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Sample records for rat liver dihydrodiol

  1. REANALYSIS AND CLARIFICATION OF THE STRUCTURES OF ALPHA-NAPHTHOFLAVONE DIHYDRODIOLS FORMED BY UNINDUCED AND INDUCED RAT LIVER MICROSOMES FROM CHARLES RIVER CD AND SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    The structures of alpha-naphthoflavone (ANF) dihydrodiols formed by uninduced and induced rat liver microsomes are identified by conversion of the metabolically formed ANF-dihydrodiols to the corresponding phenols. Comparison of these phenols with synthetic standards provides an ...

  2. Radiochemical detection of dihydrodiol dehydrogenase: distribution of the indomethacin sensitive enzyme in rat tissues

    SciTech Connect

    Ivins, J.; Penning, T.

    1986-05-01

    Dihydrodiol dehydrogenase catalyzes the NADP/sup +/ dependent oxidation of trans-dihydrodiols of polycyclic aromatic hydrocarbons (PAH) which are potent proximate carcinogens. The authors have developed a highly sensitive radiochemical assay for this enzyme in which the oxidation of trans-1,2-dihydroxy-3,5-cyclohexadiene, a model substrate for trans-dihydrodiol proximate carcinogens, is coupled to O-methylation catalyzed by catechol O-methyl transferase. Using S-adenosyl-(/sup 3/H-methyl)-methionine as methyl donor at a specific activity of 0.1 nCi/pmol and extracting the product, /sup 3/H-o-methoxyphenol, the assay provides a 5000 fold increase in sensitivity over the existing spectrophotometric method. The radiochemical assay was validated by comparing the K/sub m/ and V/sub max/ values for rat liver cytosol with those derived spectrophotometrically. In both instances there was close agreement between values (K/sub m/ = 0.77 +/- 0.11 mM and V/sub max/ = 2.14 +/- 0.13 nmoles/min/mg protein determined radiochemically; K/sub m/ = 0.96 +/- 0.10 mM and V/sub max/ = 6.31 +/- 0.50 nmoles/min/mg protein determined spectrophotometrically). Using the radiochemical method, dihydrodiol dehydrogenase activity was detected in the following rat tissues: liver > lung > heart > small intestine > testis > seminal vesicle > bladder > prostate > spleen. Specific activities ranged between 0.944 and 0.016 nmoles/min/mg protein. In liver, lung, and testis, which are sites of PAH metabolism, the dehydrogenase is sensitive to inhibition by low ..mu..M concentrations of indomethacin, suggesting that this drug can prevent the detoxification of proximate carcinogens by this route.

  3. The role of cysteine in the alteration of bovine liver dihydrodiol dehydrogenase 3 activity.

    PubMed Central

    Nanjo, H; Adachi, H; Aketa, M; Mizoguchi, T; Nishihara, T; Terada, T

    1995-01-01

    Bovine liver NADP(+)-dependent dihydrodiol dehydrogenase (DD3) is extremely sensitive to SH reagents such as N-ethylmaleimide (NEM) and 5,5'-dithiobis(2-nitrobenzoic acid). NEM produced time- and concentration-dependent inactivation of DD3 in a pseudo-first-order reaction manner. This inactivation was prevented by NADP+, 3-acetylpyridine-adenine dinucleotide phosphate, 2',5'-ADP and 2'-AMP but not by substrates, NAD+, nicotinamide mononucleotide or 5'-ADP.DD3 was absorbed by an affinity column of thiopropyl-Sepharose 6B, but enzyme incubated with both NEM and NADP+ was not. Moreover, one [14C]NEM molecule was incorporated into a cysteine of DD3 in the presence, and two cysteines of DD3 in the absence, of NADP+. These results suggested that two cysteine residues were modified per enzyme molecule by NEM, one was protected by NADP+ and the other had no significant function for the enzyme activity. Two radiolabelled peptides (P1 and P2) produced by the digestion with lysyl endopeptidase of [14C]NEM-modified DD3 could be separated by reverse-phase HPLC. P1, which was radiolabelled by [14C]NEM only in the absence of NADP+, showed the following sequence; H2N-Tyr-Lys-Pro-Val-Xaa-Asn-Gln-Val-Glu- NEM.Cys-His-Pro-Tyr-Phe-Asn-Gln-Ser-Lys-COOH (Xaa indicates a possible cysteine residue). This sequence was very similar to that of rat liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase (3 alpha-HSD/DD) (residues 184 to 201) and was also highly conserved in the aldo-keto reductase superfamily. The sequence of P2, which had radioactivity in both the absence and presence of NADP+, also contained an NEM-modified cysteine and was similar in sequence to the regions located in loop A of rat 3 alpha-HSD/DD. The present study suggests that P1, which may have a cysteine residue corresponding to Cys-193 of rat 3 alpha-HSD/DD, functions in the alteration of DD3 activity depending on the modulation of NADP(+)-binding ability through a thiol/disulphide exchange reaction similar to that of

  4. Dihydrodiol dehydrogenase and polycyclic aromatic hydrocarbon metabolism

    SciTech Connect

    Smithgall, T.E.

    1986-01-01

    Carcinogenic activation of polycyclic aromatic hydrocarbons by microsomal monoxygenases proceeds through trans-dihydrodiol metabolites to diol-epoxide ultimate carcinogens. This thesis directly investigated the role of dihydrodiol dehydrogenase, a cytosolic NAD(P)-linked oxidoreductase, in the detoxification of polycyclic aromatic trans-dihydrodiols. A wide variety of non-K-region trans-dihydrodiols were synthesized and shown to be substrates for the homogeneous rat liver dehydrogenase, including several potent proximate carcinogens derived from 7,12-dimethylbenz(a)anthracene, 5-methylchrysene, and benzo(a)pyrene. Since microsomal activation of polycyclic aromatic hydrocarbons is highly stereospecific, the stereochemical course of enzymatic trans-dihydrodiol oxidation was monitored using circular dichroism spectropolarimetry. The major product formed from the dehydrogenase-catalyzed oxidation of the trans-1,2-dihydrodiol of naphthalene was characterized using UV, IR, NMR, and mass spectroscopy, and appears to be 4-hydroxy-1,2-naphthoquinone. Mass spectral analysis suggests that an analogous hydroxylated o-quinone is formed as the major product of benzo(a)pyrene-7,8-dihydrodiol oxidation. Enzymatic oxidation of trans-dihydrodiols was shown to be potently inhibited by all of the major classes of the nonsteroidal antiinflammatory drugs. Enhancement of trans-dihydrodiol proximate carcinogen oxidation may protect against possible adverse effects of the aspirin-like drugs, and help maintain the balance between activation and detoxification of polycyclic aromatic hydrocarbons.

  5. Toxicological significance of dihydrodiol metabolites

    SciTech Connect

    Hsia, M.T.

    1982-01-01

    Dihydrodiols are often found as the major organic-extractable metabolites of various olefinic or aromatic xenobiotics in many biological samples. Studies on the chemistry of dihydrodiol metabolites have provided insight into the pharmacokinetic behavior and the mode of action of the parent compound. The toxicology of dihydrodiol is more complex than what can be deduced solely on the basis of diminished bioavailability of the epoxide precursor, and the increased hydrophilicity associated with the dihydrodiol moiety. Dihydrodiols can be intrinsically toxic and may even represent metabolically activated species. Some of the dihydrodiol metabolites may still retain sufficient lipophilic character to serve again as substrates for microsomal oxygenases. Because of the tremendous chemical and biological diversity that existed among the various dihydrodiols, more mechanistic studies are needed to examine the toxicological properties of these compounds. It may be premature to conclude dihydrodiol formation as purely a detoxification route for xenobioties.

  6. Molecular cloning of two human liver 3 alpha-hydroxysteroid/dihydrodiol dehydrogenase isoenzymes that are identical with chlordecone reductase and bile-acid binder.

    PubMed Central

    Deyashiki, Y; Ogasawara, A; Nakayama, T; Nakanishi, M; Miyabe, Y; Sato, K; Hara, A

    1994-01-01

    Human liver contains two dihydrodiol dehydrogenases, DD2 and DD4, associated with 3 alpha-hydroxysteroid dehydrogenase activity. We have raised polyclonal antibodies that cross-reacted with the two enzymes and isolated two 1.2 kb cDNA clones (C9 and C11) for the two enzymes from a human liver cDNA library using the antibodies. The clones of C9 and C11 contained coding sequences corresponding to 306 and 321 amino acid residues respectively, but lacked 5'-coding regions around the initiation codon. Sequence analyses of several peptides obtained by enzymic and chemical cleavages of the two purified enzymes verified that the C9 and C11 clones encoded DD2 and DD4 respectively, and further indicated that the sequence of DD2 had at least additional 16 residues upward from the N-terminal sequence deduced from the cDNA. There was 82% amino acid sequence identity between the two enzymes, indicating that the enzymes are genetic isoenzymes. A computer-based comparison of the cDNAs of the isoenzymes with the DNA sequence database revealed that the nucleotide and amino acid sequences of DD2 and DD4 are virtually identical with those of human bile-acid binder and human chlordecone reductase cDNAs respectively. Images Figure 1 PMID:8172617

  7. Stereoselective fungal metabolism of 7,12-dimethylbenz(a)anthracene: identification and enantiomeric resolution of a K-region dihydrodiol

    SciTech Connect

    McMillan, D.C.; Fu, P.P.; Cerniglia, C.E.

    1987-10-01

    Syncephalastrum racemosum UT-70 and Cunninghamella elegans ATCC 36112 metabolized 7,12-dimethylbenz(a)anthracene (7,12-DMBA) to hydroxymethyl metabolites as well as 7-hydroxymethyl-12-methylbenz(a)anthracene trans-3,4-, -5,6-, -8,9-, and -10,11-dihydrodiols. The 7,12-DMBA metabolites were isolated by reversed-phase high-performance liquid chromatography and identified by their UV-visible absorption, mass, and nuclear magnetic resonance spectral characteristics. A comparison of the circular dichroism spectra of the K-region (5,6-position) dihydrodiol of both fungal strains with those of the 7,12-DMBA 5S,6S-dihydrodiol formed from 7,12-DMBA by rat liver microsomes indicated that the major enantiomer of the 7-hydroxymethyl-12-methylbenz(a)anthracene trans-5,6-dihydrodiol formed by both fungal strains had a 5R,6R absolute stereochemistry. Direct resolution of the fungal trans-5,6-dihydrodiols by chiral stationary-phase high-performance liquid chromatography indicated that the ratios of the R,R and S,S, enantiomers were 88:12 and 77:23 for S. racemosum and C. elegans, respectively. These results indicate that the fungal metabolism of 7,12-DMBA at the K region (5,6-position) is highly stereoselective and different from that reported for mammalian enzyme systems.

  8. Benzene toxicity: emphasis on cytosolic dihydrodiol dehydrogenases

    SciTech Connect

    Bolcsak, L.E.

    1982-01-01

    Blood dyscrasias such as leukopenia and anemia have been clearly identified as consequences of chronic benzene exposure. The metabolites, phenol, catechol, and hydroquinone produced inhibition of /sup 59/Fe uptake in mice which followed the same time course as that produced by benzene. The inhibitor of benzene oxidation, 3-amino-1,2,4-triazole, mitigated the inhibitory effects of benzene and phenol only. These data support the contention that benzene toxicity is mediated by a metabolite and suggest that the toxicity of phenol is a consequence of its metabolism to hydroquinone and that the route of metabolism to catechol may also contribute to the production of toxic metabolite(s). The properties of mouse liver cytosolic dihydrodiol dehydrogenases were examined. These enzymes catalyze the NADP/sup +/-dependent oxidation of trans-1,2-dihydro-1,2-dihydroxybenzene (BDD) to catechol, a possible toxic metabolite of benzene produced via this metabolic route. Four distinct dihydrodiol dehydrogenases (DD1, DD2, DD3, and DD4) were purified to apparent homogeneity as judged by SDS polyacrylamide gel electrophoresis and isoelectric focusing. DD1 appeared to be identical to the major ketone reductase and 17..beta..-hydroxysteroid dehydrogenase activity in the liver. DD2 exhibited aldehyde reductase activity. DD3 and DD4 oxidized 17..beta..-hydroxysteroids, but no carbonyl reductase activity was detected. These relationships between BDD dehydrogenases and carbonyl reductase and/or 17..beta..-hydroxysteroid dehydrogenase activities were supported by several lines of evidence.

  9. BIOTRANSFORMATION OF TRANS-4,5-DIHYDROXY-4,5-DIHYDROBENZO[A]PYRENE TO BENZO[A]PYRENE-BIS-DIOLS AND DNA ADDUCTS BY INDUCED RAT LIVER MICROSOMES

    EPA Science Inventory

    The biotransformation of (+)-trans-4,5-dihydroxy-4,5-dihydrobenzo[a]pyrene trans-B[a]P-4,5-diol), the K-region dihydrodiol of B[a]P, by B-naphthoflavone (BNF)-induced rat liver microsomes was studied. Trans-B[a]P-4,5-diol was metabolized to six major products as characterized by...

  10. Regulation of human dihydrodiol dehydrogenase by Michael acceptor xenobiotics.

    PubMed

    Ciaccio, P J; Jaiswal, A K; Tew, K D

    1994-06-01

    A human oxidoreductase (H-37) that is overexpressed in ethacrynic acid-resistant HT29 colon cells (Ciaccio, P. J., Stuart, J.E., and Tew, K.D. (1993) Mol. Pharmacol. 43, 845-853) has been identified as a dihydrodiol dehydrogenase. Translated protein from a dihydrodiol dehydrogenase cDNA isolated from a library prepared from ethacrynic acid-resistant HT29 cell poly(A+) RNA was recognized by anti-H-37 IgG and was identical in molecular weight with H-37. The isolated cDNA was identical in both nucleotide and amino acid sequences with the recently cloned liver dihydrodiol dehydrogenase (Stolz, A., Hammond, L., Lou, H., Takikawa, H., Ronk, M., and Shively, J.E. (1993) J. Biol. Chem. 268, 10448-10457). Using this cDNA as probe, we have examined its induction by Michael acceptors. The steady state dihydrodiol dehydrogenase mRNA level in the ethacrynic acid-resistant line was increased 30-fold relative to that of wild-type cells. Twenty-four hour treatment of wild-type cells with ethacrynic acid or dimethyl maleate increased mRNA 10-fold and 5-fold, respectively. These changes are accompanied by both increased protein expression and increased NADP-dependent 1-acenaphthenol oxidative activity in cell cytosol. In gel shift assays, compared to wild type controls, increased binding of NAD(P)H quinone oxidoreductase human antioxidant response element (hARE) DNA to redox labile protein complexes present in treated and resistant cell nuclear extract was observed. Ethacrynic acid induced CAT activity 2-fold in Hepa1 cells stably transfected with NAD(P)H quinone oxidoreductase hARE-tk-CAT chimeric gene construct. Thus, dihydrodiol dehydrogenase protein is inducible by de novo synthesis from mRNA by structurally related monofunctional inducer Michael acceptors. Altered in vitro binding of nuclear protein to the hARE is indirect evidence for the involvement of an element similar to hARE in the regulation of dihydrodiol dehydrogenase by these agents. PMID:7515059

  11. Rat liver imidase.

    PubMed

    Yang, Y S; Ramaswamy, S; Jakoby, W B

    1993-05-25

    Imidase, an enzyme variously identified as dihydropyrimidinase (EC 3.5.2.2), hydantoinase, dihydropyrimidine hydrase, and dihydropyrimidine amidohydrolase, has been purified to electrophoretic homogeneity from rat liver. Although a component in the chain of pyrimidine catabolism, imidase is capable of serving in a broader role that includes detoxication of xenobiotics. The enzyme catalyzes the hydrolytic cleavage of imides that range from the linear to the heterocyclic and that include hydantoins, dihydropyrimidines, and phthalimide. For some substrates, the reaction is experimentally reversible. The pH activity curves are a function of the pKa of the individual substrate's imino group, with cleavage favored at a pH near the respective pKa value. There is evidence for stereoselectivity and for stereospecificity. A mechanism is proposed for the enzyme-catalyzed reaction. PMID:8388376

  12. Oxidative DNA damage induced by benz[a]anthracene dihydrodiols in the presence of dihydrodiol dehydrogenase.

    PubMed

    Seike, Kazuharu; Murata, Mariko; Hirakawa, Kazutaka; Deyashiki, Yoshihiro; Kawanishi, Shosuke

    2004-11-01

    Tobacco smoke and polluted air are risk factors for lung cancer and contain many kinds of polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene (B[a]P) and benz[a]anthracene (BA). BA, as well as B[a]P, is assessed as probably carcinogenic to humans (IARC group 2A). BA is metabolized to several dihydrodiols. Dihydrodiol dehydrogenase (DD), a member of the aldo-keto reductase superfamily, catalyzes NAD(P)+-linked oxidation of dihydrodiols of aromatic hydrocarbons to corresponding catechols. To clarify the role of DD on PAH carcinogenesis, we examined oxidative DNA damage induced by trans-dihydrodiols of BA and B[a]P treated with DD using 32P-5'-end-labeled DNA fragments obtained from the human p53 tumor suppressor gene. In addition, we investigated the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an indicator of oxidative DNA damage, in calf thymus DNA by using HPLC with an electrochemical detector. DD-catalyzed BA-1,2-dihydrodiol caused Cu(II)-mediated DNA damage including 8-oxodG formation in the presence of NAD+. BA-1,2-dihydrodiol induced a Fpg sensitive and piperidine labile G lesion at the 5'-ACG-3' sequence complementary to codon 273 of the human p53 tumor suppressor gene, which is known as a hotspot. DNA damage was inhibited by catalase and bathocuproine, suggesting the involvement of H2O2 and Cu(I). The observation of NADH production by UV-visible spectroscopy suggested that DD catalyzed BA-1,2-dihydrodiol most efficiently to the corresponding catechol among the PAH-dihydrodiols tested. A time-of-flight mass spectroscopic study showed that the catechol form of BA-1,2-dihydrodiol formed after DD treatment. In conclusion, BA-1,2-dihydrodiol can induce DNA damage more efficiently than B[a]P-7,8-dihydrodiol and other BA-dihydrodiols in the presence of DD. The reaction mechanism on oxidative DNA damage may be explained by theoretical calculations with an enthalpy change of dihydrodiols and oxidation potential of their catechol forms. DD

  13. TUMOR PROMOTION IN RAT LIVER

    EPA Science Inventory

    An initiation promotion bioassay for chemical carcinogens and tumor promoters has been developed in rat liver using presumed preneoplastic lesions, foci of gamma-glutamyltranspeptidase (GGTase)-positive hepatocytes, as the endpoint. To evaluate the tumor-promoting activity of phe...

  14. METABOLISM OF ALPHA-NAPHTHOFLAVONE BY RAT, MOUSE, RABBIT, AND HAMSTER LIVER MICROSOMES

    EPA Science Inventory

    The metabolism of alpha-naphthoflavone (ANF) was studied in hepatic microsomes from rats, mice, rabbits, and hamsters, species in which ANF exerts its biological activities. The major metabolites produced by all species were ANF-5,6-oxide, ANF-6-phenol, and ANF-7,8-dihydrodiol. M...

