to the different phases of the acute irradiation syndrome which also affects the weight of the experimental animal and of the organ studied. Cysteamine used under chemical radioprotection conditions was found to be especially useful as a means of investigation complementary to the study of enzymatic radiolesions. From the combined action of irradiation and of the radioprotector it was possible to obtain a partial idea of the mechanisms of these radiolesions [fr

Targeted hyperthermia after selective embolization with ferromagnetic nanoparticles in a VX2 rabbit liver tumor model

Directory of Open Access Journals (Sweden)

Sun HL

2013-10-01

Full Text Available Hongliang Sun,1 Linfeng Xu,1 Tianyuan Fan,2 Hongzhi Zhan,3 Xiaodong Wang,3 Yanfei Zhou,2 Ren-jie Yang3 1Department of Interventional Therapy, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, 2Pharmacy School of Beijing University, Beijing, 3Department of Interventional Therapy, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing, People's Republic of China Background: The purpose of this study was to observe the effect and feasibility of hyperthermia and the influence of heat on surrounding organs in a VX2 rabbit liver model exposed to an alternating magnetic field after embolization with ferromagnetic nanoparticles. Methods: Forty rabbits containing implanted hepatic VX2 carcinomas were divided into four groups, each containing ten rabbits. Fourteen days after tumor transplantation, we opened the abdomen to observe the size and shape of the tumor. A transfemoral retrograde approach was then used for hepatic arterial catheterization in groups B, C, and D to perform angiography and embolization. The next day, three rabbits in group B and all rabbits in group D were exposed to an alternating magnetic field, and the temperature was recorded simultaneously in the center of the tumor, at the edge of the tumor, and in the normal liver parenchyma. On day 28, all animals was euthanized to observe changes in the implanted liver tumor and the condition of the abdomen. A pathologic examination was also done. Results: Before surgery, there was no significant difference in tumor volume between the four groups. Three different temperature points (center of the tumor, edge of the tumor, and in the normal liver parenchyma of group B under an alternating magnetic field were 37.2°C ± 1.1°C, 36.8°C ± 1.2°C, and 36.9°C ± 2.1°C, none of which were significantly different from pretreatment values. Three points basal temperature in group D showed no significant difference (F = 1.038, P = 0.413. Seven to 26

The role of CYP2D6 in primary and secondary oxidative metabolism of dextromethorphan: in vitro studies using human liver microsomes.

Science.gov (United States)

Kerry, N L; Somogyi, A A; Bochner, F; Mikus, G

1994-01-01

1. The enzyme kinetics of dextromethorphan O-demethylation in liver microsomes from three extensive metabolisers (EM) with respect to CYP2D6 indicated high (Km1 2.2-9.4 microM) and low (Km2 55.5-307.3 microM) affinity sites whereas microsomes from two poor metabolisers (PM) indicated a single site (Km 560 and 157 microM). Similar differences were shown for 3-methoxymorphinan O-demethylation to 3-hydroxymorphinan (Km 6.9-9.6 microM in EM subjects; Km 307 and 213 microM in PM subjects). 2. Dextromethorphan O-demethylation was inhibited competitively by quinidine (Ki 0.1 microM), rac-perhexiline (Ki 0.4 microM), dextropropoxyphene (Ki 6 microM), rac-methadone (Ki 8 microM), and 3-methoxymorphinan (Ki 15 microM). These compounds were also potent inhibitors of 3-methoxymorphinan O-demethylation with IC50 values ranging from 0.02-12 microM. Anti-LKM1 serum inhibited both dextromethorphan and 3-methoxymorphinan O-demethylations in a titre-dependent manner. 3. The Michaelis-Menten constant for dextromethorphan N-demethylation to 3-methoxymorphinan (Km 632-977 microM) and dextrorphan N-demethylation to 3-hydroxymorphinan (Km 1571-4286 microM) did not differ between EM and PM microsomes. These N-demethylation reactions were not inhibited by quinidine and rac-methadone or LKM1 antibodies. 4. Dextromethorphan and 3-methoxymorphinan are metabolised by the same P450 isoform, CYP2D6, whereas the N-demethylation reactions are not carried out by CYP2D6. PMID:7826826

Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

Energy Technology Data Exchange (ETDEWEB)

Thomassin, J.; Tephly, T.R. (Univ. of Iowa, Iowa City (USA))

1990-09-01

Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

Effect of Angelica Sinensis on liver fibrosis after radiotherapy combined with transarterial chemoembolization for rabbits with VX 2 tumor

International Nuclear Information System (INIS)

Long Qingyun; Zhou Yunfeng; Hu Jinxiang; Zhou Jun; Le Tao

2008-01-01

Objective: To evaluate the effect of Angelica Sinensis on liver fibrosis after radiotherapy (RT) combined with transarterial chemoembolization(TACE) for rabbits with VX 2 tumor, and the mechanism of anti-hepatic fibrosis. Methods: Fifty New Zealand white rabbits were divided randomly into three groups: Control group (n=10) was given saline 2 ml by gastroduodenal artery, model group (n=10) was given pingyangmycin 1 mg and iodized oil 0.2 ml, and exposed to single fraction of 20 Gy, Angelica group (n=30) undergoing RT combined with TACE was given Angelica Sinensis injection. According to different doses of Angelica Sinensis, Angelica group was divided into low-dose group (4 ml/kg), middle dose group (6 ml/kg) and high-dose group (8 ml/kg), twice per week for 4 weeks. Serum levels of HA, LN, PCIII, CIV and liver specimens were obtained at the end of 6th week after RT combined with TACE. The histological changes were determined by HE, VG staining and TGF-β1 immunohistochemistry staining. Results: Stages of liver fibrosis in the model group were mostly stages II and III, and stages of liver fibrosis in the Angelica group were mostly stages I, there was significant difference between the model group and the Angelica group, and stages of liver fibrosis were associated with Angelica intercention treatment (r=0.7631, P<0.01). Serum HA, LN, PCIII and CIV in the model group were higher than those in the control group(P<0.01), TGF-β1 expression in the Angelica group was significantly reduced compared with the wodel group and different doses of Angelica group showed dose-effect (r=0.4427, P<0.01). Conclusions: Angelica Sinensis injection has inhibitive effect on liver fibrosis after RT combined with TACE for rabbits with VX 2 tumor, the mechanism of anti-hepatic fibrosis might possibly be associated with down-regulating TGF-β1. (authors)

Purification and characterization of an amidohydrolase for N4-long-chain fatty acyl derivatives of 1-beta-D-arabinofuranosylcytosine from mouse liver microsomes.

Science.gov (United States)

Hori, K; Tsuruo, T; Tsukagoshi, S; Sakurai, Y

1984-03-01

N4-Long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase, a metabolizing enzyme for N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with long-chain fatty acids, was purified from mouse liver microsomes. The purification was accomplished by solubilization of liver microsomes with Triton X-100, diethylaminoethyl cellulose chromatography, gel filtrations, hydroxyapatite chromatography, and concanavalin A:Sepharose chromatography. On sodium dodecyl sulfate:polyacrylamide gel electrophoresis, the purified enzyme preparation produced a single protein band with a molecular weight of 54,000. The enzyme had an optimal pH of 9.0, and the Michaelis constant for N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was 67 microM. The thiols such as dithiothreitol or 2-mercaptoethanol stabilized the enzyme and stimulated its activity. p-Chloromercuribenzoate, N-ethylmaleimide, diisopropylfluorophosphate, and phenylmethylsulfonyl fluoride strongly inhibited the reaction. Bovine serum albumin markedly stimulated the enzyme activity, whereas detergents such as Triton X-100, deoxycholate, and sodium dodecyl sulfate had little effect. The enzyme did not require monovalent or divalent cations. Among the series of N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with different chain lengths of acyl residues, the purified enzyme preferentially hydrolyzed the derivatives with long-chain fatty acids (C12 to C18), and N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was the most susceptible. The purified enzyme was inactive on various N-acylamino acids, amides, oligopeptides, proteins, N-acylsphingosines (ceramides), triglyceride, lecithin, and lysolecithin. These results suggest that N4-long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase may be a new type of linear amidase.

Luminol-and lucigenin-amplified chemiluminescence with rat liver microsomes. Kinetics and influence of ascorbic acid, glutathione, dimethylsulfoxide, N-t-butyl-a-phenyl-nitrone, copper-ions and a copper complex, catalase, superoxide dismutase, hexobarbital and aniline.

Science.gov (United States)

Klinger, W; Karge, E; Kretzschmar, M; Rost, M; Schulze, H P; Dargel, R; Reinemann, C; Rein, H

1996-07-01

For the investigation of luminol (LM)-and lucigenin (LC)-amplified chemiluminescence (CL) in rat liver microsomes using both a liquid-scintillation counter (LKB/Wallac 1219 Rackbeta) and a Berthold luminometer (AutoLumat LB 953) optimal incubation mixtures and conditions and basic kinetics have been established. Whereas calibration curves for both LM- and LC-CL are performed with hydrogenperoxide (LC quantum yield is 6.25 fold higher as that of LM), distinct differences were revealed with microsomes, indicating that different reactive oxygen species (ROS) are determined: Both LM- and LC-CL follow the kinetics of enzymatic reactions in terms of dependence on protein and NADPH or NADH concentration, time course, temperature etc., but with differences. LM-CL does not work without addition of Fe2+, whereas LC-CL does. Both copper ions and copper bound in a complex abolish CL, LC-CL being much more sensitive. Isolated cytochrome P-450 (P450) and NADPH P450 reductase from liver of pheno-barbital treated rats alone proved to be inactive in LM-and LC-CL production, whereas te combination 1:1 without and with addition of lipid was highly active in both LM-and LC-CL. Ascorbic acid and glutathione as scavengers diminish both LM- and LC-CL in concentrations higher then 10(5). Dimethyl-sulfoxide (DMSO) was ineffective in LM-CL up to concentrations of 0.2 M, the very high concentration of 2 M diminished LM-CL only to 1/3. LC-CL was diminished starting at concentrations of 100 mM and at 2 M only 10% of maximum LC-CL was observed. The trap substance N-t-butyl-a-phenylnitrone (BNP) also diminished LC-CL more effectively than LM-CL. Clearcut differences were revealed by the addition of catalase and superoxide dismutase: both enzymes diminished LM-CL only, without any influence on LC-CL. Hexobarbital, a potent uncoupler of P450, enhances LM-CL fivefold, whereas LC-CL is barely influenced. Aniline (without uncoupling capability) decreased both LM-and LC-CL increasingly with increasing

AM-2201 Inhibits Multiple Cytochrome P450 and Uridine 5′-Diphospho-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

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Ju-Hyun Kim

2017-03-01

Full Text Available AM-2201 is a synthetic cannabinoid that acts as a potent agonist at cannabinoid receptors and its abuse has increased. However, there are no reports of the inhibitory effect of AM-2201 on human cytochrome P450 (CYP or uridine 5′-diphospho-glucuronosyltransferase (UGT enzymes. We evaluated the inhibitory effect of AM-2201 on the activities of eight major human CYPs (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4 and six major human UGTs (1A1, 1A3, 1A4, 1A6, 1A9, and 2B7 enzymes in pooled human liver microsomes using liquid chromatography–tandem mass spectrometry to investigate drug interaction potentials of AM-2201. AM-2201 potently inhibited CYP2C9-catalyzed diclofenac 4′-hydroxylation, CYP3A4-catalyzed midazolam 1′-hydroxylation, UGT1A3-catalyzed chenodeoxycholic acid 24-acyl-glucuronidation, and UGT2B7-catalyzed naloxone 3-glucuronidation with IC50 values of 3.9, 4.0, 4.3, and 10.0 μM, respectively, and showed mechanism-based inhibition of CYP2C8-catalyzed amodiaquine N-deethylation with a Ki value of 2.1 μM. It negligibly inhibited CYP1A2, CYP2A6, CYP2B6, CYP2C19, CYP2D6, UGT1A1, UGT1A4, UGT1A6, and UGT1A9 activities at 50 μM in human liver microsomes. These in vitro results indicate that AM-2201 needs to be examined for potential pharmacokinetic drug interactions in vivo due to its potent inhibition of CYP2C8, CYP2C9, CYP3A4, UGT1A3, and UGT2B7 enzyme activities.

PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

Science.gov (United States)

Tedeschi, Henry; James, Joseph M.; Anthony, William

1963-01-01

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

CYP2J2 and CYP2C19 are the major enzymes responsible for metabolism of albendazole and fenbendazole in human liver microsomes and recombinant P450 assay systems.

Science.gov (United States)

Wu, Zhexue; Lee, Doohyun; Joo, Jeongmin; Shin, Jung-Hoon; Kang, Wonku; Oh, Sangtaek; Lee, Do Yup; Lee, Su-Jun; Yea, Sung Su; Lee, Hye Suk; Lee, Taeho; Liu, Kwang-Hyeon

2013-11-01

Albendazole and fenbendazole are broad-spectrum anthelmintics that undergo extensive metabolism to form hydroxyl and sulfoxide metabolites. Although CYP3A and flavin-containing monooxygenase have been implicated in sulfoxide metabolite formation, the enzymes responsible for hydroxyl metabolite formation have not been identified. In this study, we used human liver microsomes and recombinant cytochrome P450s (P450s) to characterize the enzymes involved in the formation of hydroxyalbendazole and hydroxyfenbendazole from albendazole and fenbendazole, respectively. Of the 10 recombinant P450s, CYP2J2 and/or CYP2C19 was the predominant enzyme catalyzing the hydroxylation of albendazole and fenbendazole. Albendazole hydroxylation to hydroxyalbendazole is primarily mediated by CYP2J2 (0.34 μl/min/pmol P450, which is a rate 3.9- and 8.1-fold higher than the rates for CYP2C19 and CYP2E1, respectively), whereas CYP2C19 and CYP2J2 contributed to the formation of hydroxyfenbendazole from fenbendazole (2.68 and 1.94 μl/min/pmol P450 for CYP2C19 and CYP2J2, respectively, which are rates 11.7- and 8.4-fold higher than the rate for CYP2D6). Correlation analysis between the known P450 enzyme activities and the rate of hydroxyalbendazole and hydroxyfenbendazole formation in samples from 14 human liver microsomes showed that albendazole hydroxylation correlates with CYP2J2 activity and fenbendazole hydroxylation correlates with CYP2C19 and CYP2J2 activities. These findings were supported by a P450 isoform-selective inhibition study in human liver microsomes. In conclusion, our data for the first time suggest that albendazole hydroxylation is primarily catalyzed by CYP2J2, whereas fenbendazole hydroxylation is preferentially catalyzed by CYP2C19 and CYP2J2. The present data will be useful in understanding the pharmacokinetics and drug interactions of albendazole and fenbendazole in vivo.

Purification and characterization of a novel cytosolic NADP(H)-dependent retinol oxidoreductase from rabbit liver.

Science.gov (United States)

Huang, D Y; Ichikawa, Y

1997-03-07

Rabbit liver cytosol exhibits very high retinol dehydrogenase activity. At least two retinol dehydrogenases were demonstrated to exist in rabbit liver cytosol, and the major one, a cytosolic NADP(H)-dependent retinol dehydrogenase (systematic name: retinol oxidoreductase) was purified about 1795-fold to electrophoretic and column chromatographic homogeneity by a procedure involving column chromatography on AF-Red Toyopearl twice and then hydroxyapatite. Its molecular mass was estimated to be 34 kDa by SDS-PAGE, and 144 kDa by HPLC gel filtration, suggesting that it is a homo-tetramer. The enzyme uses free retinol and retinal, and their complexes with CRBP as substrates in vitro. The optimum pH values for retinol oxidation of free retinol and CRBP-retinol were 8.8-9.2 and 8.0-9.0, respectively, and those for retinal reduction of free retinal and retinal-CRBP were the same, 7.0-7.6. Km for free retinol and Vmax for retinal formation were 2.8 microM and 2893 nmol/min per mg protein at 37 degrees C (pH 9.0) and the corresponding values with retinol-CRBP as a substrate were 2.5 microM and 2428 nmol/min per mg protein at 37 degrees C (pH 8.6); Km for free retinal and Vmax for retinol formation were 6.5 microM and 4108 nmol/min per mg protein, and the corresponding values with retinal-CRBP as a substrate were 5.1 microM and 3067 nmol/min per mg protein at 37 degrees C, pH 7.4. NAD(H) was not effective as a cofactor. 4-Methylpyrazole was a weak inhibitor (IC50 = 28 mM) of the enzyme, and ethanol was neither a substrate nor an inhibitor of the enzyme. This enzyme exhibits relatively broad aldehyde reductase activity and some ketone reductase activity, the activity for aromatic substitutive aldehydes being especially high and effective. Whereas, except in the case of retinol, oxidative activity toward the corresponding alcohols was not detected. This novel cytosolic enzyme may play an important role in vivo in maintaining the homeostasis of retinal, the substrate of retinoic

Magnetic circular dichroism studies on microsomal aryl hydrocarbon hydroxylase: comparison with cytochrome b/sub 5/ and cytochrome P-450/sub cam/

Energy Technology Data Exchange (ETDEWEB)

Vickery, L; Salmon, A; Sauer, K

1975-01-01

Magnetic circular dichroism spectra are reported for the visible and near ultraviolet spectral regions of liver microsomes from dimethylbenzanthracene-treated rats. The sequential addition of NADH, dithionite, and carbon monoxide enables us to determine contributions to the magnetic circular dichroism by cytochromes b/sub 5/ and P-450, which dominate the spectra. The magnetic circular dichroism of the microsomal preparation is compared with that of purified oxidized and reduced cytochrome b/sub 5/ from pig liver and with the camphor-complexed and camphor-free oxidized, reduced, and reduced carbonmonoxy cytochrome P-450/sub cam/ from Pseudomonas putida. The magnetic circular dichroism spectra of the membrane bound cytochrome b/sub 5/ are similar to those of the purified protein, indicating that little or no alteration in the environment of the heme occurs during the isolation procedure. The soluble bacterial cytochrome P-450/sub cam/ also appears to be a suitable model for microsomal P-450, although differences in the magnetic circular dichroism intensity are observed for the two enzymes. No effect of dimethylbenzanthracene on the magnetic circular dichroism spectra of induced compared to control rat microsomes could be observed.

Combined radiofrequency ablation and acetic acid-hypertonic saline solution instillation: an in vivo study of rabbit liver

Energy Technology Data Exchange (ETDEWEB)

Lee, Jeong-Min; Han, Joon-Koo; Kim, Se-Hyung; Choi, Byung-Ihn [Seoul National University, Seoul (Korea, Republic of); Kim, Young-Kon; Kim, Sang-Won [Chonbuk National University, Chonju (Korea, Republic of)

2004-03-15

We wanted to determine whether combined radiofrequency ablation (RFA) and acetic acid-hypertonic saline solution (AHS) instillation can increase the extent of thermally mediated coagulation in in vivo rabbit liver tissue. We also wished to determine the optimal concentration of the solution in order to maximize its effect on extent of the RFA-induced coagulation. Forty thermal ablation zones were produced in 40 rabbits by using a 17-gauge internally cooled electrode with a 1-cm active tip under ultrasound guidance. The rabbits were assigned to one of four groups: group A: RFA alone (n=10); group B: RFA with 50% AHS instillation (n=10); group C: RFA with 25% AHS instillation (n=10); group D: RFA with 15% AHS instillation (n=10). A range of acetic acid concentrations diluted in 36% NaCl to a total volume of 2 mL were instilled into the liver before RFA. The RF energy (30W) was applied for three minutes. After RFA, in each group, the maximum diameters to the thermal ablation zones in the gross specimens were compared. Technical success and the complication that arose were evaluated by CT and on the basis of autopsy findings. All procedures are technically successful. There were six procedure-related complications (6/40; 15%); two localized perihepatic hematomas and four chemical peritonitis. The incidence of chemical peritonitis was highest for group B with the 50% AHS solution instillation (30%). With instillation of 15% AHS solution, a marked decrease of tissue impedance (24.5 {+-} 15.6 {omega}) and an increase of current (250 mA) occurred as compared to RFA alone. With instillation of the solutions before RFA (group B, C and D). this produced a greater mean diameter of coagulation necrosis than the diameters for rabbits not instilled with the solution (group A) ({rho}<0.05). However, there was no significant difference between group B, C, and D. Combined AHS instillation and RFA can increase the dimension of coagulation necrosis in the liver with a single

Evaluation of liver function in carbon tetrachloride-damaged rabbits by dynamic SPECT. Comparison of 99mTc-GSA and 99mTc-Sn colloid

International Nuclear Information System (INIS)

Kiuchi, Takaaki; Kawasaki, Yukiko; Hino, Ichirou; Kojima, Kanji; Ohkawa, Motoomi; Tanabe, Masatada; Tamai, Toyosato.

1994-01-01

Technetium-99m-DTPA-galactosyl human serum albumin ( 99m Tc-GSA) is a new ligand that binds specifically to asialoglycoprotein receptors in hepatocytes. We performed liver dynamic SPECT using 99m Tc-GSA and 99m Tc-Sn colloid in nine normal control rabbits and 17 chronically CCl 4 -damaged rabbits (total 29 examinations), and also performed liver function tests (ICGR 15 , Alb, etc). Using the obtained dynamic SPECT data, we analyzed the liver kinetics of 99m Tc-Sn colloid using a one-compartment model (hepatic blood flow [K]) and 99m Tc-GSA using a two-compartment model (hepatic blood flow and receptor binding [K 1 ], catabolism [K 2 ]). As the CCl 4 -treated period increased, K 1 decreased most significantly. K 1 showed the most statistically significant correlation with the results of liver function tests, ICGR 15 (p 1 showed a correlation with the hepatic fibrosis of the HAI score. From the present results, liver dynamic SPECT using 99m Tc-GSA may be said to provide a novel method for the evaluation of hepatic functional reserve. (author)

Stereospecificity (ST) of the microsomal ethanol oxidizing system (MEOS)

International Nuclear Information System (INIS)

Alderman, J.; Kato, S.; Lasker, J.; Lieber, C.S.

1987-01-01

The ST of MEOS for the ethanol 1R hydrogen has been variously reported as absolute, partial or absent, with free radical involvement postulated in the latter case. To determine both the ST of MEOS and the participation of free radicals in the reaction, they investigated MEOS ST using 1R[1- 3 H] ethanol as substrate. ST is expressed as the fraction of 3 H labeling in acetaldehyde formed, relative to that in ethanol, and ranges from 0.5 to 0. Partial ST was observed using liver microsomes from both rats and hamsters; it significantly decreased after ethanol feeding. 0.1 mM desferrioxamine (dfx) did not increase ST in any of these microsomal preparations while ferric EDTA decreased it, suggesting that ethanol treatment induces a cytochrome P-450 with lower ST rather than increasing free radical involvement. This is supported by a virtual absence of ST observed in a reconstituted system containing purified hamster P-450/sub ALC/, a liver cytochrome P-450 isozyme induced in hamsters by ethanol treatment. Their results indicate that, unlike other enzymes that oxidize ethanol, MEOS has only partial ST. Thus, ST alone cannot be used as an index of free radical involvement but, when evaluated with the response of ST to dfx, it indicated that MEOS is unlikely to involve free radical attack on ethanol in solution

Effects of hyperthermia on the normal liver using scintigraphic methods. Functional changes of the rabbit whole-liver by local hyperthermia

International Nuclear Information System (INIS)

Ryu, Kiyotaka; Shinotsuka, Akira; Takenaka, Hiroki; Hirono, Yoshisada

1995-01-01

An experimental study was conducted to investigate effect of hyperthermia to the liver in rabbits. The whole liver was heated at 43degC for 30 min by a RF capacitive heating device, and subsequent changes were observed by scintigraphy using 99m Tc-EHIDA and 99m Tc-Sn-colloid. The excretory ratio (Ke value) of 99m Tc-EHIDA and the uptake ratio (K value) of 99m Tc-Sn-colloid were measured to estimate hyperthermia induced hepatic injury for a month. Blood chemistry analysis was also conducted during this period. Also, the uptake of 3 H-methyl-thymidine into the DNA of hepatocyted was assayed 2 and 5 days after heating. Concurrently, histopathological changes were observed. The Ke value showed a transient increase and returned to the level prior to heating after approximately one week. A distinct increase in GPT was observed. The uptake of 3 H-methyl-thymidine showed a marked rise 2 days after hyperthermia, which demonstrated regeneration of the previously damaged hepatocytes. Pathologically, overall liver congestion and hepatocytes necrosis were noted. Also, both enlargement of the nuclei and binuclear hepatocytes were present, pathologically proving hepatocytes regeneration. The K value showed a transient decrease, showing that the reticuloendothelial function and blood flow of the liver were temporarily reduced. These results indicate the whole liver function damaged by hyperthermia is reversible. (author)

Studies on estradiol-2/4-hydroxylase activity in rat brain and liver

International Nuclear Information System (INIS)

Theron, C.N.

1985-03-01

A sensitive and specific radio-enzymatic assay was used to study estradiol-2/4-hydroxylase activity in rat liver microsomes and in microsomes obtained from 6 discrete brain areas of the rat. Kinetic parameters were determined for these enzyme activities. The effects of different P-450 inhibitors on estradiol-2/4-hydroxylase activity in brain and liver microsomes were also studied. In both organs these enzyme activities were found to be located mainly in the microsomal fraction and were inhibited by the 3 P-450 inhibitors tested. The hepatic estradiol-2/4-hydroxylase activity in adult male rats was significantly higher than that of females, but the enzyme activity in the brain did not exhibit a similar sex difference. Furthermore, estradiol-2/4-hydroxylase activity in rat liver was strongly induced by phenobarbitone treatment, but not in the brain. The phenobarbitone-induced activity in male and female rats exhibited significant kinetic differences. In female rats sexual maturation was associated with significant changes in the apparent Km of estradiol-2/4-hydroxylases in the liver and hypothalamus. Evidence was found that the in vitro estradiol-2/4-hydroxylase activity in rat brain and liver is due to more than one form of microsomal P-450. Kinetic studies showed important differences between the estradiol-2/4-hydroxylase activities in the hippocampus and hypothalamus. Significant differences in estradiol-2/4-hydroxylase activities were observed in the 6 brain areas studied, with the hippocampus showing the highest, and the hypothalamus the lowest activity at all developmental stages in both male and female rats

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

Science.gov (United States)

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

OpenAIRE

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

Reproducibility and influencing factors of 31P MR spectroscopy in rabbit liver with two-dimensional chemical shift imaging

International Nuclear Information System (INIS)

Yu Risheng; Sun Jianzhong; Ding Wenhong; Xu Xiufang; Wang Zhikang

2009-01-01

Objective: To investigate the reproducibility and influencing factors of relative quantification of phosphorus metabolites with two-dimensional chemical shift imaging (2D CSI) in rabbit liver. Methods: Using 2D CSI MRS, 500 ml phosphate (NaH 2 PO 4 ) solution phantom with 0.05 mol/L concentration and one healthy rabbit were scanned 30 times respectively in one day and rescanned 30 times in the next day, and the stability of MR scanner and reproducibility of within-run and between-days in the same individual were analyzed. Each of thirty rabbits was scanned and rescanned one time respectively in different days, and the reproducibility of between-days in one group was analyzed. The data were statistically analyzed with t tests. Results: (1) Phosphate solution phantom had a good reproducibility of within-run with the coefficient variation (CV) of 4.92% and 5.12% respectively in different two days. No significant change of phosphorus metabolites was detected in between-days, which was 16.68±0.82 and 16.56± 0.85 respectively (t=0.665, P>0.05). (2) The CV of metabolites in one healthy rabbit ranged from 8.04% to 34.13%. Among the metabolites, β-ATP had the best reproducibility with the CV less than 10%. PME was 0.88±0.28 and 0.88±0.30, PDE was 4.35±0.66 and 4.35±0.66, Pi was 0.95±0.30 and 0.97±0.28, α-ATP was 5.58±0.60 and 5.61±0.61, β-ATP was 2.70±0.22 and 2.71± 0.22, γ-ATP was 2.20±0.63 and 2.18±0.44 respectively, no significant changes of metabolites were detected in between-days (P>0.05). (3) The CV of metabolites in 30 healthy rabbits ranged from 8.48% to 36.21%. Among the metabolites, β-ATP had the best reproducibility with CV less than 10%. PME was 0.84±0.30 and 0.79±0.28, PDE was 4.29±0.72 and 3.94±0.84, Pi was 0.91±0.28 and 0.92± 0.31, α-ATP was 5.65±0.66 and 5.36±0.60, β-ATP was 2.71±0.23 and 2.66±0.25, γ-ATP was 2.07±0.29 and 1.99±0.37 respectively, no significant changes of metabolites were detected in between-days (P>0

Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

International Nuclear Information System (INIS)

Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

1994-01-01

The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

FDG-PET for Evaluating the Antitumor Effect of Intraarterial 3-Bromopyruvate Administration in a Rabbit VX2 Liver Tumor Model

International Nuclear Information System (INIS)

Park, Hee Sun; Chung, Jin Wook; Jae, Hwan Jun

2007-01-01

We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. The SUV of the VX2 tumors before treatment (3.87±1.51 [mean SD]) was significantly higher than that of nontumorous liver parenchyma (1.72±0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05±1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41±0.73) than that before treatment (p 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%±15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor

FDG-PET for Evaluating the Antitumor Effect of Intraarterial 3-Bromopyruvate Administration in a Rabbit VX2 Liver Tumor Model

Energy Technology Data Exchange (ETDEWEB)

Park, Hee Sun; Chung, Jin Wook; Jae, Hwan Jun [Seoul National University College of Medicine, Seoul (Korea, Republic of)] (and others)

2007-06-15

We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. The SUV of the VX2 tumors before treatment (3.87{+-}1.51 [mean SD]) was significantly higher than that of nontumorous liver parenchyma (1.72{+-}0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05{+-}1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41{+-}0.73) than that before treatment (p 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%{+-}15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.

FDG-PET for Evaluating the Antitumor Effect of Intraarterial 3-Bromopyruvate Administration in a Rabbit VX2 Liver Tumor Model

Science.gov (United States)

Park, Hee Sun; Jae, Hwan Jun; Kim, Young Il; Son, Kyu Ri; Lee, Min Jong; Park, Jae Hyung; Kang, Won Jun; Yoon, Jung Hwan; Chung, Hesson; Lee, Kichang

2007-01-01

Objective We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. Materials and Methods VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. Results The SUV of the VX2 tumors before treatment (3.87 ±1.51 [mean ±SD]) was significantly higher than that of nontumorous liver parenchyma (1.72 ±0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05 ±1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41 ±0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48% ±15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. Conclusion Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor. PMID:17554189

Catechol estrogen formation by brain tissue: characterization of a direct product isolation assay for estrogen-2- and 4-hydroxylase activity and its application to studies of 2- and 4-hydroxyestradiol formation by rabbit hypothalamus

International Nuclear Information System (INIS)

Hersey, R.M.; Williams, K.I.; Weisz, J.

1981-01-01

A direct product isolation assay for quantifying the formation of 2- and 4-hydroxyestradiol (2-OHE2 and 4-OHE2) from [6,7-3H]estradiol by rabbit hypothalami in vitro was developed, and the assay was used to characterize some properties of estrogen-2- and 4-hydroxylase activity in this tissue. The reaction was carried out under conditions that minimized further metabolism of enzymatically formed catechol estrogens. A simple two-step separation procedure, involving the use of a neutral alumina column, followed by thin layer chromatography, was developed to isolate the enzymatically formed catechol estrogens in a radiochemically homogeneous form. The detergent, Tween-80, was found to activate the enzyme and was used routinely at a concentration of 0.1% in the assay. The formation of 2-OHE2 was linear up to 10 min and with increasing protein concentrations up to 150 micrograms/incubation. Similar values were obtained for 4-OHE2. Maximum velocities (Vmax) for the formation of 2- and 4-OHE2 were 190 and 270 pmol/mg protein . 10 min, respectively. The apparent Km values with respect to estradiol for 2-OHE2 and 4-OHE2 were 125 and 150 microM, respectively. The highest specific activity for the enzyme was present in the 100,000 X g supernatant (S3), while the activity in the microsomal fraction (P3) was less than that in the original homogenate. Enzyme activity depended on the presence of NADPH and oxygen and was inhibited by CO as well as by high concentrations of SKF-525A. Estrogen-2- and 4-hydroxylase activity in rabbit hypothalamus differed from that in rat liver in two respects. In the liver, enzyme activity was localized in the microsomal fraction and was virtually abolished by Tween-80. In contrast, enzyme activity in rabbit hypothalamus was maximal in the soluble fraction (100,000 X g supernatant)and was stimulated by the detergent

Microsomal protein synthesis inhibition: an early manifestation of gentamicin nephrotoxicity

International Nuclear Information System (INIS)

Bennett, W.M.; Mela-Riker, L.M.; Houghton, D.C.; Gilbert, D.N.; Buss, W.C.

1988-01-01

Aminoglycoside antibiotics achieve bacterial killing by binding to bacterial ribosomes and inhibiting protein synthesis. To examine whether similar mechanisms could be present in renal tubular cells prior to the onset of overt proximal tubular necrosis due to these drugs, we isolated microsomes from Fischer rats given 20 mg/kg gentamicin every 12 h subcutaneously for 2 days and from vehicle-injected controls. Concomitant studies of renal structure, function, and mitochondrial respiration were carried out. [3H]leucine incorporation into renal microsomes of treated animals was reduced by 21.9% (P less than 0.01), whereas brain and liver microsomes from the same animals were unaffected. Gentamicin concentration in the renal microsomal preparation was 56 micrograms/ml, a value 7- to 10-fold above concentrations necessary to inhibit bacterial growth. Conventional renal function studies were normal (blood urea, serum creatinine, creatinine clearance). Treated animals showed only a mild reduction of inulin clearance, 0.71 compared with 0.93 ml.min-1.100 g-1 in controls (P less than 0.05), and an increase in urinary excretion of N-acetylglucosaminidase of 20 compared with 14.8 units/l (P less than 0.05). Renal slice transport of p-aminohippuric acid, tetraethylammonium, and the fractional excretion of sodium were well preserved. There was no evidence, as seen by light microscopy, of proximal tubular necrosis. Mitochondrial cytochrome concentrations were normal and respiratory activities only slightly reduced. Processes similar to those responsible for bacterial killing could be involved in experimental gentamicin nephrotoxicity before overt cellular necrosis

The Influence of histamine H1-receptor on liver functions in immunized rabbits.

Science.gov (United States)

Tripathi, Trivendra; Shahid, Mohammad; Khan, Haris M; Khan, Rahat Ali; Siddiqui, Mashiatullah; Mahdi, Abbas Ali

2011-10-01

This study was designed to investigate the functional roles of histamine and histamine H1-receptor agonist and antagonist in the development of liver function impairment in immunized rabbits. The study comprised of six groups containing 18 rabbits each. Group III-VI received histamine (100 μg/kg, s.c.), H1R-agonist (HTMT, 10 μg/kg, s.c.), H1R-antagonist (pheniramine, 10 mg/kg, i.m.), and H1R-antagonist (pheniramine, 10 mg/kg, i.m.) plus histamine (100 μg/kg, s.c.), respectively, b.i.d. for 10 days. Group I (negative control) and group II (positive control) received sterile distilled water intramuscularly b.i.d. for 10 days. Groups II-VI were immunized on day 3 with intravenous injection of SRBC (1 × 10(9) cells/ml). Blood samples were collected on pre-immunization day 0, as well as on days 7-, 14-, 21-, 28-, and 58-post-immunization. Biochemical parameters AST, ALT, alkaline phosphatase and bilirubin [total bilirubin (TB), direct bilirubin (DB), and indirect bilirubin (IB)] were determined. On each experimental day, the mean values of serum enzymes and bilirubin in group I and group II showed no significant changes while in group III, IV, V, and VI, these enzymes and bilirubin levels showed significant changes (p pheniramine, and combination of histamine + pheniramine cause hepatic function impairment in terms of altered serum enzymes and bilirubin levels. The present findings suggest that HTMT causes moderate liver function impairment while others show mild impairment.

Increased blood-brain transfer in a rabbit model of acute liver failure

International Nuclear Information System (INIS)

Horowitz, M.E.; Schafer, D.F.; Molnar, P.; Jones, E.A.; Blasberg, R.G.; Patlak, C.S.; Waggoner, J.; Fenstermacher, J.D.

1983-01-01

The blood-to-brain transfer of [ 14 C]alpha-aminoisobutyric acid was investigated by quantitative autoradiography in normal rabbits and rabbits with acute liver failure induced by the selective hepatotoxin galactosamine. The blood-to-brain transfer of alpha-aminoisobutyric acid was similar in control animals and animals 2 and 7 h after galactosamine injections, but was increased five- to tenfold in certain gray-matter areas of the brain in animals 11 and 18 h after galactosamine treatment. No detectable differences in white-matter uptake of [ 14 C]alpha-aminoisobutyric acid were found between the control and treated groups. The increase in alpha-aminoisobutyric acid transfer within the gray-matter areas suggested that a general or nonspecific increase in brain capillary permeability occurred in these areas. No clinical signs of early hepatic encephalopathy were observed in the treated rabbits, except for 1 animal from the 18-h postgalactosamine group. Thus, enhanced blood-brain transfer of alpha-aminoisobutyric acid preceded the development of overt hepatic encephalopathy. The distribution of radioactivity after the intravenous administration of [ 14 C]galactosamine showed that virtually none of the hepatotoxin localized in the brain, suggesting that the drug itself does not have a direct effect upon the blood-brain barrier or the brain. The increased uptake of alpha-aminoisobutyric acid at 11 and 18 h implies that the transfer of other solutes would also be enhanced, that central nervous system homeostasis would be compromised, and that the resulting changes in brain fluid composition could contribute to or cause hepatic encephalopathy

Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs.

Science.gov (United States)

Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent; Hansen, Steen Honoré

2006-09-18

Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, and three major metabolites were isolated using solid phase extraction and preparative HPLC. The final structure elucidations were performed by tandem mass spectrometry and (1)H and (13)C NMR. The structures of the metabolites were found to be 2beta-hydroxy-tiamulin, 8alpha-hydroxy-tiamulin and N-deethyl-tiamulin. In addition, the LC-MS chromatograms revealed two other minor metabolites. From their chromatography and from MS(2) analysis the structures were estimated to be 2beta-hydroxy-N-deethyl-tiamulin and 8alpha-hydroxy-N-deethyl-tiamulin, but the structures were not confirmed by NMR. In these studies approximately 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid, and the preparative purification was performed under alkaline conditions. Therefore, the stability of the metabolites under these conditions was studied. The metabolites were found to be stable in the acid solution, but under alkaline conditions, particularly at room temperature, the stability of especially 8alpha-hydroxy-tiamulin was considerably reduced (40% loss after 1 week).

[The effect of alpha-tocopherol and ionol on the physical structure of the membranes of rat liver microsomes under conditions of antioxidant insufficiency].

Science.gov (United States)

Gubskiĭ, Iu I; Boldeskul, A E; Primak, R G; Zadorina, O V

1989-01-01

Physiochemical conformity of the alpha-tocopherol interaction with hepatic microsomal membranes has been studied by means of fluorescent probes (pyrene and 1-anilinonaphthalene-8-sulphonate). The microsomal membrane microviscosity is shown to sharply decrease under conditions of the antioxidant deficiency with vitamin E expelled into animals normalizes microviscosity, but feebly influences the microsomal surface charge. Microcalorimetry has been used to establish that penetration of tocopherol into microsomal membranes was accompanied by the exothermic effect.

Ethosuximide: liver enzyme induction and D-glucaric acid excretion.

Science.gov (United States)

Gilbert, J C; Scott, A K; Galloway, D B; Petrie, J C

1974-06-01

1 A study has been carried out to determine if ethosuximide induces liver enzymes. 2 Ethosuximide did not affect the urinary excretion of D-glucaric acid by healthy adult subjects nor was the mean daily D-glucaric acid excretion of three epileptic children on long term ethosuximide therapy different from that of three matched controls. 3 Ethosuximide (10 mg/kg or 50 mg/kg daily) did not influence D-glucaric acid excretion or liver microsomal protein and cytochrome P450 contents of guinea pigs but at a dose of 100 mg/kg daily in rats it increased liver microsomal protein and cytochrome P450 without altering D-glucaric acid excretion. 4 These results suggest that at anticonvulsant doses ethosuximide is unlikely to induce liver enzymes. The precise relationship between D-glucaric acid excretion and liver enzyme induction remains in doubt.

Wound healing and degradation of the fibrin sealant Beriplast P following partial liver resection in rabbits.

Science.gov (United States)

Kroez, Monika; Lang, Wiegand; Dickneite, Gerhard

2005-01-01

The objective of this study was to investigate the degradation kinetics of the fibrin sealant (FS) Beriplast P in an experimental liver surgery model in rabbits. A partial liver resection was performed in 21 rabbits, and the wound area covered with Beriplast P to ensure hemostasis. Wound healing of the resection sites was evaluated morphologically over 11 weeks. Degradation of the FS was evaluated by measuring the thickness of the remaining fibrin layer. Plasma samples were analyzed for antibodies against fibrinogen, albumin, thrombin, fibrin, and factor XIII. No postoperative hemorrhage was observed, indicating successful hemostasis throughout. The FS was degraded with a half-life of about 25 days postapplication and was completely replaced by granulation tissue within 9 weeks. The FS degradation and tissue development followed the general stages of wound healing: inflammation and resorption, proliferation, organization and production of collagen, maturation, and scarring. An immune reaction was elicited against the main four human proteins of the FS. The antibody titers peaked on day 14, with a gradual decrease thereafter. We conclude that the FS accomplished hemostasis, facilitated healing in accordance with natural processes, and was completely degraded over time. In humans, the reduced immunogenicity of the FS would potentially increase its degradation half-life.

Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo

International Nuclear Information System (INIS)

Chen, P.-J.; Padgett, William T.; Moore, Tanya; Winnik, Witold; Lambert, Guy R.; Thai, Sheau-Fung; Hester, Susan D.; Nesnow, Stephen

2009-01-01

Conazoles are fungicides used in agriculture and as pharmaceuticals. In a previous toxicogenomic study of triazole-containing conazoles we found gene expression changes consistent with the alteration of the metabolism of all trans-retinoic acid (atRA), a vitamin A metabolite with cancer-preventative properties (Ward et al., Toxicol. Pathol. 2006; 34:863-78). The goals of this study were to examine effects of propiconazole, triadimefon, and myclobutanil, three triazole-containing conazoles, on the microsomal metabolism of atRA, the associated hepatic cytochrome P450 (P450) enzyme(s) involved in atRA metabolism, and their effects on hepatic atRA levels in vivo. The in vitro metabolism of atRA was quantitatively measured in liver microsomes from male CD-1 mice following four daily intraperitoneal injections of propiconazole (210 mg/kg/d), triadimefon (257 mg/kg/d) or myclobutanil (270 mg/kg/d). The formation of both 4-hydroxy-atRA and 4-oxo-atRA were significantly increased by all three conazoles. Propiconazole-induced microsomes possessed slightly greater metabolizing activities compared to myclobutanil-induced microsomes. Both propiconazole and triadimefon treatment induced greater formation of 4-hydroxy-atRA compared to myclobutanil treatment. Chemical and immuno-inhibition metabolism studies suggested that Cyp26a1, Cyp2b, and Cyp3a, but not Cyp1a1 proteins were involved in atRA metabolism. Cyp2b10/20 and Cyp3a11 genes were significantly over-expressed in the livers of both triadimefon- and propiconazole-treated mice while Cyp26a1, Cyp2c65 and Cyp1a2 genes were over-expressed in the livers of either triadimefon- or propiconazole-treated mice, and Cyp2b10/20 and Cyp3a13 genes were over-expressed in the livers of myclobutanil-treated mice. Western blot analyses indicated conazole induced-increases in Cyp2b and Cyp3a proteins. All three conazoles decreased hepatic atRA tissue levels ranging from 45-67%. The possible implications of these changes in hepatic atRA levels

Binding of bilirubin and its structural analogues to hepatic microsomal bilirubin UDP glucuronyltransferase

International Nuclear Information System (INIS)

Vanstapel, F.; Blanckaert, N.

1987-01-01

Hepatic glucuronidation of the asymmetrical natural bilirubin molecule results in formation of two different positional isomers, bilirubin C-8 monoglucuronide and bilirubin C-12 monoglucuronide. In view of the existence of multiple isoforms of UDPglucuronyltransferase, which is the microsomal enzyme system responsible for bilirubin esterification, the authors performed kinetic analysis of microsomal glucuronidation of bilirubin and a number of its structural congeners to determine whether synthesis of the two monoglucuronide isomers involved two distinct substrate-binding sites or reflected two different modes of binding to a single catalytic site. Both isomers were found in all tested species (man, rat, guinea pig, sheep), but there were marked species differences in the C-8/C-12 ratio of monoglucuronide found in bile or formed by liver microsomes. Correspondence between in vivo and in vitro results for such regioselectivity of glucuronidation was excellent in each species. On the basis of these results of kinetic analysis of bilirubin esterification at variable pigment substrate concentrations and inhibition studies with alternative substrates, the authors postulate that both natural monoglucuronide isomers are synthesized at a single binding site. Possible mechanisms responsible for the markedly regioselective esterification of bilirubin by rat and sheep liver were investigated by study of glucuronidation of selected structural analgoues of the pigment. Collectively, their findings suggest that the molecular from(s) of bilirubin able to engage in catalytically effective binding to UDPglucuronyltransferase does (do) not correspond with intramolecularly hydrogen-bonded conformers and that the nature of the β-substituents of the outer pyrromethenone rings is a key determinant of glucuronidation rate

Molecular cloning of cDNAs of human liver and placenta NADH-cytochrome b5 reductase

International Nuclear Information System (INIS)

Yubisui, T.; Naitoh, Y.; Zenno, S.; Tamura, M.; Takeshita, M.; Sakaki, Y.

1987-01-01

A cDNA coding for human liver NADH-cytochrome b 5 reductase was cloned from a human liver cDNA library constructed in phage λgt11. The library was screened by using an affinity-purified rabbit antibody against NADH-cytochrome b 5 reductase of human erythrocytes. A cDNA about 1.3 kilobase pairs long was isolated. By using the cDNA as a probe, another cDNA (pb 5 R141) of 1817 base pairs was isolated that hybridized with a synthetic oligonucleotide encoding Pro-Asp-Ile-Lys-Tyr-Pro, derived from the amino acid sequence at the amino-terminal region of the enzyme from human erythrocytes. Furthermore, by using the pb 5 R141 as a probe, cDNA clones having more 5' sequence were isolated from a human placenta cDNA library. The amino acid sequences deduced from the nucleotide sequences of these cDNA clones overlapped each other and consisted of a sequence that completely coincides with that of human erythrocytes and a sequence of 19 amino acid residues extended at the amino-terminal side. The latter sequence closely resembles that of the membrane-binding domain of steer liver microsomal enzyme

Evidence-Based Advances in Rabbit Medicine.

Science.gov (United States)

Summa, Noémie M; Brandão, João

2017-09-01

Rabbit medicine has been continuously evolving over time with increasing popularity and demand. Tremendous advances have been made in rabbit medicine over the past 5 years, including the use of imaging tools for otitis and dental disease management, the development of laboratory testing for encephalitozoonosis, or determination of prognosis in rabbits. Recent pharmacokinetic studies have been published, providing additional information on commonly used antibiotics and motility-enhancer drugs, as well as benzimidazole toxicosis. This article presents a review of evidence-based advances for liver lobe torsions, thymoma, and dental disease in rabbits and controversial and new future promising areas in rabbit medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

Induction of phosphatidylcholine biosynthesis via CDPcholine pathway in lung and liver of rats following intratracheal administration of DDT and endosulfan

International Nuclear Information System (INIS)

Narayan, S.; Dani, H.M.; Misra, U.K.

1989-01-01

The induction of phosphatidylcholine (PC) biosynthesis via the CDPcholine pathway in lung and liver of rats has been shown following the intratracheal administration of 1,1,1-trichloro-2m2-bis(p-chlorophenyl) ethane (DDT) (5 mg/100 g body weight) and endosulfan (1 mg/100 g body weight) for 3 days. Controls received only the vehicle solution (groundnut oil, 0.1 m1/100 g body weight). The treatment of DDT and endosulfan significantly increased the PC contents and the incorporation of radioactive [methyl-3H]choline into PC of lung and liver microsomes. The incorporation of radioactive [methyl-14C]methionine into microsomal PC of lung and liver was not affected significantly by treatment with either of the insecticides. 1,4,5,6,7-hexachloro-5-norbornene-2,3-dimethano cyclic sulfite (endosulfan) administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal) of lung, whereas DDT increased the activity of only latter. In liver, both DDT and endosulfan administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal). However, the activity of phosphocholinetransferase was not affected in both lung and liver microsomes of rats treated with these insecticides. The PC precursor pool sizes, choline and phosphorylcholine, of lung and liver tissues were not altered by DDT and endosulfan treatments. The present results suggest that the increased level of PC and incorporation of radioactive [methyl-3H]choline into microsomal PC could be the result of increased activity of choline kinase and phosphocholine cytidylyltransferase of lung and liver of rats following intratracheal administration of DDT and endosulfan

Evaluating the quality of the edible offal (heart, liver, kidney of rabbits (Flemish Giant breed during storage by refrigeration following the evolution of the pH

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Gabriela FRUNZĂ

2017-11-01

Full Text Available The purpose of this paper was to determine the quality of the edible offal (heart, liver and kidney of rabbits (Flemish Giant breed during storage by refrigeration following the evolution of the pH, after slaughter, during maturation, to autolysis and alteration, from 27 individuals (15 males and 12 females. The rabbits had an average body weight of 11.5 kg being at the age of reproductive maturity (11-12 months. The pH evolution of the edible offal (heart, liver, kidney of rabbits (refrigerated at 20C was monitored during of 18 days after slaughter. The pH evolution had a fluctuant ascendant trend, quite similar for females and males, presenting insignificant differences by gender. At 24 h after slaughter, the mean values of pH of the main edible offal (from males and females had the highest average values to the kidneys 6.48, followed by the heart 6.32 and by the liver 6.23. The alteration occurred much faster in kidneys and was starting with the 13th day of storage, the pH being close to 6.8-7.

Radiological effect of single massive irradiation on the liver hilum of rabbits

International Nuclear Information System (INIS)

Todoroki, Takeshi; Tsunemoto, Hiroshi; Usui, Sadahito; Iwasaki, Yoji.

1976-01-01

In order to decide the irradiation dosage, the liver hilum of rabbits had a irradiation of single 3,000 to 5,000 rads of electron beam during the operation. In the acute period from 2 days to 4 weeks after the irradiation, histological studies were carried out to examine the effects on the liver, extrahepatic bile duct, proper hepatic artery and portal vein. On the mucous epithelium of the extrahepatic bile duct, the proliferative changes such as swelling of nuclei, dense arrangement of the nuclei in the epithelial cells were observed. Two weeks later, it was restored to the conditions of the control mucous epitherlium. With 5,000 rads irradiation, even on the 4th week, the recovery was insufficient. The epithelial cells showed atrophy, and nuclei tended to be concentrated. Fibrosis around the bile duct mucous epithelium occurred according to the irradiation doses. It was remarkable with 5,000 rads. The liver reacted the most sensitively, and sporadical and circumscribed necrotic lesions appeared in the parenchyma of the liver. Four weeks after the irradiation of 3,000 rads, necrotic lesions were reduced to become scar and were restored. With 5,000 rads, the necrotic change was stronger than that with 3,000 rads. Although 4 weeks later, necrotic lesion was reduced to become scar, fibrosis of the liver mainly consisting of Glisson's capsule. with 3,000 rads, there was no remarkable change in proper hepatic artery and portal vein. Four weeks after the irradiation of 5,000 rads, thickening of intima and proliferation of intimal cells were observed in part of proper hepatic artery, but there were no hemorrhage or arteral obstruction. Therefore, it can be said that single irradiation of 3,000 rads of electron beam is within the dose to which tissues can tolerate. (N. Kanao)

Clinical features and effect of antiviral therapy on anti-liver/kidney microsomal antibody type 1 positive chronic hepatitis C.

Science.gov (United States)

Ferri, Silvia; Muratori, Luigi; Quarneti, Chiara; Muratori, Paolo; Menichella, Rita; Pappas, Georgios; Granito, Alessandro; Ballardini, Giorgio; Bianchi, Francesco B; Lenzi, Marco

2009-06-01

Anti-liver/kidney microsomal antibody type 1 (anti-LKM1), a serological marker of type 2 autoimmune hepatitis, is also detected in a small proportion of patients with hepatitis C. This study aimed to evaluate clinical features and effect of antiviral therapy in patients with hepatitis C who are anti-LKM1 positive. Sixty consecutive anti-LKM1 positive and 120 age and sex-matched anti-LKM1 negative chronic hepatitis C patients were assessed at diagnosis and during follow-up. Of these, 26 anti-LKM1 positive and 72 anti-LKM1 negative received antiviral therapy. Anti-LKM1 was detected by indirect immunofluorescence and immunoblot. Number of HCV-infected hepatocytes and intrahepatic CD8+ lymphocytes was determined by immunohistochemistry. At diagnosis anti-LKM1 positive patients had higher IgG levels and more intrahepatic CD8+ lymphocytes (p 0.022 and 0.046, respectively). Viral genotypes distribution and response to therapy were identical. Hepatic flares during antiviral treatment only occurred in a minority of patients in concomitance with anti-LKM1 positivity. Immune system activation is more pronounced in anti-LKM1 positive patients with hepatitis C, possibly representing the expression of autoimmune mechanisms of liver damage. Antiviral treatment is as beneficial in these patients as in anti-LKM1 negative patients, and the rare necroinflammatory flares are effectively controlled by corticosteroids, allowing subsequent resumption of antiviral therapy.

Pharmacokinetic study of isocorynoxeine metabolites mediated by cytochrome P450 enzymes in rat and human liver microsomes.