  15. Cloning and sequencing of the cDNA species for mammalian dimeric dihydrodiol dehydrogenases.

    PubMed Central

    Arimitsu, E; Aoki, S; Ishikura, S; Nakanishi, K; Matsuura, K; Hara, A

    1999-01-01

    Cynomolgus and Japanese monkey kidneys, dog and pig livers and rabbit lens contain dimeric dihydrodiol dehydrogenase (EC 1.3.1.20) associated with high carbonyl reductase activity. Here we have isolated cDNA species for the dimeric enzymes by reverse transcriptase-PCR from human intestine in addition to the above five animal tissues. The amino acid sequences deduced from the monkey, pig and dog cDNA species perfectly matched the partial sequences of peptides digested from the respective enzymes of these animal tissues, and active recombinant proteins were expressed in a bacterial system from the monkey and human cDNA species. Northern blot analysis revealed the existence of a single 1.3 kb mRNA species for the enzyme in these animal tissues. The human enzyme shared 94%, 85%, 84% and 82% amino acid identity with the enzymes of the two monkey strains (their sequences were identical), the dog, the pig and the rabbit respectively. The sequences of the primate enzymes consisted of 335 amino acid residues and lacked one amino acid compared with the other animal enzymes. In contrast with previous reports that other types of dihydrodiol dehydrogenase, carbonyl reductases and enzymes with either activity belong to the aldo-keto reductase family or the short-chain dehydrogenase/reductase family, dimeric dihydrodiol dehydrogenase showed no sequence similarity with the members of the two protein families. The dimeric enzyme aligned with low degrees of identity (14-25%) with several prokaryotic proteins, in which 47 residues are strictly or highly conserved. Thus dimeric dihydrodiol dehydrogenase has a primary structure distinct from the previously known mammalian enzymes and is suggested to constitute a novel protein family with the prokaryotic proteins. PMID:10477285

  16. Surgical techniques of orthotopic rat liver transplantation.

    PubMed

    Spiegel, H U; Palmes, D

    1998-01-01

    Liver transplantation in rats is frequently used as a transplantation model. Although liver transplantation in larger laboratory animals such as dogs and pigs is technically easier, the rat has become the most important subject for experimental liver transplantation because of the availability of genetically defined animals. Numerous surgical techniques have been developed that permit the investigator to carry out studies with high clinical relevance. In this article the principal models of orthotopic rat liver transplantation and their technical modifications of vessel anastomoses, rearterialization, and bile duct reconstruction techniques are reviewed. More than 20 transplantation models are described in detail and demonstrated with clear illustrations. Finally, the advantages and uses of all the surgical procedures (e.g., suture and cuff anastomoses, bile duct anastomoses, and rearterialization techniques), specific problems, and survival criteria are discussed and the experiences of investigators who applied these techniques are analyzed. In conclusion, an overview and critical evaluation of all surgical techniques of orthotopic rat liver transplantation are given, together with instructions for learning these techniques. PMID:9700616

  17. Extensive exchange of rat liver microsomal phospholipids.

    PubMed

    Zilversmit, D B; Hughes, M E

    1977-08-15

    Liver microsomal fractions were prepared from rats injected with a single dose of choline [14C]methylchloride or with single or multiple doses of 32Pi. Exchangeability of microsomal phospholipids was determined by incubation with an excess of mitochondria and phospholipid exchange proteins derived from beef heart, beef liver or rat liver. Labeled phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were found to act as a single pool and were 85--95% exchangeable in 1--2h. High latencies of mannose-6-phosphate phosphohydrolase activities and impermeability of microsomes to EDTA proved that phospholipid exchange proteins did not have access to the intracisternal space. If microsomal membranes are largely composed of phospholipid bilayers, the experiments suggest that one or more of the phospholipid classes in microsomal membranes undergo rapid translocation between the inner and outer portions of the bilayer. PMID:889827

  18. Ozone inhalation modifies the rat liver proteome☆

    PubMed Central

    Theis, Whitney S.; Andringa, Kelly K.; Millender-Swain, Telisha; Dickinson, Dale A.; Postlethwait, Edward M.; Bailey, Shannon M.

    2013-01-01

    Ozone (O3) is a serious public health concern. Recent findings indicate that the damaging health effects of O3 extend to multiple systemic organ systems. Herein, we hypothesize that O3 inhalation will cause downstream alterations to the liver. To test this, male Sprague-Dawley rats were exposed to 0.5 ppm O3 for 8 h/day for 5 days. Plasma liver enzyme measurements showed that 5 day O3 exposure did not cause liver cell death. Proteomic and mass spectrometry analysis identified 10 proteins in the liver that were significantly altered in abundance following short-term O3 exposure and these included several stress responsive proteins. Glucose-regulated protein 78 and protein disulfide isomerase increased, whereas glutathione S-transferase M1 was significantly decreased by O3 inhalation. In contrast, no significant changes were detected for the stress response protein heme oxygenase-1 or cytochrome P450 2E1 and 2B in liver of O3 exposed rats compared to controls. In summary, these results show that an environmentally-relevant exposure to inhaled O3 can alter the expression of select proteins in the liver. We propose that O3 inhalation may represent an important unrecognized factor that can modulate hepatic metabolic functions. PMID:25544660

  19. Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

    PubMed Central

    Kuijk, Ewart W.; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M.; Cuppen, Edwin

    2016-01-01

    The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as cystic organoids, were characterized by high expression of the stem cell marker Lgr5, by the expression of liver progenitor and duct markers, and by low expression of hepatocyte markers, oval cell markers, and stellate cell markers. Prolonged cultures of rat liver organoids depended on high levels of WNT-signalling and the inhibition of BMP-signaling. Upon transplantation of clonal lines to a Fah−/− Il2rg−/− rat model of liver failure, the rat liver stem cells engrafted into the host liver where they differentiated into areas with FAH and Albumin positive hepatocytes. Rat liver stem cell lines hold potential as consistent reliable cell sources for pharmacological, toxicological or metabolic studies. In addition, rat liver stem cell lines may contribute to the development of regenerative medicine in liver disease. To our knowledge, the here described liver stem cell lines represent the first organoid culture system in the rat. PMID:26915950

  20. Rat liver endothelial and Kupffer cell-mediated mutagenicity and polycyclic aromatic hydrocarbons and aflatoxin B sub 1

    SciTech Connect

    Steinberg, P.; Schlemper, B.; Molitor, E.; Platt, K.L.; Seidel, A.; Oesch, F. )

    1990-08-01

    The ability of isolated rat liver endothelial and Kupffer cells to activate benzo(a)pyrene (BP), trans-7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene (DDBP), trans-1,2-dihydroxy-1,2-dihydrochrysene (DDCH), and aflatoxin B{sub 1} (AFB{sub 1}) to mutagenic metabolites was assessed by means of a cell-mediated bacterial mutagenicity assay and compared with the ability of parenchymal cells to activate these compounds. Endothelial and Kupffer cells from untreated rats were able to activate AFB{sub 1} and DDBP; DDBP was activated even in the absence of an NADPH-generating system. Pretreating the animals with Aroclor 1254 strongly enhanced the mutagenicity of the dihydrodiol, whereas the mutagenicity of AFB{sub 1} showed a slight increase. BP and DDCH were only activated by endothelial and Kupffer cells isolated from Aroclor 1254-pretreated rats. Parenchymal cells form untreated animals activated all four carcinogens tested; Aroclor 1254 enhanced the parenchymal cell-mediated mutagenicity of BP and DDCH but did not affect that of DDBP and clearly reduced that of AFB{sub 1}. The reduced mutagenicity of AFB{sub 1} correlates with the decrease in the amount of 2{alpha}-hydroxytestosterone formed when testosterone was incubated with parenchymal cell microsomes from Aroclor 1254-pretreated rats (compared with microsomes from untreated animals): the formation of 2{alpha}-hydroxytestosterone is specifically catalyzed by cytochrome P-450h, a hemoprotein thought to be involved in the activation of AFB{sub 1}. These results show that not only rat liver parenchymal cells, but also endothelial and Kupffer cells, activated several carcinogens to mutagenic metabolites.

  1. DNA topoisomerases from rat liver: physiological variations.

    PubMed Central

    Duguet, M; Lavenot, C; Harper, F; Mirambeau, G; De Recondo, A M

    1983-01-01

    Besides the nicking-closing (topoisomerase I) activity, an ATP-dependent DNA topoisomerase is present in rat liver nuclei. The enzyme, partially purified, is able to catenate in vitro closed DNA circles in a magnesium-dependent, ATP-dependent, histone H1-dependent reaction, and to decatenate in vitro kinetoplast DNA networks to yield free minicircles in a magnesium-dependent and ATP-dependent reaction. It is largely similar to other eukaryotic type II topoisomerases in its requirements, and presumably belongs to this class of enzymes. Type I and type II activities were measured in rat liver nuclei as a function of regenerating time after partial hepatectomy: type I activity was not significantly changed during this process. In contrast, type II activity was considerably increased, suggesting a possible involvement of the enzyme in DNA replication. Images PMID:6298730

  2. An ethoxyquin-inducible aldehyde reductase from rat liver that metabolizes aflatoxin B1 defines a subfamily of aldo-keto reductases.

    PubMed Central

    Ellis, E M; Judah, D J; Neal, G E; Hayes, J D

    1993-01-01

    Protection of liver against the toxic and carcinogenic effects of aflatoxin B1 (AFB1) can be achieved through the induction of detoxification enzymes by chemoprotectors such as the phenolic antioxidant ethoxyquin. We have cloned and sequenced a cDNA encoding an aldehyde reductase (AFB1-AR), which is expressed in rat liver in response to dietary ethoxyquin. Expression of the cDNA in Escherichia coli and purification of the recombinant enzyme reveals that the protein exhibits aldehyde reductase activity and is capable of converting the protein-binding dialdehyde form of AFB1-dihydrodiol to the nonbinding dialcohol metabolite. We show that the mRNA encoding this enzyme is markedly elevated in the liver of rats fed an ethoxyquin-containing diet, correlating with acquisition of resistance to AFB1. AFB1-AR represents the only carcinogen-metabolizing aldehyde reductase identified to date that is induced by a chemoprotector. Alignment of the amino acid sequence of AFB1-AR with other known and putative aldehyde reductases shows that it defines a subfamily within the aldo-keto reductase superfamily. Images Fig. 2 Fig. 3 Fig. 4 PMID:8234296

  3. Nicotinamide nucleotide synthesis in regenerating rat liver

    PubMed Central

    Ferris, G. M.; Clark, J. B.

    1971-01-01

    1. The concentrations and total content of the nicotinamide nucleotides were measured in the livers of rats at various times after partial hepatectomy and laparotomy (sham hepatectomy) and correlated with other events in the regeneration process. 2. The NAD content and concentration in rat liver were relatively unaffected by laparotomy, but fell to a minimum, 25 and 33% below control values respectively, 24h after partial hepatectomy. NADP content and concentration were affected similarly by both laparotomy and partial hepatectomy, falling rapidly and remaining depressed for up to 48h. 3. The effect of injecting various doses of nicotinamide on the liver DNA and NAD 18h after partial hepatectomy was studied and revealed an inverse correlation between NAD content and DNA content. 4. Injections of nicotinamide at various times after partial hepatectomy revealed that the ability to synthesize NAD from nicotinamide was impaired during the first 12h, rose to a peak at 26h and fell again by 48h after partial hepatectomy. 5. The total liver activity of NAD pyrophosphorylase (EC 2.7.7.1) remained at or slightly above the initial value for 12h after partial hepatectomy and then rose continuously until 48h after operation. The activity of NMN pyrophosphorylase (EC 2.4.2.12) showed a similar pattern of change after partial hepatectomy, but was at no time greater than 5% of the activity of NAD pyrophosphorylase. 6. The results are discussed with reference to the control of NAD synthesis in rapidly dividing tissue. It is suggested that the availability of cofactors and substrates for NAD synthesis is more important as a controlling factor than the maximum enzyme activities. It is concluded that the low concentrations of nicotinamide nucleotides in rapidly dividing tissues are the result of competition between NAD synthesis and nucleic acid synthesis for common precursor and cofactors. PMID:4398891

  4. A comparative analysis of liver transcriptome suggests divergent liver function among human, mouse and rat.

    PubMed

    Yu, Yao; Ping, Jie; Chen, Hui; Jiao, Longxian; Zheng, Siyuan; Han, Ze-Guang; Hao, Pei; Huang, Jian

    2010-11-01

    The human liver plays a vital role in meeting the body's metabolic needs and maintaining homeostasis. To address the molecular mechanisms of liver function, we integrated multiple gene expression datasets from microarray, MPSS, SAGE and EST platforms to generate a transcriptome atlas of the normal human liver. Our results show that 17396 genes are expressed in the human liver. 238 genes were identified as liver enrichment genes, involved in the functions of immune response and metabolic processes, from the MPSS and EST datasets. A comparative analysis of liver transcriptomes was performed in humans, mice and rats with microarray datasets shows that the expression profile of homologous genes remains significantly different between mouse/rat and human, suggesting a functional variance and regulation bias of genes expressed in the livers. The integrated liver transcriptome data should provide a valuable resource for the in-depth understanding of human liver biology and liver disease. PMID:20800674

  5. Turnover of metallothioneins in rat liver.

    PubMed Central

    Andersen, R D; Winter, W P; Maher, J J; Bernstein, I A

    1978-01-01

    Two electrophoretically distinguishable metallothioneins were isolated from the livers of Cd2+-treated rats and had thiol group/metal ratios of 3:1, a total metal content, in each of these proteins, of 3.6 atoms of Cd2+ + 2.4 atoms of Zn2+/molecule and 4.2 atoms of Cd2+ + 2.8 atoms of Zn2+/molecule and respective apoprotein mol.wts. of 5844 and 6251. Studies with 1 h pulse labels of [3H]cysteine, given after a single injection of ZnCl2 or CdCl2, showed that these metals stimulated radioactive isotope incorporation into the metallothioneins over the control value by 10- and 15-fold respectively. This stimulation was maximal at 4 h after a single CdCl2 injection and decreased to control values by 16 h, suggesting that either a translational event is responding to free intracellular Cd2+ or a short-lived mRNA is being produced or stabilized in response to the metal treatment. In rats chronically exposed to CdCl2, the metallothioneins increased to 0.2% of the liver wet weight from a control value of 2--4 mumol/kg of liver, with a maximum rate of accumulation of 2--3 mumol/h per kg of liver. The turnover of these proteins in control animals was 0.3--0.6 mumoles/h per kg of liver, measured by the rate of disappearance of 203Hg2+, which binds irreversibly to the metallothioneins. Pretreatment with CdCl2 completely stopped the rapid 203Hg turnover observed in untreated animals. Unlike CdCl2, treatment with ZnCl2 increased the concentration of metallothioneins to a new steady-state pool, 11 mumole/kg of liver, after 10 h. The increase in the zinc-thionein pool by exposure to ZnCl2 in vivo was determined to be primarily due to a stimulation of metallothionein biosynthesis. PMID:697759

  6. Multiphoton spectral analysis of benzo[a]pyrene uptake and metabolism in a rat liver cell line

    SciTech Connect

    Barhoumi, Rola; Mouneimne, Youssef; Ramos, Ernesto; Morisseau, Christophe; Hammock, Bruce D.; Safe, Stephen; Parrish, Alan R.; Burghardt, Robert C.

    2011-05-15

    Dynamic analysis of the uptake and metabolism of polycyclic aromatic hydrocarbons (PAHs) and their metabolites within live cells in real time has the potential to provide novel insights into genotoxic and non-genotoxic mechanisms of cellular injury caused by PAHs. The present work, combining the use of metabolite spectra generated from metabolite standards using multiphoton spectral analysis and an 'advanced unmixing process', identifies and quantifies the uptake, partitioning, and metabolite formation of one of the most important PAHs (benzo[a]pyrene, BaP) in viable cultured rat liver cells over a period of 24 h. The application of the advanced unmixing process resulted in the simultaneous identification of 8 metabolites in live cells at any single time. The accuracy of this unmixing process was verified using specific microsomal epoxide hydrolase inhibitors, glucuronidation and sulfation inhibitors as well as several mixtures of metabolite standards. Our findings prove that the two-photon microscopy imaging surpasses the conventional fluorescence imaging techniques and the unmixing process is a mathematical technique that seems applicable to the analysis of BaP metabolites in living cells especially for analysis of changes of the ultimate carcinogen benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide. Therefore, the combination of the two-photon acquisition with the unmixing process should provide important insights into the cellular and molecular mechanisms by which BaP and other PAHs alter cellular homeostasis.

  7. Ideal Experimental Rat Models for Liver Diseases.

    PubMed

    Lee, Sang Woo; Kim, Sung Hoon; Min, Seon Ok; Kim, Kyung Sik

    2011-05-01

    There are many limitations for conducting liver disease research in human beings due to the high cost and potential ethical issues. For this reason, conducting a study that is difficult to perform in humans using appropriate animal models, can be beneficial in ascertaining the pathological physiology, and in developing new treatment modalities. However, it is difficult to determine the appropriate animal model which is suitable for research purposes, since every patient has different and diverse clinical symptoms, adverse reactions, and complications due to the pathological physiology. Also, it is not easy to reproduce identically various clinical situations in animal models. Recently, the Guide for the Care and Use of Laboratory Animals has tightened up the regulations, and therefore it is advisable to select the appropriate animals and decide upon the appropriate quantities through scientific and systemic considerations before conducting animal testing. Therefore, in this review article the authors examined various white rat animal testing models and determined the appropriate usable rat model, and the pros and cons of its application in liver disease research. The authors believe that this review will be beneficial in selecting proper laboratory animals for research purposes. PMID:26421020

  8. Mutagenicity of comfrey (Symphytum Officinale) in rat liver.

    PubMed

    Mei, N; Guo, L; Fu, P P; Heflich, R H; Chen, T

    2005-03-14

    Comfrey is a rat liver toxin and carcinogen that has been used as a vegetable and herbal remedy by humans. In order to evaluate the mechanisms underlying its carcinogenicity, we examined the mutagenicity of comfrey in the transgenic Big Blue rat model. Our results indicate that comfrey is mutagenic in rat liver and the types of mutations induced by comfrey suggest that its tumorigenicity results from the genotoxicity of pyrrolizidine alkaloids in the plant. PMID:15726100

  9. Gluconeogenesis in the perfused rat liver.

    PubMed

    Hems, R; Ross, B D; Berry, M N; Krebs, H A

    1966-11-01

    1. A modification of the methods of Miller and of Schimassek for the perfusion of the isolated rat liver, suitable for the study of gluconeogenesis, is described. 2. The main modifications concern the operative technique (reducing the period of anoxia during the operation to 3min.) and the use of aged (non-glycolysing) red cells in the semi-synthetic perfusion medium. 3. The performance of the perfused liver was tested by measuring the rate of gluconeogenesis, of urea synthesis and the stability of adenine nucleotides. Higher rates of gluconeogenesis (1mumole/min./g.) from excess of lactate and of urea synthesis from excess of ammonia (4mumoles/min./g. in the presence of ornithine) were observed than are likely to occur in vivo where rates are limited by the rate of supply of precursor. The concentrations of the three adenine nucleotides in the liver tissue were maintained within 15% over a perfusion period of 135min. 4. Ca(2+), Na(+), K(+), Mg(2+) and phosphate were found to be required at physiological concentrations for optimum gluconeogenesis but bicarbonate and carbon dioxide could be largely replaced by phosphate buffer without affecting the rate of gluconeogenesis. 5. Maximal gluconeogenesis did not decrease maximal urea synthesis in the presence of ornithine and ammonia and vice versa. This indicates that the energy requirements were not limiting the rates of gluconeogenesis or of urea synthesis. 6. Addition of lactate, and especially ammonium salts, increased the uptake of oxygen more than expected on the basis of the ATP requirements of the gluconeogenesis and urea synthesis. PMID:5966267

  10. Kavalactone metabolism in rat liver microsomes.

    PubMed

    Fu, Shuang; Rowe, Anthony; Ramzan, Iqbal

    2012-07-01

    The specific CYP enzymes involved in kavalactone (KLT) metabolism and their kinetics have not been fully examined. This study used rat liver microsomes (RLM) to determine kavain (KA), methysticin (MTS) and desmethoxyyangonin (DMY) enzyme kinetic parameters, to elucidate the major CYP450 isoforms involved in KLT metabolism and to examine gender differences in KLT metabolism. Formation of the major KLT metabolites was first-order, consistent with classic enzyme kinetics. In both male and female RLM, clotrimazole (CLO) was the most potent inhibitor of KA and MTS metabolism. This suggests CYP3A1/3A23 (females) and CYP3A2 (males) are the main isoenzymes involved in the metabolism of these KLTs in rats, while the roles of CYP1A2, -2 C6, -2 C9, -2E1 and -3A4 are limited. Desmethoxyyangonin metabolism was equally inhibited by cimetidine (CIM) and CLO in females, and CIM and nortriptyline in males. This implies that DMY metabolism involves CYP2C6 and CYP2C11 in males, and CPY2C12 in females. CYP3A1/3A23 may also be involved in females. PMID:22807255

  11. The portal lobule in rat liver fibrosis: a re-evaluation of the liver unit.

    PubMed

    Bhunchet, E; Wake, K

    1998-02-01

    We re-evaluated three schemes of liver organization: the classic lobule, the portal lobule, and Rappaport's liver acinus. The lobular angioarchitecture of normal rat liver and the three-dimensional structure of pseudolubules found in rat livers with fibrosis induced by swine serum were compared with the classic lobule of the pig. Normal and fibrotic rat livers and pig livers were perfused, injected with either India ink or 0.75% OsO4 through the portal and/or hepatic vein, and immersionfixed. Whole lobes and hand-cut thick sections were made transparent with a solution of benzyl benzoate and methyl salicylate. The angioarchitecture of normal rat liver differs from pig liver. In the former, terminal portal branches and central veins interdigitate, and in the latter, numerous terminal portal branches that arise from interlobular portal veins establish a vascular basket surrounding one central vein and forming classic lobule. The structure of liver acinus is never found in the pig liver. The terminal portal branch, together with the terminal hepatic artery and bile duct, are present inside each pseudolobule of fibrotic rat livers. Blood from the terminal portal branch flows through inlet venules into radiating sinusoids, and, at the periphery converges into newly formed septal and angular outlet venules; these venules terminate in fibrotic central veins located at each corner. Pseudolobules are not rugby ball-like as Rappaport's liver acini are but are polyhedron in shape. The rat pseudolobules are comparable with the portal lobule; its structure and microcirculation are the reverse of the pig classic lobule. Rat pseudolobules are different from liver acini, as shown by the following: 1) their three-dimensional shape is different; and 2) they have a reverse relationship to classic lobules while acini are defined to subdivide classic lobules. In normal and fibrotic rat livers, the liver unit is the portal lobule with a terminal portal branch as the axial branch and

  12. Sequential Degradation of Insulin by Rat Liver Homogenates

    PubMed Central

    Varandani, P. T.; Shroyer, Lois A.; Nafz, Mary Ann

    1972-01-01

    Insulin was incubated with rat liver homogenate in the presence of glutathione. The products formed were examined by chromatography on a Sephadex G-75 column, with 50% acetic acid as eluent. The results show that insulin is degraded by rat liver homogenates in sequential order: first, a splitting of insulin into A and B chains by glutathione-insulin transhydrogenase, followed by proteolysis of the resulting polypeptides to small molecular weight components. PMID:4625885

  13. Absence of initiating activity by quercetin in the rat liver.

    PubMed

    Kato, K; Mori, H; Tanaka, T; Fujii, M; Kawai, T; Nishikawa, A; Takahashi, M; Hirono, I

    1985-08-01

    Initiating activity of quercetin was tested in rats which were treated with partial hepatectomy and given a liver cancer promoter, phenobarbital. A few intestinal neoplasms were seen but without significant difference in incidence from those in the quercetin-untreated group. Moreover, neither neoplastic nor preneoplastic liver changes were detected in quercetin-treated groups. With hepatocyte primary culture/DNA repair test, quercetin did not produce genotoxicity. The results show that quercetin has no initiating or genotoxic activities in the rat liver. PMID:4029060

  14. A rat model of liver transplantation with a steatotic donor liver after cardiac death

    PubMed Central

    Cai, Qiucheng; Fan, Hongkai; Xiong, Rihui; Jiang, Yi

    2015-01-01

    This study aimed to establish a rat liver transplantation model with a steatotic donor liver after cardiac death, reflecting clinical conditions. Rats were fed a high-fat diet for 8 weeks to establish the fatty liver model. This model simulates liver steatosis caused by various factors before clinical donation after cardiac death. A pneumothorax was created in the donor rat to induce hypoxia and cardiac arrest before incising the liver. This simulated the processes of hypoxia and cardiac arrest caused by withdrawal of treatment in actual clinical situations. The harvested cardiac death donor liver was then transplanted using the Kamada technique. Donor operative time was 45.7 ± 4.2 min; cardiac arrest time, 9 ± 0.8 min; recipient surgery time, 40.3 ± 4.9 min; and no-liver time, 15 ± 2.5 min. Of 40 liver-transplanted rats, 2 died within 24 h, with a surgical success rate of 95%. The transaminase levels on post-transplantation days 1, 3, 5, and 7 were 835.4 ± 71.33 U/L, 1334.5 ± 102.13 U/L, 536.4 ± 65.52 U/L, and 218.2 ± 36.77 U/L, respectively. This rat liver transplantation model with a steatotic donor liver after cardiac death could improve the simulation of the pathophysiological processes of clinical donation after cardiac death, and could be used as a reliable and stable animal model. PMID:26629068

  15. Vaccenic acid metabolism in the liver of rat and bovine.

    PubMed

    Gruffat, Dominique; De La Torre, Anne; Chardigny, Jean-Michel; Durand, Denys; Loreau, Olivier; Bauchart, Dominique

    2005-03-01

    Hepatic metabolism of vaccenic acid (VA), especially its conversion into CLA, was studied in the bovine (ruminant species that synthesizes CLA) and in the rat (model for non-ruminant) by using the in vitro technique of liver explants. Liver tissue samples were collected from fed animals (5 male Wistar rats and 5 Charolais steers) and incubated at 37 degrees C for 17 h under an atmosphere of 95% O2/5% CO2 in medium supplemented with 0.75 mM of FA mixture and with 55 microM [1-14C]VA. VA uptake was about sixfold lower in bovine than in rat liver slices (P< 0.01). For both species, VA that was oxidized to partial oxidation products represented about 20% of VA incorporated by cells. The chemical structure of VA was not modified in bovine liver cells, whereas in rat liver cells, 3.2% of VA was converted into 16:0 and only 0.33% into CLA. The extent of esterification of VA was similar for both animal species (70-80% of incorporated VA). Secretion of VA as part of VLDL particles was very low and similar in rat and bovine liver (around 0.07% of incorporated VA). In conclusion, characteristics of the hepatic metabolism of VA were similar for rat and bovine animals, the liver not being involved in tissue VA conversion into CLA in spite of its high capacity for FA desaturation especially in the rat. This indicates that endogenous synthesis of CLA should take place exclusively in peripheral tissues. PMID:15957256

  16. Synthesis in vitro of glycosaminoglycans in regenerating rat liver.

    PubMed

    Gressner, A M; Cadenbach, J E; Greiling, H

    1981-07-01

    Chronic liver damage is accompanied by both liver cell multiplication and stimulated synthesis of proteoglycans, but the relationship between the two biochemical processes has not been investigated so far. We found that the incorporation of [14C]glucosamine into total glycosaminoglycans of rat liver slices from regenerating tissue is depressed by about 50% 1 and 3 days after operation if referred to that measured in sham-operated control liver slices. 6 h after partial hepatectomy [14C]glucosamine incorporation into glycosaminoglycans is stimulated by more than 30% in relation to sham operated livers. The proportional rates of synthesis of heparan sulfate and chondroitin sulfate (about 8:1) did not change in regenerating liver tissue. Furthermore, there was no difference in the intracellular uptake of [14C]glucosamine by rat liver slices from sham operated and partially hepatectomized rats; the pool size of UDP-N-acetylhexosamine was only slightly larger (about 14%) under the latter experimental condition. We conclude that liver regeneration by itself is not responsible for the elevated production and the changing pattern of proteoglycans in long-lasting hepatic injury. PMID:6799611

  17. Supercooling Preservation Of The Rat Liver For Transplantation

    PubMed Central

    Bruinsma, Bote G.; Berendsen, Tim A.; Izamis, Maria-Louisa; Yeh, Heidi; Yarmush, Martin L.; Uygun, Korkut

    2015-01-01

    The current standard for liver preservation is limited in duration. Employing a novel subzero preservation technique that includes supercooling and machine perfusion can significantly improve preservation and prolong storage times. By loading rat livers with cryoprotectants to prevent both intra- and extracellular ice formation and protect against hypothermic injury, livers can be cooled to −6 °C without freezing and kept viable for up to 96 hours. Here, we describe the procedures of loading cryoprotectants by means of subnormothermic machine perfusion (SNMP), controlled cooling to a supercooled state, followed by SNMP recovery and orthotopic liver transplantation. PMID:25692985

  18. Dietary fiber supplements: effects on serum and liver lipids and on liver phospholipid composition in rats.

    PubMed

    Kritchevsky, D; Tepper, S A; Satchithanandam, S; Cassidy, M M; Vahouny, G V

    1988-04-01

    Rats (6 per group) were fed semipurified diets containing either particulate fibers (alfalfa, 10%; cellulose, 10%; bran, 10%), a soluble ionic fiber (pectin 5%), soluble, nonionic fibers (guar gum, 5%; Metamucil, 10%), a mixed fiber preparation (Fibyrax, 10%, or an insoluble, ionic bile acid-binding resin (cholestyramine, 2%). The control group was fed the unsupplemented diet. The feeding period, during which diet and water were provided ad libitum, was 28 days. Compared with the control group, serum total cholesterol levels were increased by more than 10% in rats fed alfalfa and decreased by more than 10% in rats fed cellulose, guar gum, Fibyrax and cholestyramine. There were no significant differences in percentage of plasma HDL cholesterol. Serum triglycerides were elevated in the groups fed alfalfa, pectin, guar gum or Fibyrax and reduced in the group fed Metamucil. Plasma phospholipids were elevated in rats fed alfalfa or bran, unaffected in rats fed pectin or Metamucil and reduced in the other groups. Liver total cholesterol was elevated in all groups but those fed wheat bran and cholestyramine. The percentage of liver cholesterol present as ester was elevated in every group except that fed cholestyramine. Liver triglycerides were reduced in rats fed guar gum or Metamucil and elevated in those fed alfalfa. Liver phospholipids were lowered in the group fed cellulose. Liver phospholipids were fractionated by thin layer chromatography to give phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (Sph), lysophosphatidylcholine (LPC) and phosphatidylinositol plus phosphatidylserine (PI + PS).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2840544

  19. Oxidation of PAH trans-Dihydrodiols by Human Aldo-Keto Reductase AKR1B10

    PubMed Central

    Quinn, Amy M.; Harvey, Ronald G.; Penning, Trevor M.

    2009-01-01

    AKR1B10 has been identified as a potential biomarker for human non-small cell lung carcinoma and as a tobacco exposure and response gene. AKR1B10 functions as an efficient retinal reductase in vitro, and may regulate retinoic acid homeostasis. However, the possibility that this enzyme is able to activate polycyclic aromatic hydrocarbon (PAH) trans-dihydrodiols to form reactive and redox-active o-quinones has not been investigated to date. AKR1B10 was found to oxidize a wide range of PAH trans-dihydrodiol substrates in vitro to yield PAH o-quinones. Reactions of AKR1B10 proceeded with improper stereochemistry, since it was specific for the minor (+)-benzo[a]pyrene-7S,8S-dihydrodiol diastereomer formed in vivo. However, AKR1B10 displayed reasonable activity in the oxidation of both the (−)-R,R and (+)-S,S stereoisomers of benzo[g]chrysene-11,12-dihydrodiol and oxidized the potentially relevant, albeit minor, (+)-benz[a]anthracene-3S,4S-dihydrodiol metabolite. We find that AKR1B10 is therefore likely to play a contributing role in the activation of PAH trans-dihydrodiols in human lung. AKR1B10 retinal reductase activity was confirmed in vitro and found to be 5- to 150-fold greater than the oxidation of PAH trans-dihydrodiols examined. AKR1B10 was highly expressed at the mRNA and protein levels in human lung adenocarcinoma A549 cells, and robust retinal reductase activity was measured in lysates of these cells. The much greater catalytic efficiency of retinal reduction compared to PAH trans-dihydrodiol metabolism suggests AKR1B10 may play a greater role in lung carcinogenesis through dysregulation of retinoic acid homeostasis than through oxidation of PAH trans-dihydrodiols. PMID:18788756

  20. Serial analysis of gene expression (SAGE) in rat liver regeneration

    SciTech Connect

    Cimica, Velasco . E-mail: vcimica@aecom.yu.edu; Batusic, Danko; Haralanova-Ilieva, Borislava; Chen, Yonglong; Hollemann, Thomas; Pieler, Tomas; Ramadori, Giuliano

    2007-08-31

    We have applied serial analysis of gene expression for studying the molecular mechanism of the rat liver regeneration in the model of 70% partial hepatectomy. We generated three SAGE libraries from a normal control liver (NL library: 52,343 tags), from a sham control operated liver (Sham library: 51,028 tags), and from a regenerating liver (PH library: 53,061 tags). By SAGE bioinformatics analysis we identified 40 induced genes and 20 repressed genes during the liver regeneration. We verified temporal expression of such genes by real time PCR during the regeneration process and we characterized 13 induced genes and 3 repressed genes. We found connective tissue growth factor transcript and protein induced very early at 4 h after PH operation before hepatocytes proliferation is triggered. Our study suggests CTGF as a growth factor signaling mediator that could be involved directly in the mechanism of liver regeneration induction.

  1. Modeling the mechanical properties of liver fibrosis in rats.

    PubMed

    Zhu, Ying; Chen, Xin; Zhang, Xinyu; Chen, Siping; Shen, Yuanyuan; Song, Liang

    2016-06-14

    The progression of liver fibrosis changes the biomechanical properties of liver tissue. This study characterized and compared different liver fibrosis stages in rats in terms of viscoelasticity. Three viscoelastic models, the Voigt, Maxwell, and Zener models, were applied to experimental data from rheometer tests and then the elasticity and viscosity were estimated for each fibrosis stage. The study found that both elasticity and viscosity are correlated with the various stages of liver fibrosis. The study revealed that the Zener model is the optimal model for describing the mechanical properties of each fibrosis stage, but there is no significant difference between the Zener and Voigt models in their performance on liver fibrosis staging. Therefore the Voigt model can still be effectively used for liver fibrosis grading. PMID:27017300

  2. Hepatic injury after whole-liver irradiation in the rat

    SciTech Connect

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Leitch, J.M.

    1985-03-01

    Radiation-induced hepatic injury in rats, which is characterized by marked ascites accompanied by liver necrosis, fibrosis, and vein lesions, is described in this study. These adverse sequelae are produced within 30 days after irradiation if there is surgical removal of two-thirds of the liver immediately after whole-liver irradiation. The LD/sub 50/30/ day and median survival time after liver irradiation and two-thirds partial hepatectomy is 24 Gy and 17 days, respectively. Death is preceded by reduction in liver function as measured by (/sup 131/I)-labeled rose bengal clearance. Prior to death, liver sepsis and endotoxemia were detected in most irradiated, partially hepatectomized animals. Pretreatment of the animals with endotoxin and/or antibiotic decontamination of the GI tract resulted in increased survival time, but no irradiated, partially hepatectomized animal survived beyond 63 days. This suggests that sepsis and endotoxemia resulting from the bacteria in the intestine are the immediate cause of death after 30-Gy liver irradiation and partial hepatectomy. It is concluded that the hepatectomized rat model is an economical and scientifically manageable experimental system to study a form of radiation hepatitis that occurs in compromised human livers.

  3. Impact of Propionic Acid on Liver Damage in Rats

    PubMed Central

    Al- Daihan, Sooad; Shafi Bhat, Ramesa

    2015-01-01

    Propionic acid (PA) is a short chain fatty acid, a common food preservative and metabolic end product of enteric bacteria in the gut. The present study was undertaken to investigate the effect of PA on liver injury in male rats. Male western albino rats were divided into two groups. The first group served as normal control, the second was treated with PA. The activities of serum hepatospecific markers such as aspartate transaminase, alanine transaminase, and alkaline phosphatase were estimated. Antioxidant status in liver tissues was estimated by determining the level of lipid peroxidation and activities of enzymatic and non-enzymatic antioxidants. Sodium and potassium levels were also measured in liver tissue. PA treatment caused significant changes in all hepatospecific markers. Biochemical analysis of liver homogenates from PA-treated rats showed an increase in oxidative stress markers like lipid peroxidation and lactate dehydrogenase, coupled with a decrease in glutathione, vitamin C and glutathione S- transferase. However, PA exposure caused no change in sodium and potassium levels in liver tissue. Our study demonstrated that PA persuade hepatic damage in rats. PMID:26629488

  4. Supercooling preservation and transplantation of the rat liver.

    PubMed

    Bruinsma, Bote G; Berendsen, Tim A; Izamis, Maria-Louisa; Yeh, Heidi; Yarmush, Martin L; Uygun, Korkut

    2015-03-01

    The current standard for liver preservation involves cooling of the organ on ice (0-4 °C). Although it is successful for shorter durations, this method of preservation does not allow long-term storage of the liver. The gradual loss of hepatic viability during preservation puts pressure on organ sharing and allocation, may limit the use of suboptimal grafts and necessitates rushed transplantation to achieve desirable post-transplantation outcomes. In an attempt to improve and prolong liver viability during storage, alternative preservation methods are under investigation. For instance, ex vivo machine perfusion systems aim to sustain and even improve viability by supporting hepatic function at warm temperatures, rather than simply slowing down deterioration by cooling. Here we describe a novel subzero preservation technique that combines ex vivo machine perfusion with cryoprotectants to facilitate long-term supercooled preservation. The technique improves the preservation of rat livers to prolong storage times as much as threefold, which is validated by successful long-term recipient survival after orthotopic transplantation. This protocol describes how to load rat livers with cryoprotectants to prevent both intracellular and extracellular ice formation and to protect against hypothermic injury. Cryoprotectants are loaded ex vivo using subnormothermic machine perfusion (SNMP), after which livers can be cooled to -6 °C without freezing and kept viable for up to 96 h. Cooling to a supercooled state is controlled, followed by 3 h of SNMP recovery and orthotopic liver transplantation. PMID:25692985

  5. Effects of hypergravity on rat liver regeneration

    NASA Technical Reports Server (NTRS)

    Feller, D. D.

    1982-01-01

    The effects of centrifugation on liver regrowth were examined by measuring mitotic activity. The results indicate that the increased gravity caused a delay in the onset of mitotic activity and a significant decrease in overall mitotic activity.

  6. Creatine supplementation and oxidative stress in rat liver

    PubMed Central

    2013-01-01

    Background The objective of this study was to determine the effects of creatine supplementation on liver biomarkers of oxidative stress in exercise-trained rats. Methods Forty 90-day-old adult male Wistar rats were assigned to four groups for the eight-week experiment. Control group (C) rats received a balanced control diet; creatine control group (CCr) rats received a balanced diet supplemented with 2% creatine; trained group (T) rats received a balanced diet and intense exercise training equivalent to the maximal lactate steady state phase; and supplemented-trained (TCr) rats were given a balanced diet supplemented with 2% creatine and subjected to intense exercise training equivalent to the maximal lactate steady state phase. At the end of the experimental period, concentrations of creatine, hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS) were measured as well as the enzyme activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-GPx) and catalase (CAT). Liver tissue levels of reduced glutathione (GSH), oxidized glutathione (GSSG) and the GSH/GSSG ratio were also determined. Results Hepatic creatine levels were highest in the CCr and TCr groups with increased concentration of H2O2 observed in the T and TCr animal groups. SOD activity was decreased in the TCr group. GSH-GPx activity was increased in the T and TCr groups while CAT was elevated in the CCr and TCr groups. GSH, GGS and the GSH/GSSG ratio did not differ between all animal subsets. Conclusions Our results demonstrate that creatine supplementation acts in an additive manner to physical training to raise antioxidant enzymes in rat liver. However, because markers of liver oxidative stress were unchanged, this finding may also indicate that training-induced oxidative stress cannot be ameliorated by creatine supplementation. PMID:24325803

  7. Study of soluble lipoprotein in rat liver mitochondria

    PubMed Central

    Koppikar, S. V.; Fatterpaker, P.; Sreenivasan, A.

    1971-01-01

    1. A water-soluble lipoprotein was isolated and purified from osmotically shocked preparations of rat liver mitochondria by using a technique of Sephadex-sandwich disc electrophoresis. 2. The purified lipoprotein migrates as a distinct sharp zone in high-resolution electrophoretic systems, indicating high degree of purity. 3. The lipoprotein resembles mitochondrial membranes with respect to lipid composition and lipid/protein ratio. 4. The lipoprotein and its apoprotein fraction obtained by delipidization at −18°C to −20°C have common properties with respect to their fluorescence spectra, instability to storage and electrophoretic mobility. 5. The purified lipoprotein has an excitation maximum at 325nm and a fluorescence maximum at 418nm. 6. Storage at 4°C for 4 days or repeated freezing and thawing results in 15–30% decrease in electrophoretic mobility. 7. The patterns of incorporation in vitro of [1-14C]leucine into proteins of the soluble lipoprotein and of mitochondrial membrane of isolated rat liver mitochondria suggest a probable precursor role for the apoprotein in the formation of mitochondrial membrane protein. 8. Lipoprotein preparations isolated from mitochondrial fractions of rat kidney, brain and heart and of chicken and mouse liver resemble closely that obtained from rat liver mitochondria, suggesting that the soluble lipoprotein could be a distinct entity of mitochondrial origin. ImagesFig. 4.Fig. 5. PMID:5114976

  8. MIREX INDUCES ORNITHINE DECARBOXYLASE ACTIVITY IN FEMALE RAT LIVER

    EPA Science Inventory

    Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, was significantly induced in female rat liver following oral administration of the pesticide, mirex. fter dual oral exposure (120 mg/kg; 21 and 4 hrs prior to sacrifice) induction of ODC activity in r...

  9. IN VITRO METABOLISM OF PYRETHROIDS IN RAT LIVER MICROSOMES

    EPA Science Inventory


    IN VITRO METABOLISM OF PYRETHROIDS IN RAT LIVER MICROSOMES

    SJ Godin1, RA Harrison2 MF. Hughes 2, MJ DeVito2; 1Curriculum In Toxicology, UNC-CH, Chapel Hill NC, USA; 2ETD, NHEERL, ORD, US EPA, RTP, NC, 27711, USA.

    Pyrethroids are neurotoxic pesticides that bin...