Science.gov (United States)

Zhao, Lizhu; Zang, Bin; Qi, Wen; Chen, Fangfang; Wang, Haibo; Kano, Yoshihiro; Yuan, Dan

2016-06-01

Isocorynoxeine (ICN) is one of the major bioactive tetracyclic oxindole alkaloids found in Uncaria rhynchophylla (Miq.) Jacks. that is widely used for the treatment of hypertension, vascular dementia, and stroke. The present study was undertaken to assess the plasma pharmacokinetic characteristics of major ICN metabolites, and the role of simulated gastric and intestinal fluid (SGF and SIF), human and rat liver microsomes (HLMs and RLMs), and seven recombinant human CYP enzymes in the major metabolic pathway of ICN. A rapid, sensitive and accurate UHPLC/Q-TOF MS method was validated for the simultaneous determination of ICN and its seven metabolites in rat plasma after oral administration of ICN at 40mg/kg. It was found that 18.19-dehydrocorynoxinic acid (DCA) and 5-oxoisocorynoxeinic acid (5-O-ICA) were both key and predominant metabolites, rather than ICN itself, due to the rapid and extensive metabolism of ICN in vivo. The further study indicated that ICN was mainly metabolized in human or rat liver, and CYPs 2C19, 3A4 and 2D6 were the major enzymes responsible for the biotransformation of ICN to DCA and 5-O-ICA in human. These findings are of significance in understanding of the pharmacokinetic nature of tetracyclic oxindole alkaloids, and provide helpful information for the clinical co-administration of the herbal preparations containing U. rhynchophylla with antihypertensive drugs that are mainly metabolized by CYP3A4 and CYP2C19. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Protective Activity of Curcumin in Reducing Methotrexate Induced Liver Cells Injury: An Experimental Study on Iraqi White Domestic Rabbits

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Hussain Abady Aljebori

2018-03-01

Full Text Available Background: Hepatotoxicity is a common problem in medical practice, most of the commonly used drugs are potentially hepatotoxic. Although Methotrexate is a hepa- toxic drug, it is widely used in the treatment of many cancerous and non-cancerous conditions because of its cytotoxic and immunosuppressant activity. Curcumin con- tains a variety of natural substances with antioxidant properties, it is widely used in  folk medicine.Antioxidant activity of Curcumin can reduce liver cell injury induced by Methotrexate administration. Objective: The research aims to study the methotrexate hepatoxicity on rabbits, and the hepatoprotective activity of Curcumin. Materials and Methods: Thirty white domestic rabbits were bought from animal market and grouped randomly into three groups; control group received intraperitoneal normal saline, methotrexate group received 6.5 mg/Kgm body weight intraperitoneal methotrexate, and curcumin group received oral Curcumin in addition to intraperitoneal methotrexate. Results: The study showed abnormal liver function tests, INR, liver tissues oxida- tive markers, and liver cell injury on histopathology in Methotrexate group, and normal findings in Curcumin groups. Conclusion: It is concluded that the Methotrexate is a hepatotoxic drug. The results also shoe that the concomitant administration of Curcumin reduced hepatotoxicity. Recommendation: It is recommended to use of Curcumin in clinical practice as a food supplement to patient receiving methotrexate to reduce hepatotoxicity.

Comparative study of rabbit VX2 hepatic implantation tumor and normal liver tissue on magnetic resonance perfusion weighted imaging

International Nuclear Information System (INIS)

Jiao Zimei; Wang Xizhen; Wang Bin; Liu Feng; Li Haiqing; Sun Yequan; Dong Peng

2012-01-01

Objective: To investigate the value of magnetic resonance (MR) perfusion weighted imaging (PWI) in evaluating the blood perfusion of tumor by analyzing the features and indexes of PWI on rabbit VX2 hepatic implantation tumor and normal liver tissue. Methods: Twenty-four New Zealand White rabbits with VX2 carcinoma were established under direct surgical vision embedding tumor tissue. MR examination was performed at 21 days after the tumor implantation. The signal intensity -time curve of hepatic tumor and normal liver tissue were obtained. Mean time to enhance (MTE), negative enhancement integral (NEI), time to minimum (TM), maximum slope of decrease (MSD) and maximum slope of increase (MSI) were measured. Results: MTE, NEI, TM, MSD, and MSI of the normal liver tissue were 208.341±2.226 ms, 78.334±8.152, 24.059±1.927 ms, 38.221±2.443, and 15.389±2.526, respectively. MTE, NEI, TM, MSD, and MSI of the tumor tissue were 175.437±4.182 ms, 123.203±19.455, 17.061±1.834 ms, 125.740±4.842, and 67.832±2.882, respectively. The MTE and TM of tumor were shorter than those of normal hepatic tissue (P<0.05). NEI, MSD, and MSI of tumor were higher than those of normal hepatic tissue (P<0.05). Conclusion: PWI can distinguish the normal liver tissue from the tumor tissue, which is helpful in evaluating blood perfusion of different hepatic tissues. (authors)

Monkey liver cytochrome P450 2C19 is involved in R- and S-warfarin 7-hydroxylation.

Science.gov (United States)

Hosoi, Yoshio; Uno, Yasuhiro; Murayama, Norie; Fujino, Hideki; Shukuya, Mitsunori; Iwasaki, Kazuhide; Shimizu, Makiko; Utoh, Masahiro; Yamazaki, Hiroshi

2012-12-15

Cynomolgus monkeys are widely used as primate models in preclinical studies. However, some differences are occasionally seen between monkeys and humans in the activities of cytochrome P450 enzymes. R- and S-warfarin are model substrates for stereoselective oxidation in humans. In this current research, the activities of monkey liver microsomes and 14 recombinantly expressed monkey cytochrome P450 enzymes were analyzed with respect to R- and S-warfarin 6- and 7-hydroxylation. Monkey liver microsomes efficiently mediated both R- and S-warfarin 7-hydroxylation, in contrast to human liver microsomes, which preferentially catalyzed S-warfarin 7-hydroxylation. R-Warfarin 7-hydroxylation activities in monkey liver microsomes were not inhibited by α-naphthoflavone or ketoconazole, and were roughly correlated with P450 2C19 levels and flurbiprofen 4-hydroxylation activities in microsomes from 20 monkey livers. In contrast, S-warfarin 7-hydroxylation activities were not correlated with the four marker drug oxidation activities used. Among the 14 recombinantly expressed monkey P450 enzymes tested, P450 2C19 had the highest activities for R- and S-warfarin 7-hydroxylations. Monkey P450 3A4 and 3A5 slowly mediated R- and S-warfarin 6-hydroxylations. Kinetic analysis revealed that monkey P450 2C19 had high V(max) and low K(m) values for R-warfarin 7-hydroxylation, comparable to those for monkey liver microsomes. Monkey P450 2C19 also mediated S-warfarin 7-hydroxylation with V(max) and V(max)/K(m) values comparable to those for recombinant human P450 2C9. R-warfarin could dock favorably into monkey P450 2C19 modeled. These results collectively suggest high activities for monkey liver P450 2C19 toward R- and S-warfarin 6- and 7-hydroxylation in contrast to the saturation kinetics of human P450 2C9-mediated S-warfarin 7-hydroxylation. Copyright © 2012 Elsevier Inc. All rights reserved.

Tiaozhi Tongmai Granules reduce atherogenesis and promote the expression of ATP-binding cassette transporter A1 in rabbit atherosclerotic plaque macrophages and the liver

Directory of Open Access Journals (Sweden)

Qing Sun

2014-07-01

Conclusions: Tiaozhi Tongmai Granules appear to have an anti-atherogenic effect that is most likely mediated by simultaneously upregulating the protein expression of ABCA1 in rabbit atherosclerotic plaque macrophages and in the liver.

Frequency and significance of antibodies to liver/kidney microsome type 1 in adults with chronic active hepatitis.

Science.gov (United States)

Czaja, A J; Manns, M P; Homburger, H A

1992-10-01

To assess the frequency of antibodies to liver/kidney microsome type 1 (anti-LKM1) in patients with chronic active hepatitis, 131 such patients were tested by an indirect immunofluorescence assay. Of 62 patients with type 1 autoimmune hepatitis, none were seropositive. In contrast, 3 of 11 patients with autoimmune hepatitis and antimitochondrial antibodies (27%) were seropositive for anti-LKM1. Each had responded to corticosteroid therapy, and retesting of sera confirmed that each had been misclassified as antimitochondrial antibody positive. None of the patients with chronic active hepatitis B (14 patients) or C (24 patients) had anti-LKM1. Similarly, none of the 20 patients with cryptogenic disease had these antibodies. It is concluded that anti-LKM1 is specific for type 2 autoimmune hepatitis and is infrequent in adult patients seen at a referral center in the United States for chronic active hepatitis. Anti-LKM1 reactivity may be misinterpreted as antimitochondrial antibody reactivity by indirect immunofluorescence. Chronic hepatitis B and C virus infections are not important stimuli for the production of anti-LKM1, and testing for anti-LKM 1 is unlikely to clarify the nature of cryptogenic disease.

Identification of the Metabolic Enzyme Involved Morusin Metabolism and Characterization of Its Metabolites by Ultraperformance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (UPLC/Q-TOF-MS/MS

Directory of Open Access Journals (Sweden)

Xianbao Shi

2016-01-01

Full Text Available Morusin, the important active component of a traditional Chinese medicine, Morus alba L., has been shown to exhibit many vital pharmacological activities. In this study, six recombinant CYP450 supersomes and liver microsomes were used to perform metabolic studies. Chemical inhibition studies and screening assays with recombinant human cytochrome P450s were also used to characterize the CYP450 isoforms involved in morusin metabolism. The morusin metabolites identified varied greatly among different species. Eight metabolites of morusin were detected in the liver microsomes from pigs (PLMs, rats (RLMs, and monkeys (MLMs by LC-MS/MS and six metabolites were detected in the liver microsomes from humans (HLMs, rabbits (RAMs, and dogs (DLMs. Four metabolites (M1, M2, M5, and M7 were found in all species and hydroxylation was the major metabolic transformation. CYP1A2, CYP2C9, CYP2D6, CYP2E1, CYP3A4, and CYP2C19 contributed differently to the metabolism of morusin. Compared to other CYP450 isoforms, CYP3A4 played the most significant role in the metabolism of morusin in human liver microsomes. These results are significant to better understand the metabolic behaviors of morusin among various species.

Inhibition of the phospholipid transfer within the organelles of cells in the irradiated rat liver

Energy Technology Data Exchange (ETDEWEB)

Kaznacheev, Yu S; Kolomiytseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

1975-01-01

Phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) exchange between different subcellular fractions of liver has been studied in normal rats and 1 hr after gamma-irradiation of rats at a dose of 1200 R. The rate of PC transfer in microsome-mitochondrion and microsome-nucleus systems is 1.5 to 2 times higher than that of PE. Early after irradiation the rates of PE and PC transfer decrease in both microsome-mitochondrion and microsome-nucleus systems.

Stereoselective in vitro metabolism of rhynchophylline and isorhynchophylline epimers of Uncaria rhynchophylla in rat liver microsomes.

Science.gov (United States)

Wang, Xin; Qiao, Zhou; Liu, Jia; Zheng, Mei; Liu, Wenyuan; Wu, Chunyong

2017-11-10

1. The objective was to investigate the underlying mechanism of the stereoselectivity in the metabolism of rhynchophylline (RIN) and isorhynchophylline (IRN) epimers in rat liver microsomes (RLM). 2. After incubation, eight metabolites of RIN (M1-5) and IRN (M6-8) reacted at A- and C-ring were identified using LC-Q-TOF/MS. Metabolic pathways included oxidation, hydroxylation, N-oxidation and dehydrogenation. In addition, hydroxylation at A-ring was the major metabolic pathway for RIN whereas the oxidation at C-ring was the major one for IRN. 3. Enzyme kinetics showed that the intrinsic clearance (CL int ) for IRN elimination was 1.9-fold higher than RIN and the degradation half-life (T 1/2 ) of RIN was 4.7-fold higher than that of IRN, indicating IRN was more favorable to be metabolized than RIN in RLM. 4. Data from chemical inhibition study demonstrated CYP3A was the predominant isoform involved in the metabolic elimination of both epimers, as well as the formation of M1-8. 5. In conclusion, data revealed that due to the spatial configurations at C-7 position, RIN and IRN epimers possessed different hepatic metabolic pathways and elimination rates which were mainly mediated by CYP3A.

CYP2B6, CYP2D6, and CYP3A4 catalyze the primary oxidative metabolism of perhexiline enantiomers by human liver microsomes.

Science.gov (United States)

Davies, Benjamin J; Coller, Janet K; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

2007-01-01

The cytochrome P450 (P450)-mediated 4-monohydroxylations of the individual enantiomers of the racemic antianginal agent perhexiline (PHX) were investigated in human liver microsomes (HLMs) to identify stereoselective differences in metabolism and to determine the contribution of the polymorphic enzyme CYP2D6 and other P450s to the intrinsic clearance of each enantiomer. The cis-, trans1-, and trans2-4-monohydroxylation rates of (+)- and (-)-PHX by human liver microsomes from three extensive metabolizers (EMs), two intermediate metabolizers (IMs), and two poor metabolizers (PMs) of CYP2D6 were measured with a high-performance liquid chromatography assay. P450 isoform-specific inhibitors, monoclonal antibodies directed against P450 isoforms, and recombinantly expressed human P450 enzymes were used to define the P450 isoform profile of PHX 4-monohydroxylations. The total in vitro intrinsic clearance values (mean +/- S.D.) of (+)- and (-)-PHX were 1376 +/- 330 and 2475 +/- 321, 230 +/- 225 and 482 +/- 437, and 63.4 +/- 1.6 and 54.6 +/- 1.2 microl/min/mg for the EM, IM, and PM HLMs, respectively. CYP2D6 catalyzes the formation of cis-OH-(+)-PHX and trans1-OH-(+)-PHX from (+)-PHX and cis-OH-(-)-PHX from (-)-PHX with high affinity. CYP2B6 and CYP3A4 each catalyze the trans1- and trans2-4-monohydroxylation of both (+)- and (-)-PHX with low affinity. Both enantiomers of PHX are subject to significant polymorphic metabolism by CYP2D6, although this enzyme exhibits distinct stereoselectivity with respect to the conformation of metabolites and the rate at which they are formed. CYP2B6 and CYP3A4 are minor contributors to the intrinsic P450-mediated hepatic clearance of both enantiomers of PHX, except in CYP2D6 PMs.

Effect of Cigarette Smoke on Rabbit Testicular Lipid Peroxidation ...

African Journals Online (AJOL)

The effect of cigarette smoke on oxidative status of liver and testis was evaluated. Three groups of male weaned rabbits (1.0 – 1.5kg) were used. Group 1, the basal control group consisted of 2 rabbits which were sacrificed immediately after one week acclimatization (week O). Group 2 – (S) group consisted of 6 rabbits.

Hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound in the treatment of a rabbit liver trauma model

Science.gov (United States)

Zhao, Da-wei; Tian, Meng; Yang, Jian-zheng; Du, Peng; Bi, Jie; Zhu, Xinjian

2016-01-01

The aim of our study was to investigate the hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound treatment of liver trauma. Thirty rabbits with liver trauma were randomly divided into three groups—the microbubble-enhanced ultrasound (MEUS; further subdivided based on exposure intensity into MEUS1 [0.11 W/cm2], MEUS2 [0.55 W/cm2], and MEUS3 [1.1 W/cm2]), ultrasound without microbubbles (US), and microbubbles without ultrasound (MB) groups. The pre- and post-treatment bleeding weight and visual bleeding scores were evaluated. The serum liver enzyme concentrations as well as the blood perfusion level represented by mean peak contrast intensity (PI) ratio in the treatment area were analyzed. The hemostatic mechanism was evaluated by histological and transmission electron microscopic examination of liver tissue samples. The MEUS subgroups 1–3 (grade 0–1, grade 0–2, and grade 1–2, respectively) exhibited significantly lower post-treatment visual bleeding scores than the US and MB groups (both, grade 3–4; all, P hepatic cells became edematous and compressed the hepatic sinus and associated blood vessels. However, the serum liver enzyme levels were not significantly altered. Microbubble-enhanced non-focused ultrasound does not significantly affect blood perfusion and liver function and can be used to induce rapid hemostasis in case of liver trauma. PMID:27633577

RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

Science.gov (United States)

Rainbow trout liver microsomes were used to study the rate of ring-hydroxylation of phenol (PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultroviolet (UV) and elect...

Acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in hepatic microsomes from induced mice.

Science.gov (United States)

Lewandowski, M; Chui, Y C; Levi, P; Hodgson, E

1991-02-01

A simple and sensitive method for the separation of 14C-labelled acetanilide, 4-hydroxyacetanilide, 3-hydroxyacetanilide and 2-hydroxyacetanilide was developed using thin-layer chromatography. This separation is the basis for the assay of acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in liver microsomes from DBA2/N male mice that had been treated with phenobarbital, 3-methylcholanthrene, isosafrole or n-butylbenzodioxole. Microsomes were incubated with [14C]acetanilide and extracted with benzene and ethyl acetate. The extract was applied to silica gel plates and developed with a hexane/isopropanol/ammonium hydroxide/water solvent system. The radiolabelled phenolic metabolites and the parent compound were detected using a Berthold Automatic TLC Linear Analyzer. Although the 4-hydroxylated metabolite was the primary product detected, this method can be used to detect other phenolic metabolites.

Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

International Nuclear Information System (INIS)

Puig, J.F.; Tephly, T.R.

1986-01-01

The enhancement of rat liver microsomal morphine (M) and 4-hydroxybiphenyl (4-HBP) UDP-glucuronyltransferase (UDPGT) activities by phenobarbital treatment has been proposed to represent increased activity of a single enzyme form, GT-2. They have separated M and 4-HBP UDPGT activities from Emulgen 911-solubilized microsomes obtained from livers of phenobarbital-treated Wistar rats. A sensitive assay procedure was developed to quantify M-UDPGT and 4-HBP-UDPGT activities using 14 C-UDP-glucuronic acid (UDPGA) and reversed phase C-18 minicolumns whereby the radioactive glucuronides were differentially eluted from labeled UDPGA. Trisacryl DEAE, and chromatofocusing procedures were employed to separate M-UDPGT and 4-HBP-UDPGT in the presence of exogenous phosphatidylcholine (PC). The PC is necessary to stabilize UDPGT activities. M-UDPGT was isolated to apparent homogeneity and displayed a monomeric molecular weight of 56,000 daltons on SDS-PAGE. It reacted with M but not with 4-HBP, bilirubin, p-nitrophenol, testosterone, androsterone, estrone, 4-aminobiphenyl or α-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes

Chromatographic separation of piracetam and its metabolite in a mixture of microsomal preparations, followed by an MS/MS analysis.

Science.gov (United States)

Sahu, Kapendra; Siddiqui, Anees A; Shaharyar, Mohammad; Ahmad, Niyaz; Anwar, Mohammad; Ahmad, Farhan J

2013-07-01

A rapid bioanalytical method was evaluated for the simultaneous determination of piracetam and its metabolite (M1) in human microsomal preparations by fast ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). In addition, a validated method of M1 in rat plasma was developed and successfully applied on pharmacokinetic studies. The present study was carried out to determine the metabolic pathways of piracetam for phase I metabolism and used cytochrome P450 isoforms responsible for the piracetam metabolism in human liver microsomes (HLMs). While additional potential metabolites of piracetam were suggested by computer-modeling. The resulting 2-(2-oxopyrrolidin-1-yl) acetic acid was the sole metabolite detected after the microsomal treatment. The amide hydrolysis mainly underwent to form a metabolite i.e., 2-(2-oxopyrrolidin-1-yl) acetic acid (M1). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

In vitro enantioselective human liver microsomal metabolism and prediction of in vivo pharmacokinetic parameters of tetrabenazine by DLLME-CE.

Science.gov (United States)

Bocato, Mariana Zuccherato; de Lima Moreira, Fernanda; de Albuquerque, Nayara Cristina Perez; de Gaitani, Cristiane Masetto; de Oliveira, Anderson Rodrigo Moraes

2016-09-05

A new capillary electrophoresis method for the enantioselective analysis of cis- and trans- dihydrotetrabenazine (diHTBZ) after in vitro metabolism by human liver microsomes (HLMs) was developed. The chiral electrophoretic separations were performed by using tris-phosphate buffer (pH 2.5) containing 1% (w/v) carboxymethyl-β-CD as background electrolyte with an applied voltage of +15kV and capillary temperature kept at 15°C. Dispersive liquid-liquid microextraction was employed to extract the analytes from HLMs. Dichloromethane was used as extraction solvent (75μL) and acetone as disperser solvent (150μL). The method was validated according to official guidelines and showed to be linear over the concentration range of 0.29-19.57μmolL(-1) (r=0.9955) for each metabolite enantiomer. Within- and between-day precision and accuracy evaluated by relative standard deviation and relative error were lower than 15% for all enantiomers. The stability assay showed that the analytes kept stable under handling, storage and in metabolism conditions. After method validation, an enantioselective in vitro metabolism and in vivo pharmacokinetic prediction was carried out. This study showed a stereoselective metabolism and the observed kinetic profile indicated a substrate inhibition behavior. DiHTBZ enantiomers were catalyzed mainly by CYP2C19 and the predicted clearance suggests that liver metabolism is the main route for TBZ elimination which supports the literature data. Copyright © 2016 Elsevier B.V. All rights reserved.

Interaction of rocuronium with human liver cytochromes P450.

Science.gov (United States)

Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

2015-02-01

Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver microsomal CYP3A4 down to 42% (at rocuronium concentration 189 μM) was found. This effect has been confirmed with two CYP3A4 substrates, testosterone (formation of 6β-hydroxytestosterone) and diazepam (temazepam formation). CYP2C9 and CYP2C19 activities were inhibited down to 75-80% (at the same rocuronium concentration). Activities of other microsomal CYPs have not been inhibited by rocuronium. To prove the possibility of rocuronium interaction with other drugs (diazepam), the effect of rocuronium on formation of main diazepam metabolites, temazepam (by CYP3A4) and desmethyldiazepam, (also known as nordiazepam; formed by CYP2C19) in primary culture of human hepatocytes has been examined. Rocuronium has caused inhibition of both reactions by 20 and 15%, respectively. The results open a possibility that interactions of rocuronium with drugs metabolized by CYP3A4 (and possibly also CYP2C19) may be observed. Copyright © 2014 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

A radioactive seed implant on a rabbit's liver following a voxel model representation for dosimetric proposals

Energy Technology Data Exchange (ETDEWEB)

Campos, Tarcisio P.R.; Andrade, Joao Paulo Lopes de; Costa, Igor Temponi; Teixeira, Cleuza H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares]. E-mail: campos@nuclear.ufmg

2005-07-01

Animal models have been used in experimentation with ionizing radiation. The evaluation of the energy absorbed per unit tissue mass in vivo transported by nuclear particles is a task to be performed before experimentation. Stochastic or deterministic methodology can be applied, however the dosimetric protocols applied in radiotherapy center cannot be applied directly due to the inherent small geometry and chemical composition of the animal distinct from human. The present article addresses a method in development that will predict the dose distribution into the rabbit thorax based on the solution of the transport phenomena in a voxel model. The model will be applied to simulate a seed implant experiment on a rabbit. Herein, the construction of the three-dimensional voxel model anthropomorphic -anthropometrics to the rabbit is presented. The model is assembling from a set of computer tomography of the rabbit. The computational phantom of the thorax starts at the digitalisation of the CT images, tissue definition, and color image representation of each tissue and organ. The chemical composition and mass density of each tissue is evaluated as similar date presented by ICRU-44. To treat the images, a code namely SISCODES, developed in house, was used. The in vivo experiment that will be simulated is also described. That is a implant of five seeds of 1.6x2 mm performed in a rabbit's liver. The perspective of this work is the application of the model in dosimetric studies predicting the dose distribution around the seed's implanted in vivo experiments. (author)

Activation of the microsomal glutathione-S-transferase and reduction of the glutathione dependent protection against lipid peroxidation by acrolein

NARCIS (Netherlands)

Haenen, G R; Vermeulen, N P; Tai Tin Tsoi, J N; Ragetli, H M; Timmerman, H; Blast, A

1988-01-01

Allyl alcohol is hepatotoxic. It is generally believed that acrolein, generated out of allyl alcohol by cytosolic alcohol dehydrogenase, is responsible for this toxicity. The effect of acrolein in vitro and in vivo on the glutathione (GSH) dependent protection of liver microsomes against lipid

Genetic and Histopathological Responses to Cadmium Toxicity in Rabbit's Kidney and Liver: Protection by Ginger (Zingiber officinale).

Science.gov (United States)

Baiomy, Ahmed A; Mansour, Ahmed A

2016-04-01

This study aimed to examine the protective effects of ginger (G) on the genetic response induced by cadmium (Cd) and immunohistochemical expression of Caspase3 and MKI67 in the kidney and liver of rabbits. Male rabbits were divided into three groups; each group contains 10 animals: group (C) received basic diet and tap water for 12 weeks, the second group (Cd) received 200 mg/kg b.w CdCl2 in water for 12 weeks, group (Cd + G) was given 200 mg/kg b.w CdCl2 in water and 400 mg ginger/kg b.w in food for 12 weeks. Cd administration increased the activity of mRNA expression of the examined apoptotic (Caspase3), proliferation (MKI67), proto-oncogene (C-fos), and antioxidant (GST), while decreased the expression of anti-apoptotic (Bcl2). Ginger counteracted the effects of Cd in (Cd + G) group and downregulated the previously upregulated genes under Cd administration appeared in (Cd) group. The immunohistochemical expression of Caspase3 and MKI67 in the liver and kidney cells of the (C) group was shown very faint to negative reactions, strong staining in hepatocytes and the tubular epithelium in cadmium-treated group, while slight staining in some hepatocytes and tubular epithelium in co-administration with ginger in (Cd + G) group. In conclusion, ginger administration showed a protective effect against cadmium toxicity.

Perfluorodecanoic acid enhances the formation of oleic acid in rat liver.

Science.gov (United States)

Yamamoto, A; Kawashima, Y

1997-01-01

The feeding of perfluorodecanoic acid (PFDA) to male rats at a dietary concentration of 0.005% (w/w) for 7 days resulted in a marked increase in the activity of microsomal stearoyl-CoA desaturation in the liver. This increase in the overall desaturation activity was due to the induction of terminal desaturase among the components comprising the desaturation system. In contrast, PFDA inhibited desaturation in vitro, seemingly due to interference with electron transport through the desaturation system. Accordingly, PFDA can be an inducer and also an inhibitor of delta9-desaturation. PFDA feeding enhanced the conversion of radioactive stearic acid into oleic acid in the liver in vivo, indicating that the induction of delta9-desaturase by PFDA functions in vivo. PFDA feeding increased the mass of octadecenoic acid (C18:1) in the liver and the proportion of C18:1 in microsomal lipid. A highly significant linear correlation existed between the microsomal desaturase activity and the proportion of C18:1 in microsomal lipid when compared using rats in five different physiological states: control, PFDA-fed, p-chlorophenoxyisobutyric acid (clofibric acid)-fed, starved and starved/refed. These results suggest that the increase in the hepatic level of C18:1 caused by feeding of PFDA to rats can be explained by the common concept of regulation, i.e. the hepatic level of C18:1 is under the control of delta9-desaturase. The dietary administration of PFDA also increased the content of cytochrome P-450 and the activity of 7-ethoxycoumarin O-de-ethylase in the liver. PMID:9230124

Application of radionuclide imaging to hepatic impact injury in rabbits

Institute of Scientific and Technical Information of China (English)

金榕兵; 麻晓林; 温建良; 唐维佳

2004-01-01

Objective: To investigate the role and clinical value of radionuclide imaging in hepatic impact injuries in rabbits.Methods: Rabbits were experimentally impacted on the liver with BIM-IV bio-impact machine. Liver imaging was performed with 99mTc labeled sodium phytate. Liver blood pool imaging was performed with 99mTc -stannous pyrophosphate labeled red blood cells. The results of radionuclide imaging were compared with the anatomic results.Results: There was significant difference between the images of the injured liver and the control. Radio diminution and defect were shown in the injured liver areas. Various sorts of abnormal radioactivity distribution were observed with hepatic blood pool imaging. The results of the liver imaging and liver blood pool imaging were accorded with the results of the anatomic findings.Conclusions: Radionuclide imaging may well display the changes of hepatocellular structures and functions after injury, which is valuable in locating the concrete injured position and differentiating the injured degrees of liver.

Heated lipiodol as an embolization agent for transhepatic arterial embolization in VX2 rabbit liver cancer model

International Nuclear Information System (INIS)

Cao Wei; Wan Yi; Liang Zhihui; Duan Yunyou; Liu Xi; Wang Zhimin; Liu Yiyong; Zhu Jia; Liu Xiongtao; Zhang Hongxin

2010-01-01

Purpose: To evaluate the therapeutic effect of heated (60 deg. C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer. Materials and methods: Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3 cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 deg. C) (1 mL), lipiodol (60 deg. C) (1 mL) or control (physiological saline (37 deg. C) (1 mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected before injection and at 4 and 7 days after injection, and the level of aspartate aminotransferase (AST) was checked. The survival period of the three groups of rabbits after treatment was also recorded. During the last course of their disease, the rabbits were given analgesics to relieve suffering. Results: The tumor growth rate in the lipiodol (60 deg. C) group (0.92 ± 0.21, tumor volume from 1811 ± 435 to 1670 ± 564 mm 3 ) was significantly lower than that in the control group (3.48 ± 1.17, tumor volume from 1808 ± 756 to 5747 ± 1341 mm 3 ) (P 3 ) (P -1 ) and the doxorubicin-lipiodol (37 deg. C) group (139.7 ± 12.3 U L -1 ) (P > 0.05). However, the serum AST level in the lipiodol (60 deg. C) group was significantly higher at 4 days after injection (P -1 ). Conclusions: Treatment with lipiodol (60 deg. C) resulted in an effect on serum AST levels similar to that caused by treatment with doxorubicin-lipiodol (37 deg. C). Thus, lipiodol (60 deg. C) treatment could greatly prolong the survival period of rabbits with VX2 cancer by inhibiting tumor growth.

Gadobenate dimeglumine-enhanced MR of VX2 carcinoma in rabbit liver: usefulness of the delayed phase imaging and optimal pulse sequence

Energy Technology Data Exchange (ETDEWEB)

Cho, Seung Il; Lee, Jeong Min; Kim, Young Kon; Kim, Chong Soo [College of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

2002-07-01

To assess the diagnostic value of delayed imaging using gadobenate dimeglumine (MultiHance) and to determine the optimal pulse sequence for the detection of VX2 carcinoma lesions in the rabbit. Twelve VX2 carcinomas implanted in the livers of eleven New Zealand rabbits were studied. All patients underwent an MR protocal consisting of precontrast T2-and T1-weighted sequences, followed by repetition of the T1-weighted sequence at 0 to 30 (arterial phase). 31-60 (portal phase), and 40 minutes (delayed phase) after the intravenous administration of 0.1 mmol/kg of gadobenate dimeglumine. The signal-to-noise ratio (SNR) of the liver and VX2 tumor, and the lesion-to-liver contrast-to-noise ratio (CNR) of precontrast and postcontrast MR images were quantitatively analyzed, and two experienced radiologists evaluated image quality in terms of lesion conspicuity, artifact, mass delineation, and vascular anatomy. Liver SNR was significantly higher at delayed imaging than at precontrast, arterial, and portal imaging (p<0.05), while lesion SNR was significantly higher at delayed imaging than at precontrast imaging (p<0.05). Lesion CNR was higher at delayed imaging than at precontrast and portal phase imaging (p<0.05), but there was no difference between arterial and delayed imaging. The latter provided better mass delineation than precontrast, arterial and portal phase imaging (p<0.05). While in terms of lesion conspicuity and vascular anatomy, the delayed phase was better than the arterial phase (p<0.05) but similar to the precontrast and portal phase. During the delayed phase, the gradient-echo sequence showed better results than the spin-echo in terms of liver SNR, and lesion SNR and CNR (p<0.05). Because it provides better lesion conspicuity and mass delineation by improving liver SNR and lesion-to-liver CNR, the addition of the delayed phase to a dynamic MRI sequence after gadobenate dimeglumine adminstration facilitates lesion detection. For delayed-phase imaging, the

Gadobenate dimeglumine-enhanced MR of VX2 carcinoma in rabbit liver: usefulness of the delayed phase imaging and optimal pulse sequence

International Nuclear Information System (INIS)

Cho, Seung Il; Lee, Jeong Min; Kim, Young Kon; Kim, Chong Soo

2002-01-01

To assess the diagnostic value of delayed imaging using gadobenate dimeglumine (MultiHance) and to determine the optimal pulse sequence for the detection of VX2 carcinoma lesions in the rabbit. Twelve VX2 carcinomas implanted in the livers of eleven New Zealand rabbits were studied. All patients underwent an MR protocal consisting of precontrast T2-and T1-weighted sequences, followed by repetition of the T1-weighted sequence at 0 to 30 (arterial phase). 31-60 (portal phase), and 40 minutes (delayed phase) after the intravenous administration of 0.1 mmol/kg of gadobenate dimeglumine. The signal-to-noise ratio (SNR) of the liver and VX2 tumor, and the lesion-to-liver contrast-to-noise ratio (CNR) of precontrast and postcontrast MR images were quantitatively analyzed, and two experienced radiologists evaluated image quality in terms of lesion conspicuity, artifact, mass delineation, and vascular anatomy. Liver SNR was significantly higher at delayed imaging than at precontrast, arterial, and portal imaging (p<0.05), while lesion SNR was significantly higher at delayed imaging than at precontrast imaging (p<0.05). Lesion CNR was higher at delayed imaging than at precontrast and portal phase imaging (p<0.05), but there was no difference between arterial and delayed imaging. The latter provided better mass delineation than precontrast, arterial and portal phase imaging (p<0.05). While in terms of lesion conspicuity and vascular anatomy, the delayed phase was better than the arterial phase (p<0.05) but similar to the precontrast and portal phase. During the delayed phase, the gradient-echo sequence showed better results than the spin-echo in terms of liver SNR, and lesion SNR and CNR (p<0.05). Because it provides better lesion conspicuity and mass delineation by improving liver SNR and lesion-to-liver CNR, the addition of the delayed phase to a dynamic MRI sequence after gadobenate dimeglumine adminstration facilitates lesion detection. For delayed-phase imaging, the

Detection and localization of rabbit hepatitis e virus and antigen in systemic tissues from experimentally intraperitoneally infected rabbits.

Directory of Open Access Journals (Sweden)

Jingjing Mao

Full Text Available Rabbit hepatitis E virus (HEV is a novel genotype of HEV, and is considered to pose a risk of zoonotic transmission. Research into the systemic distribution of rabbit HEV in rabbits during different periods of infection has rarely been reported. To better understand this virus, we infected rabbits with second-passage rabbit HEV via an intraperitoneal route. After inoculation, the infection showed two types, temporary and constant infection. The detection of HEV RNA in the feces varied with time, and serum antigen correlated with fecal HEV RNA. Viremia only appeared 72 days after inoculation. The rabbits remained antibody negative throughout the experimental period. When HEV was localized, several organs besides the liver were HEV RNA positive. Tissue antigen was observed immunohistochemically in the different cells of various organs, especially in parts of the small intestine and the characteristic rabbit gut-associated lymphoid tissue. These data provide valuable information for future research into the pathogenesis of HEV.

Binding properties of beetal recombinant caprine growth hormone to ...

African Journals Online (AJOL)

The aim of the study was to illustrate the radio-receptor assay of beetal recombinant caprine growth hormone (rcGH). Tracer (125I-rcGH) was prepared by iodinating beetal rcGH with iodine-125 and its biological activity was analyzed by rabbit anti-rcGH antibodies. Liver microsomal membranes of the Bovidae species ...

Early radiation impairment of the cholesterol metabolism in organelles of rat liver cells

Energy Technology Data Exchange (ETDEWEB)

Kaznacherev, Yu S; Kolomiitseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

1975-05-01

The incorporation of 1-C/sup 14/-acetate into cholesterol of the nuclear, mitochondrial, microsomal and 105000 g-supernatant fractions isolated from the rat liver in norm and 60 min after the exposure to 1200 r has been investigated. An increase has been observed in the label uptake into liver cholesterol of irradiated rats. Intracellular distribution of the newly synthesized (labelled) cholesterol is substantially changed after irradiation: maximum label incorporation into the cholesterol is observed in the 105000 g-supernatant fraction, whereas, normally, the cholesterol of microsomal fraction has the highest specific activity.

Analysis of energy metabolism of the rabbit liver in obstructive jaundice using 31P magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Kawasaki, Toshihiko; Moriyasu, Fuminori; Ban, Nobuyuki

1987-01-01

Phosphorus-31 magnetic resonance spectroscopy was used to assess the changes in hepatic high-energy phosphate metabolites in rabbits with obstructive jaundice. The rabbits, which had undergone operative ligation of the common bile duct, were studied using a 2.0 Tesla whole-body magnetic resonance imager. Comparison of the peak phosphorus signal values relative to α-ATP showed that the peak phosphodiester and γ-ATP values in the livers of the one-day-after-ligation group were significantly lower than those in the control group, and the peak phosphomonoester and phosphodiester values in the five-days-after-ligation group were larger than those in the control group, but not significantly. Comparison of the peak T 1 values in the one-day-after-ligation group with those of the control group revealed that the T 1 value of phosphodiester was significantly larger than that in control group. It is suggested that dysfunction of phospholipid metabolism appears in the early phase of hepatic dysfunction due to obstructive jaundice. (author)

Comparative quantitative monitoring of rabbit haemorrhagic disease viruses in rabbit kittens.

Science.gov (United States)

Matthaei, Markus; Kerr, Peter J; Read, Andrew J; Hick, Paul; Haboury, Stephanie; Wright, John D; Strive, Tanja

2014-06-09

Only one strain (the Czech CAPM-v351) of rabbit haemorrhagic disease virus (RHDV) has been released in Australia and New Zealand to control pest populations of the European rabbit O. cuniculus. Antigenic variants of RHDV known as RHDVa strains are reportedly replacing RHDV strains in other parts of the world, and Australia is currently investigating the usefulness of RHDVa to complement rabbit biocontrol efforts in Australia and New Zealand. RHDV efficiently kills adult rabbits but not rabbit kittens, which are more resistant to RHD the younger they are and which may carry the virus without signs of disease for prolonged periods. These different infection patterns in young rabbits may significantly influence RHDV epidemiology in the field and hence attempts to control rabbit numbers. We quantified RHDV replication and shedding in 4-5 week old rabbits using quantitative real time PCR to assess their potential to shape RHDV epidemiology by shedding and transmitting virus. We further compared RHDV-v351 with an antigenic variant strain of RHDVa in kittens that is currently being considered as a potential RHDV strain for future release to improve rabbit biocontrol in Australia. Kittens were susceptible to infection with virus doses as low as 10 ID50. Virus growth, shedding and transmission after RHDVa infection was found to be comparable or non-significantly lower compared to RHDV. Virus replication and shedding was observed in all kittens infected, but was low in comparison to adult rabbits. Both viruses were shed and transmitted to bystander rabbits. While blood titres indicated that 4-5 week old kittens mostly clear the infection even in the absence of maternal antibodies, virus titres in liver, spleen and mesenteric lymph node were still high on day 5 post infection. Rabbit kittens are susceptible to infection with very low doses of RHDV, and can transmit virus before they seroconvert. They may therefore play an important role in RHDV field epidemiology, in

Targeting of VX2 Rabbit Liver Tumor by Selective Delivery of 3-Bromopyruvate: A Biodistribution and Survival Study

Science.gov (United States)

Vali, Mustafa; Vossen, Josephina A.; Buijs, Manon; Engles, James M.; Liapi, Eleni; Ventura, Veronica Prieto; Khwaja, Afsheen; Acha-Ngwodo, Obele; Shanmugasundaram, Ganapathy; Syed, Labiq; Wahl, Richard L.; Geschwind, Jean-Francois H.

2009-01-01

The aim of this study was to determine the biodistribution and tumor targeting ability of 14C-labeled 3-bromopyruvate ([14C]3-BrPA) after i.a. and i.v. delivery in the VX2 rabbit model. In addition, we evaluated the effects of [14C]3-BrPA on tumor and healthy tissue glucose metabolism by determining 18F-deoxyglucose (FDG) uptake. Last, we determined the survival benefit of i.a. administered 3-BrPA. In total, 60 rabbits with VX2 liver tumor received either 1.75 mM [14C]3-BrPA i.a., 1.75 mM [14C]3-BrPA i.v., 20 mM [14C]3-BrPA i.v., or 25 ml of phosphate-buffered saline (PBS). All rabbits (with the exception of the 20 mM i.v. group) received FDG 1 h before sacrifice. Next, we compared survival of animals treated with i.a. administered 1.75 mM [14C]3-BrPA in 25 ml of PBS (n = 22) with controls (n = 10). After i.a. infusion, tumor uptake of [14C]3-BrPA was 1.8 ± 0.2% percentage of injected dose per gram of tissue (%ID/g), whereas other tissues showed minimal uptake. After i.v. infusion (1.75 mM), tumor uptake of [14C]3-BrPA was 0.03 ± 0.01% ID/g. After i.a. administration of [14C]3-BrPA, tumor uptake of FDG was 26 times lower than in controls. After i.v. administration of [14C]3-BrPA, there was no significant difference in tumor FDG uptake. Survival analysis showed that rabbits treated with 1.75 mM 3-BrPA survived longer (55 days) than controls (18.6 days). Intra-arterially delivered 3-BrPA has a favorable biodistribution profile, combining a high tumor uptake resulting in blockage of FDG uptake with no effects on healthy tissue. The local control of the liver tumor by 3-BrPA resulted in a significant survival benefit. PMID:18591216

Detection of hepatic VX2 tumors in rabbits: comparison of conventional US and phase- inversion harmonic US during the liver- specific late phase of contrast enhancement

International Nuclear Information System (INIS)

Lee, Jeong Min; Youk, Ji Hyun; Lee, Young Hwan; Kim, Young Kon; Kim, Chong Soo; Li, Chun Ai

2003-01-01

To compare phase-inversion sonography during the liver-specific phase of contrast enhancement using a microbubble contrast agent with conventional B-mode sonography for the detection of VX2 liver tumors. Twenty-three rabbits, 18 of which had VX2 liver tumor implants, received a bolus injection of 0.6 g of Levovist (200 mg/ml). During the liver-specific phase of this agent, they were evaluated using both conventional sonography and contrast-enhanced phase-inversion harmonic imaging (CEPIHI). Following sacrifice of the animals, pathologic analysis was performed and the reference standard thus obtained. The conspicuity, size and number of the tumors before and after contrast administration, as determined by a sonographer, were compared between the two modes and with the pathologic findings. CE-PIHI demonstrated marked hepatic parenchymal enhancement in all rabbits. For VX2 tumors detected at both conventional US and CE- PIHI, conspicuity was improved by contrast-enhanced PIHI. On examination of gross specimens, 52 VX2 tumors were identified. Conventional US correctly detected 18 of the 52 (34.6%), while PIHI detected 35 (67.3%) (p < 0.05). In particular, conventional US detected only three (8.3%) of the 36 tumors less than 10 mm in diameter, but CE-PIHI detected 19 such tumors (52.8%) (p < 0.05). Compared to conventional sonography, PIHI performed during the liver-specific phase after intravenous injection of Levovist is markedly better at detecting VX2 liver tumors

Antithyroid microsomal antibody

Science.gov (United States)

Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked with an increased risk ...

The distribution of estrogen receptor in various organs of rabbit

International Nuclear Information System (INIS)

Son, H.Y.; In, J.W.; Min, B.S.

1978-01-01

For clinical application of radioreceptor assay, we studied preliminarily the distribution of estrogen receptor in various organs of rabbit by a dextran-charcoal method using 6,7- 3 H-es-tradiol. The results were expressed as binding index, which is the ratio of specific estradiol receptor binding radioactivity to total radioactivity. The materials consist of 5 female rabbits and 3 male rabbits. For female rabbits the binding index was highest in the uterine tissue. This binding index of the uterine tissue was 9.4 times that of the liver, 21.9 times that of the kidney, 24.6 times that of the brain, 28.1 times that of the lung and 65.7 times that of the muscle. For male rabbits the binding index was highest in the liver and decreased in the order of the kidney, the testis, the lung, the brain and the muscle. It is suggested that the estrogen receptor is not confined to any specific target organ but is widely distributed in the various organs, to a different degree. (author)

The Distribution of Estrogen Receptor in Various Organs of Rabbit

International Nuclear Information System (INIS)

Son, Ho Young; In, Jae Whan; Min, Byong Sok

1978-01-01

For clinical application of radioreceptor assay, we studied preliminarily the distribution of estrogen receptor in various organs of rabbit by a dextran-charcoal method using 6, 7- 3 H-estradiol. The results were expressed as binding index, which is the ratio of specific estradiol receptor binding radioactivity to total radioactivity. The materials consist of 5 female rabbits and 3 male rabbits. The results were as follows: 1) Female rabbits. The binding index was highest in the uterine tissue. This binding index of the uterine tissue was 9.4 times that of the liver, 21.9 times that of the kidney, 24.6 times that of the brain, 28.1 times that of the lung and 65.7 times that of the muscle. 2) Male rabbits. The binding index was highest in the liver and decreased in the order of the kidney, the testis, the lung, the brain and the muscle. It is suggested that the estrogen receptor is not confined to any specific target organ but is widely distributed in the various organs, to a different degree.

Brachytherapy Using Elastin-Like Polypeptides with (131)I Inhibit Tumor Growth in Rabbits with VX2 Liver Tumor.

Science.gov (United States)

Liu, Xinpei; Shen, Yiming; Zhang, Xuqian; Lin, Rui; Jia, Qiang; Chang, Yixiang; Liu, Wenge; Liu, Wentian

2016-10-01

Brachytherapy is a targeted type of radiotherapy utilized in the treatment of cancers. Elastin-like polypeptides are a unique class of genetically engineered peptide polymers that have several attractive properties for brachytherapy. To explore the feasibility and application of brachytherapy for VX2 liver tumor using elastin-like polypeptides with (131)I so as to provide reliable experimental evidence for a new promising treatment of liver cancer. Elastin-like polypeptide as carrier was labeled with (131)I using the iodogen method. Ten eligible rabbits with VX2 liver tumor were randomly divided into the treatment group (n = 5) and control group (n = 5). The treatment group received brachytherapy using elastin-like polypeptide with (131)I, and in the control group, elastin-like polypeptide was injected into the VX2 liver tumor as a control. Periodic biochemical and imaging surveillances were required to assess treatment efficacy. The stability of elastin-like polypeptide with (131)I in vitro was maintained at over 96.8 % for 96 h. Biochemistry and imaging indicated brachytherapy using elastin-like polypeptide with (131)I for liver tumor can improve liver function and inhibit tumor growth (P Elastin-like polypeptide can be an ideal carrier of (131)I and have high labeling efficiency, radiochemical purity and stability. Brachytherapy using elastin-like polypeptide with (131)I for liver tumor is a useful therapy that possesses high antitumor efficacy advantages.

Studies on the metabolism of chlorotrianisene to a reactive intermediate and subsequent covalent binding to microsomal proteins

International Nuclear Information System (INIS)

Juedes, M.J.

1989-01-01

The studies on chlorotrianisene were conducted to determine whether metabolism of chlorotrianisene occurs via the cytochrome P450 monooxygenase system and whether a reactive intermediate is being formed that is capable of binding covalently to microsomal proteins. [ 3 H]-chlorotrianisene was incubated with liver microsomes supplemented with NADPH. At the termination of the incubation, the protein was trapped on a glass filter and the unbound chlorotrianisene was removed by extensive washing of the protein with organic solvent. A dramatic stimulation of covalent binding was demonstrated in microsomes from rats treated with methylcholanthrene (60 fold increase) versus control or phenobarbital treatment. Verification of covalent binding was achieved by localization of radiolabeled bands following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the macromolecules in the incubation mixture. Further analysis of the radiolabeled macromolecules separated on SDS-PAGE revealed that these macromolecules were degraded by protease degradation indicating that the macromolecules were proteins. Further investigations were done to determine the cause of the dramatic stimulation of covalent binding detected in microsomes from methylcholanthrene treated rats versus control or phenobarbital treated rats. Further evidence for the participation of P-450c was obtained with a reconstituted cytochrome P-450 system. Incubations of chlorotrianisene with reconstituted P-450c and NADPH-cytochrome P-450 reductase exhibited covalent binding characteristics comparable to those seen in microsomal incubations. Investigations into the nature of the binding site and the reactive intermediate are currently being conducted. By analyzing the BSA adduct, the author intends to isolate the specific amino acid binding site(s)

Monkey liver cytochrome P450 2C9 is involved in caffeine 7-N-demethylation to form theophylline.

Science.gov (United States)

Utoh, Masahiro; Murayama, Norie; Uno, Yasuhiro; Onose, Yui; Hosaka, Shinya; Fujino, Hideki; Shimizu, Makiko; Iwasaki, Kazuhide; Yamazaki, Hiroshi

2013-12-01

Caffeine (1,3,7-trimethylxanthine) is a phenotyping substrate for human cytochrome P450 1A2. 3-N-Demethylation of caffeine is the main human metabolic pathway, whereas monkeys extensively mediate the 7-N-demethylation of caffeine to form pharmacological active theophylline. Roles of monkey P450 enzymes in theophylline formation from caffeine were investigated using individual monkey liver microsomes and 14 recombinantly expressed monkey P450 enzymes, and the results were compared with those for human P450 enzymes. Caffeine 7-N-demethylation activity in microsomes from 20 monkey livers was not strongly inhibited by α-naphthoflavone, quinidine or ketoconazole, and was roughly correlated with diclofenac 4'-hydroxylation activities. Monkey P450 2C9 had the highest activity for caffeine 7-N-demethylation. Kinetic analysis revealed that monkey P450 2C9 had a high Vmax/Km value for caffeine 7-N-demethylation, comparable to low Km value for monkey liver microsomes. Caffeine could dock favorably with monkey P450 2C9 modeled for 7-N-demethylation and with human P450 1A2 for 3-N-demethylation. The primary metabolite theophylline was oxidized to 8-hydroxytheophylline in similar ways by liver microsomes and by recombinant P450s in both humans and monkeys. These results collectively suggest a high activity for monkey liver P450 2C9 toward caffeine 7-N-demethylation, whereas, in humans, P450 1A2-mediated caffeine 3-N-demethylation is dominant.

Effect of radio-detoxified endotoxin on the liver microsomal drug metabolizing enzyme system in rats

International Nuclear Information System (INIS)

Bertok, L.; Szeberenyi, S.

1983-01-01

E. coli endotoxin (LPS) depresses the hepatic microsomal mono-oxygenase activity. Radio-detoxified LPS (TOLERIN: 60 Co irradiated endotoxin preparation) decreases this biotransforming activity to a smaller extent. Phenobarbital, an inducer of this mono-oxygenase system, failed to induce in LPS-treated animals. In radio-detoxified LPS-treated rats, phenobarbital induced the mono-oxygenase and almost fully restored the biotransformation

Binding of the ligand [3H]MK-801 to the MK-801 binding site of the N-methyl-D-aspartate receptor during experimental encephalopathy from acute liver failure and from acute hyperammonemia in the rabbit

NARCIS (Netherlands)

R.J. de Knegt (Robert); J. Kornhuber (Johannes); S.W. Schalm (Solko); K. Rusche (K.); P.F. Riederer (Peter); J. Tan (J.)

1993-01-01

textabstractBinding of the ligand [3H]MK-801 to the MK-801 binding site of the N-methyl-D-aspartate (NMDA) receptor population on brain homogenates in rabbits was studied during experimental encephalopathy from acute liver failure and from acute hyperammonemia in the rabbit. Homogenates were

Clofibric acid increases the formation of oleic acid in endoplasmic reticulum of the liver of rats.

Science.gov (United States)

Hirose, Akihiko; Yamazaki, Tohru; Sakamoto, Takeshi; Sunaga, Katsuyoshi; Tsuda, Tadashi; Mitsumoto, Atsushi; Kudo, Naomi; Kawashima, Yoichi

2011-01-01

The effects of 2-(4-chlorophenoxy)-2-methylpropionic acid (clofibric acid) on the formation of oleic acid (18:1) from stearic acid (18:0) and utilization of the 18:1 formed for phosphatidylcholine (PC) formation in endoplasmic reticulum in the liver of rats were studied in vivo. [¹⁴C]18:0 was intravenously injected into control Wistar male rats and rats that had been fed on a diet containing 0.5% (w/w) clofibric acid for 7 days; and the distribution of radiolabeled fatty acids among subcellular organelles, microsomes, peroxisomes, and mitochondria, was estimated on the basis of correction utilizing the yields from homogenates of marker enzymes for these organelles. The radioactivity was mostly localized in microsomes and the radiolabeled fatty acids present in microsomes were significantly increased by the treatment of rats with clofibric acid. The formation of radiolabeled 18:1 in microsomes markedly increased and incorporations of the formed [¹⁴C]18:1 into PC and phosphatidylethanolamine in microsomes were augmented in response to clofibric acid. The [¹⁴C]18:1 incorporated into PC was mostly located at the C-2 position, but not the C-1 position, of PC, and the radioactivity in 18:1 at the C-2 position of PC was strikingly increased by clofibric acid. These results obtained from the in vivo experiments directly link the findings that clofibric acid treatment induces microsomal stearoyl-CoA desaturase and 1-acylglycerophosphocholine acyltransferase in the liver and the findings that the treatment with the drug elevated absolute mass and mass proportion of 18:1 at the C-2 position, but not the C-1 position, of PC in the liver together.

INFECTIOUS MYXOMATOSIS (SANARELLI) IN PREGNANT RABBITS

Science.gov (United States)

Sprunt, Douglas H.

1932-01-01

Pregnancy in rabbits alters the reactivity of the tissues to the virus of infectious myxomatosis. The livers of pregnant animals with the myxoma have a central acidophilic necrosis. Secondary lesions in the lungs are much more numerous and larger in the pregnant than in the non-gravid animals. In like manner the lesions in the spleen are more extensive in the pregnant rabbit. On the other hand the skin lesions of the pregnant animal are decreased in size. PMID:19870088

Autoimmune hepatitis-specific antibodies against soluble liver antigen and liver cytosol type 1 in patients with chronic viral hepatitis

OpenAIRE

Rigopoulou, Eirini I; Mytilinaiou, Maria; Romanidou, Ourania; Liaskos, Christos; Dalekos, George N

2007-01-01

Background Non-organ specific autoantibodies are highly prevalent in patients with chronic hepatitis C (HCV). Among them, anti-liver kidney microsomal type 1 (LKM1) antibody – the serological marker of type 2 autoimmune hepatitis (AIH-2)- is detected in up to 11% of the HCV-infected subjects. On the other hand, anti-liver cytosol type 1 antibodies (anti-LC1) – either in association with anti-LKM1, or in isolation- and anti-soluble liver antigen antibodies (anti-SLA) have been considered as us...