  10. Antifibrotic effect of heparin on liver fibrosis model in rats

    PubMed Central

    Shah, Binita; Shah, Gaurang

    2012-01-01

    AIM: To evaluate the effect of chronic thrombin inhibition by heparin on experimentally induced chronic liver injury (liver fibrosis) in rats. METHODS: Chronic liver injury (liver fibrosis) was induced in Wistar rats by oral administration of carbon tetrachloride (CCl4) for 7 wk, an animal model with persistent severe hepatic fibrosis. Intravenous administration of the thrombin antagonist (heparin) started 1 wk after the start of CCl4 intoxication for 6 wk. After completion of treatment (7 wk), markers of hepatic dysfunction were measured and changes evaluated histopathologically. RESULTS: Higher serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), total, direct and indirect bilirubin levels, as well as lower fibrinogen levels, were found in CCl4 intoxicated rats. Heparin, silymarin and combination of drug (heparin and silymarin) treatment for 6 wk prevented a rise in SGOT, SGPT, ALP, total, direct and indirect bilirubin levels and improved fibrinogen levels. Deterioration in hepatic function determined by the fibrosis area was retarded, as evident from hepatic histopathology. Total protein levels were not changed in all groups. CONCLUSION: Heparin, a thrombin antagonist, preserved hepatic function and reduced severity of hepatic dysfunction/fibrogenesis. Combination of heparin and silymarin produced additional benefits on liver fibrosis. PMID:23494756

  11. A new rat model of auxiliary partial heterotopic liver transplantation with liver dual arterial blood supply

    PubMed Central

    QIAO, JIANLIANG; HAN, CHUNLEI; ZHANG, JUNJING; WANG, ZHIYONG; MENG, XINGKAI

    2015-01-01

    Auxiliary partial heterotopic liver transplantation (APHLT) with portal vein arterialization is a valuable procedure to be considered in the treatment of patients with acute liver failure and metabolic liver diseases. The aim of this study was to develop a new rat model of APHLT with liver dual arterial blood supply (LDABS). A total of 20 rats were used. The donor liver was resected, and the celiac trunk was reserved. Left and medial hepatic lobes accounting for 70% of the liver mass were removed en bloc and the suprahepatic caval vein was ligated simultaneously. Thus, 30% of the donor liver was obtained as the graft. Sleeve anastomosis of the graft portal vein and splenic artery were performed after narrowing the portal vein lumen through suturing. The right kidney of the recipient was removed, and sleeve anastomosis was performed between the celiac trunk of the graft and the right renal artery of the recipient. In addition, end-to-end anastomosis was performed between the infrahepatic caval vein of the graft and the right renal vein of the recipient. Following the reperfusion of the graft, the blood flow of the arterialized portal vein was controlled within the physiological range through suturing and narrowing under monitoring with an ultrasonic flowmeter. The bile duct of the graft was implanted into the duodenum of the recipient through an internal stent catheter. A 70% section of the native liver (left and medial hepatic lobes) was resected using bloodless hepatectomy. The mean operative duration was 154.5±16.4 min, and the warm and cold ischemia times of the graft were 8.1±1.1 min and 64.5±6.6 min, respectively. The blood flow of the arterialized portal vein to the graft was 1.8±0.3 ml/min/g liver weight. The success rate of model establishment (waking with post-surgical survival of >24 h) was 70% (7/10). Following successful model establishment, all rats survived 7 days post-surgery (100%; 7/7). The graft was found to be soft in texture and bright red

  12. Aluminium toxicity in the rat liver and brain

    NASA Astrophysics Data System (ADS)

    Yumoto, S.; Ohashi, H.; Nagai, H.; Kakimi, S.; Ishikawa, A.; Kobayashi, K.; Ogawa, Y.; Ishii, K.

    1993-04-01

    To investigate the etiology of Alzheimer's disease, we examined the brain and liver tissue uptake of aluminium 5-75 days after aluminium injection into healthy rats. Ten days after the last injection, Al was detected in the brain and the brain cell nuclei by particle-induced X-ray emission (PIXE) analysis. Al was also demonstrated in the liver and the liver cell nuclei by PIXE analysis and electron energy loss spectrometry (EELS). The morphological changes of the rat brain examined 75 days after the injection were similar to those which have been reportedly observed in the brain of patients with Alzheimer's disease. These results support the theory that Alzheimer's disease is caused by irreversible accumulation of aluminium in the brain, as well as in the nuclei of brain cells.

  13. Melatonin Alleviates Liver Apoptosis in Bile Duct Ligation Young Rats

    PubMed Central

    Sheen, Jiunn-Ming; Chen, Yu-Chieh; Hsu, Mei-Hsin; Tain, You-Lin; Huang, Ying-Hsien; Tiao, Mao-Meng; Li, Shih-Wen; Huang, Li-Tung

    2016-01-01

    Bile duct ligation (BDL)-treated rats display cholestasis and liver damages. The potential protective activity of melatonin in young BDL rats in terms of apoptosis, mitochondrial function, and endoplasmic reticulum (ER) homeostasis has not yet been evaluated. Three groups of young male Sprague-Dawley rats were used: one group received laparotomy (Sham), a second group received BDL for two weeks (BDL), and a third group received BDL and intraperitoneal melatonin (100 mg/day) for two weeks (BDL + M). BDL group rats showed liver apoptosis, increased pro-inflamamtory mediators, caspases alterations, anti-apoptotic factors changes, and dysfunction of ER homeostasis. Melatonin effectively reversed apoptosis, mainly through intrinsic pathway and reversed ER stress. In addition, in vitro study showed melatonin exerted its effect mainly through the melatonin 2 receptor (MT2) in HepG2 cells. In conclusion, BDL in young rats caused liver apoptosis. Melatonin rescued the apoptotic changes via the intrinsic pathway, and possibly through the MT2 receptor. Melatonin also reversed ER stress induced by BDL. PMID:27556445

  14. Antiulcer activity of cod liver oil in rats

    PubMed Central

    Khare, Salaj; Asad, Mohammed; Dhamanigi, Sunil S.; Prasad, V. Satya

    2008-01-01

    Objective: Cod liver oil is used widely as a dietary supplement. The present study was carried out to evaluate the effect of cod liver oil (0.5 g/kg, p.o. and 1 g/kg, p.o.) on gastric and duodenal ulcers. Materials and Methods: The study was carried out on different gastric ulcer models such as acetic acid induced chronic gastric ulcers, pylorus ligation, indomethacin induced ulcers, stress induced ulcers and ethanol induced ulcers. The duodenal ulcers were induced using cysteamine hydrochloride (HCl). Ranitidine (50 mg/kg p.o.) and misoprostol (100 µg/kg, p.o.) were used as standard drugs. Results: Both doses of cod liver oil showed gastric ulcer healing effect in acetic acid induced chronic gastric ulcers, produced gastric antisecretory effect in pylorus-ligated rats and also showed gastric cytoprotective effect in ethanol-induced and indomethacin-induced ulcer. Cod liver oil also produced a significant reduction in the development of stress induced gastric ulcers and cysteamine induced duodenal ulcer. The high dose of cod liver oil (1 g/kg, p.o.) was more effective compared to the low dose (0.5 g/kg, p.o.). Conclusion: Cod liver oil increases healing of gastric ulcers and prevents the development of experimentally induced gastric and duodenal ulcers in rats. PMID:20040959

  15. Molecular cloning, expression and catalytic activity of a human AKR7 member of the aldo-keto reductase superfamily: evidence that the major 2-carboxybenzaldehyde reductase from human liver is a homologue of rat aflatoxin B1-aldehyde reductase.

    PubMed Central

    Ireland, L S; Harrison, D J; Neal, G E; Hayes, J D

    1998-01-01

    The masking of charged amino or carboxy groups by N-phthalidylation and O-phthalidylation has been used to improve the absorption of many drugs, including ampicillin and 5-fluorouracil. Following absorption of such prodrugs, the phthalidyl group is hydrolysed to release 2-carboxybenzaldehyde (2-CBA) and the pharmaceutically active compound; in humans, 2-CBA is further metabolized to 2-hydroxymethylbenzoic acid by reduction of the aldehyde group. In the present work, the enzyme responsible for the reduction of 2-CBA in humans is identified as a homologue of rat aflatoxin B1-aldehyde reductase (rAFAR). This novel human aldo-keto reductase (AKR) has been cloned from a liver cDNA library, and together with the rat protein, establishes the AKR7 family of the AKR superfamily. Unlike its rat homologue, human AFAR (hAFAR) appears to be constitutively expressed in human liver, and is widely expressed in extrahepatic tissues. The deduced human and rat protein sequences share 78% identity and 87% similarity. Although the two AKR7 proteins are predicted to possess distinct secondary structural features which distinguish them from the prototypic AKR1 family of AKRs, the catalytic- and NADPH-binding residues appear to be conserved in both families. Certain of the predicted structural features of the AKR7 family members are shared with the AKR6 beta-subunits of voltage-gated K+-channels. In addition to reducing the dialdehydic form of aflatoxin B1-8,9-dihydrodiol, hAFAR shows high affinity for the gamma-aminobutyric acid metabolite succinic semialdehyde (SSA) which is structurally related to 2-CBA, suggesting that hAFAR could function as both a SSA reductase and a 2-CBA reductase in vivo. This hypothesis is supported in part by the finding that the major peak of 2-CBA reductase activity in human liver co-purifies with hAFAR protein. PMID:9576847

  16. Changes in nuclear and polysomal polyadenylated RNA sequences during rat-liver regeneration.

    PubMed Central

    Wilkes, P R; Birnie, G D; Paul, J

    1979-01-01

    Nuclear and polysomal polyadenylated RNA populations of normal and 16 hour regenerating rat liver have been compared by mRNA-cDNA hybridisations and by unique DNA saturation experiments. It was found that nuclear polyadenylated RNA hybridises to 6.8% of unique DNA in both normal and 16 hour regenerating rat liver. However, cross-hybridisation experiments using cDNA have shown that 10-15% by weight of nuclear polyadenylated RNA sequences are specific to 16 hour regenerating rat-liver. Since both unique DNA and cDNA hybridisation have shown that normal and 16 hour regenerating rat-liver polysomal polyadenylated RNA populations are qualitatively very similar sequences specific to 16 hour regenerating rat-liver nuclear polyadenylated RNA are nucleus confined. Polysomal RNA sequences which were abundant in normal rat-liver have become less abundant in regenerating rat liver. PMID:461186

  17. Characterization of deltamethrin metabolism by rat plasma and liver microsomes

    SciTech Connect

    Anand, Sathanandam S. . E-mail: sanand@rx.uga.edu; Bruckner, James V.; Haines, Wendy T.; Muralidhara, Srinivasa; Fisher, Jeffrey W.; Padilla, Stephanie

    2006-04-15

    Deltamethrin, a widely used type II pyrethroid insecticide, is a relatively potent neurotoxicant. While the toxicity has been extensively examined, toxicokinetic studies of deltamethrin and most other pyrethroids are very limited. The aims of this study were to identify, characterize, and assess the relative contributions of esterases and cytochrome P450s (CYP450s) responsible for deltamethrin metabolism by measuring deltamethrin disappearance following incubation of various concentrations (2 to 400 {mu}M) in plasma (esterases) and liver microsomes (esterases and CYP450s) prepared from adult male rats. While the carboxylesterase metabolism in plasma and liver was characterized using an inhibitor, tetra isopropyl pyrophosphoramide (isoOMPA), CYP450 metabolism was characterized using the cofactor, NADPH. Michaelis-Menten rate constants were calculated using linear and nonlinear regression as applicable. The metabolic efficiency of these pathways was estimated by calculating intrinsic clearance (Vmax/Km). In plasma, isoOMPA completely inhibited deltamethrin biotransformation at concentrations (2 and 20 {mu}M of deltamethrin) that are 2- to 10-fold higher than previously reported peak blood levels in deltamethrin-poisoned rats. For carboxylesterase-mediated deltamethrin metabolism in plasma, Vmax = 325.3 {+-} 53.4 nmol/h/ml and Km = 165.4 {+-} 41.9 {mu}M. Calcium chelation by EGTA did not inhibit deltamethrin metabolism in plasma or liver microsomes, indicating that A-esterases do not metabolize deltamethrin. In liver microsomes, esterase-mediated deltamethrin metabolism was completely inhibited by isoOMPA, confirming the role of carboxylesterases. The rate constants for liver carboxylesterases were Vmax = 1981.8 {+-} 132.3 nmol/h/g liver and Km = 172.5 {+-} 22.5 {mu}M. Liver microsomal CYP450-mediated biotransformation of deltamethrin was a higher capacity (Vmax = 2611.3 {+-} 134.1 nmol/h/g liver) and higher affinity (Km = 74.9 {+-} 5.9 {mu}M) process than

  18. Oral administration of polyamines ameliorates liver ischemia/reperfusion injury and promotes liver regeneration in rats.

    PubMed

    Okumura, Shinya; Teratani, Takumi; Fujimoto, Yasuhiro; Zhao, Xiangdong; Tsuruyama, Tatsuaki; Masano, Yuki; Kasahara, Naoya; Iida, Taku; Yagi, Shintaro; Uemura, Tadahiro; Kaido, Toshimi; Uemoto, Shinji

    2016-09-01

    Polyamines are essential for cell growth and differentiation. They play important roles in protection from liver damage and promotion of liver regeneration. However, little is known about the effect of oral exogenous polyamine administration on liver damage and regeneration. This study investigated the impact of polyamines (spermidine and spermine) on ischemia/reperfusion injury (IRI) and liver regeneration. We used a rat model in which a 70% hepatectomy after 40 minutes of ischemia was performed to mimic the clinical condition of living donor partial liver transplantation (LT). Male Lewis rats were separated into 2 groups: a polyamine group given polyamines before and after operation as treatment and a vehicle group given distilled water as placebo. The levels of serum aspartate aminotransferase and alanine aminotransferase at 6, 24, and 48 hours after reperfusion were significantly lower in the polyamine group compared with those in the vehicle group. Polyamine treatment reduced the expression of several proinflammatory cytokines and chemokines at 6 hours after reperfusion. Histological analysis showed significantly less necrosis and apoptosis in the polyamine group at 6 hours after reperfusion. Sinusoidal endothelial cells were also well preserved in the polyamine group. In addition, the regeneration of the remnant liver at 24, 48, and 168 hours after reperfusion was significantly accelerated, and the Ki-67 labeling index and the expressions of proliferating cell nuclear antigen and phosphorylated retinoblastoma protein at 24 hours after reperfusion were significantly higher in the polyamine group compared with those in the vehicle group. In conclusion, perioperative oral polyamine administration attenuates liver IRI and promotes liver regeneration. It might be a new therapeutic option to improve the outcomes of partial LT. Liver Transplantation 22 1231-1244 2016 AASLD. PMID:27102080

  19. Borax counteracts genotoxicity of aluminum in rat liver.

    PubMed

    Turkez, Hasan; Geyikoğlu, Fatime; Tatar, Abdulgani

    2013-10-01

    This study was carried out to evaluate the protective role of borax (BX) on genotoxicity induced by aluminum (Al) in rat liver, using liver micronucleus assay as an indicator of genotoxicity. Sprague-Dawley rats were randomly separated into six groups and each group had four animals. Aluminum chloride (AlCl₃; 5 mg/kg b.w.) and BX (3.25 and 13 mg/kg b.w.) were injected intraperitoneally to rats. Besides, animals were also treated with Al for 4 consecutive days followed by BX for 10 days. Rats were anesthetized after Al and BX injections and the hepatocytes were isolated for counting the number of micronucleated hepatocytes (MNHEPs). AlCl₃ was found to significantly (p < 0.05) increase the number of MNHEPs. Rats treated with BX, however, showed no increase in MNHEPs. Moreover, simultaneous treatments with BX significantly modulated the genotoxic effects of AlCl₃ in rats. It can be concluded that BX has beneficial influences and has the ability to antagonize Al toxicity. PMID:22491726

  20. Effects of monocrotaline on energy metabolism in the rat liver.

    PubMed

    Mingatto, Fábio Erminio; Maioli, Marcos Antonio; Bracht, Adelar; Ishii-Iwamoto, Emy Luiza

    2008-11-10

    Monocrotaline (MCT) is a pyrrolizidine alkaloid present in the plants of the Crotalaria species that causes cytotoxicity and genotoxicity in animals and humans, and it is hepatically metabolized to the alkylating agent dehydromonocrotaline by cytochrome P-450. The exact cellular and molecular mechanisms of MCT-induced tissue injury remain unclear. We previously demonstrated that dehydromonocrotaline, but not monocrotaline, inhibits the activity of NADH-dehydrogenase at micromolar concentrations in isolated liver mitochondria, an effect associated with significantly reduced ATP synthesis. Impairment of energy metabolism is expected to lead to several alterations in cell metabolism. In this work, the action of different concentrations of monocrotaline (250, 500, and 750microM) on energy metabolism-linked parameters was investigated in isolated perfused rat livers. In the fed state, monocrotaline increased glycogenolysis and glycolysis, whereas in the livers of fasted rats, it decreased gluconeogenesis and urea synthesis from l-alanine. These metabolic alterations were only found in livers of phenobarbital-treated rats, indicating that active metabolites including dehydromonocrotaline were responsible for the observed activity. Our findings indicate that hepatic metabolic changes may be implicated, partly at least, in the hepatotoxicity of monocrotaline in animals and humans. PMID:18835426

  1. [Reperfusion injury in the isolated rat liver after hypothermic preservation].

    PubMed

    Kopecký, M; Balás, P; Semecký, V; Tilser, I; Rouchalová, E

    2002-03-01

    Histological changes which appear as a result of reperfusion injury of cold-preserved rat liver were studied at intervals of 0 hr, 3 hr, 24 hr and 48 hr of cold storage. The isolated livers were stored in a UW solution (University of Wisconsin), which is used in human liver transplantations. Computer image analysis of light microscopic sections (methyl green-pyronin stained) was used for the study and quantification of injured cells. The method of TUNEL was performed to prove possible apoptosis of sinusoidal endothelial cells and heptocytes. Bile production during reperfusion and ALT, AST, LDH and ACP were measured in the reperfusion medium at the end of the 90 min reperfusion. It has been confirmed that prolongation of the cold storage of liver results in extensive changes in the liver structure and increased injury of liver cells. Sinusoidal endothelial cells were damaged more and earlier than hepatocytes. It has been shown that methyl green-pyronin stained sections are advantageous for the study of these morphological changes, allowing the strongest view of these changes. The appearance of TUNEL positive cells and an increase in the levels of biochemical parameters, e.g. AST or ALT, indicate earlier cell injury. The methodology described in this article can be used for the study of reperfusion injury of the liver and for the study of this phenomenon in other experiments. PMID:11928282

  2. Paracrine renal endothelin system in rats with liver cirrhosis.

    PubMed Central

    Hocher, B.; Zart, R.; Diekmann, F.; Rohmeiss, P.; Distler, A.; Neumayer, H. H.; Bauer, C.; Gross, P.

    1996-01-01

    1. Liver cirrhosis was induced in rats by CCl4 administration. We analysed the expression of endothelin receptor subtypes in the renal cortex and medulla using Scatchard analysis and receptor autoradiography, and measured plasma as well as renal-tissue endothelin-1 concentrations using a specific radioimmunoassay. Furthermore, we analysed the effects of the non-selective (A/B) endothelin receptor antagonist, bosentan (6 and 100 mg kg-1 day-1) on mean arterial blood pressure, water and sodium excretion and glomerular filtration rate. 2. Our study revealed an overexpression of the endothelin B receptor (ETB) in the renal medulla of rats with liver cirrhosis (Cir: 2775 +/- 299 fmol mg-1; Con: 1695 +/- 255 fmol mg-1; n = 8; means +/- s.d., P < 0.01), whereas the density of ETB in the cortex and the endothelin A receptor (ETA) in the cortex and medulla were similar in both cirrhotic and control rats. Receptor autoradiography showed that the upregulation of medullary ETB in cirrhotic rats was due to an upregulation of ETB in the inner medullary collecting duct cells. 3. The tissue endothelin-1 concentrations were increased in the renal medulla of cirrhotic rats (Cir: 271 +/- 68 pg g-1wet wt.; Con: 153 +/- 36 pg g-1 wet wt., n = 8; means +/- s.d., P < 0.01). 4. The glomerular filtration rate was slightly decreased in cirrhotic rats but not altered after bosentan treatment in either cirrhotic or control rats. Bosentan decreased sodium excretion to a similar extent in both cirrhotic and control rats, whereas water excretion was significantly reduced by both dosages of bosentan in cirrhotic rats only (Cir + vehicle: 12.5 +/- 0.62 m day-1, Cir + 6 mg kg-1 day-1 bosentan: 8.6 +/- 1.0 ml day-1; Cir + 100 mg kg-1 day-1 bosentan: 7.4 +/- 0.6 ml day-1; n = 10; means +/- s.e.mean). 5. We therefore suggest that the upregulation of the medullary ETB in cirrhotic rats is involved in the regulation of water excretion in rats with CCl4-induced liver cirrhosis. Images Figure 1 Figure 5

  3. Deferoxamine alleviates liver fibrosis induced by CCl4 in rats.

    PubMed

    Mohammed, Aya; Abd Al Haleem, Ekram N; El-Bakly, Wesam M; El-Demerdash, Ebtehal

    2016-08-01

    Several chronic liver diseases can lead to the occurrence of hepatic fibrosis through the accumulation of iron, which causes induction of oxidative stress and consequently activation of fibrogenesis. The present study was designed to investigate the potential antifibrotic and anti-oxidant effects of deferoxamine (DFO), a well-known iron chelator in an experimental rat model of liver injury using carbon tetrachloride (CCl4 ). First, the potential effective dose of DFO was screened against CCl4 -induced acute hepatotoxicity. Then, rats were co-treated with DFO (300 mg/kg, i.p.) for 6 weeks starting from the third week of CCl4 induction of chronic hepatotoxicity. Liver function was assessed in addition to histopathological examination. Furthermore, oxidative stress and fibrosis markers were assessed. It was found that treatment of animals with DFO significantly counteracted the changes in liver function; histopathological lesions and hepatic iron deposition that were induced by CCl4 . DFO also significantly counteracted the CCl4 -induced lipid peroxidation increase and reduction in antioxidant activities of superoxide dismutase and glutathione peroxidase enzymes. In addition, DFO ameliorated significantly liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cells (HSCs) activation marker; alpha smooth muscle actin and transforming growth factor-beta (TGF-β). Together, these findings indicate that DFO possesses a potent antifibrotic effect due to its antioxidant properties that counteracted oxidative stress and lipid peroxidation and restored antioxidant enzymes activities as well as reducing HSCs activation and fibrogenesis. PMID:27168353

  4. Caffeic acid phenethyl ester inhibits liver fibrosis in rats

    PubMed Central

    Li, Mei; Wang, Xiu-Fang; Shi, Juan-Juan; Li, Ya-Ping; Yang, Ning; Zhai, Song; Dang, Shuang-Suo

    2015-01-01

    AIM: To investigate the hepatoprotective effects and antioxidant activity of caffeic acid phenethyl ester (CAPE) in rats with liver fibrosis. METHODS: A total of 75 male Sprague-Dawley rats were randomly assigned to seven experimental groups: a normal group (n = 10), a vehicle group (n = 10), a model group (n = 15), a vitamin E group (n = 10), and three CAPE groups (CAPE 3, 6 and 12 mg/kg, n = 10, respectively). Liver fibrosis was induced in rats by injecting CCl4 subcutaneously, feeding with high fat forage, and administering 30% alcohol orally for 10 wk. Concurrently, CAPE (3, 6 and 12 mg/kg) was intraperitoneally administered daily for 10 wk. After that, serum total bilirubin (TBil), aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured to assess hepatotoxicity. To investigate antioxidant activity of CAPE, malondialdehyde (MDA), glutathione (GSH) levels, catalase (CAT) and superoxide dismutase (SOD) activities in liver tissue were determined. Moreover, the effect of CAPE on α-smooth muscle actin (α-SMA), a characteristic hallmark of activated hepatic stellate cells (HSCs), and NF-E2-related factor 2 (Nrf2), a key transcription factor for antioxidant systems, was investigated by immunohistochemistry. RESULTS: Compared to the model group, intraperitoneal administration of CAPE decreased TBil, ALT, and AST levels in liver fibrosis rats (P < 0.05), while serum TBil was decreased by CAPE in a dose-dependent manner. In addition, the liver hydroxyproline contents in both the 6 and 12 mg/kg CAPE groups were markedly lower than that in the model group (P < 0.05 and P < 0.001, respectively). CAPE markedly decreased MDA levels and, in turn, increased GSH levels, as well as CAT and SOD activities in liver fibrosis rats compared to the model group (P < 0.05). Moreover, CAPE effectively inhibited α-SMA expression while increasing Nrf2 expression compared to the model group (P < 0.01). CONCLUSION: The protective effects of CAPE against liver

  5. Uptake of free choline by isolated perfused rat liver.

    PubMed Central

    Zeisel, S H; Story, D L; Wurtman, R J; Brunengraber, H

    1980-01-01

    The uptake of free choline by isolated perfused rat liver was characterized. A saturable uptake mechanism [Ka = 0.17 +/- 0.07 mM (SD); Vmax = 0.84 +/- 0.16 mumol/min X g dry weight] and a nonsaturable mechanism (through which uptake is proportional to choline concentration in the perfusate) were identified. Most of the choline transported into hepatocytes was converted to betaine, phosphorylcholine, or lecithin. Free choline also accumulated within the intracellular space, suggesting that choline oxidase activity does not always limit choline's uptake by the liver. PMID:6933493

  6. Role of cysteinyl-leukotrienes for portal pressure regulation and liver damage in cholestatic rat livers.

    PubMed

    op den Winkel, Mark; Gmelin, Leonore; Schewe, Julia; Leistner, Natalie; Bilzer, Manfred; Göke, Burkhard; Gerbes, Alexander L; Steib, Christian J

    2013-12-01

    Kupffer cells (KCs) have a major role in liver injury, and cysteinyl-leukotrienes (Cys-LTs) are known to be involved as well. The KC-mediated pathways for the production and secretion of Cys-LT in cholestatic liver injury have not yet been elucidated. Here, we hypothesized that KC activation by Toll-like receptor ligands results in Cys-LT-mediated microcirculatory alterations and liver injury in acute cholestasis. We hypothesized further that this situation is associated with changes in the secretion and production of Cys-LT. One week after bile duct ligation (BDL), livers showed typical histological signs of cholestatic liver injury. Associated microcirculatory disturbances caused increased basal and maximal portal pressure following KC activation. These differences were determined in BDL livers compared with sham-operated livers in vivo (KC activation by LPS 4 mg/kg b.w.) and in isolated perfused organs (KC activation by Zymosan A, 150 μg/ml). Treatment with the 5-lipoxygenase inhibitor MK-886 alone did not alter portal perfusion pressure, lactate dehydrogenase (LDH) efflux, or bile duct proliferation in BDL animals. Following KC activation, portal perfusion pressure increased. The degree of cell injury was attenuated by MK-886 (3 μM) treatment as estimated by LDH efflux. In normal rats, a large amount of Cys-LT efflux was found in the bile. Only a minor amount was found in the effluent perfusate. In BDL livers, the KC-mediated Cys-LT efflux into the sinusoidal system increased, although the absolute Cys-LT level was still grossly lower than the biliary excretion in sham-operated livers. In conclusion, our results indicate that treatment with Cys-LT inhibitors might be a relevant target for attenuating cholestatic liver damage. PMID:24061287

  7. Correlation of virtual touch tissue quantification and liver biopsy in a rat liver fibrosis model.

    PubMed

    Hu, Zhiwen; Luo, Jialun; Wei, Hongqin; Ou, Wencai; Xiao, Shuyi; Gan, Man; Ma, Suihong; He, Jingguang; Wu, Daihong; Feng, Guiying; Wei, Jinglu; Liu, Jianhua

    2015-05-01

    Liver fibrosis assessment is very important to the treatment of chronic liver disease. In the present study, Virtual Touch Tissue Quantification (VTQ) and eSie Touch™ elasticity imaging techniques were used to examine the rat liver fibrosis model. Rat liver fibrosis was induced with thioacetamide and the degree of liver fibrosis was determined using pathological diagnosis as a gold standard. The right lobe of the liver was also examined with the VTQ and eSie Touch™ techniques. The VTQ and serological results were correlated and analyzed. The results were compared with those obtained from liver biopsies to investigate the accuracy and diagnostic value of eSie Touch™ and VTQ on the classification of liver fibrosis in rats. A total of 30 successful modeling cases were obtained, with a success rate of 86%. The mean acoustic radiation force impulse (ARFI) elastography‑VTQ values were 1.08, 1.51, 1.88 and 2.50 m/sec for the normal and F1/F2, F3 and F4 fibrosis groups, respectively. A significant correlation (r = 0.969) was identified between the ARFI measurements and the degree of fibrosis assessed by pathological examination (P<0.001). The histological staging results correlated with those of the eSie Touch™ elasticity imaging of the biopsy site (r = 0.913, P<0.001). The predictive values of ARFI for various stages of fibrosis were as follows: F≥1 and 2 ‑ cut‑off >1.250 m/sec (when Vs >1.250 m/sec, the pathological grading was ≥F1/F2) [Area under receiver operating characteristic (AUROC) = 1.00], F≥3 ‑ cut‑off >1.685 m/sec (when Vs >1.685 m/sec, the pathological grading was ≥F3; AUROC = 1.00) and F≥4 ‑ cut‑off >2.166 m/sec (when Vs >2.166 m/sec, the pathological grading is cirrhosis; AUROC = 1.00). In conclusion, the eSie Touch™ elasticity imaging and VTQ techniques may be successfully adopted to assess the extent of liver stiffness. These techniques are expected to replace liver biopsy. PMID:25592825

  8. Characterization and subcellular distribution of somatogenic receptor in rat liver

    SciTech Connect

    Husman, B.; Andersson, G.; Norstedt, G.; Gustafsson, J.A.

    1985-06-01

    Binding of (/sup 125/I)iodobovine GH ((/sup 125/I)iodo-bGH) to rat liver microsomes and Golgi/endosomal fractions isolated from male and female rats has been characterized. Binding of bGH to a pure somatogenic site was suggested by the finding that 50% inhibition of (/sup 125/I)iodo-bGH binding required 5-130 ng bGH, rGH, or hGH/incubation, while around 500 ng rat PRL/incubation were needed to obtain the same effect. Binding of (/sup 125/I)iodo-bGH to microsomes and Golgi/endosomes was time, temperature, and protein dependent. Maximal specific binding occurred at 15-16 and 15-20 h at 22 C in Golgi and microsomal membranes, respectively. Subcellular distribution studies demonstrated in the Golgi/endosomal fractions compared to the total particulate fraction, while residual microsomes devoid of Golgi/endosomal-derived components were approximately 2-fold enriched. Low levels of somatogenic receptors were detected in lysosome-enriched fractions. Removal of endogenous ligand by treating Golgi/endosomal membranes with 3M MgCl/sub 2/ increased specific binding of bGH about 2- to 3-fold. These results indicate that approximately 50% of specific somatogenic binding sites in the low density fractions represent internalized ligand-receptor complexes. The level of rat liver somatogenic receptors did not show a pronounced sex differentiation; however, an endocrine dependence of somatogenic receptor levels is suggested by the finding that livers from rats in the late stages of pregnancy had a level of somatogenic receptors exceeding that of nonpregnant rats.

  9. Recruitment of Host Progenitor Cells in Rat Liver Transplants

    PubMed Central

    Sun, Zhaoli; Zhang, Xiuying; Locke, Jayme E.; Zheng, Qizhi; Tachibana, Shingo; Diehl, Anna Mae; Williams, George Melville

    2015-01-01

    Despite MHC incompatibility, Lewis to DA rat liver transplants survive indefinitely without immunosuppression, and the studies we report sought the mechanism(s) responsible for this. At one year most of the liver reacted positively to host anti-DA antibody. When small (50%) grafts were transplanted, recruitment was more rapid as most of the organ assumed the host phenotype at 3 months. After transplantation the Y-chromosome was detected in the hepatocytes of XX to XY grafts by both in-situ hybridization and PCR. Further, livers from transgenic Lewis rats carrying strong GFP markers lost the marker with time after transplantation to DA, GFP− hosts. Few liver cells contained the Y chromosome in syngeneic XX to XY liver grafts or when the hosts of Lewis XX to DA XY allografts were treated with cyclosporine A (CsA) 10mgs/kg/day. This dosage also impeded enlargement of the liver at ten days. Using GFP+ XX Lewis donors transplanted to GFP− XY DA hosts, we found little Y DNA in GFP+ cells at 10 days. Host derived OV-6 and c-kit positive, albumen positive cells were present at 3-10 days, but cells with the CD34 marker were less common and some clearly still had the donor phenotype at ten days. CXCR-4 positive cells increased with time and were abundant at 1 month after transplantation. We conclude: 1. extra-hepatic cells can differentiate into liver tissues; 2. regenerative stimuli accelerate stem cell recruitment; 3. both regeneration and recruitment are impeded by CsA immunosuppression, and 4. donor GFP positive cells contained little host Y-chromosome after transplantation suggesting that cell fusion was uncommon and, therefore, unlikely to be the mechanism leading to the changes in genotype and phenotype we observed. PMID:18972402

  10. Amelioration of radiation-induced liver damage in partially hepatectomized rats by hepatocyte transplantation.

    PubMed

    Guha, C; Sharma, A; Gupta, S; Alfieri, A; Gorla, G R; Gagandeep, S; Sokhi, R; Roy-Chowdhury, N; Tanaka, K E; Vikram, B; Roy-Chowdhury, J

    1999-12-01

    Hepatic tumors often recur in the liver after surgical resection. Postoperative radiotherapy (RT) could improve survival, but curative RT may induce delayed life-threatening radiation-induced liver damage. Because RT inhibits liver regeneration, we hypothesized that unirradiated, transplanted hepatocytes would proliferate preferentially in a partially resected and irradiated liver, providing metabolic support. We subjected F344 rats to hepatic RT and partial hepatectomy with/without a single intrasplenic, syngeneic hepatocyte transplantation. Hepatocyte transplantation ameliorated radiation-induced liver damage and improved survival of rats receiving RT after partial hepatectomy. We further demonstrated that transplanted hepatocytes extensively repopulate and function in a heavily irradiated rat liver. PMID:10606225

  11. Intestinal ischemic preconditioning reduces liver ischemia reperfusion injury in rats

    PubMed Central

    XUE, TONG-MIN; TAO, LI-DE; ZHANG, JIE; ZHANG, PEI-JIAN; LIU, XIA; CHEN, GUO-FENG; ZHU, YI-JIA

    2016-01-01

    The aim of the current study was to investigate whether intestinal ischemic preconditioning (IP) reduces damage to the liver during hepatic ischemia reperfusion (IR). Sprague Dawley rats were used to model liver IR injury, and were divided into the sham operation group (SO), IR group and IP group. The results indicated that IR significantly increased Bax, caspase 3 and NF-κBp65 expression levels, with reduced expression of Bcl-2 compared with the IP group. Compared with the IR group, the levels of AST, ALT, MPO, MDA, TNF-α and IL-1 were significantly reduced in the IP group. Immunohistochemistry for Bcl-2 and Bax indicated that Bcl-2 expression in the IP group was significantly increased compared with the IR group. In addition, IP reduced Bax expression compared with the IR group. The average liver injury was worsened in the IR group and improved in the IP group, as indicated by the morphological evaluation of liver tissues. The present study suggested that IP may alleviates apoptosis, reduce the release of pro-inflammatory cytokines, ameloriate reductions in liver function and reduce liver tissue injury. To conclude, IP provided protection against hepatic IR injury. PMID:26821057

  12. Casein kinase II stimulates rat liver mitochondrial glycerophosphate acyltransferase activity.

    PubMed

    Onorato, Thomas M; Haldar, Dipak

    2002-09-01

    Rat liver mitochondrial glycerophosphate acyltransferase (mtGAT) possesses 14 consensus sites for casein kinase II (CKII) phosphorylation. To study the functional relevance of phosphorylation to the activity of mtGAT, we treated isolated rat liver mitochondria with CKII and found that CKII stimulated mtGAT activity approximately 2-fold. Protein phosphatase-lambda treatment reversed the stimulation of mtGAT by CKII. Labeling of both solubilized and non-solubilized mitochondria with CKII and [gamma-32P]ATP resulted in a 32P-labeled protein of 85kDa, the molecular weight of mtGAT. Our findings suggest that CKII stimulates mtGAT activity by phosphorylation of the acyltransferase. The significance of this observation with respect to hormonal control of the enzyme is discussed. PMID:12207885

  13. Effect of irradiation and endogenous nucleases on rat liver chromatin

    SciTech Connect

    Gelderblom, D.; Smit, B.J.; Boehm, L.

    1984-08-01

    The assessment of the consequences of irradiation on chromatin is complicated by endogenous nucleases. Isolation and prolonged storage of rat liver nuclei in buffers containing divalent metal ions activates these enzymes and promotes the degradation of chromatin. Irradiation of rat liver nuclei to dose levels of 20,000 rad under conditions in which endogenous nucleases are inhibited and analysis of the irradiated chromatin by sucrose density gradient centrifugation gave no evidence for monosomes or oligosomes. When chromatin from irradiated nuclei was digested with micrococcal nuclease, the levels of monosomes and oligosomes were identical to those of micrococcal nuclease digests of unirradiated control nuclei. These results suggest that irradiation results in neither a direct fragmentation of linkers nor the sensitization of linkers for subsequent cleavage by micrococcal nuclease.

  14. Clearance of Immunoreactive Somatostatin by Perfused Rat Liver

    PubMed Central

    Sacks, Harold; Terry, L. Cass

    1981-01-01

    Other investigators have demonstrated that concentrations of immunoreactive somatostatin (IRS) are higher in blood from the hepatic portal vein or its tributaries than in blood from the hepatic or peripheral systemic veins of man and animals. This suggests that there is hepatic extraction of IRS from the portal system in vivo. In the rat, portal vein plasma IRS is reported to be heterogeneous and to contain, in part, a 1,600 mol wt form of IRS which is immunochemically similar to synthetic somatostatin and not significantly bound to high molecular weight plasma protein. Our study was undertaken to determine directly whether unbound synthetic cyclic somatostatin was cleared by the rat liver perfused through the hepatic portal vein in vitro with a recirculating, plasma-free, erythrocyte-containing perfusate. At 37°C and pH 7.40, perfusate IRS, at initial concentrations (1,728 pg/ml) within the range previously reported in rat portal venous blood, was removed by the liver at a rate commensurate with first-order kinetics. Hepatic clearance was 0.84±0.04 ml/min per g postperfusion wet weight (SE). Hepatic extraction was 36±2%, and t½ was 20.0±1.3 min. Recovery of IRS from the perfusate without the liver was >85%, excluding significant degradation by the medium. Clearance, extraction, and t½ of IRS were not changed by an unphysiologic IRS concentration (621,500 pg/ml), or by pharmacologic concentrations of insulin (8.2 μM) or glucagon (2.9 μM). The t½ was prolonged significantly to 28.2±1.9 and 45.6±4.7 min during perfusions at liver temperatures of 25° and 16°C, respectively. At 37°C, the t½ was also significantly increased to 28.7±3.2 and 24.2±1.1 min at perfusate pH 7.06 and 6.78, respectively. These studies indicate that the rat liver clears unbound IRS from the perfusate by a first-order kinetic process that is (a) unsaturable at pharmacologic concentrations, (b) temperature-sensitive and, to a lesser extent, influenced by lowered pH, and (c) not

  15. METABOLIC PROPERTIES OF ISOLATED RAT LIVER CELL PREPARATIONS ENRICHED IN EPITHELIAL CELLS OTHER THAN HEPATOCYTES

    EPA Science Inventory

    A selected fraction of non-parenchymal cells was prepared from the liver of untreated rats, of rats 11-13 days after ligation of the common bile duct, and of rats fed for 4-5 weeks a choline devoid diet containing DL-ethionine. The cell fraction isolated from these livers consist...

  16. Impact of fluoxetine on liver damage in rats.

    PubMed

    Inkielewicz-Stępniak, Iwona

    2011-01-01

    Fluoxetine (Flux) is a fluorine-containing drug that selectively inhibits serotonin reuptake. It is widely prescribed as a treatment for depression disorders. Hepatic side effects have been reported during Flux therapy. These reports led us to investigate the involvement of oxidative stress mechanisms in liver injury caused by Flux. It has been shown that exposure to fluoride (F(-)) induces excessive production of free radicals and affects the antioxidant defense system. Based on this knowledge, we examined the F(-) concentration in serum and urine during administration of Flux. In our study, the effects of one month of Flux treatment on lipid and protein peroxidation, the concentration of uric acid in the liver and the activity of transaminases and transferases in the serum were investigated in rats. Eighteen adult male Wistar rats were divided into three equal groups of six animals each: (I) controls who drank tap water and received 1 ml of tap water intragastrically; (II) animals that received 8 mg Flux/kg bw/day intragastrically; and (III) animals that received 24 mg Flux/kg bw/day intragastrically. Flux treatment increased of the levels of carbonyl groups, thiobarbituric acid reactive species (TBARS) and the uric acid content in the liver. The activities of alanine transaminase (ALT), aspartate transaminase (AST) and glutathione-S transferase (GST) increased in the serum of the treated groups. The Flux levels in the plasma of the treated rats increased significantly in a dose-dependent manner. We observed no changes in the concentration of fluoride in either the serum or the urine of treated rats compared to the control group. In conclusion, our study indicates that Flux induces liver damage and mediates free radical reactions. Our data also indicate that Flux does not release F(-) during metabolism and does not affect physiological levels of F(-) in the serum or urine. PMID:21602599

  17. Determination of boron distribution in rat's brain, kidney and liver.

    PubMed

    Pazirandeh, Ali; Jameie, Behnam; Zargar, Maysam

    2009-07-01

    To determine relative boron distribution in rat's brain, liver and kidney, a mixture of boric acid and borax, was used. After transcardial injection of the solution, the animals were sacrificed and the brain, kidney and liver were removed. The coronal sections of certain areas of the brain were prepared by freezing microtome. The slices were sandwiched within two pieces of CR-39. The samples were bombarded in a thermal neutron field of the TRR pneumatic facility. The alpha tracks are registered on CR-39 after being etched in NaOH. The boron distribution was determined by counting these alpha tracks CR-39 plastics. The distribution showed non-uniformity in brain, liver and kidney. PMID:19375929

  18. Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

    SciTech Connect

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

    1986-03-05

    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 /sup 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 ..cap alpha..-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes.