Effect of Momordica charantia (bitter melon on serum glucose level and various protein parameters in acetaminophen intoxicated rabbits

Directory of Open Access Journals (Sweden)

Kanwal Zahra

2012-02-01

Full Text Available Aim: Liver function tests, including total plasma proteins, albumin, bilirubin and glucose were analyzed to find out the hepatocurative and hepatoprotective effects of Momordica charantia. Method: The study was divided into two categories. In first category, the livers of rabbits were intoxicated with acetaminophen, and then Momordica fruit extract was given to observe its hepatocurative effects. Results: The results indicated significant changes in concentrations of the parameters in acetaminophen-challenged rabbits. In the second category, treatment was started by giving Momordica fruit extract dose orally for 10 days and 15 days to two groups of rabbits, respectively. Then, livers of rabbits were damaged with acetaminophen and hepatoprotective effects of Momordica were observed. Conclusion: The results showed that the animals treated with Momordica fruit extract experienced less liver damage due to acetaminophen intoxication, indicating that Momordica has hepatoprotective properties. [J Intercult Ethnopharmacol 2012; 1(1.000: 7-12

In vitro screening of reversible and time-dependent inhibition on CYP3A by TM208 and TM209 in rat liver microsomes

Directory of Open Access Journals (Sweden)

Miaoran Ning

2012-04-01

Full Text Available TM208 and TM209, dithiocarbamate derivatives with potential anti-cancer effects, were evaluated in reversible and time-dependent cytochrome P450 (CYP 3A inhibition assays in rat liver microsomes using testosterone as probe substrate. Both compounds were found to be weak reversible inhibitors and moderate mechanism-based inhibitors of rat CYP3A. For reversible inhibition on rat CYP3A, the Ki values of competitive inhibition model were 12.10±1.75 and 13.94±1.31 μM, respectively. For time-dependent inhibition, the inactivation constants (Kl were 31.93±12.64 and 32.91±15.58 μM, respectively, and the maximum inactivation rates (kinact were 0.03497±0.0069 and 0.07259±0.0172 min−1 respectively. These findings would provide useful in vitro information for future in vivo DDI studies on TM208 or TM209.

Effect of Curcuma longa on CYP2D6- and CYP3A4-mediated metabolism of dextromethorphan in human liver microsomes and healthy human subjects.

Science.gov (United States)

Al-Jenoobi, Fahad Ibrahim; Al-Thukair, Areej A; Alam, Mohd Aftab; Abbas, Fawkeya A; Al-Mohizea, Abdullah M; Alkharfy, Khalid M; Al-Suwayeh, Saleh A

2015-03-01

Effect of Curcuma longa rhizome powder and its ethanolic extract on CYP2D6 and CYP3A4 metabolic activity was investigated in vitro using human liver microsomes and clinically in healthy human subjects. Dextromethorphan (DEX) was used as common probe for CYP2D6 and CYP3A4 enzymes. Metabolic activity of CYP2D6 and CYP3A4 was evaluated through in vitro study; where microsomes were incubated with NADPH in presence and absence of Curcuma extract. In clinical study phase-I, six healthy human subjects received a single dose (30 mg) of DEX syrup, and in phase-II DEX syrup was administered with Curcuma powder. The enzyme CYP2D6 and CYP3A4 mediated O- and N-demethylation of dextromethorphan into dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Curcuma extract significantly inhibited the formation of DOR and 3-MM, in a dose-dependent and linear fashion. The 100 μg/ml dose of curcuma extract produced highest inhibition, which was about 70 % for DOR and 80 % for 3-MM. Curcuma significantly increases the urine metabolic ratio of DEX/DOR but the change in DEX/3-MM ratio was statistically insignificant. Present findings suggested that curcuma significantly inhibits the activity of CYP2D6 in in vitro as well as in vivo; which indicates that curcuma has potential to interact with CYP2D6 substrates.

Effect of chlorpromazine on lipid metabolism in aortas from cholesterol-fed rabbits and normal rats, in vitro: inhibition of sterol esterification and modification of phospholipid synthesis

International Nuclear Information System (INIS)

Bell, F.P.

1983-01-01

Chlorpromazine (CPZ), a major tranquilizer, was found to be a potent inhibitor of acylCoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) in isolated arterial microsomes and in intact arterial tissue from the rat and cholesterol-fed rabbit in vitro. In isolated rabbit arterial microsomes, CPZ resulted in a concentration-dependent inhibition of ACAT with 50% inhibition of [1-14C]oleoylCoA incorporation into [14C]cholesteryl esters occurring at 0.1 mM CPZ. CPZ also effectively inhibited the incorporation of [14C]oleate into triglycerides without affecting incorporation into diglycerides. Additionally, CPZ altered the pattern of arterial phospholipids synthesized from [1-14C]oleate. Incorporation into phosphatidylcholine was depressed while incorporation into phosphatidylinositol was increased. Since diglyceride synthesis appeared to be unaffected by CPZ, a redirection of phosphatidic acid into the CDP-diglyceride pathway of glycerolipid synthesis does not adequately account for the effect of CPZ on arterial phospholipid and triglyceride synthesis in these experiments

Selective inhibition by chloramphenicol of pregnenolone-16 α-carbonitrile-inducible rat liver cytochrome P-450 isozymes

International Nuclear Information System (INIS)

Graves, P.E.; Kaminsky, L.S.; Halpert, J.

1986-01-01

Pregnenolone-16 α-carbonitrile (PCN) has been shown to induce, in male rats, cytochrome P-450 isozymes responsible for the formation of R-10-hydroxywarfarin and R-dehydrowarfarin. Antibodies to the major PCN-inducible isozyme (PB/PCN-E) inhibit both activities in microsomal preparations. Recently the authors have shown that PCN treatment of female rats also induces the formation of both R-warfarin metabolites. However, in both sexes chloramphenicol (CAP) treatment selectively inhibits only the rate of formation of the R-dehydrowarfarin. A decrease in microsomal P-450 content occurs after in vivo administration of CAP to PCN-treated rats of both sexes. This is in contrast to the lack of effect of CAP on P-450 levels in phenobarbital-treated rats. Covalent binding of 14 C-CAP to microsomal protein in vitro was increased 3 to 4-fold following PCN treatment. Chromatographic evidences suggests the presence of at least two PCN-induced isozymes of similar molecular weights in both male and female rat liver microsomes. These data are consistent with the multiplicity of PCN-inducible P-450 in rat liver

N-nitrosamines induced infertility and hepatotoxicity in male rabbits.

Science.gov (United States)

Sheweita, S A; El Banna, Y Y; Balbaa, M; Abdullah, I A; Hassan, H E

2017-09-01

N-nitrosamines are widely spread environmental pollutants of well-known toxicity and carcinogenicity in various animal species. These compounds are metabolically activated by cytochrome P450 system predominantly in the liver and in other tissues into more active metabolites leading to generation of both alkylating agents that alkylate DNA and reactive oxygen species. In the current study, we investigated the influence of four types of N-nitrosamines that are commonly present in the environment [methyethylnitrosamine, (MEN), diethylnitrosamine (DEN), diphenylnitroasamine (DPN) and dimethylnitrosamine (DMN)] on both livers and testes of male rabbits through assessment of 17 β-hydroxysteroid dehydrogenase (17 β-HSD) activity. The protein expression of the three cytochrome P450s (CYP11A1, CYP19A1, and CYP21A2) is involved in the steroidogenesis. The levels of testosterone (T) and estradiol (E2) were also determined in the plasma of N-nitrosamines-treated rabbits after one, four-, eight- and twelve weeks of treatment of male New Zealand rabbits with an oral dose of 0.5 mg/kg B.W/day of each compound. In addition, activities of glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and levels of free radicals measured as thiobarbituric acid reactive substances (TBARS), and reduced glutathione (GSH) level were quantified in both livers and testes. The present study showed that levels of free radicals (TBARS) were markedly increased, whereas GSH levels were depleted in the tissues of both livers and testes after treatment of rabbits with any of N-nitrosamines. In addition, all tested N-nitrosamines inhibited the activities of antioxidant enzyme activities (GR, GST, SOD, and CAT) in hepatic and testicular tissues of rabbits after 12 weeks of treatment. Histopathological examination showed that N-nitrosamines caused lymphocytic infiltration with vascular degeneration and necrosis, congestion of central vein with RBCs hemolysis, dilated sinusoids, as well as

Radiofrequency ablation of rabbit liver. Correlation between dual CT findings and pathological findings

International Nuclear Information System (INIS)

Tsuda, Masashi; Rikimaru, Yuya; Saito, Haruo; Ishibashi, Tadashi; Takahashi, Shyoki; Miyachi, Hideo; Yamada, Syogo

2002-01-01

The purpose of this study was to present the time-related imaging findings and correlative pathologic findings of radiofrequency pulse-irradiated regions of the liver. Radiofrequency (RF) ablation was performed in 22 rabbit livers with 15-gauge RF probes inserted percutaneously. Regions were imaged with dual-phase CT at 3 days (n=6), 2 weeks (n=6), 4 weeks (n=6), and 12 weeks (n=4) after RF ablation. At 3 days, the regions showed a two-zone structure on plain CT and peripheral enhancement. The regions presented a three-zone structure on pathological study. Hepatocytes appeared as acidophilic bodies, and nuclei were pyknotic at the inner necrotic zone. The middle whitish zone showed enlarged sinusoids. The marginal zone was a regenerative band. At 2 weeks, the two-zone structure was obscured on unenhanced CT. The region showed a two-zone structure on pathological study. At the inner zone, acidophilic degeneration had progressed, however, cell structure remained. The marginal zone showed fibrous tissue bundles. At 12 weeks, the region was obscured on plain CT. Nuclei and cell structures had disappeared almost completely at the inner zone. Collagen fiber had replaced the marginal zone. Zone structural CT findings reflect the pathological findings and time-related changes after RF ablation. Peripheral enhancement in the arterial phase reflects the granulation tissue layer, and its time-related decrease reflects replacement by fibrous tissue. (author)

Liver microsomal fraction is known to participate in:

African Journals Online (AJOL)

Abdullahi Balarabe

Bayero Journal of Pure and Applied Sciences, 5(1): 11 – 16. Received: November 2011 ... of diet rich in fruit and vegetable may decrease the risk of cancer ((Steinmetz .... during analysis and experiment. The differences .... the liver mitochondrial membrane (Balzan et al.,. 1999). .... and Plasma Malondialdehyde in Human.

Measure of enzymatic activity coincident with 2450 MHz microwave exposure

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Ward, T R; Allis, J W; Elder, J A

1975-09-01

Enzyme preparations were exposed to microwave radiation at 2450 MHz and enzymatic activity was simultaneously monitored spectrophotometrically with a crossed-beam exposure detection system. Enzymes studied were glucose 6-phosphate dehydrogenase from human red blood cells and yeast, adenylate kinase from rat liver mitochondria and rabbit muscle, and rat liver microsomal NADPH cytochrome c reductase. No difference was found between the specific activity at 25/sup 0/C of unirradiated controls and enzyme preparations irradiated at an absorbed dose rate of 42 W/kg.

Sera of children with hepatitis C infection and anti-liver-kidney microsome-1 antibodies recognize different CYP2D6 epitopes than adults with LKM+/HCV+ sera.

Science.gov (United States)

Herzog, D; Yamamoto, A M; Jara, P; Maggiore, G; Sarles, J; Alvarez, F

1999-11-01

Liver-kidney microsome type 1 (LKM1) antibodies are specific markers of autoimmune hepatitis (AIH) type 2. Antibodies to LKM1 have been found in 2% to 3% of adults infected with hepatitis C virus (HCV) without AIH. Thirty percent of these antibodies are directed against linear sequences of CYP2D6 protein. LKM1 antibodies in HCV+/LKM1+ sera and in sera of AIH patients do not recognize the same CYP2D6 epitopes. The current study was conducted to determine whether LKM1 antibodies in HCV+/LKM1+ children's sera are the result of the same immune response as the antibodies described in AIH type 2 and in HCV+/LKM1+ adult patients. Sera from 10 HCV+/LKM1+ children were tested against human liver microsomal and cytosolic proteins by Western blot analysis and against synthetic peptides of the CYP2D6 sequence between amino acids 200 and 429 by dot blot. The same sera were tested against radiolabeled CYP2D6 by immunoprecipitation. Four of 10 sera tested by Western blot analysis showed immunoglobulin (Ig) G-type antibodies against CYP2D6, and 2 had antibodies against proteins of 58, 66, and 84 kDa. One of the sera also contained IgM-type anti-66-kDa and 84-kDa proteins. The radioligand test detected anti-CYP2D6 antibodies in 9 of 10 patients. Five of the anti-CYP2D6-positive sera recognized a peptide between amino acids 200 and 429 including amino acids 254-271. Most HCV+/LKM1+ sera from children recognize conformational epitopes of the CYP2D6 antigen, and half recognize linear epitopes. Some HCV+/LKM1+ sera demonstrated antibodies against the AIH type 2 main antigenic site of the CYP2D6. Screening of HCV RNA should be performed before starting treatment of presumed autoimmune hepatitis associated with LKM1.

Evaluation of flaxseed effects on non-alcoholic fatty liver disease (NAFLD in rabbits submitted to a hypercholesterolemic diet

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Caroline Tatim Saad

2014-10-01

Full Text Available Background: The aim of the present study is to evaluate the role of flaxseed in non-alcoholic fatty liver disease, as well as on the lipid profile in rabbits submitted to hypercholesterolemic diet. Subject and Methods: 32 male rabbits, weighing approximately 1.5kg and averaging four months of age, were distributed into three groups. Group 1 received standard food plus 0.5% of cholesterol from dried egg, during 8 weeks. Group 2 obtained the same diet in the first 4 weeks, and 8mg/kg of ground flaxseed was added in the remaining weeks. Lastly, group 3 was fed with the previous group’s increased diet throughout the entire period. In the follow-up, the animals were euthanized, and liver blades were prepared to evaluate the histopathologic study. The evaluation score of NAFLD (ESN, as well as plasma levels of total cholesterol, LDLcholesterol, HDL-cholesterol, triglycerides and body weight, were all determined. Results: Increased levels of total cholesterol were obtained in both groups, with the smallest variation found in G3 (p=0.002. This variation was also found when the levels of LDLcholesterol were assessed (p=0.001. There was a reduction of triglyceride levels at the end of the study in G3 (p=0.008. A variation was noticed between the ESN groups, but the induced reduction was not statistically significant. Conclusion: Further studies are necessary, in order to elucidate the effects of flaxseed in NAFLD as well as in diseases that have risk factors for the development of the disease

Cytochrome P-450 dependent ethanol oxidation. Kinetic isotope effects and absence of stereoselectivity

International Nuclear Information System (INIS)

Ekstroem, G.; Norsten, C.; Cronholm, T.; Ingelman-Sundberg, M.

1987-01-01

Deuterium isotope effects [/sup D/(V/K)] and stereoselectivity of ethanol oxidation in cytochrome P-450 containing systems and in the xanthine-xanthine oxidase system were compared with those of yeast alcohol dehydrogenase. The isotope effects were determined by using both a noncompetitive method, including incubation of unlabeled of [1,1- 2 H 2 ] ethanol at various concentrations, and a competitive method, where 1:1 mixtures of [1- 13 C]- and [ 2 H 6 ] ethanol or [2,2,2- 2 H 3 ]- and [1,1- 2 H 2 ] ethanol were incubated and the acetaldehyde formed was analyzed by gas chromatography/mass spectrometry. The /sup D/(V/K) isotope effects of the cytochrome P-450 dependent ethanol oxidation were about 4 with liver microsomes from imidazole-, phenobarbital- or acetone-treated rabbits or with microsomes from acetone- or ethanol-treated rats. Similar isotope effects were reached with reconstituted membranes containing the rabbit ethanol-inducible cytochrome P-450 (LMeb), whereas control rat microsomes and membranes containing rabbit phenobarbital-inducible P-450 LM 2 oxidized the alcohol with /sup D/(V/K) of about 2.8 and 1.8, respectively. Addition of Fe/sup III/EDTA either to microsomes from phenobarbital-treated rabbits or to membranes containing P-450 LMeb significantly lowered the isotope effect. Incubations of all cytochrome P-450 containing systems of the xanthine-xanthine oxidase systems with (1R)- and (1S)-[1- 2 H] ethanol, revealed, taking the isotope effects into account, that 44-66% of the ethanol oxidized had lost the 1-pro-R hydrogen. The data indicate that cytochrome P-450 dependent ethanol oxidation is not stereospecific and that cleavage of the C 1 -H bond appears to be a rate-determining step in the catalysis by the ethanol-inducible form of P-450. The contribution of hydroxyl radicals in ethanol oxidation by the various enzymic systems is discussed

Quantitative Characterization of Major Hepatic UDP-Glucuronosyltransferase Enzymes in Human Liver Microsomes: Comparison of Two Proteomic Methods and Correlation with Catalytic Activity.

Science.gov (United States)

Achour, Brahim; Dantonio, Alyssa; Niosi, Mark; Novak, Jonathan J; Fallon, John K; Barber, Jill; Smith, Philip C; Rostami-Hodjegan, Amin; Goosen, Theunis C

2017-10-01

Quantitative characterization of UDP-glucuronosyltransferase (UGT) enzymes is valuable in glucuronidation reaction phenotyping, predicting metabolic clearance and drug-drug interactions using extrapolation exercises based on pharmacokinetic modeling. Different quantitative proteomic workflows have been employed to quantify UGT enzymes in various systems, with reports indicating large variability in expression, which cannot be explained by interindividual variability alone. To evaluate the effect of methodological differences on end-point UGT abundance quantification, eight UGT enzymes were quantified in 24 matched liver microsomal samples by two laboratories using stable isotope-labeled (SIL) peptides or quantitative concatemer (QconCAT) standard, and measurements were assessed against catalytic activity in seven enzymes ( n = 59). There was little agreement between individual abundance levels reported by the two methods; only UGT1A1 showed strong correlation [Spearman rank order correlation (Rs) = 0.73, P quantitative proteomic data should be validated against catalytic activity whenever possible. In addition, metabolic reaction phenotyping exercises should consider spurious abundance-activity correlations to avoid misleading conclusions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Assessment of some Hepatic Enzyme activities in adult rabbits ...

African Journals Online (AJOL)

Therapeutic potentials of Garcinia kola (G. kola) have been extensively documented and several researches have asserted its protective uniqueness against liver disorders/diseases. It is the aim of this study to assess the level of some enzyme involved in liver cellular integrity in rabbits chronically fed G. kola. To achieve this ...

In vitro biosynthesis, isolation, and identification of predominant metabolites of 2-(4-(2-hydroxyethoxy)-3,5-dimethylphenyl)-5,7-dimethoxyquinazolin-4(3H)-one (RVX-208).

Science.gov (United States)

Khmelnitsky, Yuri L; Mozhaev, Vadim V; Cotterill, Ian C; Michels, Peter C; Boudjabi, Sihem; Khlebnikov, Vladimir; Madhava Reddy, M; Wagner, Gregory S; Hansen, Henrik C

2013-06-01

The structures of the two predominant metabolites (M4 and M5) of RVX-208, observed both in in vitro human and animal liver microsomal incubations, as well as in plasma from animal in vivo studies, were determined. A panel of biocatalytic systems was tested to identify biocatalysts suitable for milligram scale production of metabolite M4 from RVX-208. Rabbit liver S9 fraction was selected as the most suitable system, primarily based on pragmatic metrics such as catalyst cost and estimated yield of M4 (∼55%). Glucuronidation of RVX-208 catalyzed by rabbit liver S9 fraction was optimized to produce M4 in amounts sufficient for structural characterization. Structural studies using LC/MS/MS analysis and (1)H NMR spectroscopy showed the formation of a glycosidic bond between the primary hydroxyl group of RVX-208 and glucuronic acid. NMR results suggested that the glycosidic bond has the β-anomeric configuration. A synthetic sample of M4 confirmed the proposed structure. Metabolite M5, hypothesized to be the carboxylate of RVX-208, was prepared using human liver microsomes, purified by HPLC, and characterized by LC/MS/MS and (1)H NMR. The structure was confirmed by comparison to a synthetic sample. Both samples confirmed M5 as a product of oxidation of primary hydroxyl group of RVX-208 to carboxylic acid. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The iron-responsive microsomal proteome of Aspergillus fumigatus.

Science.gov (United States)

Moloney, Nicola M; Owens, Rebecca A; Meleady, Paula; Henry, Michael; Dolan, Stephen K; Mulvihill, Eoin; Clynes, Martin; Doyle, Sean

2016-03-16

Aspergillus fumigatus is an opportunistic fungal pathogen. Siderophore biosynthesis and iron acquisition are essential for virulence. Yet, limited data exist with respect to the adaptive nature of the fungal microsomal proteome under iron-limiting growth conditions, as encountered during host infection. Here, we demonstrate that under siderophore biosynthetic conditions--significantly elevated fusarinine C (FSC) and triacetylfusarinine C (TAFC) production (pproteome remodelling occurs. Specifically, a four-fold enrichment of transmembrane-containing proteins was observed with respect to whole cell lysates following ultracentrifugation-based microsomal extraction. Comparative label-free proteomic analysis of microsomal extracts, isolated following iron-replete and -deplete growth, identified 710 unique proteins. Scatterplot analysis (MaxQuant) demonstrated high correlation amongst biological replicates from each growth condition (Pearson correlation >0.96 within groups; biological replicates (n=4)). Quantitative and qualitative comparison revealed 231 proteins with a significant change in abundance between the iron-replete and iron-deplete conditions (pAspergillus fumigatus must acquire iron to facilitate growth and pathogenicity. Iron-chelating non-ribosomal peptides, termed siderophores, mediate iron uptake via membrane-localised transporter proteins. Here we demonstrate for the first time that growth of A. fumigatus under iron-deplete conditions, concomitant with siderophore biosynthesis, leads to an extensive remodelling of the microsomal proteome which includes significantly altered levels of 231 constituent proteins (96 increased and 135 decreased in abundance), many of which have not previously been localised to the microsome. We also demonstrate the first synthesis of a fluorescent version of fusarinine C, an extracellular A. fumigatus siderophore, and its uptake and localization under iron-restricted conditions. This infers the use of an A. fumigatus

Heated lipiodol as an embolization agent for transhepatic arterial embolization in VX2 rabbit liver cancer model

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Cao Wei [Department of Interventional Radiology, Tangdu Hospital, Fourth Military Medical University, No.1 Xinshi Road, Shaanxi Province, Xi' an 710038 (China)], E-mail: zjfurong2008@126.com; Wan Yi [Department of Health Statistics, Fourth Military Medical University, No. 17 West Changle Road, Xi' an 710032 (China); Liang Zhihui [Department of Radiology, Bethune International Peace Hospital, Shijiazhuang, Hebei Province 050082 (China); Duan Yunyou; Liu Xi [Department of Ultrasonography, Tangdu Hospital, Fourth Military Medical University, No. 1 Xinshi Road, Xi' an 710038 (China); Wang Zhimin; Liu Yiyong; Zhu Jia; Liu Xiongtao [Department of Interventional Radiology, Tangdu Hospital, Fourth Military Medical University, No.1 Xinshi Road, Shaanxi Province, Xi' an 710038 (China); Zhang Hongxin [Department of Interventional Radiology, Tangdu Hospital, Fourth Military Medical University, No.1 Xinshi Road, Shaanxi Province, Xi' an 710038 (China)], E-mail: cawe-001@163.com

2010-02-15

Purpose: To evaluate the therapeutic effect of heated (60 deg. C) lipiodol via hepatic artery administration in a rabbit model of VX2 liver cancer. Materials and methods: Thirty male New Zealand white rabbits were randomly divided into three groups with 10 rabbits assigned to each group. VX2 carcinoma cells were surgically implanted into the left hepatic lobe. The tumors were allowed to grow for 2 weeks, and studies were performed until the diameter of the tumors detected by ultrasonograph reached 2-3 cm. Under anesthesia, trans-catheter hepatic arterial embolization was performed and doxorubicin-lipiodol (37 deg. C) (1 mL), lipiodol (60 deg. C) (1 mL) or control (physiological saline (37 deg. C) (1 mL)) solution was injected into the hepatic arteries of animals in the three groups. One week later, the volume of the tumor was measured by ultrasonograph again. The serum of all rabbits was collected before injection and at 4 and 7 days after injection, and the level of aspartate aminotransferase (AST) was checked. The survival period of the three groups of rabbits after treatment was also recorded. During the last course of their disease, the rabbits were given analgesics to relieve suffering. Results: The tumor growth rate in the lipiodol (60 deg. C) group (0.92 {+-} 0.21, tumor volume from 1811 {+-} 435 to 1670 {+-} 564 mm{sup 3}) was significantly lower than that in the control group (3.48 {+-} 1.17, tumor volume from 1808 {+-} 756 to 5747 {+-} 1341 mm{sup 3}) (P < 0.05) and in the doxorubicin-lipiodol (37 deg. C) group (1.69 {+-} 0.26, tumor volume from 1881 {+-} 641 to 2428 {+-} 752 mm{sup 3}) (P < 0.05). Consequently, the survival period of the animals in the lipiodol (60 deg. C) group (41.0 {+-} 3.0 days) was significantly greater than that in the doxorubicin-lipiodol (37 deg. C) group (38.0 {+-} 2.5 days) (P < 0.05). On the other hand, there was no statistically significant difference in serum AST levels between the lipiodol (60 deg. C) group (148.2 {+-} 11

Grapefruit juice intake does not enhance but rather protects against aflatoxin B1-induced liver DNA damage through a reduction in hepatic CYP3A activity.

Science.gov (United States)

Miyata, Masaaki; Takano, Hiroki; Guo, Lian Q; Nagata, Kiyoshi; Yamazoe, Yasushi

2004-02-01

Influence of grapefruit juice intake on aflatoxin B1 (AFB1)-induced liver DNA damage was examined using a Comet assay in F344 rats given 5 mg/kg AFB1 by gavage. Rats allowed free access to grapefruit juice for 5 days prior to AFB1 administration resulted in clearly reduced DNA damage in liver, to 65% of the level in rats that did not receive grapefruit juice. Furthermore, rats treated with grapefruit juice extract (100 mg/kg per os) for 5 days prior to AFB1 treatment also reduced the DNA damage to 74% of the level in rats that did not receive grapefruit juice. No significant differences in the portal blood and liver concentrations of AFB1 were observed between grapefruit juice intake rats and the controls. In an Ames assay with AFB1 using Salmonella typhimurium TA98, lower numbers of revertant colonies were detected with hepatic microsomes prepared from rats administered grapefruit juice, compared with those from control rats. Microsomal testosterone 6beta-hydroxylation was also lower with rats given grapefruit juice than with control rats. Immunoblot analyses showed a significant decrease in hepatic CYP3A content, but not CYP1A and CYP2C content, in microsomes of grapefruit juice-treated rats than in non-treated rats. No significant difference in hepatic glutathione S-transferase (GST) activity and glutathione content was observed in the two groups. GSTA5 protein was not detected in hepatic cytosol of the two groups. In microsomal systems, grapefruit juice extract inhibited AFB1-induced mutagenesis in the presence of a microsomal activation system from livers of humans as well as rats. These results suggest that grapefruit juice intake suppresses AFB1-induced liver DNA damage through inactivation of the metabolic activation potency for AFB1 in rat liver.

CT spectral imaging for monitoring the therapeutic efficacy of VEGF receptor kinase inhibitor AG-013736 in rabbit VX2 liver tumours

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Lv, Peijie; Liu, Jie; Yan, Xiaopeng; Chai, Yaru; Chen, Yan; Gao, Jianbo; Pan, Yuanwei; Li, Shuai; Guo, Hua; Zhou, Yue [The First Affiliated Hospital of Zhengzhou University, The Department of Radiology, Zhengzhou, Henan Province (China)

2017-03-15

The aim of this study was to evaluate the value of computed tomography (CT) spectral imaging in assessing the therapeutic efficacy of a vascular endothelial growth factor (VEGF) receptor inhibitor AG-013736 in rabbit VX2 liver tumours. Twenty-three VX2 liver tumour-bearing rabbits were scanned with CT in spectral imaging mode during the arterial phase (AP) and portal phase (PP). The iodine concentrations(ICs)of tumours normalized to aorta (nICs) at different time points (baseline, 2, 4, 7, 10, and 14 days after treatment) were compared within the treated group (n = 17) as well as between the control (n = 6) and treated groups. Correlations between the tumour size, necrotic fraction (NF), microvessel density (MVD), and nICs were analysed. The change of nICs relative to baseline in the treated group was lower compared to the control group. A greater decrease in the nIC of a tumour at 2 days was positively correlated with a smaller increase in tumour size at 14 days (P < 0.05 for both). The tumour nIC values in AP and PP had correlations with MVD (r = 0.71 and 0.52) and NF (r = -0.54 and -0.51) (P < 0.05 for all). CT spectral imaging allows for the evaluation and early prediction of tumour response to AG-013736. (orig.)

Effect of vasopressin on rabbit hepatic energy metabolism evaluated using in vivo P-31 magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Ono, Shigeki; Moriyasu, Fuminori; Tamada, Takashi

1989-01-01

Changes in metabolic state of rabbit livers after administration of vasopressin (10 mU/kg/min d.i.v.) were evaluated using in vivo P-31 magnetic resonance (MR) spectroscopy. Targets were nine normal control rabbits and eight with chronically carbontetrachloride-damaged livers. A 2.0 Tesla whole-body MR imager was used for measurement. After administration of vasopressin, liver spectroscopy showed a mild ischemic pattern. The inorganic phosphate peak increased statistically significantly (p<0.05) both in the normal control group and in the damaged-liver group (20% and 16% above base line value respectively). In the normal control group, there was a statistically significant decrease (p<0.05) in the ATP peak to 18% below the base line value while the PME (phosphomonoester) peak increased slightly (about 10%); there was little change in the damaged-liver group. It was thought that the difference between the two groups was due to differences in blood flow mechanism and liver metabolism. Magnetic resonance spectroscopy was considered to be useful in studying the detailed changes in metabolic state of rabbit liver after administration of vasopressin. (author)

Effects of Khaya senegalensis leaves on performance, carcass traits, hemtological and biochemical parameters in rabbits

Science.gov (United States)

Abdel-Wareth, A. A. A.; Hammad, Seddik; Ahmed, Hassan

2014-01-01

One of the challenges facing farmers today is to ensure adequate integration of natural resources into animal feeds. The aim of the present study is to evaluate the effects of Khaya senegalensis (KS) leaves on the performance of growing male rabbits, carcass traits and biochemical as well as hematological parameters. Thirty New Zealand White male growing rabbits were randomly divided into 3 groups (10 rabbits per group). Group I (control) received standard rabbit diet. Rabbits in group II and group III were fed standard rabbit diet supplemented with 35 % and 65 % KS leaves, respectively. All rabbits were fed daily for 25 days. The performance parameters and carcass criteria, including daily body weight gain, final body weight, and the percentage of dressing, were increased in rabbits fed 35 % KS when compared to the control group. Kidney and liver weight ratios increased significantly in group II but dropped in group III. Furthermore, liver enzymes - alanine aminotransferase and aspartate transaminase and kidney function parameters - urea, and creatinine - increased in both group II (significant P<0.05) and in group III (significant P<0.01) when compared to the control group. Moreover, KS leaves induced a significant increase (P<0.05) in the total white blood cell count, the percentage of granulocytes and the platelet count; whereas, the percentage of lymphocytes, red blood cell count, hemoglobin content, mean corpuscular hemoglobin, mean corpuscular volume and mean corpuscular hemoglobin concentration were not statistically significantly changed. This study demonstrates that the performance parameters and carcass traits are improved by the replacement of rabbit's diet with KS leaves. However, KS leaves may adversely affect liver and kidney function in a dose-dependent manner. Therefore, further studies are required to elucidate the maximum tolerable and toxic, as well as lethal doses, and to isolate the pharmacologically active components from KS leaves. PMID

An intravenously injectable emulsified iodinated oil contrast agent for liver CT. Experimental study of lipiodol emulsion emulsified by lecithin (LEL38) in rabbits

International Nuclear Information System (INIS)

Kamei, Tsuyoshi

1994-01-01

LEL38 (lipiodol emulsion emulsified by lecithin 38 mgI/ml, mean diameter 200 nm) is a new intravenously injectable oil contrast agent for liver CT. The aim of this report was to evaluate its ability to enhance contrast in the liver of 46 rabbits with regard to the correlation of density with time at an injected dose of 76 mgI/kg (before to 120 minutes after), the correlation of density with dose (0-760 mgI/kg) and the detectability of liver mass. The time-density correlation of LEL38 in the liver, that is, peak density, was achieved after 30 minutes, and it was elevated to 20.9 H. U. Thereafter, it decreased slowly. In the blood vessels, it reached a sharp peak after immediately being elevated to 14. 7 H. U. Thereafter detectability decreased quickly. The maximum difference in density between liver and blood vessels was 34 H. U. after 60 minutes. The dose-density correlation in the liver and blood vessels was linear. Tumors were detected as clear areas of low density. The minimal detectability was about 3 mm. LEL38 may be an effective contrast agent for screening CT studies of liver disease. (author)

Hemocoagulase Combined with Microbubble-Enhanced Ultrasound Cavitation for Augmented Ablation of Microvasculature in Rabbit VX2 Liver Tumors.

Science.gov (United States)

Yang, Qian; Tang, Peng; He, Guangbin; Ge, Shuping; Liu, Liwen; Zhou, Xiaodong

2017-08-01

We investigated a new method for combining microbubble-enhanced ultrasound cavitation (MEUC) with hemocoagulase (HC) atrox. Our goal was to induce embolic effects in the vasculature and combine these with an anti-angiogenic treatment strategy. Fourteen days after being implanted with a single slice of the liver VX2 tumor, rabbits were randomly divided into five groups: (i) a control group injected intra-venously with saline using a micropump; (ii) a group given only an injection of HC; (iii) a group treated only with ultrasound cavitation; (iv) a group treated with MEUC; (v) a group treated with MEUC + HC. Contrast-enhanced ultrasound was performed before treatment and 1 h and 7 d post-treatment to measure tumor size, enhancement and necrosis range. QontraXt software was used to determine the time-intensity curve of tumor blood perfusion and microvascular changes. At 1 h and 7 d after treatment with MEUC + HC, the parameters of the time-intensity curve, which included peak value, regional blood volume, regional blood flow and area under the curve value and which were measured using contrast-enhanced ultrasound, were significantly lower than those of the other treatment groups. The MEUC + HC treatment group exhibited significant growth inhibition relative to the ultrasound cavitation only, HC and MEUC treatment groups. No damage was observed in the surrounding normal tissues. These results support the feasibility of reducing the blood perfusion of rabbit VX2 liver tumors using a new method that combines MEUC and HC. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

SUPRESSION OF MICROSOMAL OXIDATION WEAKENS HISTOCHROME’S DIURETIC EFFECT AT RATS

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O. S. Talalaeva

2013-01-01

Full Text Available Histochrome is the medicinal form of echinochrome (2, 3, 5, 6, 8-pentahydroxy-7-ethyl-1,4-naphthoquinone. Arisen during clinical application of the drug questions concerning its biotransformation have predetermined the aim of this research: to study participation liver monooxygenase system in maintenance of histochrome’s pharmacological activity.Simple and informative method of the lifetime control of liver monooxygenase systems influence on a metabolism of a medical product is the estimation of changes of pharmacological effect of a r esearched preparation on a background microsomal oxidations i nhibitor. In experiments on rats chloramphenicol action on diuretic effect of histochrome, as the most convenient for screening, was i nvestigated.To control group of animals during 10 days were hypodermically entered by histochrome in a doze of 10 mg/kg (n = 15. Experimental animals preliminary oral received 50 mg/kg of chloramphenicol before three hours of histochrome introduction (n = 16. In both groups of animals measured volume daily excretion of water, creathinin, sodium and potassium ions excretions in experimental rats each two days. The initial level of parameters of excretory kidneys functions were estimated before introduction of preparations at animals.Long-term histochrome’s injection was followed by a fivefold increasing of water excretion and simultaneously creathinin growth one. Allocation of ions of sodium was statistically significantly increased by 11-th day of experiment, and potassium ions – since the ninth day of histochrome injection. In conditions preliminary chloramphenicol applications volume daily daily urine output and creathinin excretion were essentially less control parameters. Allocation with urine of ions of sodium was decreased almost twice in comparison with the values, fixed at introduction histochrome. Excretion potassium ions ware corresponded to an initial level during all period of supervision.Taking into

Placental transfer of radioactive salts in the pregnant rabbit

Energy Technology Data Exchange (ETDEWEB)

Schachner, E.; Shani, J.; Shechtman, M.; Pfeiffer, Y.

1985-01-01

The risks of radionuclidic contamination due to the easy transfer of water-soluble ions from the circulation of the pregnant woman to her fetus, encouraged us to study whether the ease of penetration of such ions is size-dependent. Three radiochemicals--/sup 22/NaCl, /sup 99m/TcO/sub 4/Na and /sup 201/TlCl were injected i.v. into pregnant rabbits on the 16th day of their pregnancy, and the rabbits were killed 15, 30, 60 or 120 min later. From each rabbit the blood, heart, kidney, liver and muscle were sampled and counted as well as placenta, amniotic fluid and some fetuses. At 15 and 60 min hearts and livers were excised from selected fetuses and blood clearance, organ-to-muscle and fetus-to-placenta ratios were calculated. The results indicate that the transplacental transfer of the small radionuclide /sup 22/Na+ is faster than that of 99mTcO4- and /sup 201/Tl+, reaching equilibrium about 3 h after its injection to the pregnant rabbit. /sup 201/Tl+ demonstrated a high localization in the pregnant rabbits' and fetuses' heart and kidneys, with a similar myocardial retention in both groups. Due to the concentration of /sup 201/Tl+, in spite of its large diameter, into the fetuses' heart muscle, careful consideration should be taken when injecting /sup 201/TlCl into pregnant women for myocardial imaging.

Metabolism of styrene in the human liver in vitro: interindividual variation and enantioselectivity

NARCIS (Netherlands)

Wenker, M. A.; Kezić, S.; Monster, A. C.; de Wolff, F. A.

2001-01-01

1. The interindividual variation and enantioselectivity of the in vitro styrene oxidation by cytochrome P450 have been investigated in 20 human microsomal liver samples. Liver samples were genotyped for the CYP2E1*6 and CYP2E1*5B alleles. 2. Kinetic analysis indicated the presence of at least two

Distribution of sterol carrier protein2 (SCP2) in rat tissues and evidence for slow turnover in liver and adrenal cortex

International Nuclear Information System (INIS)

Kharroubi, A.; Chanderbhan, R.; Fiskum, G.; Noland, B.J.; Scallen, T.J.; Vahouny, G.V.

1986-01-01

Sterol carrier protein 2 (SCP 2 ) has been implicated in the regulation of the terminal stages of hepatic cholesterol biosynthesis, and in sterol utilization for adrenal steroid hormone and hepatic bile acid synthesis. In the present studies, a highly sensitive radioimmunoassay, using [ 125 I] SCP 2 , has been developed. Highest levels of SCP 2 were found in rat liver with progressively lower levels in intestinal mucosa, adrenal, kidney, lung and testis. SCP 2 levels were low or absent in heart, brain, skeletal muscle and serum. Liver SCP 2 was largely (44%) associated with the microsomal fraction, while in adrenal, 46% was associated with mitochondria, a distribution which is consistent with the proposed roles for SCP 2 in these tissues. Levels of SCP 2 in AS 30D hepatoma cells were only 5% of those in normal liver. In liver there was no indication of diurnal rhythm of SCP 2 in the cytosol and only slight variation of the microsomal SCP 2 levels. Fasting has only slight effects on SCP 2 concentration of rat liver microsomes and cytosol. Neither ACTH nor cycloheximide treatment of rats had a significant effect on SCP 2 distribution in the adrenal. In general, these findings indicate that SCP 2 has a low turn-over rate

Metabolism of methylstenbolone studied with human liver microsomes and the uPA⁺/⁺-SCID chimeric mouse model.

Science.gov (United States)

Geldof, Lore; Lootens, Leen; Polet, Michael; Eichner, Daniel; Campbell, Thane; Nair, Vinod; Botrè, Francesco; Meuleman, Philip; Leroux-Roels, Geert; Deventer, Koen; Eenoo, Peter Van

2014-07-01

Anti-doping laboratories need to be aware of evolutions on the steroid market and elucidate steroid metabolism to identify markers of misuse. Owing to ethical considerations, in vivo and in vitro models are preferred to human excretion for nonpharmaceutical grade substances. In this study the chimeric mouse model and human liver microsomes (HLM) were used to elucidate the phase I metabolism of a new steroid product containing, according to the label, methylstenbolone. Analysis revealed the presence of both methylstenbolone and methasterone, a structurally closely related steroid. Via HPLC fraction collection, methylstenbolone was isolated and studied with both models. Using HLM, 10 mono-hydroxylated derivatives (U1-U10) and a still unidentified derivative of methylstenbolone (U13) were detected. In chimeric mouse urine only di-hydroxylated metabolites (U11-U12) were identified. Although closely related, neither methasterone nor its metabolites were detected after administration of isolated methylstenbolone. Administration of the steroid product resulted mainly in the detection of methasterone metabolites, which were similar to those already described in the literature. Methylstenbolone metabolites previously described were not detected. A GC-MS/MS multiple reaction monitoring method was developed to detect methylstenbolone misuse. In one out of three samples, previously tested positive for methasterone, methylstenbolone and U13 were additionally detected, indicating the applicability of the method. Copyright © 2014 John Wiley & Sons, Ltd.

Irreversible binding of 14C-labelled trichloroethylene to mice liver constituents in vivo and in vitro

International Nuclear Information System (INIS)

Uehleke, H.; Poplawski-Tabarelli, S.

1977-01-01

1) 14 C-labelled trichloroethylene was injected i.p. into male mice (10 μmole/g of b.w.). The radioactivity irreversibly bound to hepatic protein reached highest levels after 6 h : 2 nmole/mg in cytosol protein, 4.4 nmole/mg in mitochondrial protein, and 7.6 nmole/mg in microsomal protein. 2) The commercial trichloroethylene contained radioactive impurities binding to proteins without metabolic activation. Purification by various extraction removed 60-70% of those materials. In aerobic incubates of mice hepatic microsomes and NADPH the covalent binding rate of the purified trichloroethylene was 1.4 nmole/mg protein in 60 min. The activity of rat liver microsomes was approximately 40% less. Covalent binding increased 2-fold with microsomes of mice pretreated with phenobarbital. (orig.) [de

Time-dependent inhibition of CYP3A4 by gallic acid in human liver microsomes and recombinant systems.

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Pu, Qiang-Hong; Shi, Liang; Yu, Chao

2015-03-01

1.Gallic acid is a main polyphenol in various fruits and plants. Inhibitory characteristics of gallic acid on CYP3A4 were still unclear. The objective of this work is hence to investigate inhibitory characteristics of gallic acid on CYP3A4 using testosterone as the probe substrate in human liver microsomes (HLMs) and recombinant CYP3A4 (rCYP3A4) systems. 2.Gallic acid caused concentration-dependent loss of CYP3A4 activity with IC50 values of 615.2 μM and 669.5 μM in HLM and rCYP3A4 systems, respectively. IC50-shift experiments showed that pre-incubation with gallic acid in the absence of NADPH contributed to 12- or 14-fold reduction of IC50 in HLM and rCYP3A4 systems, respectively, supporting a time-dependent inhibition. In HLM, time-dependent inactivation variables KI and Kinact were 485.8 μM and 0.05 min(-1), respectively. 3.Compared with the presence of NADPH, pre-incubation of gallic acid in the absence of NADPH markedly increased its inhibitory effects in HLM and rCYP3A4 systems. Those results indicate that CYP3A4 inactivation by gallic acid was independent on NADPH and was mainly mediated its oxidative products. 4.In conclusion, we showed that gallic acid weakly and time-dependently inactivated CYP3A4 via its oxidative products.

Selective inhibition of CYP2C8 by fisetin and its methylated metabolite, geraldol, in human liver microsomes.

Science.gov (United States)

Shrestha, Riya; Kim, Ju-Hyun; Nam, Wongshik; Lee, Hye Suk; Lee, Jae-Mok; Lee, Sangkyu

2018-04-01

Fisetin is a flavonol compound commonly found in edible vegetables and fruits. It has anti-tumor, antioxidant, and anti-inflammatory effects. Geraldol, the O-methyl metabolite of fisetin in mice, is reported to suppress endothelial cell migration and proliferation. Although the in vivo and in vitro effects of fisetin and its metabolites are frequently reported, studies on herb-drug interactions have not yet been performed. This study was designed to investigate the inhibitory effect of fisetin and geraldol on eight isoforms of human cytochrome P450 (CYP) by using cocktail assay and LC-MS/MS analysis. The selective inhibition of CYP2C8-catalyzed paclitaxel hydroxylation by fisetin and geraldol were confirmed in pooled human liver microsomes (HLMs). In addition, an IC 50 shift assay under different pre-incubation conditions confirmed that fisetin and geraldol shows a reversible concentration-dependent, but not mechanism-based, inhibition of CYP2C8. Moreover, Michaelis-Menten, Lineweaver-burk plots, Dixon and Eadie-Hofstee showed a non-competitive inhibition mode with an equilibrium dissociation constant of 4.1 μM for fisetin and 11.5 μM for geraldol, determined from secondary plot of the Lineweaver-Burk plot. In conclusion, our results indicate that fisetin showed selective reversible and non-competitive inhibition of CYP2C8 more than its main metabolite, geraldol, in HLMs. Copyright © 2018 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

ELISA for detection of variant rabbit haemorrhagic disease virus RHDV2 antigen in liver extracts.

Science.gov (United States)

Dalton, K P; Podadera, A; Granda, V; Nicieza, I; Del Llano, D; González, R; de Los Toyos, J R; García Ocaña, M; Vázquez, F; Martín Alonso, J M; Prieto, J M; Parra, F; Casais, R

2018-01-01

The emergence and rapid spread of variant of the rabbit hemorrhagic disease virus (RHDV2) require new diagnostic tools to ensure that efficient control measures are adopted. In the present study, a specific sandwich enzyme-linked immunosorbent assay (ELISA) for detection of RHDV2 antigens in rabbit liver homogenates, based on the use of an RHDV2-specific monoclonal antibody (Mab) 2D9 for antigen capture and an anti-RHDV2 goat polyclonal antibody (Pab), was developed. This ELISA was able to successfully detect RHDV2 and RHDV2 recombinant virions with high sensitivity (100%) and specificity (97.22%). No cross-reactions were detected with RHDV G1 viruses while low cross-reactivity was detected with one of the RHDVa samples analyzed. The ELISA afforded good repeatability and had high analytical sensitivity as it was able to detect a dilution 1:163,640 (6.10ng/mL) of purified RHDV-N11 VLPs, which contained approximately 3.4×10 8 molecules/mL particles. The reliable discrimination between closely related viruses is crucial to understand the epidemiology and the interaction of co-existing pathogens. In the work described here we design and validate an ELISA for laboratory based, specific, sensitive and reliable detection of RHDVb/RHDV2. This ELISA is a valuable, specific virological tool for monitoring virus circulation, which will permit a better control of this disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Nuclear imaging of hepatic impact injury on rabbits

International Nuclear Information System (INIS)

Jin Rongbing; Wen Jianliang; Tang Weijia; Ma Xiaolin

2002-01-01

Objective: To investigate the effect and clinic application value of nuclear imaging on hepatic impact experiment. Methods: Experimental rabbits were impact injured on liver with BIM-IV bio-impact machine. Liver imaging was performed with sodium phytate labeled by 99m Tc. Liver blood pool imaging was performed with labeled red blood cells. The results of imaging were similar with the results of anatomy. Results: There were significant difference between normal liver and injured liver. Radio diminution and defect were showed on injured liver areas in labeled hepatic cells. Many types of abnormal radioactivity distribution were observed in liver pool imaging. The results of liver imaging and liver blood pool imaging were corresponded to the results of anatomy. Conclusion: Changes of hepatic cell structures and function after injury could be showed by nuclear imaging. Nuclear imaging was valuable in determining injured liver position or injured degree

Detection on immunoblot of new proteins from the soluble fraction of the cell recognized either by anti-liver-kidney microsome antibodies type 1 or by anti-liver cytosol antibodies type 1--relationship with hepatitis C virus infection.

Science.gov (United States)

Ballot, E; Desbos, A; Monier, J C

1996-09-01

Antibodies directed against liver cytosol protein, called anti-liver cytosol type 1 (LC1 Ab), have been described by both immunofluorescence (IF) and immunodiffusion techniques in sera from patients with autoimmune hepatitis (AIH). They have never been found in association with antibodies directed against the hepatitis C virus (HCV), unlike the anti-liver-kidney microsome antibodies type 1 (LKM1 Ab), the serological marker of AIH type 2. This suggests that there are two subgroups of AIH type 2, i.e., HCV-related and non-HCV-related. In this study, immunoblotting experiments were performed using proteins from the soluble phase of the rat liver cell; 141 sera which tested positive for LKM1 Ab by IF, 24 identified as having LC1 Ab by IF, and 50 from blood donors as controls were analyzed. Three bands were stained by LC1 Ab sera more often than by the control sera, and with a statistically significant frequency. These 3 proteins were located at apparent Mr 50,000, 55,000, and 60,000. The LKM1 Ab-positive sera as defined by IF stained six bands with a statistically significant frequency compared to the controls. Their apparent Mr were 35,000, 39,000, 47,000, 50,000, 55,000, and 60,000. LKM1 Ab-positive sera which were anti-HCV negative recognized a 60,000 protein belonging to the soluble phase of the cell, with a statistically significant frequency compared to LKM1 Ab-positive sera which were anti-HCV positive. This 60,000 protein was also recognized by LC1 Ab-positive sera, which were almost always anti-HCV negative. The presence of antibodies against a 60,000 protein from the soluble phase of the cell is discussed in terms of the anti-HCV serological markers found in the sera from patients with AIH.

Growth Performance, Meat Quality and Fatty Acid Metabolism Response of Growing Meat Rabbits to Dietary Linoleic Acid

Directory of Open Access Journals (Sweden)

R. G. Li

2012-08-01

Full Text Available An experiment was conducted to determine the effects of different amounts of dietary linoleic acid (LA on growth performance, serum biochemical traits, meat quality, fatty acids composition of muscle and liver, acetyl-CoA carboxylase (ACC and carnitine palmitoyl transferase 1 (CPT 1 mRNA expression in the liver of 9 wks old to 13 wks old growing meat rabbits. One hundred and fifty 9 wks old meat rabbits were allocated to individual cages and randomly divided into five groups. Animals in each group were fed with a diet with the following LA addition concentrations: 0, 3, 6, 9 and 12 g/kg diet (as-fed basis and LA concentrations were 0.84, 1.21, 1.34, 1.61 and 1.80% in the diet, respectively. The results showed as follows: the dietary LA levels significantly affected muscle color of LL included a* and b* of experimental rabbits (p<0.05. The linear effect of LA on serum high density lipoprotein cholesterol was obtained (p = 0.0119. The saturated fatty acids (SFAs and monounsaturated fatty acids (MUFAs contents of LL decreased and the polyunsaturated fatty acids (PUFAs content of LL increased with dietary LA increase (p<0.0001. The PUFA n-6 content and PUFA n-3 content in the LL was significantly affected by the dietary LA levels (p<0.01, p<0.05. The MUFAs content in the liver decreased and the PUFAs contents in the liver increased with dietary LA increase (p<0.0001. The PUFA n-6 content and the PUFA n-6/n-3 ratio in the liver increased and PUFA n-3 content in the liver decreased with dietary LA increase (p<0.01. The linear effect of LA on CPT 1 mRNA expression in the liver was obtained (p = 0.0081. In summary, dietary LA addition had significant effects on liver and muscle fatty acid composition (increased PUFAs of 9 wks old to 13 wks old growing meat rabbits, but had little effects on growth performance, meat physical traits and mRNA expression of liver relative enzyme of experimental rabbits.

Microsomal receptor for steroid hormones: functional implications for nuclear activity.

Science.gov (United States)

Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

1988-01-01

Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of

Identification of UGT2B9*2 and UGT2B33 isolated from female rhesus monkey liver.

Science.gov (United States)

Dean, Brian; Arison, Byron; Chang, Steve; Thomas, Paul E; King, Christopher

2004-06-01

Two UDP-glucuronosyltransferases (UGT2B9(*)2 and UGT2B33) have been isolated from female rhesus monkey liver. Microsomal preparations of the cell lines expressing the UGTs catalyzed the glucuronidation of the general substrate 7-hydroxy-4-(trifluoromethyl)coumarin in addition to selected estrogens (beta-estradiol and estriol) and opioids (morphine, naloxone, and naltrexone). UGT2B9(*)2 displayed highest efficiency for beta-estradiol-17-glucuronide production and did not catalyze the glucuronidation of naltrexone. UGT2B33 displayed highest efficiency for estriol and did not catalyze the glucuronidation of beta-estradiol. UGT2B9(*)2 was found also to catalyze the glucuronidation of 4-hydroxyestrone, 16-epiestriol, and hyodeoxycholic acid, while UGT2B33 was capable of conjugating 4-hydroxyestrone, androsterone, diclofenac, and hyodeoxycholic acid. Three glucocorticoids (cortisone, cortisol, and corticosterone) were not substrates for glucuronidation by liver or kidney microsomes or any expressed UGTs. Our current data suggest the use of beta-estradiol-3-glucuronidation, beta-estradiol-17-glucuronidation, and estriol-17-glucuronidation to assay UGT1A01, UGT2B9(*)2, and UGT2B33 activity in rhesus liver microsomes, respectively.

Influence of Chloramphenicol and Amoxicillin on Rat Liver ...