  19. Epigenetic changes in the rat livers induced by pyrazinamide treatment

    SciTech Connect

    Kovalenko, V.M.; Bagnyukova, T.V.; Sergienko, O.V.; Bondarenko, L.B.; Shayakhmetova, G.M.; Matvienko, A.V.; Pogribny, I.P.

    2007-12-15

    Drug-induced liver injury, including drug-induced hepatotoxicity during the treatment of tuberculosis infection, is a major health problem with increasingly significant challenges to modern hepatology. Therefore, the assessment and monitoring of the hepatotoxicity of antituberculosis drugs for prevention of liver injury are great concerns during disease treatment. The recently emerged data showing the ability of toxicants, including pharmaceutical agents, to alter cellular epigenetic status, open a unique opportunity for early detection of drug hepatotoxicity. Here we report that treatment of male Wistar rats with antituberculosis drug pyrazinamide at doses of 250, 500 or 1000 mg/kg/day body weight for 45 days leads to an early and sustained decrease in cytosine DNA methylation, progressive hypomethylation of long interspersed nucleotide elements (LINE-1), and aberrant promoter hypermethylation of placental form glutathione-S-transferase (GSTP) and p16{sup INK4A} genes in livers of pyrazinamide-treated rats, while serum levels of bilirubin and activity of aminotransferases changed modestly. The early occurrence of these epigenetic alterations and their association with progression of liver injury specific pathological changes indicate that alterations in DNA methylation may be useful predictive markers for the assessment of drug hepatotoxicity.

  20. Vasoactive intestinal peptide receptors in rat liver after partial hepatectomy.

    PubMed Central

    Guijarro, L G; Couvineau, A; Rodriguez-Pena, M S; Juarranz, M G; Rodriguez-Henche, N; Arilla, E; Laburthe, M; Prieto, J C

    1992-01-01

    We describe the status of vasoactive intestinal peptide (VIP) receptors in regenerating liver. VIP-stimulated adenylate cyclase activity was markedly decreased in proliferating liver 3 days after partial (70%) hepatectomy. This was associated with a reduced efficacy of VIP (53% compared with controls), with no change in the potency of the peptide (ED50 0.8 nM). In contrast, forskolin- and guanosine 5'-[beta gamma-imido]triphosphate (Gpp[NH]p)-stimulated enzyme activities were not decreased after hepatectomy. The expression of Gs protein subunits (alpha and beta) was studied by cholera toxin-catalysed ADP ribosylation of alpha s and by immunoblotting of alpha s and beta subunits. Both subunits were increased in regenerating liver, further suggesting that the decreased response to VIP was not related to a decreased expression of Gs proteins. In fact, the reduced adenylate cyclase response to VIP in regenerating liver was associated with quantitative and structural changes in VIP receptors. Equilibrium binding data obtained with 125I-VIP indicated the presence of two classes of binding sites, the Kds of which were not altered after hepatectomy. In contrast, changes in binding capacity (Bmax.) were as follows: 0.11 +/- 0.01 and 0.05 +/- 0.01 pmol/mg of protein for high-affinity sites in control and hepatectomized rats respectively; and 2.3 +/- 0.2 and 0.65 +/- 0.03 pmol/mg of protein for low-affinity sites in control and hepatectomized rats respectively. Moreover, affinity labelling experiments showed that the M(r) value of 125I-VIP-receptor complexes was higher in regenerating liver than in quiescent hepatocytes, e.g. 58,000 and 53,000 respectively. It is concluded that VIP receptors are altered in regenerating liver, resulting in a decreased response of adenylate cyclase to the neuropeptide. Images Fig. 3. Fig. 4. Fig. 6. PMID:1322136

  1. The Need to Handicap the Recipient's Native Liver in the Rat Model of Heterotopic Auxiliary Liver Transplantation

    PubMed Central

    Praet, Marleen; De Hemptinne, Bernard

    1999-01-01

    In the rat model of heterotopic auxiliary liver transplantation (HALTx), the opinion varies on whether and how the recipient's native liver should be handicapped. To avoid atrophy of the transplanted organ, in this study, two different handicaps were evaluated and their effects on post-operative animal survival and liver biology are described. With a sole portacaval shunt (group 1) all rats survived longer than 3 months. An additional handicap of the liver with either a 68% partial hepatectomy (68% PH) (group 2), or both a 68% PH and a common bile duct ligation (CBDL) (group 3) led to a 100% mortality within 2 days after surgery. When an auxiliary liver was transplanted to the rats handicapped with a 68% PH (group 4), serum Bilirubin and ALAT values were significantly lower than those handicapped with both a 68% PH and a CBDL (group 5). Autopsy and histology of the long-term survivors revealed the atrophy of the engrafted livers and the regeneration of the native livers in group 4, whereas it showed the opposite in group 5. Thus the various manipulations of the native liver do influence differently the post-transplant animal survival, serum liver biochemistry and the outcome of the engrafted liver in this rat model of HALTx. PMID:10468113

  2. Molecular responses of radiation-induced liver damage in rats

    PubMed Central

    CHENG, WEI; XIAO, LEI; AINIWAER, AIMUDULA; WANG, YUNLIAN; WU, GE; MAO, RUI; YANG, YING; BAO, YONGXING

    2015-01-01

    The aim of the present study was to investigate the molecular responses involved in radiation-induced liver damage (RILD). Sprague-Dawley rats (6-weeks-old) were irradiated once at a dose of 20 Gy to the right upper quadrant of the abdomen. The rats were then sacrificed 3 days and 1, 2, 4, 8 and 12 weeks after irradiation and rats, which were not exposed to irradiation were used as controls. Weight measurements and blood was obtained from the rats and liver tissues were collected for histological and apoptotic analysis. Immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were performed to measure the expression levels of mRNAs and proteins, respectively. The serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were increased significantly in the RILD rats. Histological investigation revealed the proliferation of collagen and the formation of fibrotic tissue 12 weeks after irradiation. Apoptotic cells were observed predominantly 2 and 4 weeks after irradiation. The immunohistochemistry, RT-qPCR and western blot analysis all revealed the same pattern of changes in the expression levels of the molecules assessed. The expression levels of transforming growth factor-β1 (TGF-β1), nuclear factor (NF)-κB65, mothers against decapentaplegic homolog 3 (Smad3) and Smad7 and connective tissue growth factor were increased during the recovery period following irradiation up to 12 weeks. The expression levels of tumor necrosis factor-α, Smad7 and Smad4 were only increased during the early phase (first 4 weeks) of recovery following irradiation. In the RILD rat model, the molecular responses indicated that the TGF-β1/Smads and NF-κB65 signaling pathways are involved in the mechanism of RILD recovery. PMID:25483171

  3. Phosphoenolpyruvate carboxykinase and pyruvate carboxylase in developing rat liver

    PubMed Central

    Ballard, F. J.; Hanson, R. W.

    1967-01-01

    1. Phosphoenolpyruvate carboxykinase and pyruvate carboxylase were measured in foetal, newborn and adult rat liver extracts by a radiochemical assay involving the fixation of [14C]bicarbonate. 2. Pyruvate-carboxylase activity in both foetal and adult liver occurs mainly in mitochondrial and nuclear fractions, with about 10% of the activity in the cytoplasm. 3. Similar studies of the intracellular distribution of phosphoenolpyruvate carboxykinase show that more than 90% of the activity is in the cytoplasm. However, in the 17-day foetal liver about 90% of the activity is in mitochondria and nuclei. 4. Pyruvate-carboxylase activity in both particulate and soluble fractions is very low in the 17-day foetal liver and increases to near adult levels before birth. 5. Phosphoenolpyruvate-carboxykinase activity in the soluble cell fraction increases 25-fold in the first 2 days after birth. This same enzyme in the mitochondria has considerable activity in the foetal and adult liver and is lower in the newborn. 6. Kinetic and other studies on the properties of phosphoenolpyruvate carboxykinase have shown no differences between the soluble and mitochondrial enzymes. 7. It is suggested that the appearance of the soluble phosphoenolpyruvate carboxykinase at birth initiates the rapid increase in overall gluconeogenesis at this stage. PMID:6049928

  4. The Dimethylnitrosamine Induced Liver Fibrosis Model in the Rat.

    PubMed

    Chooi, Kum Fai; Kuppan Rajendran, Dinesh Babu; Phang, Siew Siang Gary; Toh, Han Hui Alden

    2016-01-01

    Four to six week old, male Wistar rats were used to produce animal models of liver fibrosis. The process requires four weeks of administration of 10 mg/kg dimethylnitrosamine (DMN), given intraperitoneally for three consecutive days per week. Intraperitoneal injections were performed in the fume hood as DMN is a known hepatoxin and carcinogen. The model has several advantages. Firstly, liver changes can be studied sequentially or at particular stages of interest. Secondly, the stage of liver disease can be monitored by measurement of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzymes. Thirdly, the severity of liver damage at different stages can be confirmed by sacrifice of animals at designated time points, followed by histological examination of Masson's Trichome stained liver tissues. After four weeks of DMN dosing, the typical fibrosis score is 5 to 6 on the Ishak scale. The model can be reproduced consistently and has been widely used to assess the efficacy of potential anti-fibrotic agents. PMID:27340889

  5. Differential Sympathetic Vasomotor Activation Induced by Liver Cirrhosis in Rats

    PubMed Central

    Bergamaschi, Cássia T.; Campos, Ruy R.

    2016-01-01

    We tested the hypothesis that there is a topographical sympathetic activation in rats submitted to experimental cirrhosis. Baseline renal (rSNA) and splanchnic (sSNA) sympathetic nerve activities were evaluated in anesthetized rats. In addition, we evaluated main arterial pressure (MAP), heart rate (HR), and baroreceptor reflex sensitivity (BRS). Cirrhotic Wistar rats were obtained by bile duct ligation (BDL). MAP and HR were measured in conscious rats, and cardiac BRS was assessed by changes in blood pressure induced by increasing doses of phenylephrine or sodium nitroprusside. The BRS and baseline for the control of sSNA and rSNA were also evaluated in urethane-anesthetized rats. Cirrhotic rats had increased baseline sSNA (BDL, 102 vs control, 58 spikes/s; p<0.05), but no baseline changes in the rSNA compared to controls. These data were accompanied by increased splanchnic BRS (p<0.05) and decreased cardiac (p<0.05) and renal BRS (p<0.05). Furthermore, BDL rats had reduced basal MAP (BDL, 93 vs control, 101 mmHg; p<0.05) accompanied by increased HR (BDL, 378 vs control, 356; p<0.05). Our data have shown topographical sympathetic activation in rats submitted to experimental cirrhosis. The BDL group had increased baseline sSNA, independent of dysfunction in the BRS and no changes in baseline rSNA. However, an impairment of rSNA and HR control by arterial baroreceptor was noted. We suggest that arterial baroreceptor impairment of rSNA and HR is an early marker of cardiovascular dysfunction related to liver cirrhosis and probably a major mechanism leading to sympathoexcitation in decompensated phase. PMID:27055088

  6. "Cold training" affects rat liver responses to continuous cold exposure.

    PubMed

    Venditti, Paola; Napolitano, Gaetana; Barone, Daniela; Di Meo, Sergio

    2016-04-01

    Continuous exposure of homeothermic animals to low environmental temperatures elicits physiological adaptations necessary for animal survival, which are associated to higher generation of pro-oxidants in thermogenic tissues. It is not known whether intermittent cold exposure (cold training) is able to affect tissue responses to continuous cold exposure. Therefore, we investigated whether rat liver responses to continuous cold exposure of 2 days are modified by cold training (1h daily for 5 days per week for 3 consecutive weeks). Continuous cold increased liver oxidative metabolism by increasing tissue content of mitochondrial proteins and mitochondrial aerobic capacity. Cold training did not affect such parameters, but attenuated or prevented the changes elicited by continuous cold exposure. Two-day cold exposure increased lipid hydroperoxide and protein-bound carbonyl levels in homogenates and mitochondria, whereas cold training decreased such effects although it decreased only homogenate protein damage in control rats. The activities of the antioxidant enzymes GPX and GR and H2O2 production were increased by continuous cold exposure. Despite the increase in GPX and GR activities, livers from cold-exposed rats showed increased susceptibility to in vitro oxidative challenge. Such cold effects were decreased by cold training, which in control rats reduced only H2O2 production and susceptibility to stress. The changes of PGC-1, NRF-1, and NRF-2 expression levels were consistent with those induced by cold exposure and cold training in mitochondrial protein content and antioxidant enzyme activities. However, the mechanisms by which cold training attenuates the effects of the continuous cold exposure remain to be elucidated. PMID:26808664

  7. 7-alpha-hydroxylation of cholestanol by rat liver microsomes.

    PubMed

    Shefer, S; Hauser, S; Mosbach, E H

    1968-05-01

    In a study of the mechanism whereby 5alpha-bile acids are formed from cholestanol, the 7alpha-hydroxylation of cholestanol was investigated in rat liver preparations in vitro. It was found that in the presence of NADPH and oxygen, rat liver microsomes catalyzed the 7alpha-hydroxylation of cholestanol to the same extent as that of cholesterol. The rate of the hydroxylation was enhanced by prior treatment of the experimental rats with cholestyramine (a bile acid sequestrant) or by establishment of bile fistulas-i.e., by partial or complete removal of bile acids from the enterohepatic circulation. The 7-hydroxylation reaction was further stimulated by pretreatment of the animals with phenobarbital, a drug known to produce increased biosynthesis of hepatic endoplasmic membranes. The 7alpha-hydroxylase was inhibited by the reaction product, by sterols with 7-keto or 7beta-hydroxyl groups, and also by mono- and dihydroxy bile acids of the 5beta-series, although cholic acid or taurocholate produced no inhibition unless added in high concentrations. The results of these studies are in accord with the concept that the presence of a Delta(5)-double bond is not required for the enzymatic formation of the 7alpha-hydroxy derivative. The rate of this hydroxylation reaction in vitro appears to depend on the concentration of bile salts in the enterohepatic circulation of the experimental animals from whom the microsomes were obtained. PMID:5650927

  8. Effect of Anoectochilus formosanus on fibrosis and regeneration of the liver in rats.

    PubMed

    Shih, Chun-Ching; Wu, Yueh-Wern; Hsieh, Chang-Chi; Lin, Wen-Chuan

    2004-09-01

    1. The present study examined the effects of an aqueous extract of Anoectochilus formosanus (AFE) on both hepatic fibrosis and regeneration in rats. 2. Fibrosis was induced by intraperitoneal injection of dimethylnitrosamine (DMN) for 3 consecutive days per week for 4 weeks. 3. In DMN-treated rats, liver cirrhosis-associated complications, such as liver atrophy, low concentrations of serum albumin and the accumulation of hepatic collagen, were observed. The AFE protected the liver against DMN-induced fibrosis, as determined by morphological and biochemical observations. 4. In addition, AFE was administered to two-thirds hepatectomized normal and DMN-injured rats. Three and 5 days after hepatectomy, AFE increased the extent of liver weight regeneration and the number of S-phase cells in DMN-injured rats, but not in normal rats. 5. These results show that AFE seems to be useful in the repair of liver injury, improvement of fibrotic changes and promotion of liver regeneration. PMID:15479170

  9. The Metabolism and Toxicity of Menthofuran in Rat Liver Slices and in Rats

    PubMed Central

    Khojasteh, S. Cyrus; Oishi, Shimako; Nelson, Sidney D.

    2010-01-01

    Menthofuran is a monoterpene present in mint plants that is oxidized by mammalian cytochrome P450 (CYP)1 to hepatotoxic metabolites. Evidence has been presented that p-cresol and other unusual oxidative products are metabolites of menthofuran in rats, and that p-cresol may be responsible in part for the hepatotoxicity caused by menthofuran (Madyastha and Raj, Drug Metabolism and Disposition 20, 295–301, 1992). In the present study, several oxidative metabolites of menthofuran were characterized in rat and human liver microsomes, and in rat liver slices exposed to cytotoxic concentrations of menthofuran. Metabolites that were identified were monohydroxylation products of the furanyl and cyclohexyl groups, mintlactones and hydroxymintlactones, a reactive γ-ketoenal, and a glutathione conjugate. A similar spectrum of metabolites was found in urine 24 hr after the administration of hepatotoxic doses of menthofuran to rats. In no case was p-cresol (or any of the other reported unusual oxidative metabolites of menthofuran) detected above background concentrations that were well below concentrations of p-cresol that cause cytotoxicity in rat liver slices. Thus, the major metabolites responsible for the hepatotoxic effects of menthofuran appear to be a γ-ketoenal and/or epoxides formed by oxidation of the furan ring. PMID:20945912

  10. Prostaglandin uptake and metabolism by the perfused rat liver

    PubMed Central

    Dawson, W.; Jessup, Sheila J.; McDonald-Gibson, Wendy; Ramwell, P. W.; Shaw, Jane E.

    1970-01-01

    1. The prostaglandins are C20 unsaturated fatty acids which exhibit diverse physiological effects of short duration. We have investigated the speed of removal of PGE1 and PGF1α from the circulating blood and their subsequent metabolism by the isolated perfused rat liver. 2. Following either a single injection of radiolabelled PGE1 or PGF1α into the hepatic artery or portal vein, or recirculation of prostaglandins through the liver for 2·5 h, the distribution of radioactivity within extracts of bile, blood and liver was determined. The nature of the radioactive products of meta-bolism was inferred by comparison of the distribution of radioactivity after injecting carbon and tritium labelled standards, and by thin-layer chromatography, gas-liquid chromatography, ultraviolet and bioassay analysis. 3. A single injection of 1-14C PGE1 indicated that the liver could efficiently remove 89-95% of circulating PGE1 on a single passage. Biliary excretion was excluded as a major route for elimination of unchanged PGE1, because only 0·3-0·8% of the injected radioactivity was detected in the bile. During recirculation of 1-14C PGE1, 11-19% of the injected radioactivity was detected as exchanged 14CO2. The radioactivity detected within liver was identified with further fragments resulting from decarboxylation of PGE1, which were incorporated into fatty acids and then phospholipids. 4. Studies with 5,6-3H PGE1, and comparison with the results obtained using 1-14C PGE1, revealed a 30-fold increase in the percentage of radioactivity excreted into the bile, suggesting that biliary excretion may be a major route for elimination of compounds smaller than C20 prostaglandin. Evidence that the cyclopentane ring was intact was inferred by formation of a PGB compound on treatment with alkali; similar biliary excretion of 9-3H PGF1α also occurred. In addition, the increased radioactivity detected within the liver (37%) and blood (43%) after a single injection of 5,6-3H PGE1 had the

  11. Monitoring of intracellular free calcium in perfused rat liver.

    PubMed

    Ruttner, Z; Ligeti, L; Reinlib, L; Hines, K; McLaughlin, A C

    1993-06-01

    Fluorescent calcium indicators have been widely used to assess cytoplasmic calcium concentration in cells. To examine the role of calcium ions on different physiological functions (e.g. in case of liver; bile secretion, glucose metabolism, etc.) there is a need for whole organ studies. We have developed a technique to estimate intracellular free calcium changes in perfused rat liver. Krebs-Henseleit perfused livers were loaded with 7 microM or 35 microM Indo-1/AM. An area 3 mm in diameter and approximately 300 microns in depth was illuminated at 340 nm. Fluorescence was monitored with photomultiplier tubes at 3 wavelengths (400 nm for Ca-bound dye, 504 nm for free dye and 464 nm for NADH). The viability of liver preparations was assessed by measurement of the concentrations of lactate dehydrogenase and alanine aminotransferase in the effluent. Loading of the livers with 7 microM Indo-1/AM via the portal vein resulted in a 5-fold increase of fluorescence at 400 nm. However the dye 'leaked' out of the liver with a half-time of 18 min. Probenecid (a specific anion carrier blocker) inhibited loss of dye in a dose dependent fashion (2.5-10 mM). Transient calcium elevations were observed in response to vasopressin (5-50 nM) at physiological levels, ethanol (0.3-0.8 M) and the calcium ionophore, ionomycin. Certain limitations were apparent with this approach: (1) it was necessary to use an anion carrier blocker to maintain a relatively steady dye concentration; (2) endogenous NADH fluorescence interfered with the calcium signal; and (3) absolute values of calcium concentration could not be determined. PMID:8358770