African Journals Online (AJOL)

This study examined the effect of chloramphenicol and amoxicillin on liver microsomal enzymes Ca2+-ATPase and Glucose-6-Phosphatase (G-6-P) and lipid peroxidation in rats. Male Wistar strain rats weighing 120 – 195 g were divided into four groups. Group one, the control group, received physiological saline, group ...

Immunological cross-reactivity to multiple autoantigens in patients with liver kidney microsomal type 1 autoimmune hepatitis.

Science.gov (United States)

Choudhuri, K; Gregorio, G V; Mieli-Vergani, G; Vergani, D

1998-11-01

We describe two patients with liver kidney microsomal antibody type 1 (LKM1)-positive autoimmune hepatitis (AIH) with associated endocrinopathies. The first patient had insulin-dependent diabetes (IDDM), and the second patient had Addison's disease and hypoparathyroidism, and is also positive for islet cell antibodies, without overt diabetes. To account for the existence of multiple endocrinopathy in these patients, we investigated whether there is sequence similarity between the target of LKM1 antibodies, cytochrome P4502D6 (CYP2D6), and other human proteins, and if so, whether this structural similarity produces a detectable cross-reactive immune response. Our database search identified two proteins, carboxypeptidase H, an autoantigen in insulin-dependent diabetes, and 21-hydroxylase, the major autoantigen in Addison's disease, that share sequence similarity to the second major LKM1 epitope on CYP2D6. We tested the reactivity of sera from these patients to the homologous regions of the three autoantigens using an enzyme-linked immunosorbent assay (ELISA). The cut-off for positivity was established by testing sera from 22 healthy children. To determine the significance of reactivity to the peptide homologues of the three autoantigens, we investigated 16 additional patients with LKM1 AIH and 20 children with chronic hepatitis B virus infection as pathological controls. We found that reactivity to the second major epitope of CYP2D6 is significantly associated with reactivity to the homologous regions of carboxypeptidase H (CPH) and 21-hydroxylase (21-OHase) in patients with LKM1 AIH, and that this simultaneous recognition is cross-reactive. We suggest that a cross-reactive immune response between homologous autoantigens may contribute to the development of multiple endocrinopathies in LKM1 AIH.

The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation.

Science.gov (United States)

Sharma, Hari; Zhang, Xiaoying; Dwivedi, Chandradhar

2010-04-01

Ghee, also known as clarified butter, has been utilized for thousands of years in Ayurveda as a therapeutic agent. In ancient India, ghee was the preferred cooking oil. In the last several decades, ghee has been implicated in the increased prevalence of coronary artery disease (CAD) in Asian Indians due to its content of saturated fatty acids and cholesterol and, in heated ghee, cholesterol oxidation products. Our previous research on Sprague-Dawley outbred rats, which serve as a model for the general population, showed no effect of 5 and 10% ghee-supplemented diets on serum cholesterol and triglycerides. However, in Fischer inbred rats, which serve as a model for genetic predisposition to diseases, results of our previous research showed an increase in serum total cholesterol and triglyceride levels when fed a 10% ghee-supplemented diet. In the present study, we investigated the effect of 10% dietary ghee on microsomal lipid peroxidation, as well as serum lipid levels in Fischer inbred rats to assess the effect of ghee on free radical mediated processes that are implicated in many chronic diseases including cardiovascular disease. Results showed that 10% dietary ghee fed for 4 weeks did not have any significant effect on levels of serum total cholesterol, but did increase triglyceride levels in Fischer inbred rats. Ghee at a level of 10% in the diet did not increase liver microsomal lipid peroxidation or liver microsomal lipid peroxide levels. Animal studies have demonstrated many beneficial effects of ghee, including dose-dependent decreases in serum total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate. Similar results were seen with heated (oxidized) ghee which contains cholesterol oxidation products. A preliminary clinical study showed that high doses of

Human Metabolism and Interactions of Deployment-Related Chemicals

Science.gov (United States)

2008-08-01

stimulated by CPO (Fig. 6). Coincidently, α- naphthoflavone inhibited CYP1A2 metabolism of flavonoids /23/ and stimulated CYP3A4 metabolism of...by flavonoids of benzo[a]pyrene hydroxylation by cytochrome P-450 isozymes from rabbit liver microsomes, J. Biol. Chem. 1981; 256: 10897-10901. 17...P450-mediated metabolism of dietary flavonoids , Food Chem. Toxicol. 2002; 40: 609-616. 24. Cameron MD, Wen B, Allen KE, Roberts AG, Schuman JT

Modulation of catechol estrogen synthesis by rat liver microsomes: effects of treatment with growth hormone or testosterone

International Nuclear Information System (INIS)

Quail, J.A.; Jellinck, P.H.

1987-01-01

The ability of GH from various mammalian species, administered to normal mature male rats by constant infusion, to decrease the hepatic 2-hydroxylation of estradiol (E2) to female levels, as measured by the release of 3 H 2 O from [2-3H]E2, was determined. Rat and human GH (hGH) showed the highest activity while ovine GH was inactive. PRL (0.6 IU/h X kg) administered together with hGH (0.02 IU/h X kg) did not antagonize the feminizing action of GH. Infusion of hGH into male rats decreased the affinity of estradiol 2-hydroxylase for its steroid substrate and altered the linear Lineweaver-Burk plot towards a nonlinear hyperbolic plot characteristic of the female. The apparent Michaelis-Menten constant (Km) for the reaction was 1.69 microM for males and 2.75 microM for testosterone-treated ovariectomized females. An equal mixture of liver microsomes from male and female rats gave kinetic values similar to those observed with males alone. Neonatal imprinting with androgen did not alter the magnitude of the response of female rats to treatment with testosterone and/or GH at maturity and the androgen effect could only be shown in ovariectomized animals. The results with rats of different endocrine status were corroborated by the kinetic data and by the pattern of metabolites obtained with [4- 14 C]E2 when examined by TLC and autoradiography. The hormonal control of estradiol 2-hydroxylase, the key enzyme in catechol estrogen formation, and the contribution of sex-specific multiple forms of the enzyme to this reaction are discussed

Oxidative metabolism of monensin in rat liver microsomes and interactions with tiamulin and other chemotherapeutic agents: evidence for the involvement of cytochrome P-450 3A subfamily.

Science.gov (United States)

Nebbia, C; Ceppa, L; Dacasto, M; Carletti, M; Nachtmann, C

1999-09-01

Monensin (MON) is an ionophore antibiotic widely used in veterinary practice as a coccidiostatic or a growth promoter. The aims of this study were to characterize the P-450 isoenzyme(s) involved in the biotransformation of the ionophore and to investigate how this process may be affected by tiamulin and other chemotherapeutic agents known to produce toxic interactions with MON when administered concurrently in vivo. In liver microsomes from untreated rats (UT) or from rats pretreated, respectively, with ethanol (ETOH), beta-naphthoflavone (betaNAF), phenobarbital (PB), pregnenolone 16alpha-carbonitrile (PCN), or dexamethasone (DEX), the rate of MON O-demethylation was the following: DEX > PCN > PB > UT = ETOH > betaNAF; similar results were obtained by measuring total MON metabolism. In addition, the extent of triacetyloleandomycin-mediated P-450 complexes was greatly reduced by the prior addition of 100 microM MON. In DEX-treated microsomes, MON O-demethylation was found to fit monophasic Michaelis-Menten kinetics (K(M) = 67.6 +/- 0.01 microM; V(max) = 4.75 +/- 0.76 nmol/min/mg protein). Tiamulin markedly inhibited this activity in an apparent competitive manner, with a calculated K(i) (Dixon plot) of 8.2 microM and an IC(50) of about 25 microM. At the latter concentration, only ketoconazole or metyrapone, which can bind P-450 3A, inhibited MON O-demethylase to a greater extent than tiamulin, whereas alpha-naphthoflavone, chloramphenicol, or sulphametasine was less effective. These results suggest that P-450 3A plays an important role in the oxidative metabolism of MON and that compounds capable of binding or inhibiting this isoenzyme could be expected to give rise to toxic interactions with the ionophore.

Oxidative metabolism of BDE-47, BDE-99, and HBCDs by cat liver microsomes: Implications of cats as sentinel species to monitor human exposure to environmental pollutants.

Science.gov (United States)

Zheng, Xiaobo; Erratico, Claudio; Luo, Xiaojun; Mai, Bixian; Covaci, Adrian

2016-05-01

The in vitro oxidative metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), and individual α-, β- and γ-hexabromocyclododecane (HBCD) isomers catalyzed by cytochrome P450 (CYP) enzymes was screened using cat liver microsomes (CLMs). Six hydroxylated metabolites, namely 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE-47), 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47), 4'-hydroxy-2,2',4,5'- tetrabromodiphenyl ether (4'-OH-BDE-49), and 2'-hydroxy-2,3',4,4'-tetrabromodiphenyl ether (2'-OH-BDE-66), were identified and quantified after incubation of BDE-47. A di-OH-tetra-BDE was also found as metabolite of BDE-47 with CLMs. 5-OH-BDE-47 was the major metabolite formed. Five hydroxylated metabolites (3'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (3'-OH-BDE-99), 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99), 6-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (6-OH-BDE-99), 6'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (6'-OH-BDE-99), and 4'-hydroxy-2,2',4,5,5'-pentabromodiphenyl ether (4'-OH-BDE-101) were formed from BDE-99 incubated with CLMs. Concentrations of BDE-99 metabolites were lower than those of BDE-47. Four or more mono-hydroxylated HBCD (OH-HBCDs), four or more di-hydroxylated HBCD (di-OH-HBCDs), five or more mono-hydroxylated pentabromocyclododecanes (OH-PBCDs), and five or more di-hydroxylated pentabromocyclododecenes (di-OH-PBCDs) were detected after incubation of α-, β-, or γ-HBCD with CLMs. No diastereoisomeric or enantiomeric enzymatic isomerisation was observed incubating α-, β- or γ-HBCD with CLMs. Collectively, our data suggest that (i) BDE-47 is metabolized at a faster rate than BDE-99 by CLMs, (ii) OH-HBCDs are the major hydroxylated metabolites of α-, β- and γ-HBCD produced by CLMs, and (iii) the oxidative metabolism of BDE-47 and

Adenosinetriphosphate content and adenosinetriphosphatase activity in cell fractions of the liver and brain of chick embryos and birds treated with gamma-rays

International Nuclear Information System (INIS)

Todorov, B.

1977-01-01

Studies are conducted on the level of ADP and the adenosinetriphosphatase in nuclei, mitochondria, and microsomes taken from the brain and liver of singly gamma-irradiated (1000 rd) chick embryos and birds. As a result of the treatment the ADP content dropped, while the activity of ADP rose. These changes were more strongly expressed in the nuclei, than in the mitochondria, and to a lesser extent - in the microsomes. Twelve-day chick embryos showed more markedly expressed radiosensitivity than newly hatched chicks. This embryonal stage is characterized by intense growth, differentiation and metabolic processes in the liver, which substantiate not only the higher radiosensitivity of this age group but the more strongly expressed changes in the liver as compared with the brain. (author)

Using a simple HPLC approach to identify the enzymatic products of UTL-5g, a small molecule TNF-α inhibitor, from porcine esterase and from rabbit esterase.

Science.gov (United States)

Swartz, Kenneth; Zhang, Yiguan; Valeriote, Frederick; Chen, Ben; Shaw, Jiajiu

2013-12-01

UTL-5g is a novel small-molecule chemoprotector that lowers hepatotoxicity, nephrotoxicity, and myelotoxicity induced by cisplatin through TNF-α inhibition among other factors. As a prelude to investigating the metabolites of UTL-5g, we set out to identify the enzymatic products of UTL-5g under the treatment of both porcine liver esterase (PLE) and rabbit liver esterase (RLE). First, a number of mixtures made by UTL-5g and PLE were incubated at 25°C. At predetermined time points, individual samples were quenched by acetonitrile, vortexed, and centrifuged. The supernatants were then analyzed by reversed-phase HPLC (using a C18 column). The retention times and UV/vis spectra of individual peaks were compared to those of UTL-5g and its two postulated enzymatic products; thus the enzymatic products of UTL-5g were tentatively identified. Secondly, a different HPLC method (providing different retentions times) was used to cross-check and to confirm the identities of the two enzymatic products. Based on the observations, it was concluded that under the treatment of PLE, the major enzymatic products of UTL-5g were 5-methyliosxazole-3-carboxylic acid (ISOX) and 2,4-dichloroaniline (DCA). Treatment of UTL-5g by RLE also provided the same enzymatic products of UTL-5g from esterase. These results indicate that the peptide bond in UTL-5g was cleaved by PLE/RLE. Michaelis-Menten kinetics showed that the Km values of UTL-5g were 2.07mM with PLE and 0.37mM with RLE indicating that UTL-5g had a higher affinity with RLE. In summary, by a simple HPLC approach, we have concluded that the peptide bond in UTL-5g was cleaved by esterase from either porcine liver or rabbit liver in vitro and afforded DCA (at a mole ratio of 1:1) and ISOX. However, further studies are needed in order to determine whether UTL-5g is metabolized by microsomal enzymes to produce ISOX and DCA. Copyright © 2013 Elsevier B.V. All rights reserved.

Myocardial kinetics of hexakis (trimethylphosphite) technetium-99m (I) chloride (Tc-TMP) in rats, rabbits, dogs, cats and pigs

International Nuclear Information System (INIS)

Robbins, M.S.; Adams, M.D.

1984-01-01

Tc-TMP is readily taken up by the myocardium following intravenous administration to rats and dogs. In order to assess its potential as a myocardial perfusion imaging agent, the biodistribution and pharmacokinetics of Tc-TMP were evaluated following intravenous administration to rats, rabbits, dogs, cats and miniature pigs. Rats and rabbits were killed at several time points within a 24 hr period after treatment and tissue samples were assayed for radioactivity. In rats, estimated heart, liver and lung half-lives were 14.4 hr, 24 min and 40 min, respectively. In rabbits, 0.6% dose/g was observed in the heart at 30 min. Corresponding heart/blood, heart/liver and heart/lung ratios were 39.1, 10.7 and 5.1. Gamma camera imaging experiments were conducted in rabbits, dogs, cats and pigs over a 1-2 hr period following administration of Tc-TMP. All species exhibited myocardial uptake resulting in sustained visualization, although myocardial image intensity was less pronounced in the pig compared to the other species. Regions of interest were selected over the heart, liver and background, and time-activity curves were generated. Minimal myocardial clearance was observed in all species during the imaging time course. Hepatic activity was rapidly cleared in rabbits and pigs (t1/2 < 1.0 hr) resulting in improved heart/liver ratios at later time intervals. The myocardial accumulation and retention of Tc-TMP, demonstrated in five species, supports clinical evaluation as a myocardial imaging agent

Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes.

Science.gov (United States)

Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J Shawn; Okoro, Emmanuel U; Guo, ZhongMao

2016-01-01

We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites, and

Effects of whole body x-ray irradiation on induction by phenobarbital of rat liver glucose-6-phosphate dehydrogenase and glutathione reductase

Energy Technology Data Exchange (ETDEWEB)

Bitny-Szlachto, S.; Szyszko, A. (Wojskowy Inst. Higieny i Epidemiologii, Warsaw (Poland))

1979-01-01

In rats treated with phenobarbital (3x100 mg/kg, i.p.), liver G-6-P dehydrogenase activity increased by 70% in the cytosol and in the 9.000xg supernatant, and only by 20% in microsomes. Moreover, the phenobarbital treatment increased rat liver GSSG reductase activity by 30%. On the other hand, activity of the liver microsomal G-6-P dehydrogenase was found to increase by some 20% in whole body irradiated, both control and phenobarbital treated rats. In rats irradiated with 600 R prior to the first dose of the inducer there was not noted any increase in G-6-P dehydrogenase of the 9.000xg supernatant, and increase in the cytosol activity dropped to 38%. Thus, induction of the soluble liver G-6-P dehydrogenase by phenobarbital has turned out to be radiosensitive, whereas phenobarbital induction of GSSG reductase was unaffected by irradiation.

Teratogenic effects of Khat (Catha edulis in New Zealand rabbit

Directory of Open Access Journals (Sweden)

Aref Saleh Abdul-Mughni

2018-03-01

Conclusion: Prenatal exposure of Khat in rabbit induces harmful effects in defferent visceral organs including liver, kidney, brain, spinal cord, spleen, intestine, heart and lung. [J Adv Vet Anim Res 2018; 5(1.000: 25-36

Stabilization Improves Theranostic Properties of Lipiodol{sup ®}-Based Emulsion During Liver Trans-arterial Chemo-embolization in a VX2 Rabbit Model

Energy Technology Data Exchange (ETDEWEB)

Deschamps, F., E-mail: frederic.deschamps@gustaveroussy.fr; Farouil, G. [Université Paris-Saclay, Département de radiologie Interventionnelle, Gustave Roussy (France); Gonzalez, W.; Robic, C. [Guerbet France, Guerbet (France); Paci, A.; Mir, L. M. [Université Paris-Saclay, UMR 8203 (France); Tselikas, L.; Baère, T. de [Université Paris-Saclay, Département de radiologie Interventionnelle, Gustave Roussy (France)

2017-06-15

PurposeTo demonstrate that stability is a crucial parameter for theranostic properties of Lipiodol{sup ®}-based emulsions during liver trans-arterial chemo-embolization.Materials and MethodsWe compared the theranostic properties of two emulsions made of Lipiodol{sup ®} and doxorubicin in two successive animal experiments (One VX2 tumour implanted in the left liver lobe of 30 rabbits). Emulsion-1 reproduced one of the most common way of preparation (ratio of oil/water: 1/1), and emulsion-2 was designed to obtain a water-in-oil emulsion with enhanced stability (ratio of oil/water: 3/1, plus an emulsifier). The first animal experiment compared the tumour selectivity of the two emulsions: seven rabbits received left hepatic arterial infusion (HAI) of emulsion-1 and eight received HAI of emulsion-2. 3D-CBCT acquisitions were acquired after HAI of every 0.1 mL to measure the densities’ ratios between the tumours and the left liver lobes. The second animal experiment compared the plasmatic and tumour doxorubicin concentrations after HAI of 1.5 mg of doxorubicin administered either alone (n = 3) or in emulsion-1 (n = 6) or in emulsion-2 (n = 6).ResultsEmulsion-2 resulted in densities’ ratios between the tumours and the left liver lobes that were significantly higher compared to emulsion-1 (up to 0.4 mL infused). Plasmatic doxorubicin concentrations (at 5 min) were significantly lower after HAI of emulsion-2 (19.0 μg/L) than emulsion-1 (275.3 μg/L, p < 0.01) and doxorubicin alone (412.0 μg/L, p < 0.001), and tumour doxorubicin concentration (day-1) was significantly higher after HAI of emulsion-2 (20,957 ng/g) than in emulsion-1 (8093 ng/g, p < 0.05) and doxorubicin alone (2221 ng/g, p < 0.01).ConclusionStabilization of doxorubicin in a water-in-oil Lipiodol{sup ®}-based emulsion results in better theranostic properties.

Comparative study of radiologic-pathologic findings of experimental clonorchiasis in rabbits

International Nuclear Information System (INIS)

Ryu, Kyung Nam; Lim, Jae Hoon; Cho, You Jung; Yang, Moon Ho

1993-01-01

Radiological investigation in patients with clonorchiasis is very important as this is the only method of evaluating the severity of clonorchiasis. In order to correlate the radiologic and pathologic findings of clonorchiasis, fourteen rabbits infested with Clonorchis sinensis and five control rabbits were examined radiologically by ultrasonography, computed tomography and cholangiography and the results were correlated with pathologic findings. Dilatation of the intrahepatic small bile ducts of the liver was due to obstruction by flukes: oval or elliptical, small filling defects or irregular margin of the bile ducts on cholangiogram or intraluminal echoes on sonogram represented flukes per se; periductal thickening on sonogram and periductal enhancement of bile ducts on CT were due to inflammatory cell infiltration, adenomatous hyperplasia and periductal fibrosis; band like enhancement at the periphery of the liver on CT represented proliferated bile ducts, destruction of liver cells and resultant fibrosis. The study confirmed the pathological bases for the radiological findings of clonorchiasis in liver and bile ducts and will, perhaps, serve as a basis for the future radiologic-pathological correlation of clonorchiasis and in further clinical and experimental researches in the biliary tract diseases

Comparative study of radiologic-pathologic findings of experimental clonorchiasis in rabbits

Energy Technology Data Exchange (ETDEWEB)

Ryu, Kyung Nam; Lim, Jae Hoon; Cho, You Jung; Yang, Moon Ho [College of Medicine, Kyung Hee University, Seoul (Korea, Republic of)

1993-01-15

Radiological investigation in patients with clonorchiasis is very important as this is the only method of evaluating the severity of clonorchiasis. In order to correlate the radiologic and pathologic findings of clonorchiasis, fourteen rabbits infested with Clonorchis sinensis and five control rabbits were examined radiologically by ultrasonography, computed tomography and cholangiography and the results were correlated with pathologic findings. Dilatation of the intrahepatic small bile ducts of the liver was due to obstruction by flukes: oval or elliptical, small filling defects or irregular margin of the bile ducts on cholangiogram or intraluminal echoes on sonogram represented flukes per se; periductal thickening on sonogram and periductal enhancement of bile ducts on CT were due to inflammatory cell infiltration, adenomatous hyperplasia and periductal fibrosis; band like enhancement at the periphery of the liver on CT represented proliferated bile ducts, destruction of liver cells and resultant fibrosis. The study confirmed the pathological bases for the radiological findings of clonorchiasis in liver and bile ducts and will, perhaps, serve as a basis for the future radiologic-pathological correlation of clonorchiasis and in further clinical and experimental researches in the biliary tract diseases.

Positional specificity of saturated and unsaturated fatty acids in phosphatidic acid from rat liver

NARCIS (Netherlands)

Possmayer, F.; Scherphof, G.L.; Dubbelman, T.M.A.R.; Golde, L.M.G. van; Deenen, L.L.M. van

1969-01-01

1. 1. The relative incorporation of a number of radioactive fatty acids into the different glycerolipids of rat liver microsomes has been investigated. 2. 2. Studies on the distribution of the radioactivity incorporated into phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid

Formation of glutathione conjugates by reactive metabolites of vinylidene chloride in microsomes and isolated hepatocytes

International Nuclear Information System (INIS)

Liebler, D.C.; Meredith, M.J.; Guengerich, F.P.

1985-01-01

Oxidation of the vinyl halide carcinogen and hepatotoxin vinylidene chloride (VDC) by microsomal cytochrome P-450 yields 2,2-dichloroacetaldehyde, 2-chloroacetyl chloride, 2-chloroacetic acid, and 1,1-dichloroethylene oxide. The roles of these metabolites in covalent modification of proteins and reduced glutathione (GSH) were examined. 2-Chloroacetyl chloride reacted with model thiols at least 10(3)-fold faster than did 1,1-dichloroethylene oxide and at least 10(5)-fold faster than did 2,2-dichloroacetaldehyde or 2-chloroacetic acid. Microsomal covalent binding of [ 14 C]VDC was inhibited by GSH but not by lysine, suggesting that protein thiols, rather than amino groups, are major targets. Liver microsomes catalyzed the formation of three GSH:VDC metabolite conjugates, identified as S-(2,2-dichloro-1-hydroxy)ethylglutathione, 2-(S-glutathionyl)acetate, and S-(2-glutathionyl)acetylglutathione, a novel conjugate containing both stable (thioether) and labile (thioester) linkages. The latter two conjugates also were formed in isolated rat hepatocytes and measurable amounts of 2-(S-glutathionyl)acetate were released into the incubation medium. Both 2-(S-glutathionyl)acetate and S-(2-glutathionyl)acetylglutathione were formed with [ 35 S]GSH added to the hepatic medium, indicating that reactive VDC metabolites are capable of crossing the plasma membrane to react with extracellular targets. Unlabeled S-(2-glutathionyl)-acetylglutathione underwent carbonyl substitution with added [ 35 S]GSH, suggesting that this conjugate may participate in modification of protein thiols. This conjugate also underwent hydrolysis with a half-life of approximately 3 hr. GSH:VDC metabolite conjugates may serve as accessible models for labile covalent adducts formed between VDC metabolites and protein thiols

Effect of treatment with cadmium on kinetic properties of Na+, K+-ATPase and glucose-6-phosphatase activity in rat liver microsomes

International Nuclear Information System (INIS)

Modi, Hiren R.; Patil, Nisha; Katyare, Surendra S.

2008-01-01

Studies on Cd hepatotoxicity have focused mainly on induction of cytochrome P 450 system and related enzymes. In the present study young adult male rats given a single intra-peritoneal injection of Cd (0.84 mg Cd/kg body weight) and effects on kinetic parameters rat liver microsomal Na + , K + -ATPase and G6Pase were evaluated at the end of 1 month and 1 week. The substrate and temperature kinetics parameters were examined and attempts were made to seek correlation with changes in lipid/phospholipid profiles. The Na + , K + ATPase activity decreased only in 1 week Cd-treated group but recovered at the end of 1 month. The activity resolved in two distinct kinetic components in control as well as the experimental groups. In 1 week Cd-treated group the K m value of both the components was unchanged, whereas V max value decreased. In 1-month Cd-treated group V max value only of component I increased. The catalytic efficiency of both the components was not affected in the experimental groups. In 1-week Cd-treated group the energy of activations at high-temperature range (E H ) and low-temperature range (E L ) decreased, whereas for 1-month Cd-treated group the energies of activations did not change. The G6Pase activity measured at 37 deg. C was high only in 1-month Cd-treated group. The activity resolved in two kinetically distinguishable components in control as well as in the experimental groups. K m value of component I decreased in both the Cd-treated groups. In 1-month Cd-treated group the V max value of component II increased. The catalytic efficiency of G6Pase was unchanged despite changes in K m and V max . In 1-week Cd-treated group the E H and E L decreased, whereas only E L showed decrease in 1-month Cd-treated group. Cholesterol (CHL) content increased in both the Cd-treated groups. Content of lysophospholipid (Lyso), spinghomyelin (SPM) and phosphatidic acid (PA) increased, whereas phosphatidylcholine (PC) and phosphatidylserine (PS) decreased in 1-week Cd

Ultrasound features of kidneys in the rabbit (Oryctolagus cuniculus

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R S Dimitrov

2012-10-01

Full Text Available Purpose: To determine the normal sonographic features of rabbit kidneys with regard to their use in diagnostic imaging of renal lesions in this species. Materials: Twelve sexually mature clinically healthy New Zealand White rabbits weighing 2.8 kg to 3.2 kg were examined after anaesthesia. Methods: A diagnostic ultrasound system with microconvex multifrequency 6.5 MHz probe was used. The animals were positioned in dorsal recumbency. The transabdominal paravertebral imaging approach was used. Longitudinal and transverse scans of the kidneys were obtained. Six rabbits were sacrificed, their kidneys removed and studied in isotonic liquid medium. Results: The shape of kidneys was elliptical. The fibrous capsule was visualized as a straight hyperechoic band. The fatty capsule was hyperechoic and with irregular borders. The cortex exhibited a heterogeneous echogenicity. The acoustic density of the cortex was lower than that of the liver. The echoicity of the medulla was lower as compared to the cortex and the structures of the kidney pelvis. The latter appeared as a centrally located hyperechoic structure. The post mortem examination showed that kidneys were oval and hyperechoic. The kidney pelvis was seen as a centrally located longitudinal finding, and the renal hilum – as a centrally located hyperechoic finding. Conclusions: The transabdominal paravertebral approach was a good method for visualization of rabbit kidneys. The dorsal recumbency of the subjects allowed the visualization. The in vivo results corresponded to those from the post mortem study. The rabbit kidney was oval in shape. The hypoechoic peripheral zone is occupied by the cortex and the medulla, while the hyperechoic central zone – by the kidney pelvis. The cortex was less echoic than the liver parenchyma. The kidney pelvic cavity had a lower acoustic density than its walls, due to the presence of peripelvic adipose tissue. The present results could be used in the interpretation

Virtual iron concentration imaging based on dual-energy CT for noninvasive quantification and grading of liver iron content: An iron overload rabbit model study

Energy Technology Data Exchange (ETDEWEB)

Luo, Xian Fu; Yang, Yi; Xie, Xue Qian; Zhang, Huan; Chai, Wei Min; Yan, Fu Hua [Shanghai Jiao Tong University School of Medicine, Department of Radiology, Ruijin Hospital, Shanghai (China); Yan, Jing [Siemens Shanghai Medical Equipment Ltd., Shanghai (China); Wang, Li [Fudan University, Center of Analysis and Measurement, Shanghai (China); Schmidt, Bernhard [Siemens AG, Healthcare Sector, Forchheim (Germany)

2015-09-15

To assess the accuracy of liver iron content (LIC) quantification and grading ability associated with clinical LIC stratification using virtual iron concentration (VIC) imaging on dual-energy CT (DECT) in an iron overload rabbit model. Fifty-one rabbits were prepared as iron-loaded models by intravenous injection of iron dextran. DECT was performed at 80 and 140 kVp. VIC images were derived from an iron-specific algorithm. Postmortem LIC assessments were conducted on an inductively coupled plasma (ICP) spectrometer. Correlation between VIC and LIC was analyzed. VIC were stratified according to the corresponding clinical LIC thresholds of 1.8, 3.2, 7.0, and 15.0 mg Fe/g. Diagnostic performance of stratification was evaluated by receiver operating characteristic analysis. VIC linearly correlated with LIC (r = 0.977, P < 0.01). No significant difference was observed between VIC-derived LICs and ICP (P > 0.05). For the four clinical LIC thresholds, the corresponding cutoff values of VIC were 19.6, 25.3, 36.9, and 61.5 HU, respectively. The highest sensitivity (100 %) and specificity (100 %) were achieved at the threshold of 15.0 mg Fe/g. Virtual iron concentration imaging on DECT showed potential ability to accurately quantify and stratify hepatic iron accumulation in the iron overload rabbit model. (orig.)

A rabbit model of non-typhoidal Salmonella bacteremia.

Science.gov (United States)

Panda, Aruna; Tatarov, Ivan; Masek, Billie Jo; Hardick, Justin; Crusan, Annabelle; Wakefield, Teresa; Carroll, Karen; Yang, Samuel; Hsieh, Yu-Hsiang; Lipsky, Michael M; McLeod, Charles G; Levine, Myron M; Rothman, Richard E; Gaydos, Charlotte A; DeTolla, Louis J

2014-09-01

Bacteremia is an important cause of morbidity and mortality in humans. In this study, we focused on the development of an animal model of bacteremia induced by non-typhoidal Salmonella. New Zealand White rabbits were inoculated with a human isolate of non-typhoidal Salmonella strain CVD J73 via the intra-peritoneal route. Blood samples were collected at specific time points and at euthanasia from infected rabbits. Additionally, tissue samples from the heart, lungs, spleen, gastrointestinal tract, liver and kidneys were obtained at euthanasia. All experimentally infected rabbits displayed clinical signs of disease (fever, dehydration, weight loss and lethargy). Tissues collected at necropsy from the animals exhibited histopathological changes indicative of bacteremia. Non-typhoidal Salmonella bacteria were detected in the blood and tissue samples of infected rabbits by microbiological culture and real-time PCR assays. The development of this animal model of bacteremia could prove to be a useful tool for studying how non-typhoidal Salmonella infections disseminate and spread in humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reductive metabolism of oxymatrine is catalyzed by microsomal CYP3A4

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Liu W

2015-10-01

Full Text Available Wenqin Liu,1,2,* Jian Shi,1,2,* Lijun Zhu,2 Lingna Dong,1 Feifei Luo,2 Min Zhao,2 Ying Wang,2 Ming Hu,2,3 Linlin Lu,2 Zhongqiu Liu1,2 1Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China; 2International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 3Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, USA *These authors contributed equally to this work Abstract: Oxymatrine (OMT is a pharmacologically active primary quinolizidine alkaloid with various beneficial and toxic effects. It is confirmed that, after oral administration, OMT could be transformed to the more toxic metabolite matrine (MT, and this process may be through the reduction reaction, but the study on the characteristics of this transformation is limited. The aim of this study was to investigate the characteristics of this transformation of OMT in the human liver microsomes (HLMs and human intestinal microsomes (HIMs and the cytochrome P450 (CYP isoforms involved in this transformation. The current studies demonstrated that OMT could be metabolized to MT rapidly in HLMs and HIMs and CYP3A4 greatly contributed to this transformation. All HLMs, HIMs, and CYP3A4 isoform mediated reduction reaction followed typical biphasic kinetic model, and Km, Vmax, and CL were significant higher in HLMs than those in HIMs. Importantly, different oxygen contents could significantly affect the metabolism of OMT, and with the oxygen content decreased, the formation of metabolite was increased, suggesting this transformation was very likely a reduction reaction. Results of this in vitro study elucidated the metabolic pathways and characteristics of metabolism of OMT to MT and would provide a theoretical basis and guidance for the safe application of OMT

Autoimmune liver disease 2007.

Science.gov (United States)

Muratori, Paolo; Granito, Alessandro; Pappas, Georgios; Muratori, Luigi; Lenzi, Marco; Bianchi, Francesco B

2008-01-01

Autoimmune liver disease (ALD) includes a spectrum of diseases which comprises both cholestatic and hepatitic forms: autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and the so called "overlap" syndromes where hepatitic and cholestatic damage coexists. All these diseases are characterized by an extremely high heterogeneity of presentation, varying from asymptomatic, acute (as in a subset of AIH) or chronic (with aspecific symptoms such as fatigue and myalgia in AIH or fatigue and pruritus in PBC and PSC). The detection and characterization of non organ specific autoantibodies plays a major role in the diagnostic approach of autoimmune liver disease; anti nuclear reactivities (ANA) and anti smooth muscle antibodies (SMA) mark type 1 AIH, liver kidney microsomal antibody type 1 (LKM1) and liver cytosol type 1 (LC1) are the serological markers of type 2 AIH; antimitochondrial antibodies (AMA) are associated with PBC, while no specific marker is found in PSC, since anticytoplasmic neutrophil antibodies with perinuclear pattern (atypical p-ANCA or p-ANNA) are also detected in a substantial proportion of type 1 AIH cases. Treatment options rely on immunosoppressive therapy (steroids and azathioprine) in AIH and on ursodeoxycholic acid in cholestatic conditions; in all these diseases liver transplantation remains the only therapeutical approach for the end stage of liver disease.

Mechanism of microsomal metabolism of benzene to phenol

Energy Technology Data Exchange (ETDEWEB)

Hinson, J.A.; Freeman, J.P.; Potter, D.W.; Mitchum, R.K.; Evans, F.E.

1985-05-01

The mechanism of microsomal hydroxylation of benzene to phenol has been studied by examining the microsomal metabolism of the specifically deuterated derivative 1,3,5-(/sub 2/H/sup 3/)benzene. Evidence for the formation of the following four products was obtained: 2,3,5-(/sub 2/H/sup 3/)phenol, 3,5-(/sub 2/H/sup 2/)phenol, 2,4,6-(/sub 2/H/sup 3/)phenol, and 2,4-(/sub 2/H/sup 2/)phenol. The presence of 2,3,5-(2H3)phenol and 2,4-(/sub 2/H/sup 2/)phenol shows that, in the microsomal metabolism of benzene to phenol, a NIH shift had occurred. A deuterium isotope effect (kH/kD) of approximately 4 was detected in both the meta- and para-deuterated phenols. This finding indicates that cyclohexadienone, formed either by isomerization of the epoxide or directly from the enzyme-substrate complex, is a major intermediate in the metabolism of benzene to phenol.

Transplantation of autologous bone marrow stem cells via hepatic artery for the treatment of acute hepatic injury: an experimental study in rabbits

International Nuclear Information System (INIS)

Zhu Yinghe; Han Jinling; Liu Yanping; Gao Jue; Xu Ke; Zhang Xitong; Ding Guomin

2009-01-01

Objective: To evaluate the transplantation of autologous bone marrow stem cells via hepatic artery in treating acute hepatic injury in experimental rabbit models and to clarify the synergistic effect of hepatocyte growth-promoting factor (pHGF) in stem cell transplantation therapy for liver injury. Methods Acute hepatic injury models were established in 15 experimental rabbits by daily subcutaneous injection of CCl 4 olive oil solution with the dose of 0.8 ml/kg for 4 days in succession. The experimental rabbits were randomly and equally divided into three groups: study group A (stem cell transplant, n = 5), study group B (stem cell transplant + pFHG, n = 5), and control group (n = 5). Bone marrow of 5 ml was drawn from the tibia in all rabbits of both study groups, from which bone marrow stem cells were isolated by using density gradient centrifugation, and 5 ml cellular suspension was prepared. Under fluoroscopic guidance, catheterization through the femoral artery was performed and the cellular suspension was infused into the liver via the hepatic artery. Only injection of saline was carried out in the rabbits of control group. For the rabbits in group B, pFHG (2.0 mg/kg) was administered intravenously every other day for 20 days. At 2, 4 and 8 weeks after stem cell transplantation, hepatic function was determined. Eight weeks after the transplantation all the rabbits were sacrificed and the liver specimens were collected and sent for pathological examination. Results After stem cell transplantation, the hepatic function was gradually improved.Eight weeks after the transplantation, the activity of AST, ALT and the content of ALB, TBIL were significantly lower than that before the procedure, while the content of GOLB was markedly increased in all rabbits. In addition, the difference in the above parameters between three groups was statistically significant (P < 0.05). Pathologically, the hepatocyte degeneration and the fiberous hyperplasia in the study groups

[The effect of berberine administration of evaluation of the functional state of rat liver after ligation of common bile duct].

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Zverinskiĭ, I V; Mel'nichenko, N G; Poplavskiĭ, V A; Sut'ko, I P; Telegin, P G; Shliakhtun, A G

2013-01-01

On the eighth day after ligation of the common bile duct in rats a significant increase in the serum content of total lipids, cholesterol bilirubin and ALT, alkaline phosphatase, and gamma-glutamyltransferase was observed. In the microsomal fraction there was a marked decrease in the content and activity of microsomal monooxygenases. Introperitoneal injection of berberine (10 mg/kg) for 6 days caused a partial normalization of permeability of hepatocytes plasma membranes and activity microsomal flavin-containing monooxygenases. It is suggested that berberine is a substrate and inducer of flavin-containing monooxygenases. Membrane-stabilizing effect of berberine is probably realized at the level of inhibition of prooxidant status of liver cells.

Experimental study on quantitative evaluation of fatty liver by computed tomography

International Nuclear Information System (INIS)

Kunieda, Tokuro; Kawata, Ryo; Hayashi, Koki; Nishiwaki, Tsutomu; Kunieda, Katsuyuki; Saji, Shigetoyo; Sakata, Kazuki

1984-01-01

Biochemical, histological and CT examinations of the liver were perfiormed in 32 rabbits on significance of measuring CT values in the diagnosis of fatty liver. In 2 groups of rabbits, in which 2g/kg/day and 4g/kg/day of fat emulsion were adminstered intravenously for 4 weeks respectively, post-treatment reduction in CT value of light dergree was observed. In a group, in which 8g/kg/day were given, there was a sufficient reduction in CT value for giving diagnosis of fatty liver of moderate degree. Significant correlation was found between changes in CT value of the liver on the one hand and contents of triglyceride, total cholesterol and cholesterol ester in the liver on the other hand, while there was no significant correlation between changes in CT value and contents of phospholipid, protein and water. Significcant correlation was found between changes in CT value of the liver and degress of histological fat accumulation in the liver cells. It has been evidenced experimentally that prolonged administration of fat emulsion may cause fatty liver, and that measurement of CT values of the liver is a non-aggressive method of diagnosing fatty liver. (author)

A new liver function test using the asialoglycoprotein-receptor system on the liver cell membrane, 3

International Nuclear Information System (INIS)

Hazama, Hiroshi; Kawa, Soukichi; Kubota, Yoshitsugu

1986-01-01

We evaluated the vilidity of a new liver function test using liver scintigraphy based on the asialoglycoprotein (ASGP) receptor system on the liver cell membrane in rats with galactosamine-induced acute liver disorder and those with carbon tetra-chloride-induced chronic liver disorder. Neoglycoprotein (GHSA) produced by combining human serum albumin with 32 galactose units was labeled with 99m Tc and administered (50 μg/100 g body weight) to rats with acute or chronic liver disorder. Clearance curves were produced based on liver scintigrams and analysed using the two-compartment model to obtain parameters. In acute liver disorder, the prolongation of 99m Tc-GHSA clearance and the decrease in ASGP receptor activities correlated well to the increase in serum GOT and the decrease in the esterified to total cholesterol ratio (E/T ratio); in chronic liver disorder, they correlated significantly to the increase in the content of liver hydroxyproline (Hyp) which increased in proportion to the severity of liver fibrosis studied histologically, and to the decrease in the contents of cytochrome P-450 and cytochrome b 5 in liver microsomes. Significant correlation was observed between the prolongation of 99m Tc-GHSA clearance and the decrease in ASGP receptor activities in both acute and chronic liver disorders. These findings indicate that the measurement of 99m Tc-GHSA clearance can be a new liver function test sensitively reflecting the severity of liver damage. (author)

Monolignol biosynthesis in microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.).

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Guo, Dianjing; Chen, Fang; Dixon, Richard A

2002-11-01

Microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.) contained coniferaldehyde 5-hydroxylase activity and immunodetectable caffeic acid 3-O-methyltransferase (COMT), and catalyzed the S-adenosyl L-methionine (SAM) dependent methylation of caffeic acid, caffeyl aldehyde and caffeyl alcohol. When supplied with NADPH and SAM, the microsomes converted caffeyl aldehyde to coniferaldehyde, 5-hydroxyconiferaldehyde, and traces of sinapaldehyde. Coniferaldehyde was a better precursor of sinapaldehyde than was 5-hydroxyconiferaldehyde. The alfalfa microsomes could not metabolize 4-coumaric acid, 4-coumaraldehyde, 4-coumaroyl CoA, or ferulic acid. No metabolism of monolignol precursors was observed in microsomal preparations from transgenic alfalfa down-regulated in COMT expression. In most microsomal preparations, the level of the metabolic conversions was independent of added recombinant COMT. Taken together, the data provide only limited support for the concept of metabolic channeling in the biosynthesis of S monolignols via coniferaldehyde.

Study in rabbits of portal circulation by a radioisotopic method

International Nuclear Information System (INIS)

Maliska, C.

1980-01-01

The development of a precocius - and noninvasive method for the detection of portal circulation alterations by means of time interval measurements between the rectal administration of radiotracers and their detection in liver and head is aimed at. The pertecnetate ( 99 sup(m)Tc)- and iodate ( 131 I) absorption by the terminal large intestine was tested in 22 rabbits. The time iinterval between rectal administration of the radiotracer and its appearance in liver and head was determined in 12 rabbits, by external detection with a scintillation camera. The same parameters were studied in 9 animals submitted to the ligature of the portal vein. Iodate and pertecnetate are absorbed by the terminal large intestine, the pertecnetate absorption being significantly smaller than that of iodate. The pertecnetate distribution volume is smaller than that of iodate; the rectum - liver - and rectum - head time intervals is increased in animals with the ligature of portal vein. Application of the method to larger animals will permit the necessary improvements for its utilization as a precocius - noninvasive - and inocuous test in the evaluation of alteration of the human portal circulation. (Author) [pt

Dietary Niacin Supplementation Suppressed Hepatic Lipid Accumulation in Rabbits

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Lei Liu

2016-12-01

Full Text Available An experiment was conducted to investigate the effect of niacin supplementation on hepatic lipid metabolism in rabbits. Rex Rabbits (90 d, n = 32 were allocated to two equal treatment groups: Fed basal diet (control or fed basal diet with additional 200 mg/kg niacin supplementation (niacin. The results show that niacin significantly increased the levels of plasma adiponectin, hepatic apoprotein B and hepatic leptin receptors mRNA (p0.05. However, niacin treatment significantly inhibited the hepatocytes lipid accumulation compared with the control group (p<0.05. In conclusion, niacin treatment can decrease hepatic fatty acids synthesis, but does not alter fatty acids oxidation and triacylglycerol export. And this whole process attenuates lipid accumulation in liver. Besides, the hormones of insulin, leptin and adiponectin are associated with the regulation of niacin in hepatic lipid metabolism in rabbits.

Biocompatibility of intravitreal injection of human mesenchymal stem cells in immunocompetent rabbits.

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Labrador Velandia, Sonia; Di Lauro, Salvatore; Alonso-Alonso, Maria Luz; Tabera Bartolomé, Soraya; Srivastava, Girish Kumar; Pastor, José Carlos; Fernandez-Bueno, Ivan

2018-01-01

To evaluate the feasibility, safety, and biocompatibility of intravitreal injection of human mesenchymal stem cells (MSCs) in immunocompetent pigmented rabbits. Thirty-two pigmented rabbits (24 females, 8 males; Chinchilla-New Zealand White) were divided into 8 groups of 4 animals. Commercially prepared human MSCs were injected (0.05 ml) into the post-lens vitreous of the right eyes. Groups 1 and 4 received isotonic medium (Ringer lactate-based), groups 2, 5, 7, and 8 received a low dose of 15 × 10 6 cells/ml. Groups 3 and 6 received a high dose of 30 × 10 6 cells/ml. Clinical signs were evaluated and scored before MSCs injection and weekly for 2 or 6 weeks. Animals were sacrificed at 2 or 6 weeks after injection. Eyes, liver, spleen, and gonads were assessed by histology and by fluorescent in situ hybridization to evaluate survival and extraocular migration of MSCs. There were no relevant clinical findings between control and MSC-injected rabbit eyes at any time point. There were also no relevant histological findings between control and MSC-injected rabbits related to ocular, liver, spleen, or gonad tissues modifications. MSCs survived intravitreally for at least 2 weeks after injection. Extraocular migration of MSCs was not detected. MSCs are safe and well-tolerated when administered intravitreally at a dose of 15 × 10 6 cells/ml in pigmented rabbits. These findings enable future research to explore the intravitreal use of commercially prepared allogenic human MSCs in clinical trials of retinal diseases.

Nuclear triiodothyronine receptors in rabbit heart

International Nuclear Information System (INIS)

Banerjee, S.K.; Ulrich, J.M.; Kaldor, G.J.

1986-01-01

Nuclear triiodothyronine receptors from rat liver have been characterized in detail by several investigators. However, little work has been done in this area using heart tissue. In this study they examined and characterized the triiodothyronine binding in rabbit hearts. Nuclei have been prepared from ventricular muscle cells of normal and thyrotoxic rabbits as well as from atrial muscle cells of normal rabbit. Hearts were perfused with a minimum essential medium containing collagenase and bovine serum albumin. Myocardial cells were isolated and then disrupted by sonication and washing with a Triton X-100 buffer solution. A discontinuous sucrose density gradient was then used to isolate the mycoardial nuclei. Radiolabelled triiodothyronine (T 3 ) binding to nuclei was examined using conditions described by established procedures. Scatchard analysis of the binding data yields maximum binding capacity (B/sub max/) of 0.17 +/- 0.2 pmol/mg DNA and apparent dissociation constant (K/sub d/) of 400 +/- 50 pM for normal heart T 3 -receptors. The apparent capacity for T 3 binding is approximately 40% greater in myocardial nuclei prepared from hearts of hyperthyroid rabbits. The binding capacity of atrial muscle nuclei is about fourfold lower than ventricular cell nuclei. The results suggest that binding capacity for T 3 -receptor in the atrium is considerably lower than that found in the ventricle

Clinico-chemical studies on subacute cadmium poisoning in rabbits

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, H; Ohsawa, M; Kaneta, M

1974-01-01

GOT, GPT, LDH, total Ac-P, prostatic Ac-P, cholesterol, free fatty acid, Ca, and P in plasma were measured once a week on rabbits injected subcutaneously with 0.5 and 1.0 mg Cd/kg daily for 11 weeks respectively, and Cd, Cu, Mn, and Zn contents in organs were determined at the termination of the experiment. Prostatic Ac-P activity, cholesterol, and free fatty acid levels in plasma rose in the early stage of administration, and GOT, GPT, LDH, and Al-P activities rose in the latter stage of administration. Ca and P levels in plasma did not change in any periods of the experiment. From these results, it could be concluded that a measurement of prostatic Ac-P, cholesterol, and free fatty acid is adequate to evaluate excess intake of Cd. Cd contents in heart, lungs, spleen, and testes of rabbits injected with 1.0 mg Cd/kg increased significantly compared with those with 0.5 mg Cd/kg, but a difference between the two groups in Cd contents in liver, kidneys and submandibular glands which contained high concentration of Cd was not recognized. Zn contents in organs of rabbits injected with Cd increased remarkably, while Cu contents decreased generally. This phenomenon was especially remarkable in liver and kidneys. 31 references, 7 figures, 2 tables.

86Rb Distribution in the Lung of the Rabbit with Pneumothorax

International Nuclear Information System (INIS)

Huh, Kap To

1972-01-01

86 Rb uptake of some organs and tissues, eg. both lungs, both renal cortices. small intestine, liver and skeletal muscle were studied in the control and the rabbit subjected to pneumothorax. 86 Rb in the form of chloride mixed with physiological saline was intravenously injected. The doses were 100 μc for a rabbit. The rabbits were sacrificed at intervals of 10, 20, 40, and 60 seconds after the injection of 86 Rb, by the injection of saturated KCI solution. After scarification, the organ and tissue sample were quickly removed. 86 Rb uptake in gm of the organs and tissues were measured. On the basis of uptake value, administered doses and body weight, % dose/gm tissues per 200 gm body weight was calculated. Followings were the results: 1. Pneumothorax resulted in a marked elevation in 86 Rb uptake value of collapsed lung and returned to normal level lately. 2. Contralateral lung of pneumothorax also showed marked elevation in 86 Rb uptake value and recovered to normal level. 3. Initial 86 Rb uptake value of liver, small intestine of the rabbit with pneumothorax showed some elevation as compared to control, but that of late stage were similar with control. 4. Local blood flow determination by means of 86 Rb uptake were inadequate in the collapsed lung of pneumothorax. 5. It was suggested that the mechanism for the initial elevation of 86 Rb uptake value in each organs and tissue were different from each other.

Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

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Lavado, Ramon

2010-01-01

Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlorpyrifos, parathion and fenthion, microsomal bioactivation and detoxification pathways were measured in gills, liver and olfactory tissues in juvenile rainbow trout (Oncorhynchus mykiss) and compared to juvenile coho salmon (Oncorhynchus kisutch). Consistent with species differences in acute toxicity, significantly higher chlorpyrifos bioactivation was found in liver microsomes of rainbow trout (up to 2-fold) when compared with coho salmon. Although bioactivation to the oxon was observed, the catalytic efficiency towards chlorpyrifos dearylation (detoxification) was significantly higher in liver for both species (1.82 and 0.79 for trout and salmon, respectively) when compared to desulfuration (bioactivation). Bioactivation of parathion to paraoxon was significantly higher (up to 2.2-fold) than detoxification to p-nitrophenol in all tissues of both species with rates of conversion in rainbow trout, again significantly higher than coho salmon. Production of fenoxon and fenthion sulfoxides from fenthion was detected only in liver and gills of both species with activities in rainbow trout significantly higher than coho salmon. NADPH-Dependent hydrolysis of fenthion was observed in all tissues, and was the only activity detected in olfactory tissues. These results indicate rainbow trout are more sensitive than coho salmon to the acute toxicity of OP pesticides because trout have higher catalytic rates of oxon formation. Thus, rainbow trout may serve as a conservative surrogate

Enantioselective N-demethylation and hydroxylation of sibutramine in human liver microsomes and recombinant cytochrome p-450 isoforms.

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Shinde, Dhananjay D; Kim, Min-Jung; Jeong, Eun-Sook; Kim, Yang-Weon; Lee, Ji-Woo; Shin, Jae-Gook; Kim, Dong-Hyun

2014-01-01

The enantioselective metabolism of sibutramine was examined using human liver microsomes (HLM) and recombinant cytochrome P-450 (CYP) isoforms. This drug is metabolized to N-mono-desmethyl- (M1) and N,N-di-desmethylsibutramine (M2), and subsequent hydroxylation results in hydroxyl M1 (HM1) and hydroxyl M2 (HM2). No significant difference was noted in formation of M1from sibutramine between R- and S-sibutramine in HLM. However, S-enantiomers of M1 and M2 were preferentially metabolized to M2, HM1, and HM2compared to R-enantiomers in HLM, and intrinsic clearance (Clint) ratios of S-enantiomers/R-enantiomers were 1.97, 4.83, and 9.94 for M2, HM1, and HM2, respectively. CYP3A4 and CYP3A5 were only involved in the formation of M1, whereas CYP2B6 and CYP2C19 were responsible for all metabolic reactions of sibutramine. CYP2C19 and CYP3A5 displayed catalytic preference for S-sibutramine to S-M1, whereas CYP2B6 and CYP3A4 showed little or no stereoselectivity in metabolism of sibutramine to M1. In the case of M2 formation, CYP2B6 metabolized S-M1 more rapidly than R-M1 with a Clint ratio of 2.14. However, CYP2C19 catalyzed less S-M1 than R-M1 and the Clint ratio of S-M1 to R-M1 was 0.65. The most significant enantioselectivity was observed in formation of HM1 from M1, and HM2 from M2. CYP2B6 and CYP2C19 exhibited preferential catalysis of formation of hydroxyl metabolites from S-enantiomers rather than R-enantiomers. These results indicate that S-sibutramine was more rapidly metabolized by CYP isoforms than R-sibutramine, and that enantioselective metabolism needs to be considered in drug interactions involving sibutramine and co-administered drugs.

Activation versus inhibition of microsomal glutathione S-transferase activity by acrolein. Dependence on the concentration and time of acrolein exposure.

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Sthijns, Mireille M J P E; den Hartog, Gertjan J M; Scasso, Caterina; Haenen, Jan P; Bast, Aalt; Haenen, Guido R M M

2017-09-25

The toxicity of acrolein, an α,β-unsaturated aldehyde, is due to its soft electrophilic nature and primarily involves the adduction of protein thiols. The thiol glutathione (GSH) forms the first line of defense against acrolein. The present study confirms that acrolein added to isolated rat liver microsomes can increase microsomal GSH transferase (MGST) activity 2-3 fold, which can be seen as a direct adaptive increase in the protection against acrolein. At a relatively high exposure level, acrolein appeared to inhibit MGST. The activation is due to adduction of thiol groups, and the inactivation probably involves adduction of amino groups in the enzyme by acrolein. The preference of acrolein to react with thiol groups over amino groups can explain why the enzyme is activated at a low exposure level and inhibited at a high exposure level of acrolein. These opposite forms of direct adaptation on the level of enzyme activity further narrow the thin line between survival and promotion of cell death, governed by the level of exposure. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

2,2',3,3',6,6'-Hexachlorobiphenyl (PCB 136) is Enantioselectively Oxidized to Hydroxylated Metabolites by Rat Liver Microsomes

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Wu, Xianai; Pramanik, Ananya; Duffel, Michael W.; Hrycay, Eugene G.; Bandiera, Stelvio M.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela

2011-01-01

Developmental exposure to multiple-ortho substituted polychlorinated biphenyls (PCBs) causes adverse neurodevelopmental outcomes in laboratory animals and humans by mechanisms involving the sensitization of Ryanodine receptors (RyRs). In the case of PCB 136, the sensitization of RyR is enantiospecific, with only (-)-PCB 136 being active. However, the role of enantioselective metabolism in the developmental neurotoxicity of PCB 136 is poorly understood. The present study employed hepatic microsomes from phenobarbital (PB-), dexamethasone (DEX-) and corn oil (VEH-)treated male Sprague-Dawley rats to investigate the hypothesis that PCB 136 atropisomers are enantioselectively metabolized by P450 enzymes to potentially neurotoxic, hydroxylated PCB 136 metabolites. The results demonstrated the time- and isoform-dependent formation of three metabolites, with 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) being the major metabolite. The formation of 5-OH-PCB 136 increased with the activity of P450 2B enzymes in the microsomal preparation, which is consistent with PCB 136 metabolism by rat P450 2B1. The minor metabolite 4-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol) was produced by a currently unidentified P450 enzymes. An enantiomeric enrichment of (-)-PCB 136 was observed in microsomal incubations due to the preferential metabolism of (+)-PCB 136 to the corresponding 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) atropisomer. 4-OH-PCB 136 displayed an enrichment of the atropisomer formed from (-)-PCB 136; however, the enrichment of this metabolite atropisomer didn't affect the enantiomeric enrichment of the parent PCB because 4-OH-PCB 136 is only a minor metabolite. Although the formation of 5- and 4-OH-PCB 136 atropisomers increased with time, the enantioselective formation of the OH-PCB metabolites resulted in constant enantiomeric enrichment, especially at later incubation times. These observations not only demonstrate that the chiral signatures of

Synthesis and evaluation of 4-[F-18]fluoro thalidomide for the in vivo studies of angiogenesis

International Nuclear Information System (INIS)

Kim, D. H.; Choi, Y. S.; Jeong, K. H.; Lee, K. H.; Choi, Y.; Kim, B. T.

2005-01-01

Thalidomide has been recently rediscovered for its possible utility as an antitumor agent, although it was marketed as a sedative in the 1950s and later found to be a potent teratogen. In this study, therefore, F-18 labeled thalidomide was synthesized and evaluated for the in vivo studies of angiogenesis. 4-[F-18]Fluoro thalidomide ([F-18]1) was prepared by labeling of 4-trimethylammonium thalidomide triflate with TBA[F-18]F in DMSO (90 .deg. C, 10 min) and purified by HPLC. The triflate salt was prepared from 3-fluoro phthalic anhydride in 3 steps. [F-18]1 was incubated with HUVEC cells at 37 .deg. C for 15, 30, 60, and 120 min, respectively. Dynamic PET images of [F-18]1 was obtained in mice implanted with LLC cells. In vitro metabolism study of [F-18]1 was carried out using mouse, rabbit, or human liver microsomes in the presence of NADPH, and the metabolites obtained from the mouse liver microsomal incubation of 1 were analyzed using LC-MS. Radiochemical yield of [F-18]1 was 50-60%, and the specific activity was 42-120 GBq/imol. The HUVEC cell uptake of [F-18]1 increased with time (100% at 15 min and 241% at 120 min). PET images showed that the radioactivity was accumulated in the liver, the kidneys and the bladder of the mice, and brain uptake was shown from 40 min postinjection. However, there was low level of radioactivity uptake in tumor. [F-18]1 was not metabolized by mouse, rabbit, or human liver microsomes but was hydrolyzed significantly at physiological pH. The hydrolyzed product was further analyzed by LC-MS, showing a mass peak corresponding to that of 4-fluoro-N-(o-carboxybenzoyl)glutamic acid imide. This result suggests that [F-18]1 is easily hydrolyzed at physiological pH and thus may not be suitable for the in vivo studies of tumor angiogenesis at least in rodents, although it was reported that the hydrolysis product of thalidomide may be responsible for its angiogenesis activity in humans

Transmission electron microscopy of heart and liver tissues from rats fed with gums arabic and tragacanth.

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Anderson, D M; Ashby, P; Busuttil, A; Kempson, S A; Lawson, M E

1984-04-01

Transmission electron microscopy has been used to examine the ultrastructure of rat hearts and livers after diet supplementation with (a) 0, 0.5, 1.5, 2.5 and 3.5% (w/w) gum tragacanth (GT) for 91 days, (b) 0 and 1% GT for 5 days (c) 0, 1, 4 and 8% (w/w) gum arabic (GA) for 28 days. The preparation and scrutiny of the electron micrographs was undertaken by two independent teams of specialists. There were no detectable abnormalities in any of the organelles in the heart and liver specimens from any of the test animals and no inclusions nor other pathological changes were observed. All micrographs showed normal, healthy tissues; particular attention was given to the mitochondria in hepatocytes as they serve as sensitive indicators of the health and state of activity of cells. In addition, the data obtained from assays of the microsomal protein and cytochrome P-450 content of the livers showed that GA and GT did not cause inductive effects. These results do not support earlier suggestions, based on in vitro assays, that GA and GT cause changes in the function of rat heart and liver mitochondria and liver microsomes; however, they confirm a report by Zbinden that the ingestion of GT does not produce abnormalities in the cardiac function of rats.

Treatment of chronic hepatic cirrhosis with autologous bone marrow stem cells transplantation in rabbits

International Nuclear Information System (INIS)

Zhu Yinghe; Xu Ke; Zhang Xitong; Han Jinling; Ding Guomin; Gao Jue

2008-01-01

Objective: To evaluate the feasibility of treatment for rabbit model with hepatic cirrhosis by transplantation of autologous bone marrow-derived stem cells via the hepatic artery and evaluate the effect of hepatocyte growth-promoting factors (pHGF) in the treatment of stem cells transplantation to liver cirrhosis. To provide empirical study foundation for future clinical application. Methods: Chronic hepatic cirrhosis models of rabbits were developed by subcutaneous injection with 50% CCl 4 0.2 ml/kg. Twenty-five model rabbits were randomly divided into three experimental groups, stem cells transplant group (10), stem cells transplant + pHGF group (10) and control group (5). Autologous bone marrow was harvested from fibia of each rabbit, and stem cells were disassociated using density gradient centrifugation and transplanted into liver via the hepatic artery under fluoroscopic guidance. In the stem cells transplant + pHGF group, the hepatocyte growth-promoting factor was given via intravenous injection with 2 mg/kg every other day for 20 days. Liver function tests were monitored at 4, 8,12 weeks intervals and histopathologic examinations were performed at 12 weeks following transplantation. The data were analyzed using analysis of variance Results: Following transplantation of stern cells, the liver function of rabbits improved gradually. Twelve weeks after transplantation, the activity of ALT and AST decreased from (73.0±10.6) U/L and (152.4± 22.8) U/L to (48.0±1.0) U/L and (86.7±2.1) U/L respectively; and the level of ALB and PTA increased from (27.5±1.8) g/L and 28.3% to (33.2±0.5) g/L and 44.1% respectively. The changes did not have statistically significant difference when compared to the control group (P>0.05). However, in the stem cellstransplant + pHGF group, the activity of ALT and AST decreased to (43.3±0.6) U/L and (78.7±4.0) U/L respectively and the level of ALB and PTA increased to (35.7±0.4) g/L and 50.5% respectively. The difference was

Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies.

Science.gov (United States)

Lee, I J; Kim, Y I; Kim, K W; Kim, D H; Ryoo, I; Lee, M W; Chung, J W

2012-11-01

This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma. 15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups. Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA. When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.

The effect of irradiation on biological defense system of experimental rabbits

International Nuclear Information System (INIS)

Urata, Yoshishige; Goto, Shinzi; Kondo, Takahito; Shimasaki, Tatsuya; Okumura, Yutaka

1992-01-01

Radiation effects on antioxidant factors as glutathione, glutathione peroxidase, catalase, glutathione S-transferase, γ-gluthamine cysteine synthetase, Cu, Zn-superoxide dismutase and Mn-superoxide dismutase are measured in liver, kidney and genitals of rabbits with single irradiation of 50 Gy X-ray. (J.P.N.)

Antibody to liver cytosol (anti-LC1) in patients with autoimmune chronic active hepatitis type 2.

Science.gov (United States)

Martini, E; Abuaf, N; Cavalli, F; Durand, V; Johanet, C; Homberg, J C

1988-01-01

A new autoantibody was detected by immunoprecipitation in the serum of 21 patients with chronic active hepatitis. The antibody reacted against a soluble cytosolic antigen in liver. The antibody was organ specific but not species specific and was therefore called anti-liver cytosol antibody Type 1 (anti-LC1). In seven of 21 cases, no other autoantibody was found; the remaining 14 cases had anti-liver/kidney microsome antibody Type 1 (anti-LKM1). With indirect immunofluorescence, a distinctive staining pattern was observed with the seven sera with anti-LC1 and without anti-LKM1. The antibody stained the cytoplasm of hepatocytes from four different animal species and spared the cellular layer around the central veins of mouse and rat liver that we have called juxtavenous hepatocytes. The immunofluorescence pattern disappeared after absorption of sera by a liver cytosol fraction. The 14 sera with both antibodies displayed anti-LC1 immunofluorescent pattern after absorption of anti-LKM1 by the liver microsomal fraction. The anti-LC1 was found in the serum only in patients with chronic active hepatitis of unknown cause. Anti-LC1 antibody was not found in sera from 100 patients with chronic active hepatitis associated with anti-actin antibody classic chronic active hepatitis Type 1, 100 patients with primary biliary cirrhosis, 157 patients with drug-induced hepatitis and a large number of patients with liver and nonliver diseases. This new antibody was considered a second marker of chronic active hepatitis associated with anti-LKM1 (anti-LKM1 chronic active hepatitis) or autoimmune chronic active hepatitis Type 2.

Regulation of rabbit lung cytochrome P-450 prostaglandin omega-hydroxylase (P-450/sub PG-omega/) during pregnancy

International Nuclear Information System (INIS)

Muerhoff, A.S.; Williams, D.E.; Jackson, V.; Leithauser, M.T.; Waterman, M.R.; Johnson, E.F.; Masters, B.S.S.

1987-01-01

The mechanism of induction during pregnancy of a rabbit lung prostaglandin omega-hydroxylase cytochrome P-450 has been investigated. This activity has been demonstrated to be induced over 100-fold in 28-day pregnant rabbits, as compared to nonpregnant rabbits. The induction is reflected by an increase in the amount of P-450/sub PG-omega/ protein as measured by Western blotting. P-450/sub PG-omega/ microsomal protein increases throughout gestation concomitant with an increase in PGE 1 omega-hydroxylase activity. Elucidation of the level of induction involved extraction of RNA from rabbit lungs obtained at various days of gestation followed by in vitro translation of the RNA in the presence of 35 S-methionine. Immunoprecipitation of newly synthesized P-450 and analysis of the immunoisolates by SDS-PAGE, autoradiography and densitometry of the P-450/sub PG-omega/ band revealed that the P-450/sub PG-omega/ mRNA levels followed the gestational time-dependent increase observed for both PGE 1 omega-hydroxylase activity and P-450/sub PG-omega/ protein, i.e., a gradual increase peaking at 28-days, dropping precipitously to near control levels following parturition. These data suggest that control of P-450/sub PG-omega expression occurs at the transcriptional level. Western blots of human lung bronchioloalveolar-carcinoma cell lines NCL-H322 and NCL-H358 utilizing a guinea pig IgG to P-450/sub PG-omega/ detect a cross-reactive species

Dynamics of biosynthesis of thyroglobulin sub-units and their polymerization in rabbit thyroid slices in vitro

Energy Technology Data Exchange (ETDEWEB)

Sinadinovic, J; Jovanovic, M; Kraincanic, M [Institut za Primeni Nuklearne Energije u Poljoprivedri, Veterinarstvu i Sumarstvu, Zemun (Yugoslavia)

1975-01-01

The dynamics of biosynthesis and aggregation of sub-units into thyroglobulin (TG) was studied i n v i t r o in rabbit thyroid sections incubated for 5 to 300 min in the presence of 1-/sup 14/C-leucine. The incorporation of the labelled amino acid in total soluble and microsome bound proteins and its distribution in soluble protein fractions were investigated. The incorporation of the labelled amino acid in soluble and microsome-bound proteins was found to increase with the time of incubation. The label was incorported very early, this not only into the 3-8S fraction but also into a protein corresponding to the 12S fraction. The maximum incorporation into 12S protein was achieved after 60 min of incubation; the intensity of incorporation then decreased, followed by an increase in the relative and absolute amounts of TG. /sup 14/C-leucine in the TG region was not observed before the 30th min of incubation. The dynamics of incorporation of /sup 14/C-leucine into thyroid proteins indicated a very rapid transformation of the newly synthesized 12S sub-units into TG.

Content of non-esterified fatty acids in the blood plasma of rabbits with acute arginine pancreatitis and its correction

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Y. F. Rivis

2013-01-01

Full Text Available The aim of this work was to study the content of non-esterified fatty acids in plasma and liver of rabbits with acute arginine pancreatitis and its correction by linseed oil. The experiment was carried out on male rabbits breed gray giant with live weight 3.8–4.0 kg. The material for the study was sampled from blood and liver. Lipids from plasma and liver were extracted with a mixture of chloroform and methanol. After that the non-esterified fatty acids were isolated and methylated. Methyl esters of fatty acids were studied by the gas-liquid chromatography with the chromatograph ''Chrom 5'' (Prague,CzechRepublic. We have found that the content of non-esterified fatty acids decreases in the blood plasma and liver of rabbits with the acute arginine pancreatitis. It takes place at the expense of a reduce of saturated fatty acids with odd and even number of carbon atoms in a chain, monounsaturated fatty acids of the families ω-7 and ω-9 and polyunsaturated fatty acids of the families ω-3 and ω-6. That may indicate a greater use of non-esterified fatty acids for energy metabolism and esterification of lipids. We suppose that this is a consequence of the probable increase in content of non-esterified and esterified cholesterol in the rabbits’ blood plasma. Those processes provoke the cholesterol deposits in blood vessels and therefore cardiovascular diseases. We tried to influence on the processes by addition of linseed oil to the rabbits diet. We have found that in the linseed oil-fed rabbits the content of non-esterified fatty acids decreases at the expense of saturated fatty acids with odd and even number of carbon atoms in a chain and monounsaturated fatty acids of the families ω-7 and ω-9 inblood plasma and liver of the rabbits with acute arginine pancreatitis. Furthermore the levels of non-esterified polyunsaturated fatty acids of ω-3 family increase in the rabbits’ plasma and liver. As this takes place the ratio of non

Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes

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Klein, R; Zanger, U M; Berg, T; Hopf, U; Berg, P A

1999-01-01

Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254–339 (254–273, 257–269, 270–294, 291–310, 307–324, 321–339, 373–389) as well as the novel peptide 196–218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1′-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257–269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196–218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254–273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257–269 a further immunodominant epitope exists on CYP2D6 which is recognized

Changes induced by gamma radiation in microsomal membranes of storage of garlic

International Nuclear Information System (INIS)

Perez, M.B.; Croci, C.A.; Aveldano, M.I.

2003-01-01

This study evaluates the effects of the radio inhibition process on garlic bulbs in terms of phase properties of microsomal membranes and their lipid and fatty acid composition. Garlic bulbs were irradiated with an average dose of 60 Gy of 60 Co gamma rays 30-40 days after harvest. The treatment was carried out in the facilities of the National Atomic Energy Commission (CNEA). Rough and smooth microsomal membranes were isolated by ultracentrifugation from tissues of irradiated and non-irradiated storage leaves. Wide angle X-ray diffractograms of both fractions were recorded along 270 days of storage. Lipids were separated by thin layer chromatography. The fatty acid composition of major lipid fractions was studied by gas-liquid chromatography. The diffractograms featured peaks at Bragg spacing of 4.15 Armstrong and 3.75 Armstrong, revealing the presence of a gel (crystalline) phase, while the characteristic peak of the liquid-crystalline phase (4.6 Armstrong) was not observed in both sorts of membranes. Irradiation was found to bring about modifications in the intensity of 4.15 Armstrong and 3.75 Armstrong peaks from smooth microsomal membranes, but not in the behaviour along the studied period. Data from the rough microsomal fraction were erratic. Parallel to these changes, radiation induced significant modifications in the level of smooth microsomal membrane triacylglycerols in relation to phospholipids and their fatty acids. These findings indicate that the storage leaf tissues of garlic are radiosensitive both in terms of physical and chemical properties of their microsomal membranes. From the practical point of view, these results could be the basis for the development of techniques to be applied to storage garlic to evaluate if it was irradiated. (author)

Inhibitory Effects of Aschantin on Cytochrome P450 and Uridine 5′-diphospho-glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

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Soon-Sang Kwon

2016-04-01

Full Text Available Aschantin is a bioactive neolignan found in Magnolia flos with antiplasmodial, Ca2+-antagonistic, platelet activating factor-antagonistic, and chemopreventive activities. We investigated its inhibitory effects on the activities of eight major human cytochrome P450 (CYP and uridine 5′-diphospho-glucuronosyltransferase (UGT enzymes of human liver microsomes to determine if mechanistic aschantin–enzyme interactions were evident. Aschantin potently inhibited CYP2C8-mediated amodiaquine N-de-ethylation, CYP2C9-mediated diclofenac 4′-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4′-hydroxylation, and CYP3A4-mediated midazolam 1′-hydroxylation, with Ki values of 10.2, 3.7, 5.8, and 12.6 µM, respectively. Aschantin at 100 µM negligibly inhibited CYP1A2-mediated phenacetin O-de-ethylation, CYP2A6-mediated coumarin 7-hydroxylation, CYP2B6-mediated bupropion hydroxylation, and CYP2D6-mediated bufuralol 1′-hydroxylation. At 200 µM, it weakly inhibited UGT1A1-catalyzed SN-38 glucuronidation, UGT1A6-catalyzed N-acetylserotonin glucuronidation, and UGT1A9-catalyzed mycophenolic acid glucuronidation, with IC50 values of 131.7, 144.1, and 71.0 µM, respectively, but did not show inhibition against UGT1A3, UGT1A4, or UGT2B7 up to 200 µM. These in vitro results indicate that aschantin should be examined in terms of potential interactions with pharmacokinetic drugs in vivo. It exhibited potent mechanism-based inhibition of CYP2C8, CYP2C9, CYP2C19, and CYP3A4.

Experiment of embolizing hepatocarcinoma with heated lipiodol via hepatic artery in VX2 rabbit model

International Nuclear Information System (INIS)

Cao Wei; Wang Zhimin; Zhang Hongxin; Wan Yi

2006-01-01

Objective: To evaluate the anti-tumour effect of 60 degree C Lipiodol in the embolization of VX 2 hepatocarcinoma in rabbits. Methods: VX 2 carcinoma cells were surgically implanted into the left liver lobe in 30 male New Zealand white rabbits, which were randomly divided into 3 groups by figure and table method with 10 rabbits in each group. Physiological saline, Lipiodol (37 degree C), and Lipiodol (60 degree C) were injected in each group via hepatic artery and liver cancer was embolized. The volume of tumour and serum level of aspartate aminotransferase (AST) were observed after one week, and the survival period of VX 2 rabbits was also observed. Results: In the group of Lipiodol (60 degree C), the growth rate of tumour (0.92± 0.21) was significantly lower than that of control group (3.48±) and Lipiodol (37 degree C) groups (1.69±0.26), respectively (F=34.95, P 0.05), but was significantly higher than the control group (68.6±6.6) U/L (t=19.24, P<0.05). Conclusion: Lipiodol (60 degree C) greatly decreases the tumour's growth rate and prolongs the survival period. It is a safe method and has stronger inhibitory effect than other groups. (authors)

Effects of oral administration of aflatoxin B1 and fumonisin B1 in rabbits (Oryctolagus cuniculus).

Science.gov (United States)

Orsi, R B; Oliveira, C A F; Dilkin, P; Xavier, J G; Direito, G M; Corrêa, B

2007-12-15

The effects of prolonged oral administration (21 days) of fumonisin B(1) (FB(1)) and aflatoxin B(1) (AFB(1)) were studied in male New Zealand rabbits by clinical, pathological, biochemical and sphingolipid analyses. Twenty-four animals were randomly divided into the following four experimental groups: (A) 0 mg FB(1)+0 microg AFB(1)/(kg body weight(bw)day) (control); (B) 0 mg FB(1)+30 microg AFB(1)/(kg bw day); (C) 1.5 mg FB(1)/(kg bw day)+30 microg AFB(1)/(kg bw day); (D) 1.5 mg FB(1)/(kg bw day)+0 microg AFB(1). Animals from group B and principally from group C presented clinical signs of intoxication. Rabbits from group C presented a lower body weight gain than controls. Differences were observed between intoxicated rabbits and controls with respect to absolute and relative liver and kidney weight, hepatic function, serum urea and creatinine levels and Sa/So ratio. The most frequent hepatic and renal injuries were vacuolar degeneration of the liver and kidney as shown by the histopathological and serum biochemical results. Combined administration of AFB(1) and FB(1) resulted in synergistic toxic effects both in the liver and in the kidney, but hepatic injuries were more marked.

Soybean meal fermented by Aspergillus awamori increases the cytochrome P-450 content of the liver microsomes of mice.

Science.gov (United States)

Kishida, T; Ataki, H; Takebe, M; Ebihara, K

2000-04-01

The effect of soybean meal fermented by Aspergillus awamori on the acute lethality of acetaldehyde, pentobarbital sleeping time, and cytochrome P-450 content of the hepatic microsomes was studied in mice. Most of the daidzin and genistin in soybean meal (SBM) were converted into the respective aglycones, daidzein and genistein, by fermentation. In experiment 1, mice were fed isonitrogenic test diets with one of the following five protein sources for 28 d: casein, SBM, fermented and hot-air-dried SBM (FSBM-HD), fermented and freeze-dried SBM (FSBM-FD), or methanol-extracted FSBM-FD (FSMB-FD-R). The acute lethality of acetaldehyde in mice fed the FSBM-FD diet was significantly lower than that in mice fed the SBM, FSBM-HD, or FSBM-FD-R diet. In experiments 2 and 3, mice were fed isonitrogenic test diets with one of the following four protein sources for 28 d: casein, SBM, FSBM-FD, and FSBM-FD-R. The pentobarbital sleeping time was significantly shorter and the cytochrome P-450 content was significantly higher in the mice fed the FSBM-FD diet than the respective value in mice fed the other test diets. In experiment 4, mice were fed one of eight diets which contained different levels of aglycone obtained by varying the proportion of FSBM-FD and FSBM-FD-R, for 28 d. The cytochrome P-450 content in hepatic microsomes increased as the dietary level of isoflavonoid aglycones increased, but there was a saturation phenomenon. These results suggest that soy isoflavonoid aglycones are more potent inducers of cytochrome P-450 than isoflavonoid glycosides.

Prediction of biotransformation products of the fungicide fluopyram by electrochemistry coupled online to liquid chromatography-mass spectrometry and comparison with in vitro microsomal assays.

Science.gov (United States)

Mekonnen, Tessema F; Panne, Ulrich; Koch, Matthias

2018-04-01

Biotransformation processes of fluopyram (FLP), a new succinate dehydrogenase inhibitor (SDHI) fungicide, were investigated by electrochemistry (EC) coupled online to liquid chromatography (LC) and electrospray mass spectrometry (ESI-MS). Oxidative phase I metabolite production was achieved using an electrochemical flow-through cell equipped with a boron-doped diamond (BDD) electrode. Structural elucidation and prediction of oxidative metabolism pathways were assured by retention time, isotopic patterns, fragmentation, and accurate mass measurements using EC/LC/MS, LC-MS/MS, and/or high-resolution mass spectrometry (HRMS). The results obtained by EC were compared with conventional in vitro studies by incubating FLP with rat and human liver microsomes (RLM, HLM). Known phase I metabolites of FLP (benzamide, benzoic acid, 7-hydroxyl, 8-hydroxyl, 7,8-dihydroxyl FLP, lactam FLP, pyridyl acetic acid, and Z/E-olefin FLP) were successfully simulated by EC/LC/MS. New metabolites including an imide, hydroxyl lactam, and 7-hydroxyl pyridyl acetic acid oxidative metabolites were predicted for the first time in our study using EC/LC/MS and liver microsomes. We found oxidation by dechlorination to be one of the major metabolism mechanisms of FLP. Thus, our results revealed that EC/LC/MS-based metabolic elucidation was more advantageous on time and cost of analysis and enabled matrix-free detection with valuable information about the mechanisms and intermediates of metabolism processes. Graphical abstract Oxidative metabolism of fluopyram.

Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases

International Nuclear Information System (INIS)

Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

2007-01-01

Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are ∼ 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (∼ 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected

Healthy rabbits are susceptible to Epstein-Barr virus infection and infected cells proliferate in immunosuppressed animals.

Science.gov (United States)

Khan, Gulfaraz; Ahmed, Waqar; Philip, Pretty S; Ali, Mahmoud H; Adem, Abdu

2015-02-18

Epstein-Barr virus (EBV) is an oncogenic virus implicated in the pathogenesis of several human malignancies. However, due to the lack of a suitable animal model, a number of fundamental questions pertaining to the biology of EBV remain poorly understood. Here, we explore the potential of rabbits as a model for EBV infection and investigate the impact of immunosuppression on viral proliferation and gene expression. Six healthy New Zealand white rabbits were inoculated intravenously with EBV and blood samples collected prior to infection and for 7 weeks post-infection. Three weeks after the last blood collection, animals were immunosuppressed with daily intramuscular injections of cyclosporin A at doses of 20 mg/kg for 15 days and blood collected twice a week from each rabbit. The animals were subsequently sacrificed and tissues from all major organs were collected for subsequent analysis. Following intravenous inoculation, all 6 rabbits seroconverted with raised IgG and IgM titres to EBV, but viral DNA in peripheral blood mononuclear cells (PBMCs) could only be detected intermittently. Following immunosuppression however, EBV DNA could be readily detected in PBMCs from all 4 rabbits that survived the treatment. Quantitative PCR indicated an increase in EBV viral load in PBMCs as the duration of immunosuppression increased. At autopsy, splenomegaly was seen in 3/4 rabbits, but spleens from all 4 rabbit were EBV PCR positive. EBER-in situ hybridization and immunoshistochemistry revealed the presence of a large number of EBER-positive and LMP-1 positive lymphoblasts in the spleens of 3/4 rabbits. To a lesser extent, EBER-positive cells were also seen in the portal tract regions of the liver of these rabbits. Western blotting indicated that EBNA-1 and EBNA-2 were also expressed in the liver and spleen of infected animals. EBV can infect healthy rabbits and the infected cells proliferate when the animals are immunocompromised. The infected cells expressed several EBV

In vitro metabolism studies of 18F-labeled 1-phenylpiperazine using mouse liver S9 fraction

International Nuclear Information System (INIS)

Ryu, Eun Kyoung; Choe, Yearn Seong; Kim, Dong Hyun; Ko, Bong-Ho; Choi, Yong; Lee, Kyung-Han; Kim, Byung-Tae

2006-01-01

The in vitro metabolism of 1-(4-[ 18 F]fluoromethylbenzyl)-4-phenylpiperazine ([ 18 F]1) and 1-(4-[ 18 F]fluorobenzyl)-4-phenylpiperazine ([ 18 F]2) was investigated using mouse liver S9 fraction. Results were compared to those of in vivo metabolism using mouse blood and bone and to in vitro metabolism using mouse liver microsomes. Defluorination was the main metabolic pathway for [ 18 F]1 in vitro and in vivo. Based on TLC, HPLC and LC-MS data, [ 18 F]fluoride ion and less polar radioactive metabolites derived from aromatic ring oxidation were detected in vitro, and the latter metabolites were rapidly converted into the former with time, whereas only the [ 18 F]fluoride ion was detected in vivo. Similarly, the in vitro metabolism of [ 18 F]2 using either S9 fraction or microsomes showed the same pattern as the in vivo method using blood; however, the radioactive metabolites derived from aromatic ring oxidation were not detected in vivo. These results demonstrate that liver S9 fraction can be widely used to investigate the intermediate radioactive metabolites and to predict the in vivo metabolism of radiotracers

Evaluation of possible interaction among drugs contemplated for use during manned space flights

Science.gov (United States)

1973-01-01

Possible interactions among drugs contemplated for use during manned spaceflights have been studied in several animal species. The following seven drugs were investigated: nitrofurantoin, chloral hydrate, hexobarbital, phenobarbital, flurazepam, diphenoxylate, and phenazopyridine. Particular combinations included: chloral hydrate, hexabarbital or flurazepam with nitrofurantoin; phenobarbital or flurazepam with phenazopyridine; and diphenoxylate with two does formulations of nitrofurantoin. Studies were carried out in several species to determine whether induction of liver microsomal enzymes would increase the tendency of phenazopyridine to produce methemoglobin in vivo. Animals were premedicated with phenobarbital, a known inducer of azoreductase, and in a separate experiment with flurazepam, before administration of phenazopyridine. Methemoglobin production was determined in each animal after receiving phenazopyridine. No evidence was found for increased production of methemoglobin in the rat, dog, or rabbit that could be attributed to increased amounts of microsomal enzymes.

Isotopic study of liver function after narcosis in small animals

International Nuclear Information System (INIS)

Le Qui Cuong; Kiss, Bela; Jakab, Tivadar; Szilvasi, Istvan; Spett, Borbala

1984-01-01

Dinamic functional study of the liver was performed by sup(99m)Tc-TECHIDA in narcotized (Halothane) mice and rabbits. Hepatic uptake of the radiopharmaceutical decreased in narcotized group significantly. Excretion also decreased but statistically insignificantly. These alterations in the liver function could be attributed to the hypotensive effect of Halothane. (author)

Effect of dietary linseed oil and Ganoderma lucidum or olive leaves supplementation on fatty acid composition and oxidative status of rabbits

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Tina Trebušak

2014-03-01

Full Text Available The aim of the present study was to evaluate the influence of natural antioxidant supplementation on the oxidative stress induced by a high proportion of polyunsaturated fatty acids (PUFA in rabbit diets. Forty-eight SIKA rabbits (24 male, 24 female were penned individually and after a 5-d adaptation period divided into 4 homogeneous groups (2.58±0.3 kg. The CONT– group received a diet with 60 g/kg palm fat, while the other 3 groups received a diet with 60 g/kg linseed oil which was either unsupplemented (CONT+ or supplemented with 10 g/kg of Ganoderma lucidum (REISHI or 10 g/kg of olive leaves (OLIVE. Rabbits were euthanised at 102 d of age, 22 d after the start of the experiment. Live weight, weight gain, feed intake and feed conversion rate were recorded. The fatty acid composition of back (M. longissimus dorsi and hind leg muscle (thigh muscle, adipose tissue (abdominal fat and liver were determined. To evaluate the oxidative status of rabbits, the malondialdehyde (MDA concentration in the plasma, liver and both muscles was measured. DNA damage in the leukocytes was measured. Linseed oil addition increased the PUFA ratio and decreased the proportion of saturated fatty acids in all tissues (P<0.001, with no detrimental effect on productive performance of rabbits compared to palm fat. Linseed oil also reduced n-6/n-3 PUFA ratio in all tissues (P<0.001. However, linseed oil addition increased the oxidative stress by increasing MDA concentrations in the liver and muscles (P<0.001, but did not affect the plasma MDA concentrations and the extent of DNA damage in the blood leukocytes compared to palm fat. Addition of olive leaves tended to decrease the concentration of MDA in the liver Addition of olive leaves tended to decrease the concentration of MDA in the liver compared to CONT+ (P=0.059, with no effect of Ganoderma lucidum.

Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes.

Science.gov (United States)

Kot, Marta; Daniel, Władysława A

2009-01-01

The aim of the present study was to test the effect of diethyldithiocarbamate (DDC), which is regarded as a cytochrome P450 (CYP) CYP2A6 and CYP2E1 inhibitor, and ticlopidine, an efficient CYP2B6, CYP2C19 and CYP2D6 inhibitor, on the activity of human CYP1A2 and the metabolism of caffeine (1-N-, 3-N- and 7-N-demethylation, and C-8-hydroxylation). The experiment was carried out in vitro using human cDNA-expressed CYP1A2 (Supersomes) and human pooled liver microsomes. The effects of DDC and ticlopidine were compared to those of furafylline (a strong CYP1A2 inhibitor). A comparative in vitro study provides clear evidence that ticlopidine and DDC, applied at concentrations that inhibit the above-mentioned CYP isoforms, potently (as compared to furafylline) inhibit human CYP1A2 and caffeine metabolism, in particular 1-N- and 3-N-demethylation.

[Preparation and preliminary application of rabbit anti-human PON2 antibodies(paraoxonase-2)].

Science.gov (United States)

Chen, Miao; Yang, Jin-Ju; Li, Shu-Zhen; Liu, Xiao-Lan; Liu, Ying; Zhang, Lin-Jie; Gao, Jian-En; Sun, Qi-Hong

2008-07-01

To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2). A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence. The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells. The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

Meningeal hyperaemia and myocarditis in a caged rabbit with encephalitozoonosis: Case report and literature review

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Davinson Chuka Anyogu

2017-11-01

Full Text Available Over the years, encephalitozoonosis in rabbits has raised serious concern owing to the subclinical nature of the infection in most rabbits and the danger of zoonosis in immunocompromised persons. The disease has been diagnosed by clinical signs, histopathological examination and detection of the antibody in serum. The lesions have been described mainly in the brain, kidney and liver of infected rabbits. The present report documented additional lesions seen in a male rabbit presented to the Necropsy Unit of the Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka for euthanasia. Following euthanasia, tissue samples from the rabbit were processed and stained with haematoxylin and eosin. The microscopic lesions were comprised of meningeal hyperaemia, myocarditis, chronic nonsuppurative granulomatous hepatitis, and Encephalitozoon cuniculi spores in the brain parenchyma. The study showed the importance of reporting new findings in order to elucidate the pathogenic mechanisms for the disease and to renew attention to its zoonotic potential.

Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

OpenAIRE

Kukiełka, E; Cederbaum, A I

1995-01-01

Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid...

Rabbit Model for Human EBV-Associated Hemophagocytic Syndrome (HPS)

Science.gov (United States)

Hayashi, Kazuhiko; Jin, Zaishun; Onoda, Sachiyo; Joko, Hiromasa; Teramoto, Norihiro; Ohara, Nobuya; Oda, Wakako; Tanaka, Takehiro; Liu, Yi-Xuan; Koirala, Tirtha Raj; Oka, Takashi; Kondo, Eisaku; Yoshino, Tadashi; Takahashi, Kiyoshi; Akagi, Tadaatsu

2003-01-01

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD). To elucidate the true nature of fatal LPD observed in Herpesvirus papio (HVP)-induced rabbit hemophagocytosis, reactive or neoplastic, we analyzed sequential development of HVP-induced rabbit LPD and their cell lines. All of the seven Japanese White rabbits inoculated intravenously with HVP died of fatal LPD 18 to 27 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in five of these seven rabbits. Sequential autopsy revealed splenomegaly and swollen lymph nodes, often accompanied by bleeding, which developed in the last week. Atypical lymphoid cells infiltrated many organs with a “starry sky” pattern, frequently involving the spleen, lymph nodes, and liver. HVP-small RNA-1 expression in these lymphoid cells was clearly demonstrated by a newly developed in situ hybridization (ISH) system. HVP-ISH of immunomagnetically purified lymphoid cells from spleen or lymph nodes revealed HVP-EBER1+ cells in each CD4+, CD8+, or CD79a+ fraction. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by PCR or Southern blot analysis. Clonality analysis of HVP-induced LPD by Southern blotting with TCR gene probe revealed polyclonal bands, suggesting polyclonal proliferation. Six IL-2-dependent rabbit T-cell lines were established from transplanted scid mouse tumors from LPD. These showed latency type I/II HVP infection and had normal karyotypes except for one line, and three of them showed tumorigenicity in nude mice. These data suggest that HVP-induced fatal LPD in rabbits is reactive polyclonally in nature. PMID:12707056

Changes of serum IL-2, IL-4, IL-10 and IFN-γ levels after treatment with 131I-17-allylamino-17-demethoxygeldanamycin in VX2 rabbit models

International Nuclear Information System (INIS)

Gao Wen; Liu Lu; Zhou Yun

2007-01-01

Objective: To study the influence of 131 I-17-allylamino-17-demethoxygeldanamycin( 131 I-17-AAG) therapy on immune function in VX2 rabbit models with transplanted liver cancer. Methods: Serum IL-2, IL-4, IL-10 and IFN-γ levels were measured with RIA in 8 VX2 rabbit models with transplanted liver cancer 1-2 weeks after 10mCi 131 I-17-AAG treatment as well as in 8 controls rabbits (models with tumor but without treatment). Results: 1 week after 10mCi 131 I treatment, the serum IL - 2 and IFN-γ levels were significantly lower in the treated rabbits than those in controls (P 0.05). Serum IL-4 and IL-10 levels in the treated rabbits (both at 1 and 2 week) were not significantly different from those in controls (P>0.05). Conclusion: 131 I-17-AAG treatment had transient effects on cellular immunity with no influence on humoral immunity. As a whole, it is a safe to treat VX2 rabbit models with this preparation. (authors)

Subcellular distribution of styrene oxide in rat liver

International Nuclear Information System (INIS)

Pacifici, G.M.; Cuoci, L.; Rane, A.

1984-01-01

The subcellular distribution of ( 3 H)-styrene-7,8-oxide was studied in the rat liver. The compound was added to liver homogenate to give a final concentration of 2 X 10(-5); 2 X 10(-4) and 2 X 10(-3) M. Subcellular fractions were obtained by differential centrifugation. Most of styrene oxide (59-88%) was associated with the cytosolic fraction. Less than 15 percent of the compound was retrieved in each of the nuclear, mitochondrial and microsomal fractions. A considerable percentage of radioactivity was found unextractable with the organic solvents, suggesting that styrene oxide reacted with the endogenous compounds. The intracellular distribution of this epoxide was also studied in the perfused rat liver. Comparable results with those previously described were obtained. The binding of styrene oxide to the cytosolic protein was investigated by equilibrium dialysis and ultrafiltration. Only a small percentage of the compound was bound to protein

Studies to further investigate the inhibition of human liver microsomal CYP2C8 by the acyl-β-glucuronide of gemfibrozil.

Science.gov (United States)

Jenkins, S M; Zvyaga, T; Johnson, S R; Hurley, J; Wagner, A; Burrell, R; Turley, W; Leet, J E; Philip, T; Rodrigues, A D

2011-12-01

In previous studies, gemfibrozil acyl-β-glucuronide, but not gemfibrozil, was found to be a mechanism-based inhibitor of cytochrome P450 2C8. To better understand whether this inhibition is specific for gemfibrozil acyl-β-glucuronide or whether other glucuronide conjugates are potential substrates for inhibition of this enzyme, we evaluated several pharmaceutical compounds (as their acyl glucuronides) as direct-acting and metabolism-dependent inhibitors of CYP2C8 in human liver microsomes. Of 11 compounds that were evaluated as their acyl glucuronide conjugates, only gemfibrozil acyl-β-glucuronide exhibited mechanism-based inhibition, indicating that CYP2C8 mechanism-based inhibition is very specific to certain glucuronide conjugates. Structural analogs of gemfibrozil were synthesized, and their glucuronide conjugates were prepared to further examine the mechanism of inhibition. When the aromatic methyl groups on the gemfibrozil moiety were substituted with trifluoromethyls, the resulting glucuronide conjugate was a weaker inhibitor of CYP2C8 and mechanism-based inhibition was abolished. However, the glucuronide conjugates of monomethyl gemfibrozil analogs were mechanism-based inhibitors of CYP2C8, although not as potent as gemfibrozil acyl-β-glucuronide itself. The ortho-monomethyl analog was a more potent inhibitor than the meta-monomethyl analog, indicating that CYP2C8 favors the ortho position for oxidation and potential inhibition. Molecular modeling of gemfibrozil acyl-β-glucuronide in the CYP2C8 active site is consistent with the ortho-methyl position being the favored site of covalent attachment to the heme. Moreover, hydrogen bonding to four residues (Ser100, Ser103, Gln214, and Asn217) is implicated.

Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

Energy Technology Data Exchange (ETDEWEB)

Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

2006-03-15

Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

Biochemical and Histopathological study of Mesobuthus eupeus scorpion venom in the experimental rabbits

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Koohi, M.K.

2011-12-01

Full Text Available In tropical and subtropical countries, envenomation by scorpions (so-called scorpionism represents a serious public health problem. In the present study, the toxic effects of mice LD50 injections of Mesobuthus eupeus (Me venom on the kidney and liver of anesthetized rabbits were investigated. Six rabbits were selected and ALT, AST, BUN and creatinine were measured at 0, 1 and 3 hours after envenomation and histopathological studies were carried out postmortem. All the animals showed signs and symptoms ofenvenomation within 30-40 minutes and died 3 to 3.5 hours after venom injection. Histopathological examinations revealed glumerolar congestion, dilated vessels of interstitium and focal interstitial congestion in the kidney and focal hemorrhage, central vein congestion, congested vessels in portal areas and dilatedsinusoids in the liver at 3 to 3.5 hrs following venom injection. In addition, biochemical analyses indicated significant rise in the levels of ALT and creatinine following Mesobuthus eupeus envenomation in animals at 3 hrs. However no significant changes were observed at 1 hr. In conclusion, scorpion (Mesobuthuseupeus venom leads to damage in vital organs such as liver and kidney.

Efficient generation of biliary epithelial cells from rabbit intrahepatic bile duct by Y-27632 and Matrigel.

Science.gov (United States)

Jin, Lifang; Ji, Shaohui; Sun, Aijing

2013-06-01

Efficient culture of primary biliary epithelial cells (BECs) from adult liver is useful for both experimental studies and clinical applications of tissue engineering. However, an effective culture system for long-term proliferation of adult BECs is still unachieved. Laboratory rabbit has been used in a large number of studies; however, there are no reports of BECs from normal adult rabbit. As little as 5 g of normal rabbit liver tissue were minced, digested, and then clonally cultured in medium containing FBS and ITS. Cells were characterized by cell morphology, immunoassaying, and growth rate assay. Different combination of growth factors and substrates, including Y-27632 and Matrigel, were employed to assess their effect on cell proliferation. In the primary culture, the BECs cellular sheets consisting of cuboidal cells, as well as fibroblast-like cells and other hepatic cells, emerged with time of culture. The BECs cellular sheets were then manually split into cells clumps for further characterization. The subcultured cells had typical cell morphology of cholangiocytes, expressed the specific markers of BECs, including GGT, cytokeratin (CK18), and CK19, and possessed the capacity to form duct-like structure in three-dimensional Matrigel. Y-27632 and Matrigel-treated BECs had a steady growth rate as well as colony-formation capacity. The BECs were maintained in Y-27632 and Matrigel culture system for more than 3 mo. This is the first example, to our knowledge, of the successful culture of BECs from normal adult rabbit liver. Furthermore, our results indicate that treatment of BECs with Y-27632 and Matrigel is a simple method for efficient output of BECs.

An experimental microangiographic study on injured liver acinus by ligation of common bile duct

International Nuclear Information System (INIS)

Park, Jong Yeon; Kim, Yoon Gyu; Moon, Ki Ho; Lee, Suek Hong; Kim, Byung Soo; Han, Gun Taik

1994-01-01

The purpose of this study was to evaluate the morphologic changes of the injured hepatic acini following ligation of common bile duct and to investigate the pathophysiologic process of hepatic failure and biliary liver cirrhosis in the extrahepatic cholestasis. The common bile ducts of 18 rabbits were ligated partially. The rabbits were killed and selective microangiography was carried out with infusion of barium suspensio via portal vein 4 to 24 weeks after ligation. Selective microangiography was also carried out in two normal rabbits. The microangiographic findings were evaluated and correlated with histopathologic features. The sinusoids of the liver acinus showed distortion, varying degrees of luminal widening, and irregularities in architecture. Terminal branches of the portal vein (TPV) showed increased number of branches, luminal narrowing, tortuosity, distortion, and beaded appearance. Peribiliary plexi were found as thin curvilinear, barium-filled structures along the wall of the dilated bile duct. The microangiographic findings were well correlated with histopathologic findings. The grades of microangiographic and histopathologic findings were poorly correlated with the duration of the ligation of CBD. Changes in microvasculature of the liver scinus following partial ligation of common bile duct were demonstrated by microangiography. Although the microvascular changes were evoked secondary to the injury, they might have some active roles in the pathophysiologic process in the liver

Photoeffects of near ultraviolet light upon a polycyclic aromatic hydrocarbon exposed to mouse skin microsomes

International Nuclear Information System (INIS)

Peirano, W.B.

1991-01-01

Near ultraviolet (UV) light has been reported to both enhance and inhibit the tumor incidence in mice dermally exposed to benzo(a)pyrene (BaP) or polycyclic aromatic hydrocarbon (PAH) mixtures. Near UV light interacts with PAHs producing a variety of oxygenated products such as phenols, endoperoxides and quinones. However, little is known about BaP products formed from near UV irradiation of BaP-exposed mouse skin. Therefore, 14 C-BaP was incubated with 3-methylcholanthrene (3-MC) induced C 3 H/HeJ and DBA/2J mouse skin microsomes with or without a 365 nm light source. The results indicated that the concurrent 365 nm light irradiation of induced mouse skin microsomes and BaP greatly enhanced the total conversion of BaP to its products, approximately 3-fold for the C 3 H/HeJ and approximately 7-fold for the DBA/2J mouse microsomes, compared to the induced mouse skin microsomes and BaP alone. HPLC analyses of organic extracts indicated a more than additive enhancement of the formation of most of the individual cochromatographed BaP metabolites due to the combined interaction of 365 nm light with BaP and skin microsomes. Similar interactions were observed using benz(a)anthracene (BaA) in this system. These data show that near UV light alters the metabolic profile of PAHs produced by mouse skin microsomes

Early quantification of the therapeutic efficacy of the vascular disrupting agent, CKD-516, using dynamic contrast-enhanced ultrasonography in rabbit VX2 liver tumors

Energy Technology Data Exchange (ETDEWEB)

Joo, Ijin; Kim, Jung Hoon; Lee, Jeong Min; Choi, Jin Woo; Han, Joon Koo; Choi, Byung Ihn [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

2014-03-15

To evaluate the usefulness of dynamic contrast-enhanced ultrasonography (DCE-US) in the early quantification of hemodynamic change following administration of the vascular disrupting agent (VDA) CKD-516 using a rabbit VX2 liver tumor model. This study was approved by our institutional animal care and use committee. Eight VX2 liver-tumor-bearing rabbits were treated with intravenous CKD-516, and all underwent DCE-US using SonoVue before and again 2, 4, 6, and 24 hours following their treatment. The tumor perfusion parameters were obtained from the time-intensity curve of the DCE-US data. Repeated measures analysis of variance was performed to assess any significant change in tumor perfusion over time. Relative changes in the DCE-US parameters between the baseline and follow-up assessments were correlated with the relative changes in tumor size over the course of seven days using Pearson correlation. CKD-516 treatment resulted in significant changes in the DCE-US parameters, including the peak intensity, total area under the time-intensity curve (AUCtotal), and AUC during wash-out (AUCout) over time (P<0.05). Pairwise comparison tests revealed that the AUCtotal and AUC during wash-in (AUCin) seen on the two-hour follow-up were significantly lower than the baseline values (P<0.05). However, none of early changes in the DCE-US parameters until 24-hour follow-up showed a significant correlation with the relative changes in tumor size during seven days after CKD-516 treatment. Our results suggest that a novel VDA (CKD-516) can cause disruption of tumor perfusion as early as two hours after treatment and that the therapeutic effect of CKD-516 treatment can be effectively quantified using DCE-US.

Abetalipoproteinemia: A novel mutation of microsomal triglyceride ...

African Journals Online (AJOL)

Hager Barakizou

2016-01-25

Jan 25, 2016 ... Abetalipoproteinemia: A novel mutation of microsomal triglyceride transfer protein (MTP) gene in a young Tunisian patient. Hager Barakizou a,. *, Souha Gannouni a. , Khalil Messaoui a. , Mathilde Difilippo b. ,. Agne`s Sassolas b. , Fethi Bayoudh a a Department of Pediatrics, Military Hospital of Tunis, ...

Use of recovered frying oils in chicken and rabbit feeds: effect on the fatty acid and tocol composition and on the oxidation levels of meat, liver and plasma.

Science.gov (United States)

Tres, A; Bou, R; Guardiola, F; Nuchi, C D; Magrinyà, N; Codony, R

2013-03-01

The addition of some fat co- and by-products to feeds is usual nowadays; however, the regulations of their use are not always clear and vary between countries. For instance, the use of recycled cooking oils is not allowed in the European Union, but they are used in other countries. However, oils recovered from industrial frying processes could show satisfactory quality for this purpose. Here we studied the effects of including oils recovered from the frying industry in rabbit and chicken feeds (at 30 and 60 g/kg, respectively) on the fatty acid (FA) and tocol (tocopherol + tocotrienol) compositon of meat, liver and plasma, and on their oxidative stability. Three dietary treatments (replicated eight times) were compared: fresh non-used oil (LOX); oil discarded from the frying industry, having a high content of secondary oxidation compounds (HOX); and an intermediate level (MOX) obtained by mixing 50 : 50 of LOX and HOX. The FA composition of oil diets and tissues was assessed by GC, their tocol content by HPLC, the thiobarbituric acid value was used to assess tissue oxidation status, and the ferrous oxidation-xylenol orange method was used to assess the susceptibility of tissues to oxidation. Our results indicate that FA composition of rabbit and chicken meat, liver and plasma was scarcely altered by the addition of recovered frying oils to feed. Differences were encountered in the FA composition between species, which might be attributed mainly to differences in the FA digestion, absorption and metabolism between species, and to some physiological dietary factors (i.e. coprophagy in rabbits that involves fermentation with FA structure modification). The α-tocopherol (αT) content of tissues was reduced in response to the lower αT content in the recovered frying oil. Differences in the content of other tocols were encountered between chickens and rabbits, which might be attributable to the different tocol composition of their feeds, as well as to species

Spirulina improves antioxidant status by reducing oxidative stress in rabbits fed a high-cholesterol diet.

Science.gov (United States)

Kim, Mi Yeon; Cheong, Sun Hee; Lee, Jeung Hee; Kim, Min Ji; Sok, Dai-Eun; Kim, Mee Ree

2010-04-01

The beneficial effect of Spirulina (Spirulina platensis) on tissue lipid peroxidation and oxidative DNA damage was tested in the hypercholesterolemic New Zealand White rabbit model. After hypercholesterolemia was induced by feeding a high cholesterol (0.5%) diet (HCD) for 4 weeks, then HCD supplemented with 1% or 5% Spirulina (SP1 or SP5, respectively) was provided for an additional 8 weeks. Spirulina supplementation significantly reduced the increased lipid peroxidation level in HCD-fed rabbits, and levels recovered to control values. Oxidative stress biomarkers such as glutathione, glutathione peroxidase, glutathione reductase, and glutathione S-transferase were significantly improved in the liver and red blood cells of rabbits fed SP1. Furthermore, SP5 induced antioxidant enzyme activity by 3.1-fold for glutathione, 2.5-fold for glutathione peroxidase, 2.7-fold for glutathione reductase, and 2.3-fold for glutathione S-transferase in liver, compared to the HCD group. DNA damage in lymphocytes was significantly reduced in both the SP1 and SP5 groups, based on the comet assay. Findings from the present study suggest that dietary supplementation with Spirulina may be useful to protect the cells from lipid peroxidation and oxidative DNA damage.

The incorporation of labelled amino acids into the subcellular fractions of the rabbit brain

International Nuclear Information System (INIS)

Ogrodnik, W.

1980-01-01

Radioactive amino acids were injected into the fourth ventriculum of adult rabbits. After 3, 6 and 13 hours the animals were killed and tissue subcellular fractions were prepared from their brains. Nucleic acids were extracted and quantitatively determined from nucleic, myelin, mitochondrial, microsomal and cytoplasmic fractions. The radioactivity was determined in the protein and nucleic acid fractions. It was found out that the incorporation of radioactive amino acids increased in relation to time. In the analyzed subcellular fractions a very rapid incorporation of glutamic acid and leucine into cytoplasmic proteins was observed. The chromatographic analysis of the nucleic acids showed that radioactivity in the nucleic acid fractions depended on a radioactive protein contamination. Radioactive aminoacyl-tRNA was not found in the nucleic acid fractions, extracted from different subcellular fractions. (author)

Cytochrome P-450-catalyzed desaturation of valproic acid in vitro. Species differences, induction effects, and mechanistic studies

International Nuclear Information System (INIS)

Rettie, A.E.; Boberg, M.; Rettenmeier, A.W.; Baillie, T.A.