  12. Hepatoprotective Activity of Heptoplus on Isoniazid and Rifampicin Induced Liver Damage in Rats

    PubMed Central

    Sankar, M.; Rajkumar, Johanna; Sridhar, Dorai

    2015-01-01

    The present study is designed to evaluate the efficacy of heptoplus a polyherbal formulation as an oral supplementary agent for isoniazid and rifampicin induced hepatotoxicity in rats. 50 and 100 mg/kg of heptoplus supplement were fed orally to the rats along with isoniazid and rifampicin and compared to rats treated with 100 mg/kg Liv 52 standard drug. Rats treated with isoniazid and rifampicin suffered from severe oxidative stress by the virtue of free radicals induced lipid per oxidation. As a result abnormal index of serum biochemical markers for liver function and increased liver lysosomal enzymes activity was observed. However rats nourished with 100 mg/kg of heptoplus and Liv 52 protected the liver from oxidative damage by maintaining normal antioxidant profile status and restored normal serum liver biochemical markers. Increased liver lysosomal enzymes activity is prevented in the rats supplemented with heptoplus and Liv 52. Histopathological analysis also revealed severe vascular changes and lobular necrosis in the treatment of isoniazid and rifampicin. Heptoplus (100 mg/kg) and Liv 52 supplemented rats liver apparently revealed normal architecture of liver. This study confirms that heptoplus has liver protective activity against Isoniazid and Rifampicin induced liver injury in rats, in par with Liv 52. PMID:26798170

  13. Metabolic and structural studies on serum- and liver-glycosaminoglycans in normal and liver-injured rats.

    PubMed

    Gressner, A M; Köster-Eiserfunke, W; Van de Leur, E; Greiling, H

    1980-05-01

    The incorporation of [35S]sulfate into total and specific types of serum glycosaminoglycans was studied in rats with acute, subacute or chronic liver injury (liver cirrhosis), and compared with that of normal rats. The macromolecular (protein-bound) nature of serum glycosaminoglycans in normal and diseased animals was also analysed. The results show a strong increase in rate and extent of [35S]sulfate incorporation into total serum glycosaminoglycans for acutely but a decrease for subacutely and chronically liver damaged rats. The time-course of distribution of label between serum chondroitin sulfate and dermatan sulfate exhibits significant changes in liver-injured animals, in particular a relatively high proportion of dermatan [35S]sulfate in rats with cirrhotic livers. In comparison with serum glycosaminoglycans the labeling profile of glycosaminoglycans in the cirrhotic liver was quite different (heparan sulfate:dermatan sulfate:chondroitin sulfate = 1:0.34:0.09) and changed only insignificantly during a 1 h labeling period. The protein-bound moiety of serum glycosaminoglycans was not affected by liver disease; but the elution profile of chondroitin [35S]sulfate from Dowex 1 X 2 for treated rats was altered, thus indicating a structural modification of its carbohydrate chain. PMID:7430957

  14. Histopathological changes in rat liver after a single high dose of aluminium.

    PubMed

    Bogdanović, Milka; Janeva, Ana Begić; Bulat, Petar

    2008-06-01

    Aluminium (Al) exposure may affect the liver of experimental animals. This investigation aimed at evaluating morphological changes in rat liver after a single high dose of Al (as metallic powder suspension). A total of forty female Wistar rats were divided in one exposed and one control group, 20 rats each. The exposed rats received 0.5 mL of sterile physiological suspension of fine Al powder in the concentration of 100 mg mL-1 intraperitoneally (50 mg Al per rat). After 7 weeks all animals were killed (by exsanguination from the abdominal aorta in ether anaesthesia). Liver aluminium was analysed using electrothermal atomic absorption spectrometry. For light microscopy the liver tissue was stained with hematoxylin and eosin, and for histochemical analysis with aurin threecarbocsillic acid (aluminon). Liver Al level was markedly higher in the exposed (37.1 microg g-1) than in control rats (0.71 microg g-1). The exposed rats showed crystalloid Al inclusions in the capsular, subcapsular, and portal liver tissue. The basic liver structure remained intact. Slightly multiplied bile ductuli were found in 16 of 20 exposed and in 8 of 20 control rats. Three exposed rats had mycrovesicular steatosis. The peritoneum and Glisson's capsule showed strong macrophage infiltration and a foreign-body-like reaction with multiple giant macrophages containing Al crystalloid inclusions. Although this reaction was a defense against the metal, some Al passed this barrier and entered the liver tissue, exerting toxic effects in bile ductuli and hepatocytes. PMID:18573746

  15. Early biochemical alterations induced by 2-acetylaminofluorene in rat liver.

    PubMed

    Elliott, W L; Sawick, D P; Creek, K E; Deutscher, S L; Quinn, J F; Yeo, E; Webb, W R; Morré, D M; Harrington, D D; Heinstein, P F

    1984-01-01

    Livers from rats fed the carcinogen 2-acetylaminofluorene (AAF) were analyzed at weekly or semiweekly intervals to correlate appearance of enzymatic markers in total liver homogenates with histochemical events accompanying formation of hyperplastic liver nodules. gamma-Glutamyltranspeptidase (gamma-GT)-positive foci appeared by day 11 and visible nodules were present by days 28-35. Specific activity of homogenate gamma-GT increased in parallel to formation of hyperplastic foci and nodules, declined and then rose again to 20-fold that of controls by day 77. Specific activity of ornithine decarboxylase increased in advance of that of gamma-GT, to a level of 8-fold above control during the period of formation of hyperplastic foci. An early response was a 2-fold rise in the specific activity of nucleoside diphosphate phosphatase during the first week of carcinogen administration. The specific activity of 5'-nucleotidase, known to increase during liver regeneration, declined as the animals aged and was not increased by the dietary AAF. The enzymatic alterations induced by AAF could not be mimicked by cell proliferation, diet stress or the hepatotoxicity induced by feeding 1.87% 4-acetamidophenol. PMID:6148271

  16. Compartmentation between glycolysis and gluconeogenesis in rat liver

    PubMed Central

    Threlfall, C. J.; Heath, D. F.

    1968-01-01

    1. The specific radioactivity–time relationships of glucose, glucose 6-phosphate, glycerol 1-phosphate and UDP-glucose were determined in rat liver after the intravenous injection of [U-14C]fructose, and a kinetic analysis was carried out. The glucose 6-phosphate pool was found to be compartmented into gluconeogenic and glycolytic components, and evidence was obtained that the triose phosphates were similarly compartmented. The glycolytic pathway was fed by glycogenolysis and glucose phosphorylation. There was no direct evidence that glycogenolysis fed only the glycolytic pathway, but this interpretation would make the liver resemble other organs in this respect. 2. UDP-glucose was not formed solely from gluconeogenic glucose 6-phosphate, as there was some dilution of label in the intervening glucose 1-phosphate pool, probably from glycogenolysis, though other pathways cannot be excluded. 3. The data cannot be explained by isotopic exchange. PMID:5726210

  17. Effect of cobalt chloride on content of lipids and lipoproteins in serum and liver of rats.

    PubMed

    Kaliman, P A; Shalamov, R V; Zagaiko, A L

    1997-07-01

    Lipids and the composition of lipoproteins in blood serum and liver cytosol, total lipid, and phospholipid contents in liver subcellular fractions and the spectrum of microsomal liver lipids were studied in male Wistar rats after a single injection of cobalt chloride. Virtually all lipid and lipoprotein fractions in blood and liver were increased and lipoprotein composition was changes. The lipid composition of liver microsomes did not change under these conditions. Thus, microsomal membranes are stable under developing oxidative stress. PMID:9331964

  18. Lactoferrin Enhanced Apoptosis and Protected Against Thioacetamide-Induced Liver Fibrosis in Rats

    PubMed Central

    Hessin, Alyaa; Hegazy, Rehab; Hassan, Azza; Yassin, Nemat; Kenawy, Sanaa

    2015-01-01

    BACKGROUND: Liver fibrosis is the common pathologic consequence of all chronic liver diseases. AIM: Lactoferrin (Lf) was investigated for its possible hepatoprotective effect against thioacetamide (TAA)-induced liver fibrosis rat model. MATERIAL AND METHODS: Rats received TAA (200 mg/kg/biweekly, ip) for four successive weeks. Lf (200 mg/kg/day, p.o.) or vehicle (VHC) was administered for one month before and another month during TAA injection. Body weight and mortality rate were assessed during the month of TAA-intoxication. Thereafter, serum and liver tissues were analyzed for liver function, oxidative, fibrotic and apoptotic markers. RESULTS: Lf conserved rats against TAA-induced body weight-loss and mortality. Preservation of serum albumin, alkaline phosphatase and total bilirubin levels was also observed. Lf also protected rats against TAA-induced decrease in reduced glutathione and increase in malondialdehyde liver contents. Normal liver contents of hydroxyproline, nuclear factor kappa B and alpha fetoprotein; as markers of fibrosis; were increased with TAA and conserved with Lf-TAA. Lf maintained the normal architecture of the liver and immunohistochemical findings revealed increase in apoptotic bodies compared to TAA that favored necrosis. CONCLUSION: In conclusion, Lf improved liver function, reduced oxidative stress and liver fibrosis, and enhanced apoptosis in rats with liver fibrosis, suggesting it to have useful therapeutic potential in patients with liver fibrosis. PMID:27275221

  19. Purification and photoaffinity labelling of lipid methyltransferase from rat liver.

    PubMed Central

    Pajares, M A; Alemany, S; Varela, I; Marin Cao, D; Mato, J M

    1984-01-01

    An enzyme that catalyses the three-step methylation of phosphatidylethanolamine to phosphatidylcholine as well as the methylation of fatty acids and that uses S-adenosylmethionine as the methyl donor has been purified about 200-fold from rat liver. Irradiation of the purified enzyme with a short-wavelength u.v. light in the presence of [methyl-3H]8-azido-S-adenosylmethionine followed by electrophoresis results in the incorporation of radioactivity into a single protein band of about 25 kDa. It is concluded that a single catalytic subunit catalyses the conversion of phosphatidylethanolamine into phosphatidylcholine and fatty acid methylation. Images Fig. 4. PMID:6497846

  20. Glycyrrhetinic acid-induced permeability transition in rat liver mitochondria.

    PubMed

    Salvi, Mauro; Fiore, Cristina; Armanini, Decio; Toninello, Antonio

    2003-12-15

    Glycyrrhetinic acid, a hydrolysis product of one of the main constituents of licorice, the triterpene glycoside of glycyrrhizic acid, when added to rat liver mitochondria at micromolar concentrations induces swelling, loss of membrane potential, pyridine nucleotide oxidation, and release of cytochrome c and apoptosis inducing factor. These changes are Ca(2+) dependent and are prevented by cyclosporin A, bongkrekic acid, and N-ethylmaleimide. All these observations indicate that glycyrrhetinic acid is a potent inducer of mitochondrial permeability transition and can trigger the pro-apoptotic pathway. PMID:14637195

  1. Xanthine oxidase status in ethanol-intoxicated rat liver.

    PubMed

    Abbondanza, A; Battelli, M G; Soffritti, M; Cessi, C

    1989-12-01

    The status of xanthine oxidase in ethanol-induced liver injury has been investigated in the rat, by acute and chronic ethanol treatments. A 38% increase of the enzyme O-form was observed after repeated ethanol administration. Chronic intoxication caused a significant decrease of total xanthine oxidase activity after both prolonged ethanol feeding and life span ethanol ingestion. The intermediate D/O-form of xanthine oxidase (that can act either as an oxidase or as a dehydrogenase, being able to react with O2 as well as with NAD+ as electron acceptor) increased 5.5-fold after prolonged ethanol feeding. PMID:2690670

  2. Stabilization and purification of tyrosine aminotransferase from rat liver.

    PubMed

    Hargrove, J L

    1990-01-01

    Purification of unmodified tyrosine aminotransferase from rat liver requires that the activity of cathepsin T be minimized, and that losses of enzyme due to dilution or oxidation by prevented. The enzyme was stabilized by pyridoxal 5'-phosphate, dithiothreitol, and potassium phosphate, but was destabilized by L-tyrosine or L-glutamate. A rapid, efficient method for purification of this enzyme included the following steps: twenty-fold induction with a high-casein diet plus dexamethasone phosphate administered in the drinking water; a heat step (65 degrees C) followed by precipitation from 0.20 M sucrose at pH 5.0; and small-scale chromatography on DEAE-cellulose, hydroxyapatite and CM-Sephadex C50 at pH 6.0. These steps yielded more than 10 mg of native enzyme from 35 rats, with a recovery of 68% of the initial activity. PMID:1973296

  3. Mistletoe alkali inhibits peroxidation in rat liver and kidney

    PubMed Central

    Shi, Zheng-Ming; Feng, Ping; Jiang, Dong-Qiao; Wang, Xue-Jiang

    2006-01-01

    AIM: To explore the antioxidant and free radical scavenger properties of mistletoe alkali (MA). METHODS: The antioxidant effect of mistletoe alkali on the oxidative stress induced by carbon tetrachloride (CCl4) in rats was investigated. The rats were divided into four groups (n = 8): CCl4-treated group (1 mL/kg body weight), MA -treated group (90 mg/kg), CCl4+MA-treated group and normal control group. After 4 wk of treatment, the level of malondialdehyde (MDA), a lipid peroxidation product (LPO) was measured in serum and homogenates of liver and kidney. Also, the level of glutathione (GSH), and activities of glutathione reductase (GR), glutathione peroxidase (GSPx), superoxide dismutase (SOD), and glutathione-S-transferase (GST) in liver and kidney were determined. Scavenging effects on hydroxyl free radicals produced in vitro by Fenton reaction were studied by ESR methods using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap reagent and H2O2/UV as the OH· source. Urinary 8-hydroxydeoxyguanosine (8-OHdG) was determined by competitive ELISA. RESULTS: In CCl4-treated group, the level of LPO in serum of liver and kidney was significantly increased compared to controls. The levels of GSH and enzyme activities of SOD, GSPx and GR in liver and kidney were significantly decreased in comparison with controls. In CCl4+MA-treated group, the changes in the levels of LPO in serum of liver and kidney were not statistically significant compared to controls. The levels of SOD, GSPx and GR in liver and kidney were significantly increased in comparison with controls. There was a significant difference in urinary excretion of 8-OHdG between the CCl4-treated and MA-treated groups. CONCLUSION: Oxidative stress may be a major mechanism for the toxicity of CCl4. MA has a protective effect against CCl4 toxicity by inhibiting the oxidative damage and stimulating GST activities. Thus, clinical application of MA should be considered in cases with carbon tetrachloride-induced injury

  4. Protective Role of Phyllanthus niruri Extract against Thioacetamide-Induced Liver Cirrhosis in Rat Model

    PubMed Central

    Amin, Zahra A.; Bilgen, Mehmet; Alshawsh, Mohammed A.; Ali, Hapipah M.; Hadi, A. Hamid A.; Abdulla, Mahmood A.

    2012-01-01

    A preclinical study was performed to determine if the extract from Phyllanthus niruri (PN) plays a protective role against liver cirrhosis induced by thioacetamide (TAA) in rats. Initially, acute toxicity was tested and the results showed that the extract was benign when applied to healthy rats. Next, the therapeutic effect of the extract was investigated using five groups of rats: control, TAA, silymarin, and PN high dose and low dose groups. Significant differences were observed between the TAA group and the other groups regarding body and liver weights, liver biochemical parameters, total antioxidant capacity, lipid peroxidation, and oxidative stress enzyme levels. Gross visualization indicated coarse granules on the surface of the hepatotoxic rats' livers, in contrast to the smoother surface in the livers of the silymarin and PN-treated rats. Histopathological analysis revealed necrosis, lymphocytes infiltration in the centrilobular region, and fibrous connective tissue proliferation in the livers of the hepatotoxic rats. But, the livers of the treated rats had comparatively minimal inflammation and normal lobular architecture. Silymarin and PN treatments effectively restored these measurements closer to their normal levels. Progression of liver cirrhosis induced by TAA in rats can be intervened using the PN extract and these effects are comparable to those of silymarin. PMID:22649471

  5. Noninvasive Blood Perfusion Measurements of an Isolated Rat Liver and an Anesthetized Rat Kidney

    PubMed Central

    Mudaliar, Ashvinikumar V.; Ellis, Brent E.; Ricketts, Patricia L.; Lanz, Otto I.; Lee, Charles Y.; Diller, Thomas E.; Scott, Elaine P.

    2008-01-01

    A simple, cost effective, and noninvasive blood perfusion system is tested in animal models. The system uses a small sensor to measure the heat transfer response to a thermal event (convective cooling) imposed on the tissue surface. Heat flux data are compared with a mathematical model of the tissue to estimate both blood perfusion and thermal contact resistance between the tissue and the probe. The perfusion system was evaluated for repeatability and sensitivity using isolated rat liver and exposed rat kidney tests. Perfusion in the isolated liver tests was varied by controlling the flow of the perfusate into the liver, and the perfusion in the exposed kidney tests was varied by temporarily occluding blood flow through the renal artery and vein. The perfusion estimated by the convective perfusion probe was in good agreement with that of the metered flow of the perfusate into the liver model. The liver tests indicated that the probe can be used to detect small changes in perfusion (0.005 ml/ml/s). The probe qualitatively tracked the changes in the perfusion in the kidney model due to occlusion of the renal artery and vein. PMID:19045542

  6. Long-term fatty liver-induced insulin resistance in orotic acid-induced nonalcoholic fatty liver rats.

    PubMed

    Han, Xiuqing; Liu, Chunhua; Xue, Yong; Wang, Jingfeng; Xue, Changhu; Yanagita, Teruyoshi; Gao, Xiang; Wang, Yuming

    2016-04-01

    We investigated whether fatty liver preceded insulin resistance or vice versa using a long-term orotic acid (OA)-induced nonalcoholic fatty liver disease (NAFLD) model without the confounding effects of obesity and hyperlipidemia and explored the role of the liver in insulin resistance. Male Wistar rats were fed with or without OA supplementation for 30, 60, and 90 days. The NAFLD group showed increased liver lipid at 30, 60, and 90 days; glucose intolerance was noted at 60 and 90 days. Furthermore, partial liver proteins and gene expressions related to upstream signaling of insulin were decreased. However, the liver glycogen content was elevated, and gluconeogenesis genes expressions were obviously decreased at 90 days. The occurrence of fatty liver preceded insulin resistance in OA-induced NAFLD without the interference of obesity and hyperlipidemia, and hepatic insulin resistance may not play a conclusive role in insulin resistance in this model. PMID:26775542

  7. Resveratrol inhibits nonalcoholic fatty liver disease in rats

    PubMed Central

    Bujanda, Luis; Hijona, Elizabeth; Larzabal, Mikel; Beraza, Marta; Aldazabal, Pablo; García-Urkia, Nerea; Sarasqueta, Cristina; Cosme, Angel; Irastorza, Belen; González, Alberto; Arenas, Juan I

    2008-01-01

    Background The prevalence of nonalcoholic fatty liver disease (NAFLD) is high. NAFLD is linked to obesity, diabetes mellitus, and hypertriglyceridemia. Approximately 20% of patients with NAFLD will eventually develop cirrhosis. Our purpose was to investigate whether resveratrol decreased hepatic steatosis in an animal model of steatosis, and whether this therapeutic approach resulted in a decrease in tumor necrosis factor α (TNF-α) production, lipid peroxidation and oxidative stress. Methods Male Wistar CRL: Wi (Han) (225 g) rats were randomized into three groups. A control group (n = 12) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 12) and resveratrol (n = 12) groups were given free access to feed (a high carbohydrate-fat free modified diet) and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. Rats in the resveratrol group were given resveratrol 10 mg daily by the oral route. All rats were killed at 4 weeks and assessed for fatty infiltration and bacterial translocation. Levels of TNF-α in serum, hepatic malondialdehyde (MDA), oxidative stress (superoxide dismutase, glutathione peroxidase, catalase and nitric oxide synthase) and biochemical parameters were measured. Results Fat deposition was decreased in the resveratrol group as compared to the steatosis group (Grade 1 vs Grade 3, P < 0.05). TNF-α and MDA levels were significantly increased in the steatosis group (TNF-α; 33.4 ± 5.2 vs 26.24 ± 3.47 pg/ml and MDA; 9.08 ± 0.8 vs 3.17 ± 1.45 μM respectively, P < 0.05). This was accompanied by increased superoxide dismutase, glutathione peroxidase and catalase and decreased nitric oxide synthase in the liver of resveratrol group significantly (P < 0.05 vs steatosis group). Bacterial translocation was not found in any of the groups. Glucose levels were decreased in the group of rats given resveratrol (P < 0.05). Conclusion Resveratrol decreased NAFLD severity in rats. This effect was mediated, at least

  8. Multiple chromatographic forms of ATP citrate lyase from rat liver.

    PubMed Central

    Corrigan, A P; Rider, C C

    1983-01-01

    ATP citrate lyase is shown to exist as multiple forms in extracts of rat liver. DEAE-Sephadex ion-exchange chromatography of liver supernatants reveals two peaks of activity. A minor, basic, component, comprising 14% of the recovered activity, is eluted without retention, whereas the major, acidic, form is eluted by a KCl gradient. Gel filtration of similar extracts shows the presence of a high-Mr form of ATP citrate lyase (Mr around 10(7) in addition to the tetrameric enzyme (Mr 4.1 X 10(5). This associated state, which represents 10% of the total activity, is unstable, breaking down to the tetramer, and appears to be disrupted by Mg2+. The basic form changes in the partially purified state to give the acidic form. Most of the high-Mr enzyme is acidic in nature. No evidence could be found for an association of the enzyme with mitochondrial or microsomal membranes. ATP citrate lyase from rat brain also shows two peaks of activity on DEAE-Sephadex ion-exchange chromatography, but the activity is distributed between the peaks in almost equal proportions. However, only the tetrameric enzyme was observed on gel filtration. PMID:6615476