1988-01-01

The cytochrome P-450-mediated desaturation of valproic acid (VPA) to its hepatotoxic metabolite, 2-n-propyl-4-pentenoic acid (4-ene-VPA), was examined in liver microsomes from rats, mice, rabbits and humans. The highest substrate turnover was found with microsomes from rabbits (44.2 +/- 2.7 pmol of product/nmol P-450/15 min), while lower activities were observed in preparations from human, mouse, and rat liver, in that order. Pretreatment of animals with phenobarbital led to enhanced rates of formation of 4-ene-VPA in vitro and yielded induction ratios for desaturation ranging from 2.5 to 8.4, depending upon the species. Comparative studies in the rat showed that phenobarbital is a more potent inducer of olefin formation than either phenytoin or carbamazepine. The mechanism of the desaturation reaction was studied by inter- and intramolecular deuterium isotope effect experiments, which demonstrated that removal of a hydrogen atom from the subterminal C-4 position of VPA is rate limiting in the formation of both 4-ene- and 4-hydroxy-VPA. Hydroxylation at the neighboring C-5 position, on the other hand, was highly sensitive to deuterium substitution at that site, but not to deuteration at C-4. Based on these findings, it is proposed that 4-ene- and 4-hydroxy-VPA are products of a common P-450-dependent metabolic pathway, in which a carbon-centered free radical at C-4 serves as the key intermediate. 5-Hydroxy-VPA, in contrast, derives from an independent hydroxylation reaction

The effect of fenbuconazole on cell proliferation and enzyme induction in the liver of female CD1 mice

International Nuclear Information System (INIS)

Juberg, Daland R.; Mudra, Daniel R.; Hazelton, George A.; Parkinson, Andrew

2006-01-01

Fenbuconazole, a triazole fungicide, has been associated with an increase in the incidence of liver adenomas in female mice following long-term dietary exposure. The aim of this study was to evaluate whether the mode of action for liver tumor formation by fenbuconazole is similar to that of phenobarbital. Treatment of CD1 mice with 0, 20, 60, 180 or 1300 ppm fenbuconazole for up to 4 weeks caused a dose-dependent increase in liver weight that was associated with centrilobular hepatocellular hypertrophy, cytoplasmic eosinophilia and panlobular hepatocellular vacuolation, as well as an initial increase in the cell proliferation labeling index. Fenbuconazole also caused a dose-dependent increase in liver microsomal cytochromes b 5 and P450 and the levels of immunoreactive CYP2B10 and its associated activity 7-pentoxyresorufin O-dealkylation (PROD). Treatment of mice with 1000 ppm phenobarbital elicited the same effects as treatment of mice with 1300 ppm fenbuconazole, except that phenobarbital was more effective than fenbuconazole at inducing PROD activity, even though fenbuconazole induced CYP2B10 to the same extent as did phenobarbital. This difference was attributed to the ability of fenbuconazole to bind tightly to CYP2B10 and partially mask its catalytic activity in liver microsomes, which is characteristic of several azole-containing drugs. All hepatocellular changes and induced enzyme activity returned to control levels within 4 weeks of discontinuing treatment with fenbuconazole or phenobarbital, indicating that the observed changes were fully reversible. We conclude that fenbuconazole is a phenobarbital-type inducer of mouse liver cytochrome P450, and the mode of action by which fenbuconazole induces liver adenomas in mice is similar to that of phenobarbital

Insulin receptors in the mammary gland

International Nuclear Information System (INIS)

Smith, D.H.

1986-01-01

Insulin binding studies were conducted using mammary membrane preparations to further the authors understanding of insulin's role in regulating mammary metabolism, particularly ruminant mammary metabolism. Specific objectives were to: (1) characterize insulin binding to bovine mammary microsomes and determine if the specificity and kinetics of binding indicate the presence of insulin receptors in bovine mammary gland; (2) examine and compare insulin binding by liver and mammary microsomes of the pig and dairy cow; (3) examine insulin binding to bovine milk fat globule membranes (MFGM) and evaluate this model's usefulness in assessing insulin receptor regulation in the mammary gland of the cow; (4) examine the effect of dietary fat in insulin binding by rat mammary and liver microsomes. The specificity and kinetics of 125 I-insulin binding of bovine mammary microsomes indicated the presence of insulin receptors in bovine mammary gland. Bovine liver and mammary microsomes specifically bound less 125 I-insulin than did the corresponding porcine microsomes, and mammary microsomes, regardless of species, specifically bound less 125 I-insulin than did liver microsomes. These differences in binding suggest differences in insulin responsiveness between pigs and cattle, as well as between the liver and mammary glands

The effect of trimethoprim on CYP2C8 mediated rosiglitazone metabolism in human liver microsomes and healthy subjects

Science.gov (United States)

Hruska, M W; Amico, J A; Langaee, T Y; Ferrell, R E; Fitzgerald, S M; Frye, R F

2005-01-01

Aims Rosiglitazone, a thiazolidinedione antidiabetic medication used in the treatment of Type 2 diabetes mellitus, is predominantly metabolized by the cytochrome P450 (CYP) enzyme CYP2C8. The anti-infective drug trimethoprim has been shown in vitro to be a selective inhibitor of CYP2C8. The purpose of this study was to evaluate the effect of trimethoprim on the CYP2C8 mediated metabolism of rosiglitazone in vivo and in vitro. Methods The effect of trimethoprim on the metabolism of rosiglitazone in vitro was assessed in pooled human liver microsomes. The effect in vivo was determined by evaluating rosiglitazone pharmacokinetics in the presence and absence of trimethoprim. Eight healthy subjects (four men and four women) completed a randomized, cross-over study. Subjects received single dose rosiglitazone (8 mg) in the presence and absence of trimethoprim 200 mg given twice daily for 5 days. Results Trimethoprim inhibited rosiglitazone metabolism both in vitro and in vivo. Inhibition of rosiglitazone para-hydroxylation by trimethoprim in vitro was found to be competitive with apparent Ki and IC50 values of 29 µm and 54.5 µm, respectively. In the presence of trimethoprim, rosiglitazone plasma AUC was increased by 31% (P = 0.01) from 2774 ± 645 µg l−1 h to 3643 ± 1051 µg l−1 h (95% confidence interval (Cl) for difference 189, 1549), and half-life was increased by 27% (P = 0.006) from 3.3 ± 0.5 to 4.2 ± 0.8 h (95% Cl for difference 0.36, 1.5). Trimethoprim reduced the para-O-sulphate rosiglitazone/rosiglitazone and the N-desmethylrosiglitazone/rosiglitazone AUC(0–24) ratios by 22% and 38%, respectively. Conclusions These results indicate that trimethoprim is a competitive inhibitor of CYP2C8-mediated rosiglitazone metabolism in vitro and that trimethoprim administration increases plasma rosiglitazone concentrations in healthy subjects. PMID:15606443

3.0 T MR diffusion weighted imaging in the evaluation of radio-frequency ablation of the liver VX2 tumors

International Nuclear Information System (INIS)

Liu Yubao; Liang Changhong; Wang Qiushi; Xie Shufei; Yu Yuanxin; Liu Zaiyi; Zhang Zhonglin

2010-01-01

Objective: To evaluate 3.0 T MR DWI techniques in detecting the lesions of pre and post-radiofrequency ablation of the rabbit liver VX2 tumors. Methods: Twenty two New Zealand white rabbits were used in this experiment. Twenty tumor fragments were implanted into the livers of 20 rabbits respectively. Two normal rabbits were used as controls for radiofrequency ablation of the normal liver. 3. 0 T MR DWI was performed 14 to 21 days after tumor implantation (mean, 17 days) in the tumor-bearing animals. Radiofrequency ablation was performed in the 18 tumor-bearing animals and in the two healthy animals. 3.0 T MRI and DWI were performed 7 to 10 days after radiofrequency ablation (mean, 8 days). Pathology was obtained immediately after the completion of post radiofrequency ablation MR imaging. The MRI features and ADC values of pre- and post -radiofrequency ablation lesions in the livers with VX2 tumors and normal rabbits were analyzed and correlation was made with histopathologic findings. Analysis of variance repeated measures were performed in analyzing the differences among the ADC values of different tissues with the same b value. Results: All 20 rabbit liver models of VX2 tumors were constructed successfully. One rabbit died of anesthetic overdose, another one showed necrosis within the implanted tumor. All 18 untreated VX2 tumors had predominantly low or iso-signal intensity on T 1 WI and high signal intensity on T 2 WI. All 18 VX2 tumors and 2 normal rabbits were treated by radiofrequency ablation successfully. Lesions treated by Radiofrequency ablation displayed low signal intensity on T 1 WI, and high signal intensity on T 2 WI. Seven to 10 days after radiofrequency ablation, lesions varied from having low signal intensity to slightly increased signal intensity on T 1 WI, with areas of mixed (high, intermediate, and low) signal intensity. A peripheral rim of high signal intensity with varying thickness on T 2 WI correlated with granulation tissue, which

Evaluation of acute toxicity of genabilic acid (menbutone 10% in rabbits

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S. O. El Okle

2014-09-01

Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 A complete investigation of the acute toxicity of a choleretic compound, menbutone, was performed in rabbits, including lethal dose for 50% of rabbits determination, clinical signs observation and in vivo and post-mortem examinations. Haematological, biochemical and histopathological changes resulting from intramuscular injection of menbutone were also investigated at dose 400 mg/kg body weight. Acute toxicity of menbutone at dose of 400 mg/kg BW induced interstitial myocarditis and multifocal necrosis, whereas serum creatine phosphokinase, creatinine phosphokinase-MB isoenzyme and aspartate aminotransferase activities were significantly increased. Elevation of serum alanine aminotransferase and alkaline phosphatase activities and total bilirubin level associated with lowered albumin content was consistent with histopathological changes of hepatic tissues; hepatic necrosis and fatty infiltration were pronounced indicators of injuries. Renal tubular necrosis and interstitial nephritis were also observed in intoxicated rabbits. Menbutone also induced variations in some haematological parameters. We concluded that acute toxicity of menbutone in rabbits occurred at accidental high doses, as the lethal dose was about 50 fold over the recommended therapeutic dose for other animals. Cardiac muscle, liver and kidneys are the main target organs for menbutone toxicity. Menbutone is not recommended for use in rabbits suffering from any cardiacand hepatic disorders, especially in overdosing situations.

Metabolism of polybrominated diphenyl ethers and tetrabromobisphenol A by fish liver subcellular fractions in vitro.

Science.gov (United States)

Shen, Mengnan; Cheng, Jie; Wu, Ruohan; Zhang, Shenghu; Mao, Liang; Gao, Shixiang

2012-06-15

Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are two major flame retardants that accumulate in fish tissues and are potentially toxic. Their debrominated and oxidated derivatives were also reported in fish tissues although the sources of theses derivatives were unidentified. Our study was to determine whether PBDEs and TBBPA could be metabolized by fish liver subcellular fractions in vitro and to identify what types of metabolites were formed. Liver microsomes and S9 fractions of crucian carp (Carassius auratus) were exposed to 4,4'-dibromodiphenyl ether (BDE 15), 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) or TBBPA solutions for 4h. Exposure of liver subcellular fractions to BDE 15 resulted in the formation of bromophenol and two monohydroxylated dibromodiphenyl ether metabolites. Neither in microsomes nor in S9 studies has revealed the presence of hydroxylated metabolites with BDE 47 exposure which indicated that the oxidation reactions in vitro were hindered by the increased number of bromine substituents on the PBDEs. TBBPA underwent an oxidative cleavage near the central carbon of the molecule, which led to the production of 2,6-dibromo-4-isopropyl-phenol and three unidentified metabolites. Another metabolite of TBBPA characterized as a hexa-brominated compound with three aromatic rings was also found in the liver subcellular fractions. These results suggest that the biotransformation of BDE 15 and TBBPA in fish liver is mediated by cytochrome P450 (CYP450) enzymes, as revealed by the formation of hydroxylated metabolites and oxidative bond cleavage products. Moreover, further studies on the identification of specific CYP450 isozymes involved in the biotransformation revealed that CYP1A was the major enzyme responsible for the biotransformation of BDE 15 and TBBPA in fish liver subcellular fractions and CYP3A4 also played a major role in metabolism of TBBPA. Copyright © 2012 Elsevier B.V. All rights reserved.

Metabolites of 5F-AKB-48, a synthetic cannabinoid receptor agonist, identified in human urine and liver microsomal preparations using liquid chromatography high-resolution mass spectrometry.

Science.gov (United States)

Holm, Niels Bjerre; Pedersen, Anders Just; Dalsgaard, Petur Weihe; Linnet, Kristian

2015-03-01

New types of synthetic cannabinoid designer drugs are constantly introduced to the illicit drug market to circumvent legislation. Recently, N-​(1-Adamant​yl)-​1-​(5-​fluoropentyl)-​1H-​indazole-​3-​carboxamide (5F-AKB-48), also known as 5F-APINACA, was identified as an adulterant in herbal products. This compound deviates from earlier JHW-type synthetic cannabinoids by having an indazole ring connected to an adamantyl group via a carboxamide linkage. Synthetic cannabinoids are completely metabolized, and identification of the metabolites is thus crucial when using urine as the sample matrix. Using an authentic urine sample and high-resolution accurate-mass Fourier transform Orbitrap mass spectrometry, we identified 16 phase-I metabolites of 5F-AKB-48. The modifications included mono-, di-, and trihydroxylation on the adamantyl ring alone or in combination with hydroxylation on the N-fluoropentylindazole moiety, dealkylation of the N-fluoropentyl side chain, and oxidative loss of fluorine as well as combinations thereof. The results were compared to human liver microsomal (HLM) incubations, which predominantly showed time-dependent formation of mono-, di-, and trihydroxylated metabolites having the hydroxyl groups on the adamantyl ring. The results presented here may be used to select metabolites specific of 5F-AKB-48 for use in clinical and forensic screening. Copyright © 2014 John Wiley & Sons, Ltd.

Multiple viral/self immunological cross-reactivity in liver kidney microsomal antibody positive hepatitis C virus infected patients is associated with the possession of HLA B51.

Science.gov (United States)

Bogdanos, D-P; Lenzi, M; Okamoto, M; Rigopoulou, E I; Muratori, P; Ma, Y; Muratori, L; Tsantoulas, D; Mieli- Vergani, G; Bianchi, F B; Vergani, D

2004-01-01

Liver Kidney Microsomal autoantibody type 1(LKM1) directed to cytochrome P4502D6 (CYP2D6) characterises autoimmune hepatitis type-2 (AIH-2), but is also found in a proportion of chronic hepatitis C virus (HCV) infected patients, CYP2D6252-271 being a major B- cell autoepitope. Molecular mimicry and immunological cross-reactivity between CYP2D6252-271, HCV polyprotein and the infected cell protein 4 (ICP4) of herpes simplex virus type 1 (HSV-1) have been suggested as triggers for the induction of LKM1, but reactivity and cross-reactivity to the relevant sequences have not been investigated experimentally. CYP2D6252-271 and its viral homologues were constructed and tested by ELISA in the sera of 46 chronically infected HCV patients, 23 of whom were LKM1 positive. Reactivity to the E1 HCV and ICP4 HSV1 mimics was frequently found in HCV infected patients irrespectively of their LKM1 status; viral/self cross-reactivity (as indicated by inhibition studies), however, was present in the only 2 of the 23 LKM1 seropositive HCV patients, who possessed the HLA allotype B51. Our results indicate that in HCV infected patients virus/self cross-reactivity is dependent on a specific immunogenetic background, a finding awaiting confirmation by studies in larger series of patients.

[Detection and the production mechanism of antinuclear antibodies (ANA) and anti-liver/kidney microsomal tpe 1 antibodies (anti-LKM1) in patients with chronic hepatitis C].

Science.gov (United States)

Bai, Li; Lu, Hai-Ying; Feng, Zhen-Ru; Yu, Min; Li, Wen-Gang; Gong, Wei-Bo; Zhao, Nu-en-ji-ya; Xu, Xiao-Yuan

2009-08-01

To investigate the prevalence of antinuclear antibodies (ANA) and anti-liver/ kidney microsomal type 1 antibodies (anti-LKM1) in patients with chronic hepatitis C (CHC)and to explore the mechanism of production of these autoantibodies. Serum samples were collected from 360 patients with CHC (case group), 69 patients with chronic hepatitis B (CHB) and 69 patients with autoimmune hepatitis (AIH) (control group). Serum ANA and anti-LKM1 were detected by indirect immunofluorescence (HF) technique and enzyme-linked immunosorbent assay (ELISA), respectively. Multi-factor analysis was performed to explore the correlations of the production of autoantibodies with some factors such as age, sex, viral loads, HCV genotype, biochemical parameters and clinical characteristics. Fifty-four (15%) of 360 patients infected with HCV were positive in autoantibodies. The prevalence of ANA and anti-LKM1 were 12.5% (45/360) and 2.5% (9/ 360), respectively. The positive rate of autoantibodies in patients with CHC was significantly higher than that in patients with CHB (15% vs 2.9%, P = 0.006), but significantly lower than that in patients with AIH (15% vs 47.9%, P 0.05). Autoantibodies related to AIH can be detected in CHC patients; interferon may not induce the production of autoantibodies; it is very likely that HCV infection induces the autoimmune reaction and the production of autoantibodies.

Hepatic Intra-arterial Delivery of a "Trojan-horses" Gene Therapy: A Pilot Study on Rabbit VX2 Hepatic Tumor Model.

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Pellerin, Olivier; Amara, Ikram; Sapoval, Marc; Méachi, Tchao; Déan, Carole; Beaune, Philippe; de Waziers, Isabelle

2018-01-01

Gene-directed enzyme prodrug therapy (GDEPT) is a "Trojan-horses" suicide gene therapy that consists of tumor-targeted gene delivery (vectorized by mesenchymal stem cells MSCs) encoding an enzyme that converts a harmless prodrug into cytotoxic metabolites in situ. Then, cytotoxic metabolites passively diffuse in the neighboring tumor cells and kill them (bystander effect). The goal of our study was to assess the feasibility and efficacy of intra-arterial administration of MSCs transduced with an optimized gene (MSC-CYP2B6TM-RED) followed by intravenous administration of cyclophosphamide (CPA) into the VX2 rabbit liver tumor. Nine rabbits with a VX2 liver tumor were randomly assigned into three groups: Control group A (one rabbit) free of any treatment; Control group B (two rabbits) receiving intravenous injection of cyclophosphamide at day 3 and CPA at day 14; and Group C (six rabbits) receiving the GDEPT treatment, consisting of successive intra-arterial injection of transduced-MSCs at days 0 (n = 6) and 11 (n = 3), followed by injection of CPA at days 3 (n = 6) and 14 (n = 3). The tumor response was assessed by ultrasound scan every 7 days and histopathological analysis at sacrifice (D25). There was a significant difference in the tumor volume between control groups (A + B) and group C at D7: 38/19 cm 3 (p = 0.024); D11: 51/20 cm 3 (p = 0.024), and D25: 121/37 cm 3 (p = 0.048). Tumor necrosis was significantly greater and metastatic spread was lower for rabbits who received GDEPT (78% of total tumor surface) than for control animals (A + B) (22% of total tumor surface (p = 0.006). Intra-arterial delivery of transduced-MSCs is feasible and, after CPA injection, resulted in 78% tumor necrosis (p = 0.006) and less metastasis in a VX2 liver tumor model.

Dynamic contrast-enhanced MRI using a macromolecular MR contrast agent (P792): Evaluation of antivascular drug effect in a rabbit VX2 liver tumor model

Energy Technology Data Exchange (ETDEWEB)

Park, Hee Sun [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of); Han, Joon Koo; Lee, Jeong Min; Woo, Sung Min; Choi, Byung Ihn [Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Young Il [Dept. of Radiology, Sheikh Khalifa Specialty Hospital, Ras Al Khaimah (United Arab Emirates); Choi, Jin Young [Dept. of Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2015-10-15

To evaluate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using macromolecular contrast agent (P792) for assessment of vascular disrupting drug effect in rabbit VX2 liver tumor models. This study was approved by our Institutional Animal Care and Use Committee. DCE-MRI was performed with 3-T scanner in 13 VX2 liver tumor-bearing rabbits, before, 4 hours after, and 24 hours after administration of vascular disrupting agent (VDA), using gadomelitol (P792, n = 7) or low molecular weight contrast agent (gadoterate meglumine [Gd-DOTA], n = 6). P792 was injected at a of dose 0.05 mmol/kg, while that of Gd-DOTA was 0.2 mmol/kg. DCE-MRI parameters including volume transfer coefficient (Ktrans) and initial area under the gadolinium concentration-time curve until 60 seconds (iAUC) of tumors were compared between the 2 groups at each time point. DCE-MRI parameters were correlated with tumor histopathology. Reproducibility in measurement of DCE-MRI parameters and image quality of source MR were compared between groups. P792 group showed a more prominent decrease in Ktrans and iAUC at 4 hours and 24 hours, as compared to the Gd-DOTA group. Changes in DCE-MRI parameters showed a weak correlation with histologic parameters (necrotic fraction and microvessel density) in both groups. Reproducibility of DCE-MRI parameters and overall image quality was not significantly better in the P792 group, as compared to the Gd-DOTA group. Dynamic contrast-enhanced magnetic resonance imaging using a macromolecular contrast agent shows changes of hepatic perfusion more clearly after administration of the VDA. Gadolinium was required at smaller doses than a low molecular contrast agent.

Dynamic contrast-enhanced MRI using a macromolecular MR contrast agent (P792): Evaluation of antivascular drug effect in a rabbit VX2 liver tumor model

International Nuclear Information System (INIS)

Park, Hee Sun; Han, Joon Koo; Lee, Jeong Min; Woo, Sung Min; Choi, Byung Ihn; Kim, Young Il; Choi, Jin Young

2015-01-01

To evaluate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using macromolecular contrast agent (P792) for assessment of vascular disrupting drug effect in rabbit VX2 liver tumor models. This study was approved by our Institutional Animal Care and Use Committee. DCE-MRI was performed with 3-T scanner in 13 VX2 liver tumor-bearing rabbits, before, 4 hours after, and 24 hours after administration of vascular disrupting agent (VDA), using gadomelitol (P792, n = 7) or low molecular weight contrast agent (gadoterate meglumine [Gd-DOTA], n = 6). P792 was injected at a of dose 0.05 mmol/kg, while that of Gd-DOTA was 0.2 mmol/kg. DCE-MRI parameters including volume transfer coefficient (Ktrans) and initial area under the gadolinium concentration-time curve until 60 seconds (iAUC) of tumors were compared between the 2 groups at each time point. DCE-MRI parameters were correlated with tumor histopathology. Reproducibility in measurement of DCE-MRI parameters and image quality of source MR were compared between groups. P792 group showed a more prominent decrease in Ktrans and iAUC at 4 hours and 24 hours, as compared to the Gd-DOTA group. Changes in DCE-MRI parameters showed a weak correlation with histologic parameters (necrotic fraction and microvessel density) in both groups. Reproducibility of DCE-MRI parameters and overall image quality was not significantly better in the P792 group, as compared to the Gd-DOTA group. Dynamic contrast-enhanced magnetic resonance imaging using a macromolecular contrast agent shows changes of hepatic perfusion more clearly after administration of the VDA. Gadolinium was required at smaller doses than a low molecular contrast agent

Hepatic parenchymal changes following transcatheter embolization and chemoembolization in a rabbit tumor model.

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Yong Wang

Full Text Available OBJECTIVE: To compare the effects of transcatheter arterial chemoembolization (TACE with transcatheter arterial embolization (TAE on liver function, hepatic damage, and hepatic fibrogenesis in a rabbit tumor model. MATERIALS AND METHODS: Thirty-nine New Zealand white rabbits implanted with VX2 tumors in the left liver lobes were randomly divided into three groups: TAE, TACE, and control group. In the TAE group (n = 15, polyvinyl alcohol particles (PVAs were used for left hepatic artery embolization. In the TACE group (n = 15, the tumors were treated with left hepatic arterial infusions of a suspension of 10-hydroxycamptothecin and lipiodol, followed by embolization with PVAs. In the control group (n = 9, the animals received sham treatment with distilled water. Serum and liver samples were collected at 6 hours, 3 days and 7 days after treatment. Liver damage was measured using a liver function test and histological analyses. Liver fibrogenesis and hepatic stellate cell (HSC activation were evaluated using Sirius Red and anti-alpha-smooth muscle actin (α-SMA immunohistochemical stains. RESULTS: TACE caused liver injury with greater increases in serum alanine aminotransferase and aspartate aminotransferase levels on day 3 (P<0.05. Histological analyses revealed increased hepatic necrosis in adjacent non-tumorous liver tissue from day 3 compared to the TAE group (Suzuki score of 2.33±1.29 versus 1.13±1.18, P = 0.001. HSC activation and proliferation were significantly increased in the TACE group compared to the control group at 3 and 7 days after treatment (0.074±0.014 vs. 0.010±0.006, and 0.088±0.023 vs. 0.017±0.009, P<0.05. Sirius Red staining demonstrated a statistically significant increase in collagen deposition in the livers in the TACE group 7 days after embolization compared to the control group (0.118±0.012 vs. 0.060±0.017, P = 0.05. CONCLUSION: The results of this animal study revealed that TACE induced

Trichostatin A (TSA) improves the development of rabbit-rabbit intraspecies cloned embryos, but not rabbit-human interspecies cloned embryos.

Science.gov (United States)

Shi, Li-Hong; Miao, Yi-Liang; Ouyang, Ying-Chun; Huang, Jun-Cheng; Lei, Zi-Li; Yang, Ji-Wen; Han, Zhi-Ming; Song, Xiang-Fen; Sun, Qing-Yuan; Chen, Da-Yuan

2008-03-01

The interspecies somatic cell nuclear transfer (iSCNT) technique for therapeutic cloning gives great promise for treatment of many human diseases. However, the incomplete nuclear reprogramming and the low blastocyst rate of iSCNT are still big problems. Herein, we observed the effect of TSA on the development of rabbit-rabbit intraspecies and rabbit-human interspecies cloned embryos. After treatment with TSA for 6 hr during activation, we found that the blastocyst rate of rabbit-rabbit cloned embryos was more than two times higher than that of untreated embryos; however, the blastocyst rate of TSA-treated rabbit-human interspecies cloned embryos decreased. We also found evident time-dependent histone deacetylation-reacetylation changes in rabbit-rabbit cloned embryos, but not in rabbit-human cloned embryos from fusion to 6 hr after activation. Our results suggest that TSA-treatment does not improve blastocyst development of rabbit-human iSCNT embryos and that abnormal histone deacetylation-reacetylation changes in iSCNT embryos may account for their poor blastocyst development. (c) 2008 Wiley-Liss, Inc.

Molecular Pathogenesis of Liver Steatosis Induced by Hepatitis C Virus

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Cheng Jun

2012-09-01

Full Text Available Liver steatosis is a pathological hallmark in patients with chronic hepatitis C (CHC. Increased lipid uptake, decreased lipid secretion, increased lipid synthesis and decreased lipid degradation are all involved in pathogenesis of steatosis induced by hepatitic C virus (HCV infection. Level of low density lipoprotein receptor (LDL-R and activity of peroxisome proliferator-activated receptor (PPAR α is related to liver uptake of lipid from circulation, and affected by HCV. Secretion via microsomal triglyceride transfer protein (MTTP, and formation of very low density lipoprotein (VLDL have been hampered by HCV infection. Up-regulation of lipid synthesis related genes, such as sterol regulatory element-binding protein (SREBP-1, SREBP-2, SREBP-1c, fatty acid synthase (FASN, HMG CoA reductase (HMGCR, liver X receptor (LXR, acetyl-CoA carboxylase 1 (ACC1, hepatic CB (1 receptors, retinoid X receptor (RXR α, were the main stay of liver steatosis pathogenesis. Degradation of lipid in liver is decreased in patients with CHC. There is strong evidence that heterogeneity of HCV core genes of different genotypes affect their effects of liver steatosis induction. A mechanism in which steatosis is involved in HCV life cycle is emerging.

Hypocholesterolemic and Antiatherosclerotic Potential of Basella alba Leaf Extract in Hypercholesterolemia-Induced Rabbits

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Gunasekaran Baskaran

2015-01-01

Full Text Available Hypercholesterolemia is the major risk factor that leads to atherosclerosis. Nowadays, alternative treatment using medicinal plants gained much attention since the usage of statins leads to adverse health effects, especially liver and muscle toxicity. This study was designed to investigate the hypocholesterolemic and antiatherosclerotic effects of Basella alba (B. alba using hypercholesterolemia-induced rabbits. Twenty New Zealand white rabbits were divided into 5 groups and fed with varying diets: normal diet, 2% high cholesterol diet (HCD, 2% HCD + 10 mg/kg simvastatin, 2% HCD + 100 mg/kg B. alba extract, and 2% HCD + 200 mg/kg B. alba extract, respectively. The treatment with B. alba extract significantly lowered the levels of total cholesterol, LDL, and triglycerides and increased HDL and antioxidant enzymes (SOD and GPx levels. The elevated levels of liver enzymes (AST and ALT and creatine kinase were noted in hypercholesterolemic and statin treated groups indicating liver and muscle injuries. Treatment with B. alba extract also significantly suppressed the aortic plaque formation and reduced the intima: media ratio as observed in simvastatin-treated group. This is the first in vivo study on B. alba that suggests its potential as an alternative therapeutic agent for hypercholesterolemia and atherosclerosis.

The interaction of representative members from two classes of antimycotics--the azoles and the allylamines--with cytochromes P-450 in steroidogenic tissues and liver.

Science.gov (United States)

Schuster, I

1985-06-01

Spectrophotometric studies with ketoconazole, clotrimazole and miconazole show strong type-II interactions with several cytochromes P-450, particularly (Ks greater than 10(7)M-1; pH7.4; 25 degrees C) with the 11 beta-hydroxylase of adrenal mitochondria, with the 17 alpha/20 lyase of testis microsomes and with some forms of cytochromes P-450 of liver. A tight binding of the azoles also occurs to the reduced cytochromes, giving rise to an impeded CO binding to the haem iron. The binding of the azoles to 11 beta-hydroxylase and 17 alpha/20 lyase is much tighter than the binding of endogenous substrates, and consequently inhibition of steroidogenesis will occur at these sites. The metabolism of xenobiotic substrates by the cytochromes P-450 of liver will also be severely impeded. In contrast, the allylamines naftifine and SF 86-327 are type-I substrates for a small portion of cytochromes P-450 of liver microsomes only and there is no spectral evidence for binding to the cytochromes P-450 involved in steroid biosynthesis.

Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

NARCIS (Netherlands)

Burt, S.A.; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; van der Poel, Wim H.M.

2016-01-01

Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates.

A comparative study of precision cut liver slices, hepatocytes, and liver microsomes from the Wistar rat using metronidazole as a model substance

DEFF Research Database (Denmark)

Sidelmann, U. G.; Cornett, Claus; Tjornelund, J.

1996-01-01

1. Metronidazole is metabolized by rat liver in vitro models to form a hydroxy metabolite, an acetic acid metabolite, a glucuronic acid conjugate, and a sulphate conjugate. 2. Four different in vitro systems for investigation of drug metabolism based on liver preparations from the male Wistar rat...

Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands

NARCIS (Netherlands)

Burt, Sara A.; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; Poel, van der Wim H.M.

2016-01-01

Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates.

THE PRESENCE OF ENDOGENOUS PYROGEN IN NORMAL RABBIT TISSUES.

Science.gov (United States)

SNELL, E S; ATKINS, E

1965-06-01

Saline extracts of homogenized, uninfected, rabbit tissues produced febrile responses when injected intravenously into rabbits. Extracts of muscle, lung, and heart evoked fevers that were similar to those induced by leucocyte pyrogen; extracts of spleen, liver, and kidney caused more sustained fevers. The minimal pyrogenic dose appeared to be between 1.5 and 3 gm wet weight of tissue. Evidence is presented that neither Gram-negative bacterial endotoxin nor polymorphonuclear leucocytes (circulating or sequestered in the tissues) can be implicated as the source of pyrogen in tissue extracts. It seems likely, therefore, that a pyrogenic material of truly endogenous origin is widely distributed in tissues. Tissue pyrogen appears to be a large molecule which is relatively resistant to treatment with acid but not with alkali. Possible pathological roles for this endogenous agent (or agents) are briefly indicated.

The in vitro NADPH-dependent inhibition by CCl4 of the ATP-dependent calcium uptake of hepatic microsomes from male rats. Studies on the mechanism of the inactivation of the hepatic microsomal calcium pump by the CCl3 radical

International Nuclear Information System (INIS)

Srivastava, S.P.; Chen, N.Q.; Holtzman, J.L.

1990-01-01

The hepatotoxicity of CCl4 is mediated through its initial reduction by cytochrome P-450 to the CCl3 radical. This radical then damages important metabolic systems such as the ATP-dependent microsomal Ca2+ pump. Previous studies from our laboratory on isolated microsomes have shown that NADPH in the absence of toxic agents inhibits this pump. We have now found in in vitro incubations that CCl4 (0.5-2.5 mM) enhanced the NADPH-dependent inhibition of Ca2+ uptake from 28% without CCl4 to a maximum of 68%. These concentrations are in the range found in the livers and blood of lethally intoxicated animals and are toxic to cultured hepatocytes. The inhibition of Ca2+ uptake was due both to a decrease in the Ca2(+)-dependent ATPase and to an enhanced release of Ca2+ from the microsomes. The NADPH-dependent CCl4 inhibition was greater under N2 and was totally prevented by CO. GSH (1-10 mM) added during the incubation with CCl4 prevented the inhibition. This protection was also seen when the incubations were performed under nitrogen. When samples were preincubated with CCl4, the CCl4 metabolism was stopped, and then the Ca2+ uptake was determined; GSH reversed the CCl4 inhibition of Ca2+ uptake. This reversal showed saturation kinetics for GSH with two Km values of 0.315 and 93 microM when both the preincubation and the Ca2+ uptake were performed under air, and 0.512 and 31 microM when both were performed under nitrogen. Cysteine did not prevent the NADPH-dependent CCl4 inhibition of Ca2+ uptake. CCl4 increased lipid peroxidation in air, but no lipid peroxidation was seen under nitrogen. Lipid peroxidation was only modestly reversed by GSH. GSH did not remove 14C bound to samples preincubated with the 14CCl4

Identification of AKB-48 and 5F-AKB-48 Metabolites in Authentic Human Urine Samples Using Human Liver Microsomes and Time of Flight Mass Spectrometry.

Science.gov (United States)

Vikingsson, Svante; Josefsson, Martin; Gréen, Henrik

2015-01-01

The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 35 urine samples from authentic cases were analyzed with liquid chromatography quadrupole tandem time of flight mass spectrometry. Using HLMs 41 metabolites of AKB-48 and 37 metabolites of 5F-AKB-48 were identified, principally represented by hydroxylation but also ketone formation and dealkylation. Monohydroxylated metabolites were replaced by di- and trihydroxylated metabolites within 30 min. The metabolites from the HLM incubations accounted for on average 84% (range, 67-100) and 91% (range, 71-100) of the combined area in the case samples for AKB-48 and 5F-AKB-48, respectively. While defluorinated metabolites accounted for on average 74% of the combined area after a 5F-AKB-48 intake only a few identified metabolites were shared between AKB-48 and 5F-AKB-48, illustrating the need for a systematic approach to identify unique metabolites. HLMs in combination with case samples seem suitable for this purpose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Relation of dietary carbohydrates to lipid metabolism and the status of zinc and chromium in rabbits.

Science.gov (United States)

Moersen, T J; Borgman, R F

1984-06-01

Rabbits were fed a purified ration known to produce alterations in lipid metabolism and cholelithiasis. During a 14-week period, group 1 was fed sucrose as the sole dietary carbohydrate, whereas group 2 was fed corn starch; the rations were equicaloric and the carbohydrate provided 43% of the calories. Serum cholesterol and triglyceride concentrations increased when the purified rations were fed, and these concentrations were often greater (toward the end of the trial) in rabbits fed the sucrose than in rabbits fed corn starch. Liver weight was increased by the sucrose feeding, but there were no differences as to concentrations of lipid, cholesterol, Cr, or Zn between treatments. The aortas of the sucrose group contained more lipid, and the cholesterol concentrations tended to be greater; but dietary carbohydrate had no effect on concentrations of Cr or Zn. A reduction in hair Cr concentration was noticed over time in the rabbits fed sucrose, but changes were not noticed in the Zn concentrations. Cholelithiasis tended to be more severe in rabbits fed sucrose.

Effect of sulfur dioxide inhalation on CYP2B1/2 and CYP2E1 in rat liver and lung

Energy Technology Data Exchange (ETDEWEB)

Guohua Qin; Ziqiang Meng [Shanxi University, Taiyuan (China). Institute of Environmental Medicine and Toxicology

2006-07-15

Sulfur dioxide (SO{sub 2}) is a ubiquitous air pollutant, present in low concentrations in the urban air and in higher concentrations in the working environment. In this study, we investigated the effects of inhaled SO{sub 2} on the O-dealkylase of pentoxyresorufin (PROD) and p-nitrophenol hydroxylases (p-NP) activities and mRNA levels of CYP2B1/2 and CYP2E1 in the lung and liver of Wistar rats. Male Wistar rats were housed in exposure chambers and treated with 14.11 {+-}1.53, 28.36 {+-} 2.12, and 56.25 {+-} 4.28 mg /m{sup 3}SO{sub 2} for 6 h/day for 7 days, while control rats were exposed to filtered air in the same condition. The mRNAs of CYP2B1/2 and -2E1 were analyzed in livers and lungs by using reverse-transcription polymerase chain reaction (RT-PCR). Results showed that the PROD activities and mRNA of CYP2B1/2 were decreased in livers and lungs of rats exposed to SO{sub 2}. The p-NP activities and mRNA of CYP2E1 were decreased in lungs but not in livers of rats exposed to SO{sub 2}. Total liver microsomal cytochrome P-450 (CYP) contents were diminished in SO{sub 2} -exposed rats. These results lead to two conclusions: (1) SO{sub 2} exposure can suppress CYP2B1/2 and CYP2E1 in lungs and CYP2B1/2 in livers of rats, thus modifying the liver and lung toxication/detoxication potential, and (2) the total liver microsomal CYP contents were diminished, although the activity and mRNA expression of CYP2E1 in rat livers were not affected by SO{sub 2} exposure.

Cytochrome P4502D6(193-212): a new immunodominant epitope and target of virus/self cross-reactivity in liver kidney microsomal autoantibody type 1-positive liver disease.

Science.gov (United States)

Kerkar, Nanda; Choudhuri, Kaushik; Ma, Yun; Mahmoud, Ayman; Bogdanos, Dimitrios P; Muratori, Luigi; Bianchi, Francesco; Williams, Roger; Mieli-Vergani, Giorgina; Vergani, Diego

2003-02-01

Cytochrome P4502D6 (CYP2D6), target of liver kidney microsomal autoantibody type 1 (LKM1), characterizes autoimmune hepatitis type 2 (AIH2) but is also found in patients with chronic hepatitis C virus (HCV) infection. To provide a complete linear epitope B cell map of CYP2D6, we tested peptides spanning the entire sequence of CYP2D6. In addition to confirming previously described antigenic sites, we identified four new epitopes (193-212, 238-257, 268-287, and 478-497). CYP2D6(193-212) is immunodominant and was the target of 12 of 13 (93%) patients with AIH2 and 5 of 10 (50%) HCV/LKM1-positive patients. Because LKM1 is present in both AIH2 and a viral infection, we tested whether Abs to CYP2D6(193-212) arise through cross-reactive immunity between virus and self. We identified a hexameric sequence "RLLDLA" sharing 5 of 6 aa with "RLLDLS" of HCV(2985-2990) and all 6 aa with CMV(130-135). Of 17 CYP2D6(193-212)-reactive sera, 11 (7 AIH and 4 HCV) reacted by ELISA with the HCV homologue, 8 (5 AIH and 3 HCV) with the CMV homologue, and 8 (5 AIH and 3 HCV) showed double reactivity. Autoantibody binding to CYP2D6(193-212) was inhibited by preincubation with HCV(2977-2996) or CMV(121-140). Recombinant HCV-nonstructural protein 5 and CMV-UL98 proteins also inhibited Ab binding to CYP2D6(193-212). Affinity-purified CYP2D6(193-212)-specific Ab inhibited the metabolic activity of CYP2D6. The demonstrated similarity and cross-reactivity between CYP2D6(193-212) and two unrelated viruses suggests that multiple exposure to viruses mimicking self may represent an important pathway to the development of autoimmunity.

Antiatherosclerotic and Cardioprotective Potential of Acacia senegal Seeds in Diet-Induced Atherosclerosis in Rabbits

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Heera Ram

2014-01-01

Full Text Available Acacia senegal L. (Fabaceae seeds are essential ingredient of “Pachkutta,” a specific Rajasthani traditional food. The present study explored antiatherosclerotic and cardioprotective potential of Acacia senegal seed extract, if any, in hypercholesterolemic diet-induced atherosclerosis in rabbits. Atherosclerosis in rabbits was induced by feeding normal diet supplemented with oral administration of cholesterol (500 mg/kg body weight/day mixed with coconut oil for 15 days. Circulating total cholesterol (TC, HDL-cholesterol (HDL-C, LDL-cholesterol (LDL-C, triglycerides, and VLDL-cholesterol (VLDL-C levels; atherogenic index (AI; cardiac lipid peroxidation (LPO; planimetric studies of aortal wall; and histopathological studies of heart, aorta, kidney, and liver were performed. Apart from reduced atherosclerotic plaques in aorta (6.34±0.72 and increased lumen volume (51.65±3.66, administration with ethanolic extract of Acacia senegal seeds (500 mg/kg/day, p.o. for 45 days to atherosclerotic rabbits significantly lowered serum TC, LDL-C, triglyceride, and VLDL-C levels and atherogenic index as compared to control. Atherogenic diet-induced cardiac LPO and histopathological abnormalities in aorta wall, heart, kidney, and liver were reverted to normalcy by Acacia senegal seed extract administration. The findings of the present study reveal that Acacia senegal seed extract ameliorated diet-induced atherosclerosis and could be considered as lead in the development of novel therapeutics.

Influence of nutrition on liver oxidative metabolism.

Science.gov (United States)

Jorquera, F; Culebras, J M; González-Gallego, J

1996-06-01

The liver plays a major role in the disposition of the majority of drugs. This is due to the presence of several drug-metabolizing enzyme systems, including a group of membrane-bound mixed-function oxidative enzymes, mainly the cytochrome P450 system. Hepatic oxidative capacity can be assessed by changes in antipyrine metabolism. Different drugs and other factors may induce or inhibit the cytochrome P450-dependent system. This effect is important in terms of the efficacy or toxicity of drugs that are substrates for the system. Microsomal oxidation in animals fed with protein-deficient diets is depressed. The mixed-function oxidase activity recovers after a hyperproteic diet or the addition of lipids. Similar findings have been reported in patients with protein-calorie malnutrition, although results in the elderly are conflicting. Different studies have revealed that microsomal oxidation is impaired by total parenteral nutrition and that this effect is absent when changing the caloric source from carbohydrates to a conventional amino acid solution or after lipid addition, especially when administered as medium-chain/long-chain triglyceride mixtures. Peripheral parenteral nutrition appears to increase antipyrine clearance.

Effect of low level of dietary aflatoxins on baladi rabbits.

Science.gov (United States)

Abdelhamid, A M; el-Shawaf, I; el-Ayoty, S A; Ali, M M; Gamil, T

1990-01-01

Aflatoxins B1, B2, G1 & G2 were administered in a low concentration (100 ppb of each aflatoxin (AN] in a mash offered to Baladi rabbits. An other group of rabbits were fed on the same contaminated mash in addition to 0.25% charcoal (CC). The two groups were compared to control animals fed on AN-free mash. Inclusion of AN in the diet decreased feed and water consumption, body weight and survival rate. Charcoal improved somewhat feed and water consumption and growth rate than AN-group. However, CC-group affected digestibility of organic matter more than AN-group. Relative weights of liver, kidneys, heart and adrenal glands were significantly higher in AN and CC groups than the control group. Blood haemoglobin content, packed cell volume percentage and sedimentation rate were lower in AN group. Although there were an increase in each of serum, calcium, inorganic phosphorus, cholesterol, phospholipids and glutamic-pyruvic transaminase in AN group, yet the serum nitrogen and glutamic-oxalacetic transaminase were reduced. Charcoal had alleviated AN-effects concerning N, GPT and phospholipids. Chemical analysis revealed elevation of water, ash and silica contents of liver and water content of muscles from AN-animals. On the other hand, fat content, GOT and vitamin A in the liver as well as muscles ash were reduced. Addition of CC to the diet reduced AN-effects on liver fat, ash and silica but resulted in a rise of the water content of liver and muscles and liver GPT activity. Charcoal also resulted in a sharp decrease in vitamin A content of the liver. Aflatoxin treatments (in AN and CC groups) reduced bone ash, silica and magnesium as well as bone volume. Charcoal administration increased Ca-content of bones. Aflatoxin feeding (in AN group) resulted in a high residual percentage of AN in muscles, serum, liver, heart and kidneys with relationships of 51 :24 : 3 :2 : 1, respectively. Only 1.42% of the fed AN was excreted in the faeces. Charcoal usage had a good effect as

Identification of rabbit cytochromes P450 2C1 and 2C2 as arachidonic acid epoxygenases.

Science.gov (United States)

Laethem, R M; Koop, D R

1992-12-01

Microsomes prepared from COS-1 cells transiently expressing rabbit cytochromes P450 2C1 and 2C2 catalyzed the metabolism of arachidonic acid to predominantly 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) when microsomal epoxide hydrolase activity was inhibited by 0.2 mM 1,2-epoxy-3,3,3-trichloropropane. P450 2C2 catalyzed the formation of 11,12-EET and 14,15-EET at a ratio of 3.0 and also produced 19-hydroxyeicosatetraenoic acid (19-HETE). The 11,12-EET, 14,15-EET, and 19-HETE represented 48.3, 15.9, and 12.8%, respectively, of the total metabolites formed. P450 2C1 produced a similar but distinct ratio of 11,12-EET to 14,15-EET (2.0) and did not produce any detectable 19-HETE. The 11,12-EET and 14,15-EET represented 63.0 and 31.1%, respectively, of the total metabolites formed. The 8,9- and 5,6-EETs were not detected with either enzyme. The ratio of the 11,12-EET to 14,15-EET was 1.5 with P450 2CAA, a P450 arachidonic acid epoxygenase (P450 2CAA) that had an amino-terminal sequence identical to that of P450 2C2 [J. Biol. Chem. 267:5552-5559 (1992)]. P450 2C1, 2C2, and 2CAA metabolized lauric acid. The ratio of omega-1- to omega-hydroxylated laurate was 3.6, 3.4, and 2.4 for P450 2CAA, P450 2C2, and P450 2C1, respectively. Purified P450 2CAA had a slightly greater apparent molecular weight than expressed P450 2C2 on sodium dodecyl sulfate-polyacrylamide gels. The results clearly establish that rabbit P450 2C1 and 2C2 are arachidonic acid epoxygenases, and they suggest that P450 2CAA and 2C2 are very similar but may not be identical isoforms.

Ultrastructural changes in rabbits liver after irradiation

Energy Technology Data Exchange (ETDEWEB)

Cieciura, L; Bartel, H; Orkisz, S

1975-01-01

Ultrastructural changes in hepatocytes observed 1 to 30 days after irradiation are presented. The dose absorbed was 550 rad (LD 33/30). Electron microscopy studies showed that early and more distinct changes were observed in mitochondria within 24 hours. Disintegration of endoplasmic reticulum and vacuolization of cytoplasm were seen on the 3rd day after irradiation. From the 9th day, the ultrastructural picture of hepatocytes became normal. In the liver in this period the increase in number of large hypertrophic macrophages was noted.

In vitro Inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea, and Curcuma xanthorrhiza Extracts and Constituents on Human Liver Glucuronidation Activity.

Science.gov (United States)

Husni, Zulhilmi; Ismail, Sabariah; Zulkiffli, Mohd Halimhilmi; Afandi, Atiqah; Haron, Munirah

2017-07-01

Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza are commonly consumed as herbal medicines. However their effects on human liver glucuronidation activity are not yet evaluated. In this study, we evaluate the inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza extracts and their constituents on human liver glucuronidation activity. Herbal extracts (aqueous, methanolic and ethanolic extracts) and their constituents were incubated with human liver microsomes with the addition of UDPGA to initiate the reaction. Working concentrations of herbal extracts and their constituents ranged from 10 μg/mL to 1000 μg/mL and 10 μM to 300 μM respectively. IC50 was determined by monitoring the decrement of glucuronidation activity with the increment of herbal extracts or phytochemical constituent's concentrations. All herbal extracts inhibited human liver glucuronidation activity in range of 34.69 μg/mL to 398.10 μg/mL whereas for the constituents, only xanthorrhizol and curcumin (constituents of Curcuma xanthorrhiza ) inhibited human liver glucuronidation activity with IC50 of 538.50 and 32.26 μM respectively. In the present study, we have proved the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to interfere with in vitro glucuronidation process in human liver microsomes. This study documented the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to inhibit human liver glucuronidation activity which may affect the metabolism of therapeutic drugs or hazardous toxicants that follow the same glucuronidation pathway. Abbreviations used: UGT: Uridine 5'-diphospho-glucuronosyltransferase; 4-MU: 4-methylumbelliferone; IC50: Half Maximal Inhibitory Concentration; Km: Michaelis constant; Vmax: Maximum velocity.

[125I]2-iodo-3,7,8-trichlorodibenzo-p-dioxin-binding species in mouse liver induced by agonists for the Ah receptor: Characterization and identification

International Nuclear Information System (INIS)

Poland, A.; Teitelbaum, P.; Glover, E.

1989-01-01

The admininistration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to C57BL/6J mice produces a dose-related increase in the hepatic uptake of [ 125 I]2-iodo-3,7,8-trichlorodibenzo-p-dioxin ([ 125 I]Cl3DpD) in vivo and the binding of the radioligand to liver homogenate in vitro. The TCDD-induced hepatic binding species was found to be predominantly in the microsomal fraction and was inactivated by heating at 60 degree, trypsin, and mercurials. The TCDD-induced binding species was found to have an apparent equilibrium dissociation constant, KD, ([ 125 I]Cl3DpD) of 56 +/- 16 nM and a pool size, Bmax, of 22 +/- 5 nmol/g of liver. A number of halogenated dibenzo-p-dioxins, biphenyls, and polycyclic aromatic hydrocarbons compete with [ 125 I]Cl3DpD binding to this species; all are aromatic and planar. The distinctive profile of this binding species, a protein of large pool size induced in the microsomal fraction of liver but not other tissues and induced by agonists for the Ah receptor, suggested that this moiety might be cytochrome P3-450. The coincidence of the major microsomal species covalently labeled with the photoaffinity ligand [ 125 I]2-iodo-3-azido-7,8-dibromodibenzo-p-dioxin and that immunochemically stained with polyclonal antiserum that binds to cytochrome P3-450 confirms this hypothesis. This is a novel role for a cytochrome P-450 isozyme, as an induced sequestration site that enhances the hepatic localization of the agonist drug

The antibiotic tiamulin is a potent inducer and inhibitor of cytochrome P4503A via the formation of a stable metabolic intermediate complex. Studies in primary hepatocyte cultures and liver microsomes of the pig.

Science.gov (United States)

Witkamp, R F; Nijmeijer, S M; Monshouwer, M; Van Miert, A S

1995-05-01

Tiamulin is a semisynthetic antibiotic frequently used in agricultural animals. The drug has been shown to produce clinically important--often lethal--interactions with other compounds that are simultaneously administered. To explain this, it has been suggested that tiamulin selectively inhibits oxidative drug metabolism via the formation of a cytochrome P450 metabolic intermediate complex. The aim of the present study was to provide further support for this hypothesis. When hepatic microsomes and cultured primary pig hepatocytes were incubated with tiamulin, a maximum in the absorbance spectrum at 455 nm was observed, which disappeared after adding KFe(CN)6. When hepatocytes were incubated with tiamulin for 72 hr, cytochrome P450 content and cytochrome P4503A apoprotein levels were increased. Tiamulin strongly inhibited and concentration dependently inhibited the hydroxylation rate of testosterone at the 6 beta-position in both microsomes and hepatocytes, and the microsomal N-demethylation rate of ethylmorphine. Other testosterone hydroxylations were inhibited to a lesser extent or not affected. The relative inhibition of the hydroxylation of testosterone at the 6 beta-position was more pronounced in microsomes from rifampicin- and triacetyloleandomycin-treated pigs. The results indicate that cytochrome P450 complex formation can at least partly explain the interactions observed with tiamulin. Tiamulin seems to be a strong, probably selective, inhibitor of the cytochrome P4503A subfamily and an interesting tool for further research.

Studies on the metabolism and bioactivation of (S)-nicotine and beta-nicotyrine

International Nuclear Information System (INIS)

Shigenaga, M.K.

1989-01-01

(S)-Nicotine has long been suspected of contributing to the chronic toxicities associated with the use of cigarettes and other tobacco products. The possibility that (S)-nicotine could contribute to these chronic toxicities by causing irreversible damage to cellular macromolecules has prompted studies aimed at characterizing the metabolic pathways of (S)-nicotine that form reactive metabolites which bind covalently. In order to study these processes, (S)-5- 3 H-nicotine was synthesized by catalytic tritiolysis of (S)-5-bromonicotine with carrier-free tritium gas, purified by HPLC and characterized by tritium NMR, diode array VV and HPLC chromatographic analysis. The metabolism of (S)-5- 3 H-nicotine by rabbit liver and lung microsomal enzymes produced reactive intermediates which bound covalently to microsomal macromolecules in a time, NADPH and cytochrome P-450 dependent manner. The results of studies employing rabbit lung microsomes and agents which inhibit or alter the expression of the cytochrome P-450 isozyme composition in this tissue indicated that the covalent binding of (S)-nicotine requires (S)-nicotine Δ 1',5' -iminium ion as an obligate intermediate and the catalytic activity of lung cytochrome P-450 isozyme-2. Investigations of the effects of (S)-nicotine and related tobacco alkaloids on the oxidation of the Parkinson's disease inducing agent MPTP by the mitochondrial enzyme MAO-B were prompted by the inverse correlation between cigarette smoking and Parkinson's disease. In the author studies (S)-nicotine A 1',5' -iminium bisperchlorate inhibited the MAOB catalyzed oxidation of MPTP by a linear-mixed type mechanism. Subsequent studies identified β-nicotyrine as a MAO-B catalyzed oxidation product of (S)-nicotine A 1',5' -iminium ion

Molecular diagnosis of Eimeria stiedae in hepatic tissue of experimentally infected rabbits.

Science.gov (United States)

Hassan, Khaled M; Arafa, Waleed M; Mousa, Waheed M; Shokier, Khaled A M; Shany, Salama A; Aboelhadid, Shawky M

2016-10-01

The early detection of Eimeria stiedae in the hepatic tissue of experimentally infected rabbits was investigated using molecular assay. Forty 6-week-old male New Zealand rabbits were divided into two groups. Group A (30 animals) was infected with 2.5 × 10(4) sporulated oocysts of E. stiedae per animal on Day 0 and Group B (10 animals) was used as the uninfected controls. Three animals from Group A and one from Group B were sacrificed at 0, 3, 6, 9, 12, 15, 18, 21, 24 and 27 days post infection (PI). Gross and microscopic post-mortem findings were recorded. Polymerase chain reaction (PCR) of the E. stiedae internal transcribed spacer 1 genomic region was conducted on blood, liver tissue, and feces from the Group A experimentally infected animals. Macroscopically, the liver showed irregular yellowish white nodules pathognomonic to E. stiedae infection beginning on Day 15 PI. Hepatomegaly and ascites were obvious from Day 21-24 PI. The presence of different E. stiedae schizonts and gametocytes in the histopathological sections of the biliary epithelium were evident on Day 15 PI. The E. stiedae PCR was first positive in liver tissues on Day 12 and in fecal samples on Day 18 PI, but the blood samples were negative. In conclusion, the PCR can be used for early diagnosis and control of E. stiedae schizonts before shedding of the oocysts in feces. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of exogenous CNT on kinetics of 3H-lysine in haerbin white rabbits

International Nuclear Information System (INIS)

Liu Dengke; Zan Linsen; Liu Yongfeng

2007-01-01

Haerbin White rabbits was used as testimonial and trace kinetics and radioimmunoassay and other techniques were used to study the distribution, transportation and metabolism of 3 H-Lysine in the animal. The metabolic kinetics of 3 H-Lysine could be described by the follows equation: (Y-circumflex) (t) =983.6281e -0.021935t + 1773.9999e -0.083932t - 983.6281e -0.432590t - 0773.9999e -0.050399t + 300.2820. Experimental results showed that 3 H-Lysine was accumulated mainly in kidney, heart, liver, spleen and muscle in check group; accumulated mainly in muscle, stomach, liver, heart and genitalia in cAMP treated group; accumulated in bladder, muscle, lung and intestine in cGMP treated group; and accumulated mainly in muscle, bladder, genitalia an fat in cAMP + cGMP treated group, respectively. The distribution of 3 H-Lysine was of evidently variations being treated with exogenous CNT. The results indicated that the distribution, transportation and metabolism of 3 H-Lysine were significantly affected by exogenous CNT in the Haerbin White rabbit. (authors)

Accumulation of 125I-factor XI in atheroma of rabbit with hereditary hyperlipidemia (WHHL-rabbit)

International Nuclear Information System (INIS)

Komiyama, Y.; Masuda, M.; Murakami, T.; Nishikado, H.; Egawa, H.; Nishimura, T.; Morii, S.; Murata, K.

1989-01-01

We have studied the turnover and accumulation of rabbit factor XI (F.XI) in atherosclerotic lesion in Watanabe-hereditable hyperlipidemic rabbit (WHHL rabbit) to reveal the participation of blood coagulation in atherosclerotic lesion. Rabbit F.XI was iodinated and administered intravenously to WHHL rabbits and Japanese white rabbits. The turnover of 125 I-rabbit F.XI was significantly faster in WHHL rabbits (T1/2 = 2.84 +/- 0.44 days) than in normal rabbits (T1/2 = 4.44 +/- 0.42 days). The thoracic aorta of WHHL rabbit was strongly labelled with 125 I-rabbit F.XI, in sections obtained after 5 days by en-face autoradiography, whereas no radioactivity was detected in normal aorta. By an immunohistochemical study of WHHL rabbit aorta, we confirmed that many F.XI- and fibrin-related compounds existed in the atheroma, whereas albumin did not in these area. These results suggest that the activation of F.XI proceeds on the atherosclerotic lesions of WHHL rabbits

Allergy to Rabbits. 1

International Nuclear Information System (INIS)

Price, J.A.; Longbottom, J.L.

1986-01-01

Investigations have been carried out into the presence of antibody light chains in rabbit allergenic extracts and the interference in RAST and crossed-radioimmunoelectrophoresis (XRIE) caused by antibodies directed against them. A ''non-specific'' uptake of radioactivity in XRIE has been demonstrated to be caused by direct cross-linking of the 125 I rabbit anti-human IgE by the sheep antibodies in the immunoprecipitate of rabbit light chains. Preincubation with normal rabbit serum blocked this direct uptake of the labelled antibody and enabled specific IgE uptake on the light chains to be demonstrated for rabbit allergic sera. Verification of the allergenicity of the light chains was obtained from a specific light chain RAST. Elution from a Sephacryl S-200 gel filtration column indicated a MW of approx. 50Kd and confirmation of the components as light chain dimers, not Fab fragments, was obtained by allotyping for loci present on heavy chains and light chains in the Fab region. Light chains were detected in urine from rabbits of all ages and in an extract of dust collected in a rabbit housing area. No background staining was observed in XRIE using rabbit antisera, either with rabbit allergic sera with specific IgE or with a human serum containing specific IgG antibodies to rabbit IgG. This latter serum also showed no evidence of uptake on all immunoprecipitates in systems using rabbit antisera, and did not give false positive RAST results when the labelled rabbit anti-human IgE contained unlabelled rabbit IgG. Those sera with specific IgE to light chains showed no uptake in XRIE using rabbit antisera, indicating that the IgE was possibly specific for epitopes revealed by the dissociation on the whole IgG molecule. (author)

Characterization of binding of N'-nitrosonornicotine to protein

International Nuclear Information System (INIS)

Hughes, M.F.

1986-01-01

The NADPH-dependent activation of the carcinogenic nitrosamine, N'-nitrosonornicotine (NNN) to a reactive intermediate which binds covalently to protein was assessed using male Sprague-Dawley rat liver and lung microsomes. The NADPH-dependent covalent binding of [ 14 C]NNN to liver and lung microsomes was linear with time up to 90 and 45 min, respectively and was also linear with protein concentrations up to 3.0 and 2.0 mg/ml, respectively. The apparent K/sub m/ and V/sub max/ of the NADPH-dependent binding to liver microsomes were determined from the initial velocities. Addition of the thiols glutathione, cystein, N-acetylcysteine or 2-mercapthoethanol significantly decreased the non-NADPH-dependent binding to liver microsomal protein, but did not affect the NADPH-dependent binding. Glutathione was required in order to observe any NADPH-dependent binding to lung microsomal protein. In lung microsomes, SKF-525A significantly decreased the NADPH-dependent binding by 79%. Replacement of an air atmosphere with N 2 or CO:O 2 (8:2) significantly decreased the NADPH-dependent binding of [ 14 C]NNN to liver microsomal protein by 40% or 27% respectively. Extensive covalent binding of [ 14 C]NNN to liver and muscle microsomal protein occurred in the absence of an NADPH-generating system, in the presence of 50% methanol and also to bovine serum albumin, indicating a nonenzymatic reaction. These data indicate that cytochrome P-450 is at least in part responsible for the metabolic activation of the carcinogen NNN, but also suggest additional mechanisms of activation

Increased Hepatic Expression of Endothelial Lipase Inhibits Cholesterol Diet-Induced Hypercholesterolemia and Atherosclerosis in Transgenic Rabbits.

Science.gov (United States)

Wang, Chuan; Nishijima, Kazutoshi; Kitajima, Shuji; Niimi, Manabu; Yan, Haizhao; Chen, Yajie; Ning, Bo; Matsuhisa, Fumikazu; Liu, Enqi; Zhang, Jifeng; Chen, Y Eugene; Fan, Jianglin

2017-07-01

Endothelial lipase (EL) is a key determinant in plasma high-density lipoprotein-cholesterol. However, functional roles of EL on the development of atherosclerosis have not been clarified. We investigated whether hepatic expression of EL affects plasma lipoprotein metabolism and cholesterol diet-induced atherosclerosis. We generated transgenic (Tg) rabbits expressing the human EL gene in the liver and then examined the effects of EL expression on plasma lipids and lipoproteins and compared the susceptibility of Tg rabbits with cholesterol diet-induced atherosclerosis with non-Tg littermates. On a chow diet, hepatic expression of human EL in Tg rabbits led to remarkable reductions in plasma levels of total cholesterol, phospholipids, and high-density lipoprotein-cholesterol compared with non-Tg controls. On a cholesterol-rich diet for 16 weeks, Tg rabbits exhibited significantly lower hypercholesterolemia and less atherosclerosis than non-Tg littermates. In Tg rabbits, gross lesion area of aortic atherosclerosis was reduced by 52%, and the lesions were characterized by fewer macrophages and smooth muscle cells compared with non-Tg littermates. Increased hepatic expression of EL attenuates cholesterol diet-induced hypercholesterolemia and protects against atherosclerosis. © 2017 American Heart Association, Inc.

Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry.

Science.gov (United States)

Chavan, Balasaheb B; Kalariya, Pradipbhai D; Tiwari, Shristy; Nimbalkar, Rakesh D; Garg, Prabha; Srinivas, R; Talluri, M V N Kumar

2017-12-15

Vilazodone is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of major depressive disorder (MDD). An extensive literature search found few reports on the in vivo and in vitro metabolism of vilazodone. Therefore, we report a comprehensive in vivo and in vitro metabolic identification and structural characterization of vilazodone using ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS/MS) and in silico toxicity study of the metabolites. To identify in vivo metabolites of vilazodone, blood, urine and faeces samples were collected at different time intervals starting from 0 h to 48 h after oral administration of vilazodone to Sprague-Dawley rats. The in vitro metabolism study was conducted with human liver microsomes (HLM) and rat liver microsomes (RLM). The samples were prepared using an optimized sample preparation approach involving protein precipitation followed by solid-phase extraction. The metabolites have been identified and characterized by using LC/ESI-MS/MS. A total of 12 metabolites (M1-M12) were identified in in vivo and in vitro matrices and characterized by LC/ESI-MS/MS. The majority of the metabolites were observed in urine, while a few metabolites were present in faeces and plasma. Two metabolites were observed in the in vitro study. A semi-quantitative study based on percentage counts shows that metabolites M11, M6 and M8 were observed in higher amounts in urine, faeces and plasma, respectively. The structures of all the 12 metabolites were elucidated by using LC/ESI-MS/MS. The study suggests that vilazodone was metabolized via hydroxylation, dihydroxylation, glucuronidation, oxidative deamination, dealkylation, dehydrogenation and dioxidation. All the metabolites were screened for toxicity using an in silico tool. Copyright © 2017 John Wiley & Sons, Ltd.

Hepatitis B spliced protein (HBSP) promotes the carcinogenic effects of benzo [alpha] pyrene by interacting with microsomal epoxide hydrolase and enhancing its hydrolysis activity

International Nuclear Information System (INIS)

Chen, Jin-Yan; Chen, Wan-Nan; Jiao, Bo-Yan; Lin, Wan-Song; Wu, Yun-Li; Liu, Ling-Ling; Lin, Xu

2014-01-01

The risk of hepatocellular carcinoma (HCC) increases in chronic hepatitis B surface antigen (HBsAg) carriers who often have concomitant increase in the levels of benzo[alpha]pyrene-7,8-diol-9,10-epoxide(±) (BPDE)-DNA adduct in liver tissues, suggesting a possible co-carcinogenesis of Hepatitis B virus (HBV) and benzo[alpha]pyrene in HCC; however the exact mechanisms involved are unclear. The interaction between hepatitis B spliced protein (HBSP) and microsomal epoxide hydrolase (mEH) was confirmed using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assay; the effects of HBSP on mEH-mediated B[alpha]P metabolism was examined by high performance liquid chromatography (HPLC); and the influences of HBSP on B[alpha]P carcinogenicity were evaluated by bromodeoxyuridine cell proliferation, anchorage-independent growth and tumor xenograft. HBSP could interact with mEH in vitro and in vivo, and this interaction was mediated by the N terminal 47 amino acid residues of HBSP. HBSP could greatly enhance the hydrolysis activity of mEH in cell-free mouse liver microsomes, thus accelerating the metabolism of benzo[alpha]pyrene to produce more ultimate carcinnogen, BPDE, and this effect of HBSP requires the intact HBSP molecule. Expression of HBSP significantly increased the formation of BPDE-DNA adduct in benzo[alpha]pyrene-treated Huh-7 hepatoma cells, and this enhancement was blocked by knockdown of mEH. HBSP could enhance the cell proliferation, accelerate the G1/S transition, and promote cell transformation and tumorigenesis of B[alpha]P-treated Huh-7 hepatoma cells. Our results demonstrated that HBSP could promote carcinogenic effects of B[alpha]P by interacting with mEH and enhancing its hydrolysis activity

Rabbit analgesia.

Science.gov (United States)

Barter, Linda S

2011-01-01

With the increasing popularity of rabbits as household pets, the complexity of diagnostic and surgical procedures performed on rabbits is increasing, along with the frequency of routine surgical procedures. More practitioners are faced with the need to provide adequate analgesia for this species. Preemptive analgesia prior to planned surgical interventions may reduce nervous system changes in response to noxious input, as well as reduce postoperative pain levels and analgesic drug requirements. Concurrent administration of analgesic drugs to anesthetized rabbits undergoing painful procedures is warranted both pre- and intraoperatively as well as postoperatively. This article discusses the neuropharmacologic and pharmacologic aspects of pain in rabbits, and reviews current protocols for the use of analgesic drugs. Published by Elsevier Inc.

Diagnosis and Management of Paediatric Autoimmune Liver Disease: ESPGHAN Hepatology Committee Position Statement.

Science.gov (United States)

Mieli-Vergani, Giorgina; Vergani, Diego; Baumann, Ulrich; Czubkowski, Piotr; Debray, Dominique; Dezsofi, Antal; Fischler, Björn; Gupte, Girish; Hierro, Loreto; Indolfi, Giuseppe; Jahnel, Jörg; Smets, Françoise; Verkade, Henkjan J; Hadzic, Nedim

2017-11-03

Paediatric autoimmune liver disease is characterised by inflammatory liver histology, circulating autoantibodies and increased levels of IgG, in the absence of a known etiology. Three conditions have a likely autoimmune pathogenesis: autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. Two types of paediatric AIH are recognized according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, AIH-1) or liver kidney microsomal type 1 and/or anti-liver cytosol type 1 antibodies (anti-LKM-1/anti-LC-1; AIH-2).Pertinent issues addressing the diagnosis, treatment and long term follow up were formulated by a core group of ESPGHAN members. They have commissioned the first authors with execution of this project. Initially, they have performed a systematic literature search on MEDLINE, ResearchGate and Mendeley databases over the last 30 years and produced a document focusing on prospective and retrospective studies in children. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique.

Quantitative assessment of iron load in myocardial overload rabbit model: preliminary study of MRI T2* map

International Nuclear Information System (INIS)

Huang Lu; Han Rui; Li Zhiwei; Yuan Sishu; Xia Liming

2014-01-01

Objective: To preliminarily investigate the feasibility of MRI-T 2 * map in evaluating myocardial iron load of myocardial iron overload rabbit models. Methods: Eleven rabbits were included in this study and divided into two groups, myocardial iron overload group (n =10) and the control group (n = 1). Iron dextrin (dose of 50 mg/kg) was injected in muscles of thigh once a week, totally 12 weeks. Serum iron test and MRI examination were performed before iron injection,and 1 week to 12 weeks after iron injection. MRI scan protocol included short axial T 2 * map of the left ventricle and cross-section T 2 * map of the liver. T 2 * and R 2 * of the heart and the liver were measured. One rabbit was killed after MRI examination at pre-iron injection, 1 week to 8 weeks, 11 weeks and 12 weeks after iron injection,respectively. Heart and liver were avulsed to undergo in vitro MRI scan and then paraffin embedded for pathological slices. MRI scan protocol and measurements of the heart and the liver samples were the same to that of in vivo ones. Pearson correlation was used to calculate the relationships between the parameters. Results: Myocardial T 2 * [(32.5 ± 8.3 ms)] and R 2 * values [(38.4 ± 7.9) Hz] had significant correlation with injecting iron content (1033.2 ± 673.4 mg), the Pearson coefficients were -0.799 (P = 0.001) and 0.770 (P = 0.002), respectively. Myocardial T 2 * had no significant correlation with liver T 2 * values (r = 0.556, P = 0.070). T 2 * values of heart and liver in vivo [(32.5 ± 8.3) ms and (8.8 ± 5.4) ms], respectively had strong correlation with those in vitro [(19.4 ± 6.5) ms and (9.8 ± 5.0) ms], respectively (r = 0.757, P = 0.007 and r = 0.861, P = 0.001). T 2 * and R 2 * values of the heart and the liver in vivo and in vitro had no significant correlations with serum iron (P>0.05). On Prussian blue staining slices,blue particles of myocardium, sinus hepaticas and hepatocyte increased with injecting iron content. Conclusions: It is

Metabolic profiling of five flavonoids from Dragon's Blood in human liver microsomes using high-performance liquid chromatography coupled with high resolution mass spectrometry.

Science.gov (United States)

Li, Yujuan; Zhang, Yushi; Wang, Rui; Wei, Lizhong; Deng, Yulin; Ren, Wei

2017-05-01

Although much is known about the pharmacological activities of Dragon's Blood (DB, a traditional Chinese herb), its metabolism in human liver microsomes (HLMs) and the cytochrome P450 (CYP) enzymes has not been studied. This study aims to identify the metabolic profile of five flavonoids (loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone) from DB in HLMs as well as the CYP enzymes that are involved in the metabolism of them. High-resolution mass spectrometry was used to characterize the structures of their metabolites and 10 cDNA-expressed CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) were used to verify which isozymes mediate in the metabolism of the metabolites. Totally, 29 metabolites including 10 metabolites of loureirin A, 10 metabolites of loureirin B, 4 metabolites of loureirin C, 2 metabolites of 7,4'-dihydroxyflavone and 3 metabolites of 5,7,4'-trihydroxyflavanone were elucidated and identified on the basis of the high-resolution MS n data. The metabolic profile of the five flavonoids in HLMs involved hydroxylation, oxidation and demethylation. Among them, hydroxylation was the predominant biotransformation of the five flavonoids in HLMs, occurring in combination with other metabolic reactions. Assay with recombinant P450s revealed that CYP2C9 and CYP2C19 played an important role in the hydroxylation of flavonoids in HLMs. To the best of our knowledge, this is the first in vitro evaluation of the metabolic profile of loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone in HLMs. Copyright © 2017 Elsevier B.V. All rights reserved.

Sorafenib metabolism is significantly altered in the liver tumor tissue of hepatocellular carcinoma patient.

Directory of Open Access Journals (Sweden)

Ling Ye

Full Text Available BACKGROUND: Sorafenib, the drug used as first line treatment for hepatocellular carcinoma (HCC, is metabolized by cytochrome P450 (CYP 3A4-mediated oxidation and uridine diphosphate glucuronosyl transferase (UGT 1A9-mediated glucuronidation. Liver diseases are associated with reduced CYP and UGT activities, which can considerably affect drug metabolism, leading to drug toxicity. Thus, understanding the metabolism of therapeutic compounds in patients with liver diseases is necessary. However, the metabolism characteristic of sorafenib has not been systematically determined in HCC patients. METHODS: Sorafenib metabolism was tested in the pooled and individual tumor hepatic microsomes (THLMs and adjacent normal hepatic microsomes (NHLMs of HCC patients (n = 18. Commercial hepatic microsomes (CHLMs were used as a control. In addition, CYP3A4 and UGT1A9 protein expression in different tissues were measured by Western blotting. RESULTS: The mean rates of oxidation and glucuronidation of sorafenib were significantly decreased in the pooled THLMs compared with those in NHLMs and CHLMs. The maximal velocity (Vmax of sorafenib oxidation and glucuronidation were approximately 25-fold and 2-fold decreased in the pooled THLMs, respectively, with unchanged Km values. The oxidation of sorafenib in individual THLMs sample was significantly decreased (ranging from 7 to 67-fold than that in corresponding NHLMs sample. The reduction of glucuronidation in THLMs was observed in 15 out of 18 patients' samples. Additionally, the level of CYP3A4 and UGT1A9 expression were both notably decreased in the pooled THLMs. CONCLUSIONS: Sorafenib metabolism was remarkably decreased in THLMs. This result was associated with the down regulation of the protein expression of CYP3A4 and UGT1A9.

Early effects of dietary orotic acid upon liver lipid synthesis and bile cholesterol secretion in rats

International Nuclear Information System (INIS)

Tokmakjian, S.D.; Haines, D.S.

1985-01-01

Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. The authors found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1- 14 C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl ester was observed. These changes may result from the known decreases in liver levels of adenine nucleotides or, as reported here, from decreased liver CoASH levels in orotic acid-fed rats. The increase in hepatic cholesterol synthesis occurred during the second day of orotic acid feeding. It was detected by increased incorporation of [1,2- 14 C]acetate into cholesterol by liver slices and by a 7-fold increase in HMG-CoA reductase activity. At the same time the biliary output of cholesterol was increased 2-fold and studies using 3 H 2 O revealed that the output of newly synthesized cholesterol in bile was increased 5-fold. The content of cholesteryl ester in hepatic microsomes decreased during orotic acid feeding but free cholesterol was unchanged. The findings are interpreted to suggest that the increased bile cholesterol secretion caused by orotic acid is a result of impaired hepatic cholesterol esterification and that the increase in HMG-CoA reductase activity is a result of diminished negative feedback due to the depleted content of cholesteryl ester in the hepatic microsomes

Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes.

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Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

2014-01-21

Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e., styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. A dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes relative to that in the wild-type mouse lung microsomes; however, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knockout and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed a susceptibility to lung toxicity of styrene similar to that of the wild-type animals; however, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene.

Purification and immunochemical detections of ?-naphthoflavone- and phenobarbital-induced avian cytochrome P450 enzymes

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Brown, R.L.; Levi, P.E.; Hodgson, E.; Melancon, M.J.

1996-01-01

Livers from mallards (Anas platyrhynchos) were treated with either -naphthoflavone (50 mg/kg) or phenobarbital (70 mg/kg). Purification of induced hepatic cytochrome P450 was accomplished using both DEAE and hydroxyapatite columns, as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis separation. Polyclonal antibodies to these proteins were then produced in young male New Zealand White rabbits. ?-naphthoflavone (?NF)- and phenobarbital(PB)-treated red-winged blackbird, screech owl, European starling and lesser scaup liver microsomes were analyzed in western blots for species cross-reactivity. Although all four of these avian species exhibited cross-reactivity with antibodies to ?NF-induced mallard P450, all but the lesser scaup revealed a protein of higher molecular weight than that of the ?NF-induced mallard. In addition, only the lesser scaup exhibited cross-reactivity with the anti-PB-induced mallard P450 antibodies.

Changes in vascularization of internal organs in rabbits with experimental atherosclerosis, treated with protein hydrolysate

International Nuclear Information System (INIS)

Demireva, K.; Popdimitrov, I.

1979-01-01

The vascularization of the internal organs of rabbits with experimental atherosclerosis was studied by the method of Sapirstein with 86 rubidium. Experiments were carried out on male Chinchilla rabbits, fed cholesterol in a dose of 0,2 g/kg of body weight daily for a period of 90 days. Part of the animals were treated with protein hydrolysate in a dose of 5 ml/kg of body weight subcutaneously and the remaining - with physiologic saline. There was reduced vascularization in the heart, kidneys, intestines, liver, adrenals, pancreas and other internal organs in rabbits fed cholestrol and treated with physiologic saline. Administration of protein hydrolysate had protective effect on organ vascularization. Accumulation of 86 rubidium in a large part of the animals was greater than in control group. It is shown that protein hydrolysate amino acids stabilize the endothelial cells and stimulate the local vascularization. (author)

Calmodulin stimulation of calcium transport in carrot microsomal vesicles

International Nuclear Information System (INIS)

Pierce, W.S.; Sze, H.

1987-01-01

ATP-dependent 45 Ca 2+ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca 2+ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca 2+ uptake (at 1.17 g/cc) was not affected by oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca 2+ . These results are consistent with the ER being an important site of intracellular Ca 2+ regulation

Pharmacokinetics of 99mTc-technefit in radionuclide investigations of liver and spleen

International Nuclear Information System (INIS)

Ovdienko, N.I.; Starovojtova, L.P.; Kodina, G.E.; Malysheva, A.O.; Tul'skaya, T.I.

1987-01-01

The authors present the results of an experimental study of pharmacokinetics of a new Soviet drug 99m Tc-technefit for scintigraphy of the liver and spleen. The results of biological distribution of the agent in rat, scintigrams of the liver and spleen in rabbits and dogs have shown a high accumulation of 99m Tc-technefit in the liver (up to 90%). The agent is prepared within one stage from a kit of reagents and 99m Tc-sodium pertechnate obtained using a generator

An experimental study on the effect of mixture of absolute ethanol and lipiodol injected into normal liver of rabbit : CT features and histopathologic changes

International Nuclear Information System (INIS)

Lee, Mee Ran; Kim, Yun Hwan; Cha, In Ho; Chung, Kyoo Byung; Suh, Won Hyuk; Um, Soon Ho; Choi, Young Hee

1999-01-01

To investigate the safety and usefulness of Lipiodol-percutaneous transhepatic ethanol injection(LPEI) and to determine the appropriate concentration of Lipiodol during L-PEI. This was achieved by evalvating CT findings and histopathologic changes according to the concentration of Lipiodol, amount of ethanol, and the time interval after injection into normal rabbit liver. This experimental study involved 18 New Zealand rabbits under US guidance. They were divided into five groups according to injected materials; two rabbits with 0.4cc of normal saline(group I), six with 0.4cc of ethanol in the left hepatic lobe(group II), and 0.4cc of Lipiodol in the right hepatic lobe(group III), five rabbits with 5% Lipiodol-ethanol(5% vol. of Lipiodol+95% vol. of ethanol), 0.2cc in the right hepatic lobe, and 0.4cc in the left(group IV); and five rabbits with 10% Lipiodol-ethanol as per group IV(group V). CT was performed immediately, one week, two weeks, and three-four weeks after injection, and pathologic specimens were obtained on the third day(acute phase) and during the third or fourth week(chronic phase) after injection. On CT, intrahepatic localization of the L-PEI injection site was well demonstrated as a focal high attenuated area which gradually decreased in attenuation on follow up CT. The opacification of the inferior vena cava by Lipiodol, the linear distribution of Lipiodol along portal veins or fissures, and peritoneal leakage were clearly demonstrated in groups III-V, though the effects gradually disappeared during follow-up CT. There was no remarkable difference in gross CT attenuation between group IV and group V. The main pathologic findings during the acute phase of group II were coagulation necrosis surrounded by macrophage, inflammatory reaction, and early periportal and subcapsular fibrosis. The findings in group IV and V were similar to those in group II and additional fat vacuole accumulations in the necrotic area were also seen. During the chronic phase

Aetiology and pathogenesis of alcoholic liver disease.

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Lieber, C S

1993-09-01

Until the 1960s, liver disease of the alcoholic patient was attributed exclusively to dietary deficiencies. Since then, however, our understanding of the impact of alcoholism on nutritional status has undergone a progressive evolution. Alcohol, because of its high energy content, was at first perceived to act exclusively as 'empty calories' displacing other nutrients in the diet, and causing primary malnutrition through decreased intake of essential nutrients. With improvement in the overall nutrition of the population, the role of primary malnutrition waned and secondary malnutrition was emphasized as a result of a better understanding of maldigestion and malabsorption caused by chronic alcohol consumption and various diseases associated with chronic alcoholism. At the same time, the concept of the direct toxicity of alcohol came to the forefront as an explanation for the widespread cellular injury. Some of the hepatotoxicity was found to result from the metabolic disturbances associated with the oxidation of ethanol via the liver alcohol dehydrogenase (ADH) pathway and the redox changes produced by the generated NADH, which in turn affects the metabolism of lipids, carbohydrates, proteins and purines. Exaggeration of the redox change by the relative hypoxia which prevails physiologically in the perivenular zone contributes to the exacerbation of the ethanol-induced lesions in zone 3. In addition to ADH, ethanol can be oxidized by liver microsomes: studies over the last twenty years have culminated in the molecular elucidation of the ethanol-inducible cytochrome P450IIE1 (CYP2E1) which contributes not only to ethanol metabolism and tolerance, but also to the selective hepatic perivenular toxicity of various xenobiotics. Their activation by CYP2E1 now provides an understanding for the increased susceptibility of the heavy drinker to the toxicity of industrial solvents, anaesthetic agents, commonly prescribed drugs, 'over the counter' analgesics, chemical

Autoimmune liver disease in children.

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Mieli-Vergani, G; Vergani, D

2003-03-01

Autoimmune liver disorders are characterised by an inflammatory liver histology, circulating non-organ specific autoantibodies and increased levels of immunoglobulin G (IgG) in the absence of a known aetiology. They respond to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. Liver disorders with a likely autoimmune pathogenesis include autoimmune hepatitis (AIH) and autoimmune sclerosing cholangitis (ASC). Two types of AIH are recognised according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1-positive patients tend to present more acutely, at a younger age, and commonly have immunoglobulin A (IgA) deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological and histological presentation of ASC is often indistinguishable from that of AIH. In both, there are high IgG, non-organ specific autoantibodies and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalisation of biochemical parameters and decreased inflammatory activity on follow-up liver biopsies. However, the cholangiopathy can progress and there may be an evolution from AIH to ASC over the years, despite treatment. Whether the juvenile autoimmune form of sclerosing cholangitis and AIH are 2 distinct entities, or different aspects of the same condition, remains to be elucidated.

Effects of intra-arterial infusion therapy or systemic chemotherapy with docetaxel for VX2 tumor in rabbit hind limb

International Nuclear Information System (INIS)

Qian Yuanxin; Wu Xiaomei; He Miao; Liu Tao; Deng Duo

2010-01-01

Objective: To discuss the efficacy and safety of intra-arterial infusion therapy with docetaxel. Methods: Animal model of VX2 tumor in rabbit hind limb was set up. Intra-arterial infusion therapy or systemic chemotherapy with docetaxel was performed. Concentrations of docetaxel in VX2 tumor, wall of stomach, liver, kidney and plasma of rabbits with VX2 tumors in hind limbs were determined. Difference of drug concentrations between intra-arterial infusion therapy and systemic chemotherapy was compared using Student t-test. Results: Concentrations of docetaxel in VX2 tumor and wall of stomach of rabbits with intra-arterial infusion therapy were significantly higher than those with systemic chemotherapy (p<0.05). The drug concentration in VX2 tumor of rabbits with intra-arterial infusion was 14 times higher than that with systemic chemotherapy. Concentration of docetaxel in plasma of rabbits with intra-arterial infusion therapy was not significantly lower than that with systemic chemotherapy (P<0.05). Conclusion: Intra-arterial infusion therapy with docetaxel for tumor is effective. However, there is increased risk of toxicity and the dose should adjusted accordingly. (authors)

Detection of endotoxins in radiopharmaceutical preparations. III. Limulus test assessment using radiopharmaceutical preparations; correlation with the rabbit pyrogen test

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Cohen, Y; Bahri, F; Bruneau, J; Dubuis, M; Dubuis, N; Merlin, L; Michaud, T; Peysson, S

1986-01-01

Experiments using 17 radiopharmaceuticals containing known amounts of added endotoxin show that none of them inhibits the pyrogenic reaction of the rabbit. Gelation of the Limulus amoebocyte lysate (LAL) is inhibited by 4 of them: colloidal erbium 169Er citrate, colloidal rhenium 186Re sulfide, colloidal technetium /sup 99m/Tc (Re) sulfide for liver scintigraphy and the colloidal technetium /sup 99m/Tc (Re) sulfide for lymphography. This inhibition is cancelled, either by dilution or after neutral pH adjustment. Both controls were performed on 313 batches of various radiopharmaceuticals, 95% of results were identical (93% negative, 2% positive). The remaining 5% correspond to positive LAL tests vs negative rabbit tests on the same batches. No negative LAL test vs positive rabbit test was observed.

Rabbit model for human EBV-associated hemophagocytic syndrome (HPS): sequential autopsy analysis and characterization of IL-2-dependent cell lines established from herpesvirus papio-induced fatal rabbit lymphoproliferative diseases with HPS.

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Hayashi, Kazuhiko; Jin, Zaishun; Onoda, Sachiyo; Joko, Hiromasa; Teramoto, Norihiro; Ohara, Nobuya; Oda, Wakako; Tanaka, Takehiro; Liu, Yi-Xuan; Koirala, Tirtha Raj; Oka, Takashi; Kondo, Eisaku; Yoshino, Tadashi; Takahashi, Kiyoshi; Akagi, Tadaatsu

2003-05-01

Epstein-Barr virus-associated hemophagocytic syndrome (EBV-AHS) is often associated with fatal infectious mononucleosis or T-cell lymphoproliferative diseases (LPD). To elucidate the true nature of fatal LPD observed in Herpesvirus papio (HVP)-induced rabbit hemophagocytosis, reactive or neoplastic, we analyzed sequential development of HVP-induced rabbit LPD and their cell lines. All of the seven Japanese White rabbits inoculated intravenously with HVP died of fatal LPD 18 to 27 days after inoculation. LPD was also accompanied by hemophagocytic syndrome (HPS) in five of these seven rabbits. Sequential autopsy revealed splenomegaly and swollen lymph nodes, often accompanied by bleeding, which developed in the last week. Atypical lymphoid cells infiltrated many organs with a "starry sky" pattern, frequently involving the spleen, lymph nodes, and liver. HVP-small RNA-1 expression in these lymphoid cells was clearly demonstrated by a newly developed in situ hybridization (ISH) system. HVP-ISH of immunomagnetically purified lymphoid cells from spleen or lymph nodes revealed HVP-EBER1+ cells in each CD4+, CD8+, or CD79a+ fraction. Hemophagocytic histiocytosis was observed in the lymph nodes, spleen, bone marrow, and thymus. HVP-DNA was detected in the tissues and peripheral blood from the infected rabbits by PCR or Southern blot analysis. Clonality analysis of HVP-induced LPD by Southern blotting with TCR gene probe revealed polyclonal bands, suggesting polyclonal proliferation. Six IL-2-dependent rabbit T-cell lines were established from transplanted scid mouse tumors from LPD. These showed latency type I/II HVP infection and had normal karyotypes except for one line, and three of them showed tumorigenicity in nude mice. These data suggest that HVP-induced fatal LPD in rabbits is reactive polyclonally in nature.

A strain-specific multiplex RT-PCR for Australian rabbit haemorrhagic disease viruses uncovers a new recombinant virus variant in rabbits and hares.

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Hall, R N; Mahar, J E; Read, A J; Mourant, R; Piper, M; Huang, N; Strive, T

2018-04-01

Rabbit haemorrhagic disease virus (RHDV, or GI.1) is a calicivirus in the genus Lagovirus that has been widely utilized in Australia as a biological control agent for the management of overabundant wild European rabbit (Oryctolagus cuniculus) populations since 1996. Recently, two exotic incursions of pathogenic lagoviruses have been reported in Australia; GI.1a-Aus, previously called RHDVa-Aus, is a GI.1a virus detected in January 2014, and the novel lagovirus GI.2 (previously known as RHDV2). Furthermore, an additional GI.1a strain, GI.1a-K5 (also known as 08Q712), was released nationwide in March 2017 as a supplementary tool for wild rabbit management. To discriminate between these lagoviruses, a highly sensitive strain-specific multiplex RT-PCR assay was developed, which allows fast, cost-effective and sensitive detection of the four pathogenic lagoviruses currently known to be circulating in Australia. In addition, we developed a universal RT-qPCR assay to be used in conjunction with the multiplex assay that broadly detects all four viruses and facilitates quantification of viral RNA load in samples. These assays enable rapid detection, identification and quantification of pathogenic lagoviruses in the Australian context. Using these assays, a novel recombinant lagovirus was detected in rabbit tissue samples, which contained the non-structural genes of GI.1a-Aus and the structural genes of GI.2. This variant was also recovered from the liver of a European brown hare (Lepus europaeus). The impact of this novel recombinant on Australian wild lagomorph populations and its competitiveness in relation to circulating field strains, particularly GI.2, requires further studies. © 2017 Blackwell Verlag GmbH.

Gas-chromatographic resolution of enantiomeric secondary alcohols. Stereoselective reductive metabolism of ketones in rabbit-liver cytosol.

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Gal, J; DeVito, D; Harper, T W

1981-01-01

Chiral secondary alcohols were treated with (S)-(-)-1-phenylethyl isocyanate. For each racemic alcohol, the resulting diastereomeric urethane derivatives were resolved on flexible fused-silica capillary GLC columns with retention times of 15 min or less. Derivatization of individual enantiomers showed that the urethane derivatives of (R)-(-)-2-octanol, (R)-(+)-1-phenylethyl alcohol, and (S)-(+)-2,2,2-trifluoro-1-phenylethanol are eluted before the corresponding diastereomers. The procedure is simple and rapid, and is suitable for the determination of the enantiomeric composition of chiral alcohols extracted from biological media. A series of aliphatic alcohols, aryl alkyl carbinols, and arylalkyl alkyl carbinols were resolved with the procedure, and the degree of resolution varied from good to excellent. Eight achiral ketones were incubated, individually, with rabbit-liver 90,000 g supernatant fractions, and the enantiomeric composition of the alcohol metabolites was determined with the GLC procedure. The reductions proceeded with high stereoselectivity to give alcohol products of 90% or greater enantiomeric purity. The reduction of 2-octanone and acetophenone gave predominant alcohols of (S)-configuration, in agreement with the Baumann-Prelog rule. The configuration of the predominant alcohols arising in the reduction of the remainder of the ketones could not be firmly established, but the evidence suggests that they are also of the (S)-configuration. Fluorine or methyl substitution in the ortho position of acetophenone produced an increase in the stereoselectivity, and the alcohol produced from ortho-methylacetophenone was enantiomerically greater than 99% pure.

Antimutagenic activity of some naturally occurring compounds towards cigarette-smoke condensate and benzo(a)pyrene in the Salmonella/microsome assay

Energy Technology Data Exchange (ETDEWEB)

Terwel, L.; van der Hoeven, J.C.

1985-10-01

Several compounds, occurring in food, were tested for antimutagenic activity towards cigarette-smoke condensate (CSC) and benzo(a)pyrene (BaP). Antimutagenicity was determined in the Salmonella/microsome test, with tester strain TA98, in the presence of rat-liver homogenate. Dose-response curves did show reduction of CSC- and BaP-induced mutagenicity by ellagic acid, riboflavin and chlorophyllin. Chlorophyll a and chlorophyll b, although less distinct, also inhibited CSC- and BaP-induced mutagenicity. Ascorbic acid, beta-carotene, tocopherol acetate, chlorogenic acid and butyl hydroxyanisole did not have any influence on the mutagenicity of CSC and BaP. The similarity in results for cigarette-smoke condensate and for BaP indicates that a general mechanism may be involved in the inhibition of CSC- and BaP-induced mutagenicity.

Purification of dihydropyridine receptor from rabbit skeletal muscle

International Nuclear Information System (INIS)

Nakayama, N.; Vaghy, P.; Schwartz, A.

1986-01-01

Dihydropyridine (DHP)receptor was purified from T-tubules isolated from freeze-thawed rabbit skeletal muscle after French press treatment of microsomal membranes. DHP receptor was labeled with 25 nM [ 3 H]-(+)-PN-200-110 (PN, one of the most potent Ca-antagonists) and solubilized with 1% digitonin. The solubilized receptor was purified in the presence of protease inhibitors (0.1 mM PMSF, 1 mM iodoacetamide, 1μM pepstatin A, 1 mg/l antipain and 0.2 mM o-phenanthroline) using WGA-Sepharose and DEAE-Biogel A column chromatography as well as sucrose density gradient (SDG) centrifugation. The pooled fractions of the SDG had a maximum binding of 590 pmol/mg protein even without correcting for dissociation of PN from the receptors during purification. On SDS-PAGE, a single major band (191 K dalton) was shown both in presence and absence of 20 mM N-ethyl maleimide. However, two major (145 and 103 K dalton) a few minor bands (55,46,32 and 31K dalton) were obtained if the fraction was treated with 20 mM dithiothreitol prior to electrophoresis. The authors data suggest that 191 and 145 k dalton proteins correspond to the α-subunit of the DHP receptor as reported by Curtis and Catterall

Biotransformation of trans-1-chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd)

International Nuclear Information System (INIS)

Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Tveit, Ann; Dekant, Wolfgang

2013-01-01

trans-1-Chloro-3,3,3-trifluoropropene (trans-HCFO-1233zd) is a novel foam blowing and precision cleaning agent with a very low impact for global warming and ozone depletion. trans-HCFO-1233zd also has a low potential for toxicity in rodents and is negative in genotoxicity testing. The biotransformation of trans-HCFO-1233zd and kinetics of metabolite excretion with urine were assessed in vitro and in animals after inhalation exposures. For in vitro characterization, liver microsomes from rats, rabbits and humans were incubated with trans-HCFO-1233zd. Male Sprague Dawley rats and female New Zealand White rabbits were exposed to 2,000, 5,000 and 10,000 ppm for 6 h and urine was collected for 48 h after the end of the exposure. Study specimens were analyzed for metabolites using 19 F NMR, LC-MS/MS and GC/MS. S-(3,3,3-trifluoro-trans-propenyl)-glutathione was identified as predominant metabolite of trans-HCFO-1233zd in all microsomal incubation experiments in the presence of glutathione. Products of the oxidative biotransformation of trans-HCFO-1233zd were only minor metabolites when glutathione was present. In rats, both 3,3,3-trifluorolactic acid and N-acetyl-(3,3,3-trifluoro-trans-propenyl)-L-cysteine were observed as major urinary metabolites. 3,3,3-Trifluorolactic acid was not detected in the urine of rabbits. Quantitation showed rapid excretion of both metabolites in both species (t 1/2 1/2 < 6 h). ► Glutathione adduct as predominant in vitro metabolite in all tested species. ► Toxic metabolites could not be detected in any great extent

Epidemiology of RHDV2 (Lagovirus europaeus/GI.2) in free-living wild European rabbits in Portugal.

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Rouco, C; Abrantes, J; Serronha, A; Lopes, A M; Maio, E; Magalhães, M J; Blanco, E; Bárcena, J; Esteves, P J; Santos, N; Alves, P C; Monterroso, P

2018-04-01

As the detection of the first outbreak of a novel aetiological agent of rabbit haemorrhagic disease commonly called RHDV2 or RHDVb (Lagovirus europaeus/GI.2, henceforth GI.2) in France in 2010, the virus rapidly spread throughout continental Europe and nearby islands such as Great Britain, Sardinia, Sicily, the Azores and the Canary Islands among others. The outbreaks of this new lagovirus cause important economic losses in rabbitries, and ecological disruptions by affecting the conservation of rabbit-sensitive top predators. We analysed 550 rabbit carcasses collected in the field between May 2013 and March 2016, to investigate the epidemiology of GI.2 in free-living populations and to perform a comparative analysis with the epidemiology of classical rabbit haemorrhagic disease virus forms (RHDV, henceforth GI.1) in Portugal. Rabbits were sexed, aged and liver and blood samples were collected for subsequent RHDV screening and serology. A total of 172 samples were PCR-positive to GI.2, whereas GI.1 strains were not detected in any of the samples. The outbreaks of GI.2 revealed a marked seasonality, with peaks during the breeding season (November-May). We also found that approximately, one-third of free-ranging European rabbits in Portugal have seroconverted to GI.2. We demonstrate that the GI.2 lagovirus is currently widespread in wild populations in Portugal and is affecting a high proportion of adults and juveniles. Therefore, ongoing monitoring and surveillance are required to assess the effects of GI.2 on wild rabbit populations, its evolution, and to guide management actions aimed at mitigating the impacts of rabbit declines in the ecosystem and in rural economies. © 2017 Blackwell Verlag GmbH.

Autoimmune paediatric liver disease.

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Mieli-Vergani, Giorgina; Vergani, Diego

2008-06-07

Liver disorders with a likely autoimmune pathogenesis in childhood include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is divided into two subtypes according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1 positive patients tend to present more acutely, at a younger age, and commonly have partial IgA deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment, and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological, and histological presentation of ASC is often indistinguishable from that of AIH type 1. In both, there are high IgG, non-organ specific autoantibodies, and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalization of biochemical parameters, and decreased inflammatory activity on follow up liver biopsies. However, the cholangiopathy can progress. There may be evolution from AIH to ASC over the years, despite treatment. De novo AIH after liver transplantation affects patients not transplanted for autoimmune disorders and is strikingly reminiscent of classical AIH, including elevated titres of serum antibodies, hypergammaglobulinaemia, and histological findings of interface hepatitis, bridging fibrosis, and collapse. Like classical AIH, it responds to treatment with prednisolone and azathioprine. De novo AIH post liver transplantation may derive from interference by calcineurin inhibitors with the intrathymic physiological mechanisms of T-cell maturation and selection. Whether this condition is a

Enantioselective metabolism of hydroxychloroquine employing rats and mice hepatic microsomes

Directory of Open Access Journals (Sweden)

Carmem Dickow Cardoso

2009-12-01

Full Text Available Hydroxychloroquine (HCQ is an important chiral drug used, mainly, in the treatment of rheumatoid arthritis, systemic lupus erythematosus and malaria, and whose pharmacokinetic and pharmacodynamic properties look to be stereoselective. Respecting the pharmacokinetic properties, some previous studies indicate that the stereoselectivity could express itself in the processes of metabolism, distribution and excretion and that the stereoselective metabolism looks to be a function of the studied species. So, the in vitro metabolism of HCQ was investigated using hepatic microsomes of rats and mice. The microsomal fraction of livers of Wistar rats and Balb-C mice was separated by ultracentrifugation and 500 μL were incubated for 180 minutes with 10 μL of racemic HCQ 1000 μg mL-1. Two stereospecific analytical methods, high performance liquid chromatography (HPLC and capillary electrophoresis (CE, were used to separate and quantify the formed metabolites. It was verified that the main formed metabolite is the (--(R-desethyl hydroxychloroquine for both animal species.A hidroxicloroquina (HCQ é um importante fármaco quiral usado, principalmente, no tratamento de artrite reumatóide, lupus eritematoso sistêmico e malária e cujas propriedades farmacocinéticas e farmacodinâmicas parecem ser estereosseletivas. Em relação às propriedades farmacocinéticas, alguns estudos prévios indicam que a estereosseletividade pode se expressar nos processos de metabolismo, distribuição e excreção e que o metabolismo estereosseletivo parece ser função da espécie estudada. Sendo assim, o metabolismo in vitro da HCQ foi investigado usando microssomas de fígado de ratos e de camundongos. A fração microssômica de fígados de ratos Wistar e de camundongos Balb-C foi isolada por ultracentrifugação e 500 μL foram incubados por 180 minutos com 10 μL de HCQ racêmica 1000 μg mL-1. Dois métodos analíticos estereoespecíficos, por cromatografia líquida de

The effects of multiply ionizing gamma irradiations on the xenobiotic metabolizing system in the liver of rats

International Nuclear Information System (INIS)

Zavodnik, L.B.; Buko, V.U.

2009-01-01

The aim of the work was the studying the effect of multiply low doses of gamma-irradiation in a total doze 1 and 2 Gy on processes lipid peroxidation and xenobiotics metabolizing in rat liver. It was shown the multiply irradiation causes the expressed activation of lipid peroxidation, by increase of TBARS level and dien conjugates. The system of microsomal oxidations was broken at the same time. (authors)

Kefiran reduces atherosclerosis in rabbits fed a high cholesterol diet.

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Uchida, Masashi; Ishii, Itsuko; Inoue, Chika; Akisato, Yoshie; Watanabe, Kenta; Hosoyama, Saori; Toida, Toshihiko; Ariyoshi, Noritaka; Kitada, Mitsukazu

2010-09-30

Kefiran is an exopolysaccharide produced by Lactobacillus kefiranofaciens, and has been proposed to have many health-promoting properties. We investigated the antiatherogenic effect of kefiran on rabbits fed a high-cholesterol diet. Male New Zealand White rabbits were fed a 0.5% cholesterol diet without (control group, n = 7) or with kefiran (kefiran group, n = 8) for eight weeks. The aorta was analyzed by histochemistry and atherosclerotic lesions were quantified. Lipids and sugars in serum were measured. Foam cell formation of RAW264.7 by βVLDL derived from both groups of rabbits was also investigated. Cholesterol, triglyceride and phospholipids levels of serum and lipoprotein fractions were not significantly different between these groups. Atherosclerotic lesions of the aorta in the kefiran group were statistically lower than those of the control group, with marked differences in the abdominal aorta. T-lymphocytes were not detectable in the aorta of the kefiran group. Cholesterol contents in stools were almost identical in both groups. Cholesterol content in the liver of the kefiran group was statistically lower than in the control group. Galactose content of βVLDL derived from the kefiran group was higher, and the lipid peroxidation level was much lower than in the control group. RAW264.7 macrophages treated with βVLDL from the kefiran group showed a more spherical shape and accumulated statistically lower cholesterol than macrophages treated with βVLDL from the control group. Orally derived kefiran is absorbed in the blood. Kefiran prevents the onset and development of atherosclerosis in hypercholesterolemic rabbits by anti-inflammatory and anti-oxidant actions.

Metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes

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Ohhira, Shuji; Watanabe, Masatomo; Matsui, Hisao [Department of Hygiene, Dokkyo University School of Medicine, Mibu-machi, 321-0293, Tochigi (Japan)

2003-03-01

Tributyltin and triphenyltin are metabolized by cytochrome P-450 system enzymes, and their metabolic fate may contribute to the toxicity of the chemicals. In the current study, the in vitro metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes was investigated to elucidate the metabolic competence for these compounds in humans. The metabolic reaction using microsome-NADPH system that is usually conducted was not applicable to in vitro metabolism of organotins, especially triphenyltin. We therefore examined the effects of dithiothreitol (DTT), one of the antioxidants for sulfhydryl groups, to determine the in vitro metabolism of tributyltin and triphenyltin. As a result, the treatment with 0.1 mM DTT in vitro increased the activity of the microsomal monooxygenase system for metabolism of tributyltin as well as triphenyltin; the total yield of tributyltin and triphenyltin metabolites as tin increased, respectively, by approximately 1.8 and 8.9 times for rat, 2.1 and 1.2 times for hamster, and 1.6 and 1.5 times for human. It is suggested that the organotins directly inactivate cytochrome P-450 because of the interaction with critical sulfhydryl groups of the hemoprotein. We confirmed the utility of this in vitro metabolic system using DTT in the hepatic microsomes of phenobarbital (PB)-pretreated and untreated hamsters. Thus, the in vitro metabolic system described here was applied to a comparative study of the metabolism of organotins in rats, hamsters and humans. Tributyltin was metabolized more readily than triphenyltin in all the species. In humans, the in vitro metabolic pattern resembled that of hamsters, which were susceptible to in vivo triphenyltin toxicity because of incompetent metabolism. It is possible that the hamster is a qualitatively and quantitatively suitable animal model for exploring the influence of tributyltin and triphenyltin in humans. (orig.)

Effect of p-amino-diphenyl ethers on hepatic microsomal cytochrome P450.

Science.gov (United States)

Jiang, Huidi; Xuan, Guida

2003-09-01

The present paper aims to investigate whether p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450. Mice were given daily intraperitoneal (ip) injections of p-amino-2',4'-dichlorodiphenyl ether (0.25 mmol/kg) or p-amino-4'-methyldiphenyl ether (0.25 mmol/kg) for 4 days and tested at 24 h and 48 h after the last dose injection. The results showed the mice pentobarbital sleeping time was shorter and the P450 content of hepatic microsome increased significantly in the group pretreated with p-amino-4'-methyldiphenyl ether when compared with the control group, while in mice pretreated with p-amino-2',4'-dichlorodiphenyl ether the hepatic microsome P450 content increased but the pentobarbital sleeping time was extended in clear contrast to the control group. The sleeping time of the phenobarbital group (80 mg/kg daily ip injection for 4 days) was shortened at 24 h after the last injection with increased P450 content of hepatic microsome, but it showed no difference at 48 h. The zoxazolamine-paralysis times of mice treated with p-amino-2',4'-dichlorodiphenyl ether were longer than those of the control mice, while the same dose of zoxazolamine did not lead to paralysis in mice pretreated with BNF. p-Amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether inhibited the activity of 7-ethoxyresorufin O-deethylase from rat hepatic microsome induced by BNF in vitro by 70.0% and 50.1% respectively. These results suggest that p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450.

Identification and analysis of cytochrome P450IID6 antigenic sites recognized by anti-liver-kidney microsome type-1 antibodies (LKM1).

Science.gov (United States)

Yamamoto, A M; Cresteil, D; Boniface, O; Clerc, F F; Alvarez, F

1993-05-01

Anti-liver-kidney microsome type-1 antibodies (LKM1), present in sera from a group of patients with autoimmune hepatitis, are directed against P450IID6. Previous work, using cDNA constructions spanning most of the P450IID6 protein defined the main immunogenic site between the amino acids (aa), 254-271 and predicted the presence of other putative immunogenic sites in the molecule. Fusion proteins from new cDNA constructions, spanning so-far-untested regions between aa 1-125 and 431-522, were not recognized by LKM1-positive sera. Synthetic peptides, representing sequences from putative immunogenic regions or previously untested regions, allowed a precise definition of four antigenic sites located between peptides 257-269, 321-351, 373-389 and 410-429, which were recognized, respectively, by 14, 8, 1 and 2 out of 15 LKM1-positive sera tested. The minimal sequence of the main antigenic site (peptide 257-269) recognized by the autoantibody was established to be WDPAQPPRD (peptide 262-270). In addition, deletion and replacement experiments showed that aa 263 (Asp) was essential for the binding of the autoantibody to peptide 262-270. Analysis of the second most frequently recognized peptide between aa 321-351, was performed using peptides 321-339 and 340-351 in competitive inhibition studies. Complete elimination of antibody binding to peptide 321-351 obtained by absorption of both shorter peptides indicated that peptide 321-351 is a discontinuous antigenic site. LKM1-positive sera reacting against peptide 321-351 recognized either both the shorter peptides or just one of them preferentially. Results of the present study suggest that the production of LKM1 antibodies is an antigen-driven, poly- or oligoclonal B cell response. The identification of antigenic sites will allow: (i) the development of specific diagnostic tests and (ii) further studies on the pathogenic value of LKM1 antibodies in autoimmune hepatitis.

Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

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Hye Young Ji

2012-01-01

Full Text Available DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP enzymes and four UDP-glucuronosyltransferase (UGT enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50 values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol 1′-hydroxylation with an inhibition constant (Ki value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol 1′-hydroxylation, with a Ki value of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50 equivalent concentration (volume per dose index value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate the in vivo extent of the observed in vitro interactions.

Etiology of fatty liver in dairy cattle: effects of nutritional and hormonal status on hepatic microsomal triglyceride transfer protein.

Science.gov (United States)

Bremmer, D R; Trower, S L; Bertics, S J; Besong, S A; Bernabucci, U; Grummer, R R

2000-10-01

We conducted three experiments to determine the effects of nutritional and hormonal status on microsomal triglyceride transfer protein (MTP) activity and mass. In experiment 1, 18 nonlactating Holstein cows, 75 d before expected calving date, in their second gestation or greater were monitored from d 75 to 55 prepartum. Cows were fed a control diet from d 75 to 62 prepartum for covariable measurements. From d 61 to 55 prepartum, six cows continued to receive the control diet, six cows were restricted to 2.3 kg of grass hay/d, and six cows were fed the control diet plus 1.8 kg of concentrate/d and 500 ml of propylene glycol given 2 times/d as an oral drench. Plasma glucose and serum insulin concentrations were highest in cows that received propylene glycol and lowest in feed restricted cows. Plasma nonesterified fatty acids (NEFA) and liver triglyceride (TG) concentrations were highest in feed restricted cows and not different between cows that received the control diet and cows that received propylene glycol. Hepatic MTP activity and mass were not affected by treatment in experiment 1. In experiment 2, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with either 0, 0.5, 1.0, or 2.0 mM NEFA for 48 h. Intracellular TG increased linearly as NEFA concentration in the media increased. Concentration of NEFA in the incubation media had no effect on MTP activity or mass. There was a quadratic effect of concentration of NEFA in the incubation media on MTP mRNA. In experiment 3, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with 2 mM [1-14C]oleate for 24 h to accumulate TG, followed by a 36-h period of TG depletion, during which hepatocytes were incubated with no hormone, 10 nM insulin, or 10 nM glucagon. There was no effect of insulin or glucagon on intracellular TG, MTP activity or mass. Cells incubated with no hormone had higher levels of MTP m

In vitro biotransformation of tris(2-butoxyethyl) phosphate (TBOEP) in human liver and serum

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Van den Eede, Nele, E-mail: nele.vandeneede@uantwerpen.be [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Erratico, Claudio [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Exarchou, Vassiliki [Natural Products & Food Research and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Maho, Walid; Neels, Hugo [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium)

2015-04-15

Tris(2-butoxyethyl) phosphate (TBOEP) is a plasticizer present in indoor dust, reaching levels of several micrograms per gram. Such levels could lead to significant daily exposure of adults and children. Currently, no toxicokinetic data are available to estimate TBOEP clearance in humans after uptake and therefore, one objective of this study was to investigate intrinsic clearance of TBOEP by human liver microsome (HLM) and serum enzymes. Another objective was to generate information to identify and prioritize several metabolites of TBOEP for investigation of human exposure by biomonitoring. 1D and 2D-NMR methodologies were successfully applied on a mixture of the metabolites to confirm the structure of 3-HO-TBOEP (bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate) and to tentatively assign structures to 1-HO-TBOEP and 2-HO-TBOEP. HO-TBOEP isomers and bis(2-butoxyethyl) phosphate (BBOEP), bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) were further monitored by liquid chromatography–tandem mass spectrometry. Rates of formation of BBOEHEP and HO-TBOEP metabolites by liver enzymes were best described by the Michaelis–Menten model. Apparent K{sub m} values for BBOEHEP, 3-HO-TBOEP, and sum of 1- and 2-HO-TBOEP isomer formation were 152, 197 and 148 μM, respectively. Apparent V{sub max} values for the formation of BBOEHEP, 3-HO-TBOEP, and the sum of 1- and 2-HO-TBOEP isomers were 2560, 643, and 254 pmol/min/mg protein, respectively. No detectable formation of BBOEP occurred with liver or serum enzymes. Our findings indicate that intrinsic clearance of TBOEP is mainly catalyzed by oxidative enzymes in the liver and that its major in vitro metabolite is BBOEHEP. These findings can be applied in human biomonitoring studies and risk assessment. - Highlights: • First steps in the elucidation of TBOEP toxicokinetics • Quantification of TBOEP metabolites in human serum and liver microsomes • No detectable formation of BBOEP occurred with liver or serum

Lipid peroxide levels of serum lipoprotein fractions of diabetic patients with angiopathy and 60Co-irradiated rabbit

International Nuclear Information System (INIS)

Tsunekawa, Hiroshi

1982-01-01

For a better understanding of the relationship between lipid peroxide (LPO) and vascular diseases, the author determined LPO levels and lipid contents of serum lipoprotein fractions of diabetics with angiopathy. The LPO level in high density lipoprotein (HDL) fraction of diabetic serum was significantly higher than that of normal serum whereas no significant increase was observed in the levels of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions of diabetic serum. As to the ratios of LPO to total lipids in these lipoprotein fractions, it was found that the ratio in HDL fraction of the diabetics was markedly higher than that of the normals. These results suggest that the increase in LPO levels in the sera of diabetic patiens is due to that in HDL fraction. To study further this problem, the author employed 60 Co-irradiated rabbit as a model, since it was already reported that radiation affects lipid metabolism and LPO formation, and that it induces the development of atherosclerosis. Upon irradiation with 60 Co ranging from 100R to 700R, serum LPO level of rabbit was significantly increased. Although elevation of LPO level was found in each serum lipoprotein fraction of VLDL, LDL and HDL, LPO level per lipid content was significantly increased only in HDL fraction. In the irradiated rabbit, significant elevation of the level of LPO was also observed in the liver, while no significant increase was found in the kidney and spleen. These results indicate that high level of LPO observed in the serum of irradiated rabbit would be the reflection of the increased LPO in the liver. (J.P.N.)

Automation of metabolic stability studies in microsomes, cytosol and plasma using a 215 Gilson liquid handler.

Science.gov (United States)

Linget, J M; du Vignaud, P

1999-05-01

A 215 Gilson liquid handler was used to automate enzymatic incubations using microsomes, cytosol and plasma. The design of automated protocols are described. They were based on the use of 96 deep well plates and on HPLC-based methods for assaying the substrate. The assessment of those protocols was made with comparison between manual and automated incubations, reliability and reproducibility of automated incubations in microsomes and cytosol. Examples of the use of those programs in metabolic studies in drug research, i.e. metabolic screening in microsomes and plasma were shown. Even rapid processes (with disappearance half lives as low as 1 min) can be analysed. This work demonstrates how stability studies can be automated to save time, render experiments involving human biological media less hazardous and may be improve inter-laboratory reproducibility.

Studies on distribution and excretion of 14C-glycerol in rats, rabbits and mice

International Nuclear Information System (INIS)

Takanashi, Shigeru; Kamiyama, Hiroshi; Suzuki, Hidetaka; Tohira, Yasuo; Ogawa, Machiko

1978-01-01

Tissue distribution and excretion of uniformly labeled 14 C-glycerol were investigated using rats, rabbits and mice. Blood disappearance half life of 14 W/V% 14 C-glycerol in mice (1 ml/head), rats (1 ml/head) and rabbits (2 ml/head) given intravenously was 0.4, 1.8 and 2.4 hours, respectively. When 14 W/V% 14 C-glycerol was injected in rats (1 ml/head) and rabbits (2 ml/head), 65% of administered radioactivity was excreted in to expired air within 48 hrs. This suggests that glycerol is mostly metabolised via the Embden-Meyehof pathway and the TCA cycle, and finally converted to CO 2 and H 2 O. At a low dose, the conversion ratio to CO 2 was greater than the case of a high dose, and a inverse relationship was observed between the CO 2 -conversion ratio and the dose. At levels above 1 ml of 56 W/V% glycerol, an approximately constant portion of the administered dose appeared to be oxidized. The results of the whole body autoradiogram showed the distribution of the radioactivity throughout the body. Disappearance of radioactivity from liver and blood was rapid, but transport to brain, excretion to the salivary gland, and secretion to Harder's gland were slow. The distribution in tissues showed that the highest distribution of 14 C-glycerol was found in the carcass; liver showed the next highest distribution; high distribution was also found initially in the kidneys; brain, heart, lung and spleen showed low distribution, but they decreased with time elapsed. Disappearance of radioactivity from the brain was relatively slower than the liver. Besides, another result indicated that in pregnant mice 14 C-glycerol did not cross the placenta very quickly. The fact that the apparent disappearance rate from the foetuses does not seem to parallel that of the placenta is suggestive of selective accumulation in foetal tissues. (auth.)

In vitro biotransformation of pyrrolizidine alkaloids in different species. Part I: Microsomal degradation.

Science.gov (United States)

Kolrep, Franziska; Numata, Jorge; Kneuer, Carsten; Preiss-Weigert, Angelika; Lahrssen-Wiederholt, Monika; Schrenk, Dieter; These, Anja

2018-03-01

Pyrrolizidine alkaloids (PA) are secondary metabolites of certain flowering plants. The ingestion of PAs may result in acute and chronic effects in man and livestock with hepatotoxicity, mutagenicity, and carcinogenicity being identified as predominant effects. Several hundred PAs sharing the diol pyrrolizidine as a core structure are formed by plants. Although many congeners may cause adverse effects, differences in the toxic potency have been detected in animal tests. It is generally accepted that PAs themselves are biologically and toxicologically inactive and require metabolic activation. Consequently, a strong relationship between activating metabolism and toxicity can be expected. Concerning PA susceptibility, marked differences between species were reported with a comparatively high susceptibility in horses, while goat and sheep seem to be almost resistant. Therefore, we investigated the in vitro degradation rate of four frequently occurring PAs by liver enzymes present in S9 fractions from human, pig, cow, horse, rat, rabbit, goat, and sheep liver. Unexpectedly, almost no metabolic degradation of any PA was observed for susceptible species such as human, pig, horse, or cow. If the formation of toxic metabolites represents a crucial bioactivation step, the found inverse conversion rates of PAs compared to the known susceptibility require further investigation.

Development of achiral and chiral 2D HPLC methods for analysis of albendazole metabolites in microsomal fractions using multivariate analysis for the in vitro metabolism.

Science.gov (United States)

Belaz, Kátia Roberta A; Pereira-Filho, Edenir Rodrigues; Oliveira, Regina V

2013-08-01

In this work, the development of two multidimensional liquid chromatography methods coupled to a fluorescence detector is described for direct analysis of microsomal fractions obtained from rat livers. The chiral multidimensional method was then applied for the optimization of the in vitro metabolism of albendazole by experimental design. Albendazole was selected as a model drug because of its anthelmintics properties and recent potential for cancer treatment. The development of two fully automated achiral-chiral and chiral-chiral high performance liquid chromatography (HPLC) methods for the determination of albendazole (ABZ) and its metabolites albendazole sulphoxide (ABZ-SO), albendazole sulphone (ABZ-SO2) and albendazole 2-aminosulphone (ABZ-SO2NH2) in microsomal fractions are described. These methods involve the use of a phenyl (RAM-phenyl-BSA) or octyl (RAM-C8-BSA) restricted access media bovine serum albumin column for the sample clean-up, followed by an achiral phenyl column (15.0×0.46cmI.D.) or a chiral amylose tris(3,5-dimethylphenylcarbamate) column (15.0×0.46cmI.D.). The chiral 2D HPLC method was applied to the development of a compromise condition for the in vitro metabolism of ABZ by means of experimental design involving multivariate analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Liver cytosolic 1 antigen-antibody system in type 2 autoimmune hepatitis and hepatitis C virus infection.

Science.gov (United States)

Lenzi, M; Manotti, P; Muratori, L; Cataleta, M; Ballardini, G; Cassani, F; Bianchi, F B

1995-01-01

Within the multiform liver/kidney microsomal (LKM) family, a subgroup of sera that reacts with a liver cytosolic (LC) protein has been isolated and the new antigen-antibody system is called LC1. Unlike LKM antibody type 1 (anti-LKM1), anti-LC1 is said to be unrelated to hepatitis C virus (HCV) infection and has therefore been proposed as a marker of 'true' autoimmune hepatitis type 2. Altogether 100 LKM1 positive sera were tested by immunodiffusion (ID). Twenty five gave a precipitation line with human liver cytosol; 17 of the 25 also reacted with rat liver cytosol. Thirteen of the 25 sera were anti-HCV positive by second generation ELISA: anti-HCV positive patients were significantly older (p LKM1, and that it is an additional marker of juvenile autoimmune hepatitis type 2. It does not, however, discriminate between patients with and without HCV infection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7797126

Experiment of embolizing hepatocarcinoma with heated lipiodol via hepatic artery in VX{sub 2} rabbit model

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Wei, Cao; Zhimin, Wang; Hongxin, Zhang [Department of Interventional Radiology, Tangdu Hospital, The Fourth Military Medical Univ., Xi' an (China); Yi, Wan

2006-09-15

Objective: To evaluate the anti-tumour effect of 60 degree C Lipiodol in the embolization of VX{sub 2} hepatocarcinoma in rabbits. Methods: VX{sub 2} carcinoma cells were surgically implanted into the left liver lobe in 30 male New Zealand white rabbits, which were randomly divided into 3 groups by figure and table method with 10 rabbits in each group. Physiological saline, Lipiodol (37 degree C), and Lipiodol (60 degree C) were injected in each group via hepatic artery and liver cancer was embolized. The volume of tumour and serum level of aspartate aminotransferase (AST) were observed after one week, and the survival period of VX{sub 2} rabbits was also observed. Results: In the group of Lipiodol (60 degree C), the growth rate of tumour (0.92{+-} 0.21) was significantly lower than that of control group (3.48{+-}) and Lipiodol (37 degree C) groups (1.69{+-}0.26), respectively (F=34.95, P<0.05). The survival period of Lipiodol (60 degree C) group (41.0{+-}3.0) d was significantly longer than the control group (31.5{+-}3.0) d (t=29.18, P<0.05). Four days after the embolization, the serum level of AST of Lipiodol (60 degree C) (148.2{+-}11.3) U/L was not higher than that of Lipiodol (37 degree C) (139.7{+-}12.3) U/L (t=1.61, P>0.05), but was significantly higher than the control group (68.6{+-}6.6) U/L (t=19.24, P<0.05). Conclusion: Lipiodol (60 degree C) greatly decreases the tumour's growth rate and prolongs the survival period. It is a safe method and has stronger inhibitory effect than other groups. (authors)

Clearance Prediction Methodology Needs Fundamental Improvement: Trends Common to Rat and Human Hepatocytes/Microsomes and Implications for Experimental Methodology.

Science.gov (United States)

Wood, F L; Houston, J B; Hallifax, D

2017-11-01

Although prediction of clearance using hepatocytes and liver microsomes has long played a decisive role in drug discovery, it is widely acknowledged that reliably accurate prediction is not yet achievable despite the predominance of hepatically cleared drugs. Physiologically mechanistic methodology tends to underpredict clearance by several fold, and empirical correction of this bias is confounded by imprecision across drugs. Understanding the causes of prediction uncertainty has been slow, possibly reflecting poor resolution of variables associated with donor source and experimental methods, particularly for the human situation. It has been reported that among published human hepatocyte predictions there was a tendency for underprediction to increase with increasing in vivo intrinsic clearance, suggesting an inherent limitation using this particular system. This implied an artifactual rate limitation in vitro, although preparative effects on cell stability and performance were not yet resolved from assay design limitations. Here, to resolve these issues further, we present an up-to-date and comprehensive examination of predictions from published rat as well as human studies (where n = 128 and 101 hepatocytes and n = 71 and 83 microsomes, respectively) to assess system performance more independently. We report a clear trend of increasing underprediction with increasing in vivo intrinsic clearance, which is similar both between species and between in vitro systems. Hence, prior concerns arising specifically from human in vitro systems may be unfounded and the focus of investigation in the future should be to minimize the potential in vitro assay limitations common to whole cells and subcellular fractions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Cytochrome P450 2C8 and flavin-containing monooxygenases are involved in the metabolism of tazarotenic acid in humans.

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Attar, Mayssa; Dong, Dahai; Ling, Kah-Hiing John; Tang-Liu, Diane D-S

2003-04-01

Upon oral administration, tazarotene is rapidly converted to tazarotenic acid by esterases. The main circulating agent, tazarotenic acid is subsequently oxidized to the inactive sulfoxide metabolite. Therefore, alterations in the metabolic clearance of tazarotenic acid may have significant effects on its systemic exposure. The objective of this study was to identify the human liver microsomal enzymes responsible for the in vitro metabolism of tazarotenic acid. Tazarotenic acid was incubated with 1 mg/ml pooled human liver microsomes, in 100 mM potassium phosphate buffer (pH 7.4), at 37 degrees C, over a period of 30 min. The microsomal enzymes that may be involved in tazarotenic acid metabolism were identified through incubation with microsomes containing cDNA-expressed human microsomal isozymes. Chemical inhibition studies were then conducted to confirm the identity of the enzymes potentially involved in tazarotenic acid metabolism. Reversed-phase high performance liquid chromatography was used to quantify the sulfoxide metabolite, the major metabolite of tazarotenic acid. Upon incubation of tazarotenic acid with microsomes expressing CYP2C8, flavin-containing monooxygenase 1 (FMO1), or FMO3, marked formation of the sulfoxide metabolite was observed. The involvement of these isozymes in tazarotenic acid metabolism was further confirmed by inhibition of metabolite formation in pooled human liver microsomes by specific inhibitors of CYP2C8 or FMO. In conclusion, the in vitro metabolism of tazarotenic acid to its sulfoxide metabolite in human liver microsomes is mediated by CYP2C8 and FMO.

Evaluation of the antifertility effect of magainin-A in rabbits: in vitro and in vivo studies.

Science.gov (United States)

Reddy, V R; Manjramkar, D D

2000-02-01

To evaluate the safety and contraceptive potential of magainin-A in rabbits. Controlled laboratory study. Department of Immunology, Institute for Research in Reproduction, Mumbai, Parel, India. Forty-eight female New Zealand white rabbits. The effect of magainin-A on sperm motility (in vitro and in vivo studies) and on vaginal epithelium (histologic study) was assessed along with serum and liver biochemical profiles. Suitability of magainin-A for contraceptive use. Magainin-A arrested sperm motility, and 1 mg of magainin-A administered intravaginally blocked conception. No histopathologic abnormalities in the vaginal tissue or any changes in serum biochemical profiles were observed. Magainin-A may be used as an effective and safe intravaginal contraceptive compound that also has antibacterial properties.

Lipid peroxide levels of serum lipoprotein fractions of diabetic patients with angiopathy and /sup 60/Co-irradiated rabbit

Energy Technology Data Exchange (ETDEWEB)

Tsunekawa, Hiroshi [Nagoya Univ. (Japan). Faculty of Medicine

1982-09-01

For a better understanding of the relationship between lipid peroxide (LPO) and vascular diseases, the author determined LPO levels and lipid contents of serum lipoprotein fractions of diabetics with angiopathy. The LPO level in high density lipoprotein (HDL) fraction of diabetic serum was significantly higher than that of normal serum whereas no significant increase was observed in the levels of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions of diabetic serum. As to the ratios of LPO to total lipids in these lipoprotein fractions, it was found that the ratio in HDL fraction of the diabetics was markedly higher than that of the normals. These results suggest that the increase in LPO levels in the sera of diabetic patients is due to that in HDL fraction. To study further this problem, the author employed /sup 60/Co-irradiated rabbit as a model, since it was already reported that radiation affects lipid metabolism and LPO formation, and that it induces the development of atherosclerosis. Upon irradiation with /sup 60/Co ranging from 100R to 700R, serum LPO level of rabbit was significantly increased. Although elevation of LPO level was found in each serum lipoprotein fraction of VLDL, LDL and HDL, LPO level per lipid content was significantly increased only in HDL fraction. In the irradiated rabbit, significant elevation of the level of LPO was also observed in the liver, while no significant increase was found in the kidney and spleen. These results indicate that high level of LPO observed in the serum of irradiated rabbit would be the reflection of the increased LPO in the liver.

In vitro metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl(CB187) with liver microsomes of rats, hamsters and guinea pigs

Energy Technology Data Exchange (ETDEWEB)

Koga, N.; Ohta, C.; Kanamaru, T. [Nakamura Gakuen Univ., Fukuoka (Japan); Haraguchi, K. [Daiichi Coll. of Pharmaceutical Sciences, Fukuoka (Japan); Kato, Y.; Yamada, S. [Univ. of Shizuoka, Shizuoka (Japan)

2004-09-15

PCB congeners possess extremely high lipophilicity and biological stability, and as a result they are not easily eliminated from the body once ingested. In particular, not only 2,4,5-trichlorosubstituted but also 6 or more chlorine-substituted PCBs such as 2,2',3',4,4',5-hexa-chlorobiphenyl (hexaCB) (CB138), 2,2',4,4',5,5'-hexaCB (CB153), 2,2',3,4,4',5,5'-heptachloro-biphenyl (heptaCB) (CB180) and 2,2',3,4',5,5',6-heptaCB (CB187) have been detected in blood and adipose tissues of mammals and human mother's milk at higher concentration. In addition, the 4-hydroxy (OH)-metabolite of CB187 has been reported to be present in human blood at the highest concentration of that derived from other PCB congeners. Although CB187, a tri-ortho-PCB, is one of the minor component in the commercial PCB preparations such as Clophen, Aroclor and Kanechlor, the toxic equivalency factor (TEF) which is used for dioxin-like PCB congeners including coplanar-PCBs and mono-ortho-PCBs to assess the potency of the toxicity has not been set up for di- and tri-ortho-PCB congeners. These facts indicate that 4-OH-PCB187 become more persistent and more important toxicologically than the parent CB187. However, there is little report about biotransformation in vivo or in vitro of CB187 in animals. Therefore, we examined CB187 metabolism by liver microsomes of rats, hamsters and guinea pigs.

Fundamental studies on the insulin receptor in rabbit erythrocytes

Energy Technology Data Exchange (ETDEWEB)

Shinomiya, Y; Kagawa, S; Konishi, Y; Morimoto, H; Tsumura, Y [Hyogo Medical Coll. (Japan)

1975-09-01

The authors studied the binding of insulin to rabbit erythrocytes as a mode case in the hope of characterizing the physiologic role of the binding of insulin to receptor in both normal adults and patients. Specific binding sites for insulin were detected in rabbit erythrocytes. The characteristics of the binding were similar to those observed in other target tissues. The specific binding of /sup 125/I-labeled insulin was competitively inhibited by a small amount of unlabeled insulin and was completely inhibited by 1,000 ng/ml of unlabeled insulin. Glucagon, however, had no effect on the insulin binding to fat cells or liver membranes nor had it any effect on the binding of insulin to rabbit erythrocytes. Scatchard analysis of this binding reaction indicated two different binding sites with Ksub(aff)=3.2 x 10/sup 8//M, Ksub(diss)=3.1 x 10/sup -9/M; Ksub(aff)=1.4 x 10/sup 8//M, Ksub(diss)=7.1 x 10/sup -9/M respectively, and the binding capacities of each site were estimated at 0.011 ng/4 x 10/sup 8/ cells and 0.138 ng/4 x 10/sup 8/ cells. The binding of /sup 125/I-insulin to rabbit erythrocytes was a saturable function of the insulin concentration and was a linear function of cell concentration. The pH optimum for the reaction was 7.4 at 0/sup 0/C, the amount of insulin binding increased continuously under the reaction and this binding reaction reached a steady state after 10 to 15hr. On the other hand, the specific binding of insulin at higher temperatures showed maximal amounts after 20 to 30 min. and subsequently fell off at later time points.

In vitro inactivation of hepatic microsomal phospholipase A2 by the marine natural product manoalide

International Nuclear Information System (INIS)

Master, M.M.; Jacobs, R.S.

1986-01-01

The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A 2 (PLA 2 ) activity was investigated. Microsomal PLA 2 , a membrane bound, Ca ++ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA 2 activity was assayed by preincubating MLD or analogs (2.5-100μM) with microsomes for 60 min. at 37 0 C, combining this mixture with 14 C-phosphatidylcholine and CaCl 2 , and incubating at 37 0 C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted 14 C-arachidonic acid product. MLD inhibited PLA 2 in a dose-dependent manner, with an IC 50 = 94μM. Lineweaver-Burk analysis suggests that MLD inhibits PLA 2 noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC 50 = 33μM). Another analog facilitated PLA 2 activity (15%) at 25μM, followed by inactivation at higher doses (IC 50 > 100 μM). Facilitation of PLA 2 activity was seen with concentrations as low as 2.5μM of a third analog, and significant inactivation of PLA 2 was evident. These results indicate that MLD is not as potent against microsomal PLA 2 as has been shown with purified bee venom and cobra venom PLA 2 's

Polyiodinated triglycerides for CT of the liver

International Nuclear Information System (INIS)

Weichert, J.P.; Longino, M.A.; Ullrich, K.A.; Schwendner, S.W.; Glazer, G.M.; Counsell, R.E.

1989-01-01

Several polyiodinated aryl triglyceride analogs have been synthesized, radioiodinated, emulsified, and administered to rats and normal or tumor-bearing rabbits in tracer or radiologic doses for tissue distribution (TD) and CT studies. The authors present preliminary TD results in rats with three of these analogs: glyceryl 1,3-diiopanoyl 2-palmitate; glyceryl 1,3-diiopanoyl 2-oleate; and glyceryl 1,3-di-7-(3-amino-2,4,6-triiodophenyl) heptanoyl 2-oleate. Respectively, 74%, 28%, and 55% of the injected radioactivity was present in the liver 1/2 hours after administration. Chemical structure and method of formulation bad a pronounced effect on the uptake, metabolism, and clearance properties of the agent. Initial CT studies with analog 1 (32 mg I/kg) in rabbits bearing hepatic VX2 tumors revealed tumors ranging in diameter from 0.3 to 3 cm

Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

DEFF Research Database (Denmark)

Demant, Erland J.F.; Nystrøm, Birthe T.

2001-01-01

acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

Metabolism and binding of cyclophosphamide and its metabolite acrolein to rat hepatic microsomal cytochrome P-450

International Nuclear Information System (INIS)

Marinello, A.J.; Bansal, S.K.; Paul, B.; Koser, P.L.; Love, J.; Struck, R.F.; Gurtoo, H.L.

1984-01-01

The hepatic cytochrome P-450-mediated metabolism and metabolic activation of [chloroethyl-3H]cyclophosphamide [( chloroethyl-3H]CP) and [4-14C]cyclophosphamide [( 4-14C]CP) were investigated in vitro in the reconstituted system containing cytochrome P-450 isolated from phenobarbital-treated rats. In addition, hepatic microsomal binding and the hepatic microsome-mediated metabolism of [14C]acrolein, a metabolite of [4-14C]CP, were also investigated. The metabolism of [chloroethyl-3H]CP and [4-14C]CP to polar metabolites was found to depend on the presence of NADPH and showed concentration dependence with respect to cytochrome P-450 and NADPH:cytochrome P-450 reductase. Km and Vmax values were essentially similar. The patterns of inhibition by microsomal mixed-function oxidase inhibitors, anti-cytochrome P-450 antibody, and heat denaturation of the cytochrome P-450 were essentially similar, with subtle differences between [4-14C]CP and [chloroethyl-3H]CP metabolism. The in vitro metabolic activation of CP in the reconstituted system demonstrated predominant binding of [chloroethyl-3H]CP to nucleic acids and almost exclusive binding of [4-14C]CP to proteins. Gel electrophoresis-fluorography of the proteins in the reconstituted system treated with [4-14C]CP demonstrated localization of the 14C label in the cytochrome P-450 region. To examine this association further, hepatic microsomes were modified with [14C]acrolein in the presence and the absence of NADPH. The results confirmed covalent association between [14C]acrolein and cytochrome P-450 in the microsomes and also demonstrated further metabolism of [14C]acrolein, apparently to an epoxide, which is capable of binding covalently to proteins. The results of these investigations not only confirm the significance of primary metabolism but also emphasize the potential role of the secondary metabolism of cyclophosphamide in some of its toxic manifestations

A new liver function test using the asialoglycoprotein-receptor system on the liver cell membrane, 2

International Nuclear Information System (INIS)

Kawa, Soukichi; Hazama, Hiroshi; Kojima, Michimasa

1986-01-01

We produced labeled neoglycoprotein (GHSA) that is physiologically equivalent to ASGP, and quantitatively examined whether its uptake by the liver is dose-related using the following methods: 1) binding assay between GHSA and ASGP receptors, 2) measurement of the liver extraction ratio in the initial circulation following administration into the portal vein, and 3) measurement of clearance in normal rats and rats with galacosamine-induced acute liver disorder. The binding assay showed a linear relationship between the concentration of 125 I-GHSA and the amount of ASGP receptors obtained from the rat liver. A membrane assay using 125 I-GHSA and the liver cell membrane revealed similar results. The liver extraction ratio in the initial circulation following the administration into the portal vein of normal rabbits was highly dose-dependent (r = -0.95 in the range of 5 - 100 μg GHSA). Serial imaging of 99m Tc-GHSA during two-hour period after administration into the peripheral blood showed specific accumulation in the liver beginning immediately after the intravenous injection and subsequent transport mainly via the biliary system into the small intestine in the normal rat and mainly into the urine in the bile duct ligated rat. As a dynamic model of 99m Tc-GHSA, its circulation through the heart and liver and inactivated release from the liver was used, and two-compartment analysis was made on measurement curves in the heart and liver to obtain clearance parameters. The concentration of administered 99m Tc-GHSA (50 - 100 μg/100 g body weight) showed a positive linear relationship with clearance. Administration of 50 μg/100 g body weight of 99m Tc-GHSA revealed a significant correlation (p < 0.001) between clearance and ASGP receptor activity in normal rats and rats with galactosamine-induced acute liver disorder. (J.P.N.)

Inhibition of rat mammary microsomal oxidation of ethanol to acetaldehyde by plant polyphenols.

Science.gov (United States)

Maciel, María Eugenia; Castro, José Alberto; Castro, Gerardo Daniel

2011-07-01

We previously reported that the microsomal fraction from rat mammary tissue is able to oxidize ethanol to acetaldehyde, a mutagenic-carcinogenic metabolite, depending on the presence of NADPH and oxygen but not inhibited by carbon monoxide or other cytochrome P450 inhibitors. The process was strongly inhibited by diphenyleneiodonium, a known inhibitor of NADPH oxidase, and by nordihydroguaiaretic acid, an inhibitor of lipoxygenases. This led us to suggest that both enzymes could be involved. With the purpose of identifying natural compounds present in food with the ability to decrease the production of acetaldehyde in mammary tissue, in the present studies, several plant polyphenols having inhibitory effects on lipoxygenases and of antioxidant nature were tested as potential inhibitors of the rat mammary tissue microsomal pathway of ethanol oxidation. We included in the present screening study 32 polyphenols having ready availability and that were also tested against the rat mammary tissue cytosolic metabolism of ethanol to acetaldehyde. Several polyphenols were also able to inhibit the microsomal ethanol oxidation at concentrations as low was 10-50 μM. The results of these screening experiments suggest the potential of several plant polyphenols to prevent in vivo production and accumulation of acetaldehyde in mammary tissue.

Comparison of gadolinium Cy2DOTA, a new hepatobiliary agent, and gadolinium HP-DO3A, an extracellular agent, in healthy liver and metastatic disease

International Nuclear Information System (INIS)

Runge, V.M.; Wells, J.W.; Williams, N.M.

1995-01-01

A new gadolinium (Gd) chelate with preferential hepatobiliary uptake, Gd Cy 2 DOTA, was compared in two animal species with Gd HP-DO3A (gadoteridol), a clinically approved contrast agent with extracellular distribution. Liver enhancement was evaluated for these two contrast agents using magnetic resonance imaging, whereas an experimental model of metastatic disease was used to evaluate the agents' efficacy for liver-lesion delineation. The two agents were compared in four healthy Rhesus monkeys (eight studies) and five New Zealand White rabbits with implanted VX-2 liver tumors (ten studies). The contrast dose was 0.1 mmol/kg, with the agents given in random order and at least 72 hours between contrast injections. Breathhold T1-weighted spin echo scans were obtained at 1.5 tesla (T) before and after contrast was administered. Postcontrast scans were obtained 1 to 90 minutes after injection in the monkeys and 1 to 240 minutes after injection in the rabbits. Prolonged hepatic enhancement, superior in degree to that with Gd HP-DO3A, was noted to both monkeys and rabbits after injection of Gd Cy 2 DOTA. Two minutes after contrast, liver SI was 1.94 ± 0.05 with Gd Cy 2 DOTA compared with 1.5 ± 0.05 with Gd HP-DO3A in monkeys. Sixty minutes after contrast, liver SI was 1.60 ± 0.09 compared with 1.20 ± 0.02. The difference between agents was significant at all times from 2 to 60 minutes after contrast injection (P 2 DOTA but not with Gd HP-DO3A. The maximum improvement in lesion conspicuity (rabbit) occurred 45 minutes after injection of Gd Cy 2 DOTA and 5 minutes after injection of Gd HP-DO3A. 22 refs., 12 figs

Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver

International Nuclear Information System (INIS)

Charles, A.K.; Rosenbaum, D.P.; Ashok, L.; Abraham, R.

1985-01-01

In vivo uptake and disposition of [ 14 C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers

[Glucose-6-phosphatase from nuclear envelope in rat liver].

Science.gov (United States)

González-Mujica, Freddy

2008-06-01

Nuclear envelope (NE) and microsomal glucosa-6-phosphatase (G-6-Pase) activities were compared. Intact microsomes were unable to hydrolyze mannose-6-phosphate (M-6-P), on the other hand, intact NE hydrolyzes this substrate. Galactose-6-phosphate showed to be a good substrate for both NE and microsomal enzymes, with similar latency to that obtained with M-6-P using microsomes. In consequence, this substrate was used to measure the NE integrity. The kinetic parameters (Kii and Kis) of the intact NE G-6-Pase for the phlorizin inhibition using glucose-6-phosphate (G-6-P) and M-6-P as substrates, were very similar. The NE T1 transporter was more sensitive to amiloride than the microsomal T1. The microsomal system was more sensitive to N-ethylmalemide (NEM) than the NE and the latter was insensitive to anion transport inhibitors DIDS and SITS, which strongly affect the microsomal enzyme. The above results allowed to postulate the presence of a hexose-6-phosphate transporter in the NE which is able to carry G-6-P and M-6-P, and perhaps other hexose-6-phosphate which could be different from that present in microsomes or, if it is the same, its activity could by modified by the membrane system where it is included. The higher PPi hydrolysis activity of the intact NE G-6-Pase in comparison to the intact microsomal, suggests differences between the Pi/PPi transport (T2) of both systems. The lower sensitivity of the NE G-6-Pase to NEM suggests that the catalytic subunit of this system has some differences with the microsomal isoform.

Altered carbohydrate, lipid, and xenobiotic metabolism by liver from rats flown on Cosmos 1887

Science.gov (United States)

Merrill, A. H. Jr; Hoel, M.; Wang, E.; Mullins, R. E.; Hargrove, J. L.; Jones, D. P.; Popova, I. A.; Merrill AH, J. r. (Principal Investigator)

1990-01-01

To determine the possible biochemical effects of prolonged weightlessness on liver function, samples of liver from rats that had flown aboard Cosmos 1887 were analyzed for protein, glycogen, and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the glycogen content and hydroxymethylglutaryl-CoA (HMG-CoA) reductase activities for the rats flown on Cosmos 1887 and decreases in the amount of microsomal cytochrome P-450 and the activities of aniline hydroxylase and ethylmorphine N-demethylase, cytochrome P-450-dependent enzymes. These results support the earlier finding of differences in these parameters and suggest that altered hepatic function could be important during spaceflight and/or the postflight recovery period.

Effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet.

Science.gov (United States)

Charoenwanthanang, Puttavee; Lawanprasert, Somsong; Phivthong-Ngam, Laddawal; Piyachaturawat, Pawinee; Sanvarinda, Yupin; Porntadavity, Sureerut

2011-04-12

Curcuma comosa has been known to have potential use in cardiovascular diseases, but its immunoregulatory role in atherosclerosis development and liver toxicity has not been well studied. We therefore investigated the effects of Curcuma comosa on the expression of atherosclerosis-related cytokine genes in rabbits fed a high-cholesterol diet. Twelve male New Zealand White rabbits were treated with 1.0% cholesterol for one month and were subsequently treated with 0.5% cholesterol either alone, or in combination with 5mg/kg/day of simvastatin or with 400mg/kg/day of Curcuma comosa powder for three months. The expression of IL-1, MCP-1, TNF-α, IL-10, and TGF-β in the isolated abdominal aorta and liver were determined by real-time RT-PCR. Liver toxicity was determined by hepatic enzyme activity. Curcuma comosa significantly decreased the expression of pro-inflammatory cytokines, leading to a stronger reduction in IL-1, MCP-1, and TNF-α expression compared to that was suppressed by simvastatin treatment. However, neither Curcuma comosa nor simvastatin affected the expression of anti-inflammation cytokines. In the liver, Curcuma comosa insignificantly decreased the expression of pro-inflammatory cytokines and significantly increased the expression of the anti-inflammatory cytokine IL-10 without altering the activity of hepatic enzymes. In contrast, simvastatin significantly increased the MCP-1 and TNF-α expressions and serum ALT level, without affecting the expression of anti-inflammatory cytokines. In this study, we demonstrated that Curcuma comosa exerts anti-inflammatory activity in the aorta and liver without causing liver toxicity, indicating that Curcuma comosa is a potential candidate as an alternative agent in cardiovascular disease therapy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

[Effects of intra-arterial infusion of 3-bromopyruvate on metastases and survival benefit of hepatic VX2 tumor in rabbits].

Science.gov (United States)

Jiang, Xiong-ying; Zhang, Xiao-ping; Huang, Jin-hua; Luo, Rong-guang; Miao, Bi-jian; Wang, Yan

2013-10-22

To evaluate the metastasis and survival of an intra-arterial infusion of 3-bromopyruvate (3-BrPA) on hepatic VX2 tumor in rabbits. VX2 tumor was implanted in left lateral lobe of liver of 18 white New Zealand rabbits. The animals were randomized into 3 groups (n = 6 each) and underwent an intra-arterial infusion of phosphate-buffered saline or 3-BrPA via hepatic artery at 14 days post-implantation. At 28 days post-implantation, 3 rabbits in each group were sacrificed. The abdomen of these rabbits was opened and inspected for metastases. Then the survival of the remaining rabbits was observed. At 28 days post-implantation, in PBS group, there were intrahepatic metastasis and abdominal cavity dissemination (n = 3), renal metastases (n = 2) and lung metastases (n = 2); in early 3-BrPA infusion group, intrahepatic metastasis (n = 2), abdominal cavity dissemination (n = 1) and lung metastases (n = 1); in late 3-BrPA infusion group, intrahepatic metastasis (n = 1) and lung metastases (n = 1). The survival of the remaining animals was observed. Rabbits in early 3-BrPA infusion group survived significantly longer than those in PBS group [(27 ± 5) vs (17 ± 3) days, P = 0.041]; rabbits in late 3-BrPA infusion group [(42 ± 6) days] survived significantly longer than those in early 3-BrPA infusion group (P = 0.007). An intra-arterial infusion of 3-BrPA could reduce metastasis and prolong survival in rabbits with hepatic VX2 tumor. The earlier the infusion, the better the outcome.

Antioxidant status and hormonal profile reflected by experimental feeding of probiotics.

Science.gov (United States)

Ghoneim, Magdy A; Moselhy, Said S

2016-04-01

Excessive production of free radicals can result in tissue damage, which mainly involves generation of hydroxyl radical and other oxidants. Such free radical-induced cell damage appears to play a major role in the pathogenesis of many diseases. Probiotics have been used therapeutically to modulate immunity, improve digestive processes, lower cholesterol, treat rheumatoid arthritis, and prevent cancer. The proposed research was designed to evaluate the changes in oxidative and antioxidative profile in addition to metabolic-related hormones of living animal model, which may generally affect the health status. Two groups of rabbits (10 animals each) were allocated in hygienic cages of controlled animal house. Control group received standard diet, and the other group received the same diet containing one probiotic for 30 days. Lactate dehydrogenase (LDH) activity in leukocytes, blood glucose, reduced glutathione (GSH), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were estimated in different tissues. Malondialdehyde (MDA) and total proteins were also determined in different tissues. Certain hormones related to metabolism and growth were also evaluated. Leukocytic LDH activity was significantly increased along with nonsignificant increase of blood glucose in probiotics-fed animals. Results showed significant decreases in the levels of triiodothyronine and thyroid-stimulating hormone but showed significant elevations in thyroxine, insulin, growth hormone, and testosterone levels in animals fed with probiotics. Total proteins content was highly significantly elevated in liver, kidneys, and muscles of probiotic-administered animals. Microsomal GSH level was significantly decreased only in skeletal muscles of probiotic-treated animals. MDA was significantly lowered in animal tissues fed with probiotics. GSH-Px activity was elevated in hepatic and muscular microsomes of probiotic-supplemented animals while it was nonsignificantly increased in renal

The Rabbit Stream Cipher

DEFF Research Database (Denmark)

Boesgaard, Martin; Vesterager, Mette; Zenner, Erik

2008-01-01

The stream cipher Rabbit was first presented at FSE 2003, and no attacks against it have been published until now. With a measured encryption/decryption speed of 3.7 clock cycles per byte on a Pentium III processor, Rabbit does also provide very high performance. This paper gives a concise...... description of the Rabbit design and some of the cryptanalytic results available....

Does Artificial Ascites Induce the Heat-Sink Phenomenon during Percutaneous Radiofrequency Ablation of the Hepatic Subcapsular Area?: an in vivo Experimental Study Using a Rabbit Model

International Nuclear Information System (INIS)

Kim, Young Sun; Rhim, Hyun Chul; Choi, Dong Il; Lim, Hyo K.

2009-01-01

To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the 'W' group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups 'W' and 'R' throughout the procedures (39.2± 0.4 .deg. C in group W and 33.4±4.3 .deg. C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4±237.3 mL in group C, 1,172.0±468.9 mL in group R, and 1,030.6±665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group 'C' rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region

Does artificial ascites induce the heat-sink phenomenon during percutaneous radiofrequency ablation of the hepatic subcapsular area?: an in vivo experimental study using a rabbit model.

Science.gov (United States)

Kim, Young Sun; Rhim, Hyunchul; Choi, Dongil; Lim, Hyo K

2009-01-01

To evaluate the effect of the heat-sink phenomenon induced by artificial ascites on the size of the ablation zone during percutaneous radiofrequency (RF) ablation of the hepatic subcapsular area in an in vivo rabbit model. A total of 21 percutaneous rabbit liver RF ablations were performed with and without artificial ascites (5% dextrose aqueous solution). The rabbits were divided into three groups: a) control group (C, n = 7); b) room temperature ascites group (R, n = 7); and c) warmed ascites group (W, n = 7). The tip of a 1 cm, internally cooled electrode was placed on the subcapsular region of the hepatic dome via ultrasound guidance, and ablation was continued for 6 min. Changes in temperature of the ascites were monitored during the ablation. The size of the ablation zones of the excised livers and immediate complications rates were compared statistically between the groups (Mann-Whitney U test, Kruskal-Wallis test, linear-by-linear association, p = 0.05). One rabbit from the "W" group expired during the procedure. In all groups, the ascites temperatures approached their respective body temperatures as the ablations continued; however, a significant difference in ascites temperature was found between groups "W" and "R" throughout the procedures (39.2+/-0.4 degrees C in group W and 33.4+/-4.3 degrees C in group R at 6 min, p = 0.003). No significant difference was found between the size of the ablation zones (782.4+/-237.3 mL in group C, 1,172.0+/-468.9 mL in group R, and 1,030.6+/-665.1 mL in group W, p = 0.170) for the excised liver specimens. Diaphragmatic injury was identified in three of seven cases (42.9%) upon visual inspection of group "C" rabbits (p = 0.030). Artificial ascites are not likely to cause a significant heat-sink phenomenon in the percutaneous RF ablation of the hepatic subcapsular region.

Establishment of a novel radioligand assay using eukaryotically expressed cytochrome P4502D6 for the measurement of liver kidney microsomal type 1 antibody in patients with autoimmune hepatitis and hepatitis C virus infection.

Science.gov (United States)

Ma, Y; Gregorio, G; Gäken, J; Muratori, L; Bianchi, F B; Mieli-Vergani, G; Vergani, D

1997-06-01

Liver kidney microsomal type 1 antibody (LKM1) is the diagnostic marker of autoimmune hepatitis (AIH) type 2 and is also found in patients with hepatitis C virus (HCV) infection. Cytochrome P4502D6 (CYP2D6) is the documented target antigen of LKM1 in AIH, but not in HCV infection. To compare the reactivity in the two conditions, we established a radioligand assay using eukaryotically expressed CYP2D6 as target. A 1.2-kb human CYP2D6 cDNA was isolated from a human liver cDNA library and subcloned into an in vitro transcription vector pSP64 Poly(A). Recombinant CYP2D6 was then produced by in vitro transcription/translation, metabolically labelled with 35S methionine and used in the immunoprecipitation assay. Antibodies that bound radiolabelled CYP2D6 were immunoprecipitated and their levels assessed as cpm. Sera from 50 LKM1-positive patients (26 with AIH; 24 with HCV infection), 128 LKM1-negative patients and 57 normal controls were tested. Reactivity to 35S labelled CYP2D6 was observed in all LKM1-positive sera from patients with AIH and HCV infection, but in none of the controls. The cpm in both conditions were significantly higher than in normal controls (pLKM1 (r 0.87, p<0.001 and r=0.64, p<0.001 for AIH and HCV infection, respectively). Reactivity to 35S labelled CYP2D6 was inhibited by addition of an excess of eukaryotically expressed CYP2D6. CYP2D6 is a major target antigen of both AIH and HCV infection. The novel radioligand assay is highly sensitive and specific.

Sex-related differences in NADPH-dependent lipid peroxidation induced by cadmium

Energy Technology Data Exchange (ETDEWEB)

Sato, Masao; Nagai, Yasushi

1986-10-01

Male and female rats were dosed once a day for 2 days with injections of 1.5 mg Cd/kg. Formation of thiobarbituric acid reactive substances (TBA-RS) was significantly increased in male rat liver but not in the females. NADPH-dependent lipid peroxidation in vitro in microsomes derived from untreated rat liver was greater in males than in females. Furthermore, addition of cadmium (Cd) to microsomes isolated from male rat liver produced a dose-dependent potentiation of NADPH-dependent lipid peroxidation from low concentrations of CD. In microsomes derived from females a significant increase in lipid peroxidation was observed only at high Cd concentrations. NADPH-dependent lipid peroxidation enhanced by Cd was greater in the males than in the females. These data suggest that a sex-related difference in the ability of Cd to induce lipid peroxidation in vivo in rat liver appears to be mediated partly through differences in hepatic microsomal NADPH-dependent lipid peroxidation.

Role of CYP2B6 and CYP3A4 in the in vitro N-dechloroethylation of (R)- and (S)-ifosfamide in human liver microsomes.

Science.gov (United States)

Granvil, C P; Madan, A; Sharkawi, M; Parkinson, A; Wainer, I W

1999-04-01

The central nervous system toxicity of ifosfamide (IFF), a chiral antineoplastic agent, is thought to be dependent on its N-dechloroethylation by hepatic cytochrome P-450 (CYP) enzymes. The purpose of this study was to identify the human CYPs responsible for IFF-N-dechloroethylation and their corresponding regio- and enantioselectivities. IFF exists in two enantiomeric forms, (R) - and (S)-IFF, which can be dechloroethylated at either the N2 or N3 positions, producing the corresponding (R,S)-2-dechloroethyl-IFF [(R, S)-2-DCE-IFF] and (R,S)-3-dechloroethyl-IFF [(R,S)-3-DCE-IFF]. The results of the present study suggest that the production of (R)-2-DCE-IFF and (S)-3-DCE-IFF from (R)-IFF is catalyzed by different CYPs as is the production of (S)-2-DCE-IFF and (R)-3-DCE-IFF from (S)-IFF. In vitro studies with a bank of human liver microsomes revealed that the sample-to-sample variation in the production of (S)-3-DCE-IFF from (R)-IFF and (S)-2-DCE-IFF from (S)-IFF was highly correlated with the levels of (S)-mephenytoin N-demethylation (CYP2B6), whereas (R)-2-DCE-IFF production from (R)-IFF and (R)-3-DCE-IFF production from (S)-IFF were both correlated with the activity of testosterone 6beta-hydroxylation (CYP3A4/5). Experiments with cDNA-expressed P-450 and antibody and chemical inhibition studies supported the conclusion that the formation of (S)-3-DCE-IFF and (S)-2-DCE-IFF is catalyzed primarily by CYP2B6, whereas (R)-2-DCE-IFF and (R)-3-DCE-IFF are primarily the result of CYP3A4/5 activity.

Fenproporex N-dealkylation to amphetamine--enantioselective in vitro studies in human liver microsomes as well as enantioselective in vivo studies in Wistar and Dark Agouti rats.

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Kraemer, Thomas; Pflugmann, Thomas; Bossmann, Michael; Kneller, Nicole M; Peters, Frank T; Paul, Liane D; Springer, Dietmar; Staack, Roland F; Maurer, Hans H

2004-09-01

Fenproporex (FP) is known to be N-dealkylated to R(-)-amphetamine (AM) and S(+)-amphetamine. Involvement of the polymorphic cytochrome P450 (CYP) isoform CYP2D6 in metabolism of such amphetamine precursors is discussed controversially in literature. In this study, the human hepatic CYPs involved in FP dealkylation were identified using recombinant CYPs and human liver microsomes (HLM). These studies revealed that not only CYP2D6 but also CYP1A2, CYP2B6 and CYP3A4 catalyzed this metabolic reaction for both enantiomers with slight preference for the S(+)-enantiomer. Formation of amphetamine was not significantly changed by quinidine and was not different in poor metabolizer HLM compared to pooled HLM. As in vivo experiments, blood levels of R(-)-amphetamine and S(+)-amphetamine formed after administration of FP were determined in female Dark Agouti rats (fDA), a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats (mDA), an intermediate model, and in male Wistar rats (WI), a model of the human CYP2D6 extensive metabolizer phenotype. Analysis of the plasma samples showed that fDA exhibited significantly higher plasma levels of both amphetamine enantiomers compared to those of WI. Corresponding plasma levels in mDA were between those in fDA and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher amphetamine plasma levels, which did not significantly differ from those in fDA. The in vivo studies suggested that CYP2D6 is not crucial to the N-dealkylation but to another metabolic step, most probably to the ring hydroxylation. Further studies are necessary for elucidating the role of CYP2D6 in FP hydroxylation.

RabbitMQ essentials

CERN Document Server

Dossot, David

2014-01-01

This book is a quick and concise introduction to RabbitMQ. Follow the unique case study of Clever Coney Media as they progressively discover how to fully utilize RabbitMQ, containing clever examples and detailed explanations.Whether you are someone who develops enterprise messaging products professionally or a hobbyist who is already familiar with open source Message Queuing software and you are looking for a new challenge, then this is the book for you. Although you should be familiar with Java, Ruby, and Python to get the most out of the examples, RabbitMQ Essentials will give you the push y

Imaging of Rabbit VX-2 Hepatic Cancer by Cold and Thermal Neutron Radiography

Science.gov (United States)

Tsuchiya, Yoshinori; Matsubayashi, Masahito; Takeda, Tohoru; Lwin, Thet Thet; Wu, Jin; Yoneyama, Akio; Matsumura, Akira; Hori, Tomiei; Itai, Yuji

2003-11-01

Neutron radiography is based on differences in neutron mass attenuation coefficients among the elements and is a non-destructive imaging method. To investigate biomedical applications of neutron radiography, imaging of rabbit VX-2 liver cancer was performed using thermal and cold neutron radiography with a neutron imaging plate. Hepatic vessels and VX-2 tumor were clearly observed by neutron radiography, especially by cold neutron imaging. The image contrast of this modality was better than that of absorption-contrast X-ray radiography.

Effects of Ischemic Preconditioning of Different Intraoperative Ischemic Times of Vascularized Bone Graft Rabbit Models

Directory of Open Access Journals (Sweden)

Ahmad Sukari Halim

2013-11-01

Full Text Available BackgroundIschemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.MethodsSixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed.ResultsThe results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18-hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups.ConclusionsIn conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.

Change of hepatic volume after selective bile duct ligation: an experimental study in the rabbit

International Nuclear Information System (INIS)

Lee, Hye Won; Yoon, Yup; Ko, Young Tae; Choi, Woo Suk; Lim, Joo Won; Oh, Joo Hyeong; Rim, Hyeong Teck; Kim, Youn Wha; Lee, Seok Hwan

1998-01-01

To evaluate the role of bile duct obstuction in the development of atrophy of the liver, using an animal model. Seven rabbits were divided into two groups: group 1(n=3D5), in which there was selective bile duct ligation, and group 2(n=3D2), which underwent a sham operation. Each group was evaluated using CT for changes in hepatic volume after selective bile duct ligation or a sham operation. In group I, the diameter of dilated bile duct was measured 2, 4, 8, 12 and 16 weeks after bile duct ligation, while gross and histologic change were evaluated in all cases. In group 1, bile duct dilatation was seen on CT two weeks after selective bile duct ligation, and did not change significantly during follow-up. In four of five cases, CT revealed no evidence of significant atrophy of the involved segment. Pathologic specimens, however, revealed dilatation of the bile duct, periductal fibrosis, infiltration of chronic inflammatory cells, and periportal fibrosis. One of five cases showed segmental liver atrophy after selective bile duct ligation. In addion to the above pathologic findings, there was obstruction of the portal vein by foreign body reaction. In group 2, no evidence of dilated bile duct or liver atrophy was revealed by CT or pathologic specimen after a sham operation. During long-term follow-up of 16 weeks, obstruction of the bile duct did not play a major role in the development of lobar atrophy in the rabbit.=20