  9. Enzymic oxidation of unconjugated bilirubin by rat liver.

    PubMed Central

    Cardenas-Vazquez, R; Yokosuka, O; Billing, B H

    1986-01-01

    The presence of the enzyme bilirubin oxidase, which degrades bilirubin in vitro, was demonstrated in the liver. Subcellular-fractionation experiments indicate that bilirubin oxidase is located in both the inner and outer membranes of the mitochondria. The mean rate of the reaction is 1.57 +/- 0.38 (S.D.) nmol of bilirubin degraded/min per mg of mitochondrial protein (munits/mg of protein). With respect to the overall breakdown of bilirubin, the enzyme has a Km' of 136 microM-bilirubin and a Vmax.' of 9.13 munits/mg of protein. Its activity is influenced by the ionic strength of the media and is inhibited by KCN, thiol reagents, NADH and albumin. The enzyme is aerobic, and between 1 and 1.5 mol of O2 are consumed per mol of bilirubin degraded. The products of the reaction include propentdyopents. The hepatic bilirubin oxidase activity of the jaundiced Gunn-rat liver is not significantly different from that of the Sprague-Dawley rat, and it is not induced by beta-naphthoflavone. PMID:3790083

  10. Purification of phospholipid methyltransferase from rat liver microsomal fraction.

    PubMed Central

    Pajares, M A; Villalba, M; Mato, J M

    1986-01-01

    Phospholipid methyltransferase, the enzyme that converts phosphatidylethanolamine into phosphatidylcholine with S-adenosyl-L-methionine as the methyl donor, was purified to apparent homogeneity from rat liver microsomal fraction. When analysed by SDS/polyacrylamide-gel electrophoresis only one protein, with molecular mass about 50 kDa, is detected. This protein could be phosphorylated at a single site by incubation with [alpha-32P]ATP and the catalytic subunit of cyclic AMP-dependent protein kinase. A less-purified preparation of the enzyme is mainly composed of two proteins, with molecular masses about 50 kDa and 25 kDa, the 50 kDa form being phosphorylated at the same site as the homogeneous enzyme. After purification of both proteins by electro-elution, the 25 kDa protein forms a dimer and migrates on SDS/polyacrylamide-gel electrophoresis with molecular mass about 50 kDa. Peptide maps of purified 25 kDa and 50 kDa proteins are identical, indicating that both proteins are formed by the same polypeptide chain(s). It is concluded that rat liver phospholipid methyltransferase can exist in two forms, as a monomer of 25 kDa and as a dimer of 50 kDa. The dimer can be phosphorylated by cyclic AMP-dependent protein kinase. Images Fig. 3. Fig. 4. Fig. 6. PMID:3800912

  11. Abate Cytochrome C induced apoptosome to protect donor liver against ischemia reperfusion injury on rat liver transplantation model

    PubMed Central

    Zhuang, Zhuonan; Lian, Peilong; Wu, Xiaojuan; Shi, Baoxu; Zhuang, Maoyou; Zhou, Ruiling; Zhao, Rui; Zhao, Zhen; Guo, Sen; Ji, Zhipeng; Xu, Kesen

    2016-01-01

    Objective: Aim of this study is to protect donor liver against ischemia-reperfusion injury by abating Cytochrome C induced apoptosome on rat model. Methods: A total of 25 clean SD inbred male rats were used in this research. The rats in ischemia-reperfusion injury group (I/R group, n=5) were under liver transplantation operation; rats in dichloroacetate diisopropylamine group (DADA group, n=5) were treated DADA before liver transplantation; control group (Ctrl group, n=5); other 10 rats were used to offer donor livers. Results: In DADA therapy group, Cytochrome C expression in donor hepatocellular cytoplasm was detected lower than that in I/R group. And the Cytochrome C induced apoptosome was also decreased in according to the lower expressions of Apaf-1 and Caspase3. Low level of cleaved PARP expression revealed less apoptosis in liver tissue. The morphology of donor liver mitochondria in DADA group was observed to be slightly edema but less than I/R group after operation 12 h. The liver function indexes of ALT and AST in serum were tested, and the results in DADA group showed it is significantly lower than I/R group after operation 12 h. The inflammation indexes of IL-6 and TNF-α expressions in DADA group were significantly lower than that in I/R group after operation 24 h. Conclusion: The dichloroacetate diisopropylamine treatment could protect the hepatocellular mitochondria in case of the spillage of Cytochrome C induced apoptosome, and protect the liver against ischemia-reperfusion injury. Thus, it may be a method to promote the recovery of donor liver function after transplantation. PMID:27186297

  12. Effective Prevention of Liver Fibrosis by Liver-targeted Hydrodynamic Gene Delivery of Matrix Metalloproteinase-13 in a Rat Liver Fibrosis Model.

    PubMed

    Abe, Hiroyuki; Kamimura, Kenya; Kobayashi, Yuji; Ohtsuka, Masato; Miura, Hiromi; Ohashi, Riuko; Yokoo, Takeshi; Kanefuji, Tsutomu; Suda, Takeshi; Tsuchida, Masanori; Aoyagi, Yutaka; Zhang, Guisheng; Liu, Dexi; Terai, Shuji

    2016-01-01

    Liver fibrosis is the final stage of liver diseases that lead to liver failure and cancer. While various diagnostic methods, including the use of serum marker, have been established, no standard therapy has been developed. The objective of this study was to assess the approach of overexpressing matrix metalloproteinase-13 gene (MMP13) in rat liver to prevent liver fibrosis progression. A rat liver fibrosis model was established by ligating the bile duct, followed by liver-targeted hydrodynamic gene delivery of a MMP13 expression vector, containing a CAG promoter-MMP13-IRES-tdTomato-polyA cassette. After 14 days, the serum level of MMP13 peaked at 71.7 pg/ml in MMP13-treated group, whereas the nontreated group only showed a level of ~5 pg/ml (P < 0.001). These levels were sustained for the next 60 days. The statistically lower level of the hyaluronic acids in treated group versus the nontreated group (P < 0.05) reveals the therapeutic effect of MMP13 overexpression. Quantitative analysis of tissue stained with sirius red showed a statistically larger volume of fibrotic tissue in the nontreated group compared to that of MMP13-treated rats (P < 0.05). These results suggest that the liver-targeted hydrodynamic delivery of MMP13 gene could be effective in the prevention of liver fibrosis. PMID:26730813

  13. Characteristics of chylomicron remnant uptake into rat liver.

    PubMed

    Huettinger, M; Retzek, H; Eder, M; Goldenberg, H

    1988-04-01

    We have investigated uptake of 125I-labeled chylomicron remnants into livers of rats in the presence of lactoferrin. This glycoprotein possesses a cluster of four arginines at the N-terminus similar to the arginine rich binding sequence of apoprotein E (apoE) to the LDL-receptor. We found that this protein inhibits uptake of 125I-chylomicron remnant radioactivity by 50% when measured as accumulation of radioactivity into the intact organ, and even more pronounced, over 75%, when measured as uptake into an endosomal fraction prepared therefrom. Provided that the arginine rich sequence is responsible for the inhibition, a similarity in the characteristics of binding of apoE to the LDL (low density lipoprotein)- and chylomicron remnant-receptor is likely. Second, transferrin having sequence homologies with lactoferrin, but lacking the arginine cluster does not interfere with chylomicron remnant uptake. Third, lactoferrin does not inhibit the uptake of chylomicron remnants by the spleen, which is most likely mediated through scavenger cells by a mechanism different from the chylomicron remnant uptake system of the liver. We hypothesize from this that lactoferrin specifically interferes with the physiologically relevant chylomicron remnant uptake system of the liver. Investigation of the mechanism of this inhibition will provide information about the physical characteristics of the remnant receptor system. PMID:3390901

  14. Guanine deaminase inhibitor from rat liver. Isolation and characterization.

    PubMed

    Ali, S; Sitaramayya, A; Kumar, K S; Krishnan, P S

    1974-01-01

    1. An inhibitor of cytoplasmic guanine deaminase of rat liver was isolated from liver ;heavy mitochondrial' fraction after freezing and thawing and treatment with Triton X-100. 2. Submitochondrial fractionation revealed that the inhibitor was localized in the outer-membrane fraction. 3. The method of purification of inhibitor, involving precipitation with (NH(4))(2)SO(4) and chromatography on DEAE-cellulose, its precipitability by trichloroacetic acid and the pattern of absorption in the u.v. indicated that the inhibitor was a protein. In confirmation, tryptic digestion of the isolated material resulted in destruction of the inhibitor activity. The inhibitor was stable to acid, but labile to heat. 4. The isolated inhibitor required phosphatidylcholine (lecithin) for activity. Phosphatidylcholine also partially protected the inhibitor against heat inactivation. 5. When detergent treatment was omitted, the inhibitor activity of frozen mitochondria was precipitated by (NH(4))(2)SO(4) in a fully active form without supplementation with phosphatidylcholine, indicating that Triton X-100 ruptured the linkage between inhibitor and lipid. 6. A reconstituted sample of inhibitor-phosphatidylcholine complex was precipitated in a fully active form by dialysis against 2-mercaptoethanol, but treatment of the precipitate with NaCl yielded an extract which was inactive unless supplemented with fresh phosphatidylcholine. 7. We interpret the results as evidence that the inhibitor was present in vivo as a lipoprotein and that once the complex was dissociated by the action of detergent and the protein precipitated, there was an absolute need for exogenous phosphatidylcholine for its activity. The manner in which inhibitor associated with the outer membrane of rat liver mitochondria might regulate the activity of the enzyme in the supernatant has been suggested. PMID:4821397

  15. Hormonal modulation of alpha-fetoprotein gene expression in newborn rat livers.

    PubMed Central

    Chiu, J F; Massari, R J; Schwartz, C E; Meisler, N T; Thanassi, J W

    1981-01-01

    Suppression of serum alpha-fetoprotein (AFP) levels in glucocorticoid treated newborn rats was investigated. Daily intraperitoneal injection of 2 micrograms/g body weight of dexamethasone into newborn rats greatly reduced the concentration of AFP in the serum and liver cytosol. In contrast, this treatment stimulated liver ornithine decarboxylase activity. The reduction in AFP levels is not due to a change of distribution of AFP molecular variants, inhibition of secretion of synthesized AFP by the liver or disruption of liver polysomes. Glucocorticoids decrease the AFP levels in hormone-treated rats by supressing the synthesis of AFP. The size of AFP polysomes isolated from the livers of dexamethasone-treated rats were as large as those from normal rats. However, the amount of AFP-producing polysomes in hormone-treated rat liver is only 14% of the controls. By hybridization assays, it was found that dexamethasone treated livers contained decreased amounts of AFP mRNA sequences in liver cytoplasmic and nuclear RNAs. The decreased amounts of AFP mRNA sequences in hormone-treated liver are caused by both a decrease in the rate of AFP mRNA transcription and in AFP mRNA stability. Images PMID:6174948

  16. Rhinacanthus nasutus Improves the Levels of Liver Carbohydrate, Protein, Glycogen, and Liver Markers in Streptozotocin-Induced Diabetic Rats

    PubMed Central

    Visweswara Rao, Pasupuleti; Madhavi, K.; Dhananjaya Naidu, M.; Gan, Siew Hua

    2013-01-01

    The present study was designed to investigate the total carbohydrate, total protein, and glycogen levels in the liver and to measure functional liver markers such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in streptozotocin-(STZ-) induced diabetic rats after treatment with methanolic extract of Rhinacanthus nasutus (R. nasutus). The methanolic extract of R. nasutus was orally administered at 200 mg/kg/day while glibenclamide was administered at 50 mg/kg/day. All animals were treated for 30 days before being sacrificed. The amounts of carbohydrate, glycogen, proteins, and liver markers (AST and ALT) were measured in the liver tissue of the experimental animals. The levels of carbohydrate, glycogen, and proteins were significantly reduced in the diabetic rats but were augmented considerably after 30 days of R. nasutus treatment. The elevated AST and ALT levels in diabetic rats showed a significant decline after treatment with R. nasutus for 30 days. These results show that the administration of R. nasutus ameliorates the altered levels of carbohydrate, glycogen, proteins, and AST and ALT observed in diabetic rats and indicate that R. nasutus restores overall metabolism and liver function in experimental diabetic rats. In conclusion, the outcomes of the present study support the traditional belief that R. nasutus could ameliorate the diabetic state. PMID:24204387

  17. Lipoprotein receptors in copper-deficient rats: high density lipoprotein binding to liver membranes

    SciTech Connect

    Hassel, C.A.; Lei, K.Y.; Marchello, J.A.

    1986-03-05

    In copper-deficient rats, the observed hyperlipoproteinemia was mainly due to the elevation in high density lipoproteins (HDL). This study was designed to determine whether an impairment in the binding of HDL to liver membrane is responsible for the hyperlipoproteinemia. Sixty male Sprague-Dawley rats were randomly divided into 2 treatments, namely copper (Cu) deficient and adequate (less than 1 and 8 mg Cu/kg of diet). After 8 weeks, plasma, heart and liver tissues were obtained. Reduction in liver Cu content and elevation in heart to body weight ratio and plasma cholesterol confirmed that rats fed the test diet were Cu-deficient. Plasma HDL isolated from both Cu-deficient and control rats were iodinated and bound to liver membranes prepared from rats of each treatment. Binding of /sup 125/I-HDL was competitively inhibited by unlabelled rat HDL from both treatments, but not by human LDL. Scatchard analysis of specific binding data showed that maximal /sup 125/I-HDL binding (per mg membrane protein) to membranes prepared from Cu-deficient rats was not lower than controls. Furthermore, the amount of /sup 125/I-HDL from deficient rats specifically bound to liver membranes prepared from either treatment was not less than the amount of /sup 125/I-HDL from control rats bound to the same membranes. The data suggest that the hyperlipoproteinemia in Cu-deficient rats may not have resulted from a decrease in the number of hepatic HDL binding sites.

  18. Regulation of Bile Salt Transport in Rat Liver

    PubMed Central

    Simon, Francis R.; Sutherland, Eileen M.; Gonzalez, Manuel

    1982-01-01

    Expansion of the bile salt pool size in rats increases maximum excretory capacity for taurocholate. We examined whether increased bile salt transport is due to recruitment of centrolobular transport units or rather to adaptive changes in the hepatocyte. Daily sodium cholate (100 mg/100 g body wt) was administered orally to rats. This treatment was well tolerated for at least 4 d and produced an 8.2-fold expansion of the bile salt pool. This expanded pool consisted predominently (99%) of cholic and deoxycholic acids. Significantly increased bile salt transport was not observed until 16 h after bile acid loading, and maximum elevations of transport capacity to 2.3-fold of control required ∼2 d. In contrast, maximum sulfobromophthalein excretion rates increased 2.2-fold as early as 4 h and actually fell to 1.5-fold increase at 4 d. We studied the possibility that this adaptive increase in bile salt secretory transport was due to changes in canalicular surface membrane area, lipid composition, or increased number of putative carriers. Canalicular membrane protein recovery and the specific activities of leucine aminopeptidase, Mg++-ATPase and 5′-nucleotidase activities were unaltered by bile salt pool expansion. The content of free and esterified cholesterol and total phospholipids was unchanged in liver surface membrane fractions compared with control values. In contrast, sodium cholate administration selectively increased specific [14C]cholic acid binding sites twofold in liver surface membrane fractions. Increased numbers of [14C]cholic acid receptors (a) was associated with the time-dependent increase in bile salt transport, and (b) was selective for the taurine conjugate of cholate and (c) was reduced by chenodeoxycholate. Changes in bile acid binding sites 16 h following taurocholate and chenodeoxycholate and the lack of change with glycocholate was associated with comparable changes in bile salt transport. In conclusion, selective bile salts increase bile

  19. Alcoholic fatty liver in rats: Role of fat and ethanol intake

    SciTech Connect

    Sankaran, H.; Deveney, C.W. ); Larkin, E.C.; Rao, G.A. )

    1991-03-11

    The claim that high intake of both ethanol and fat is essential to induce fatty liver and high blood alcohol levels (BAL) was tested. Two groups of rats were fed liquid diets containing 26% and 36% of calories as ethanol respectively. After 4 weeks, all rats were bled for BAL and some were sacrificed to obtain liver morphology. Remaining rats in Group 1 (26% ethanol) were switched to 36% ethanol diet and Group 2 (36% ethanol) to 26% ethanol diet. All rats were sacrificed after 4 weeks to obtain blood for BAL and liver morphology. The results indicate that high ethanol intake and high fat ingestion is not the criterion for induction of fatty liver. Inadequate ingestion of macronutrients plays a major role in alcoholic fatty liver and BAL.

  20. Marginal Copper Deficiency Increases Liver Neutrophil Accumulation After Ischemia/Reperfusion in Rats

    PubMed Central

    Sakai, Nozomu; Shin, Thomas; Schuster, Rebecca; Blanchard, John; Lentsch, Alex B.; Johnson, William Thomas

    2010-01-01

    Copper deficiency can cause a host of major cardiovascular complications including an augmented inflammatory response through effects on both neutrophils and the microvascular endothelium. In the present study, we evaluated the effect of marginal copper deficiency on the neutrophilic response to hepatic ischemia/reperfusion injury, a condition that induces an inflammatory response. Male weanling Sprague–Dawley rats were fed purified diets which were either copper-adequate (6.3 mg/kg) or copper-marginal (1.62 mg/kg) for 4 weeks prior to undergoing 90 min of partial hepatic ischemia followed by 8 h of reperfusion. Liver injury was assessed by serum levels of alanine aminotransferase and by liver histology. Liver neutrophil accumulation was determined by tissue myeloperoxidase content. There was no significant difference in liver injury between copper-adequate and copper-marginal rats. However, liver neutrophil accumulation was significantly increased in copper-marginal rats. These findings were confirmed histologically. Liver expression of the adhesion molecule, intercellular adhesion molecule-1 (ICAM-1), was increased in copper-marginal rats compared to copper-adequate rats. The results suggest that neutrophil accumulation is increased through enhanced ICAM-1 expression in liver of copper-marginal rats after ischemia/reperfusion, but that this does not result in increased liver injury. PMID:20544302

  1. Tissue distribution comparison between healthy and fatty liver rats after oral administration of hawthorn leaf extract.

    PubMed

    Yin, Jingjing; Qu, Jianguo; Zhang, Wenjie; Lu, Dongrui; Gao, Yucong; Ying, Xixiang; Kang, Tingguo

    2014-05-01

    Hawthorn leaves, a well-known traditional Chinese medicine, have been widely used for treating cardiovascular and fatty liver diseases. The present study aimed to investigate the therapeutic basis treating fatty liver disease by comparing the tissue distribution of six compounds of hawthorn leaf extract (HLE) in fatty liver rats and healthy rats after oral administration at first day, half month and one month, separately. Therefore, a sensitive and specific HPLC method with internal standard was developed and validated to determine chlorogenic acid, vitexin-4''-O-glucoside, vitexin-2''-O-rhamnoside, vitexin, rutin and hyperoside in the tissues including heart, liver, spleen, kidney, stomach and intestine. The results indicated that the six compounds in HLE presented some bioactivity in treating rat fatty liver as the concentrations of the six compounds varied significantly in inter- and intragroup comparisons (healthy and/or fatty liver group). PMID:24254959

  2. Metabolism of γ-hydroxybutyrate in perfused rat livers.

    PubMed

    Zhang, Guo-Fang; Sadhukhan, Sushabhan; Ibarra, Rafael A; Lauden, Stephanie M; Chuang, Chia-Ying; Sushailo, Sophia; Chatterjee, Priya; Anderson, Vernon E; Tochtrop, Gregory P; Brunengraber, Henri

    2012-06-01

    GHB (γ-hydroxybutyrate) is both a neurotransmitter and a drug of abuse (date-rape drug). We investigated the catabolism of this compound in perfused rat livers. Using a combination of metabolomics and mass isotopomer analysis, we showed that GHB is metabolized by multiple processes, in addition to its previously reported metabolism in the citric acid cycle via oxidation to succinate. A substrate cycle operates between GHB and γ-aminobutyrate via succinic semialdehyde. Also, GHB undergoes (i) β-oxidation to glycolyl-CoA+acetyl-CoA, (ii) two parallel processes which remove C-1 or C-4 of GHB and form 3-hydroxypropionate from C-2+C-3+C-4 or from C-1+C-2+C-3 of GHB, and (iii) degradation to acetyl-CoA via 4-phosphobutyryl-CoA. The present study illustrates the potential of the combination of metabolomics and mass isotopomer analysis for pathway discovery. PMID:22428548

  3. Burn trauma disrupts circadian rhythms in rat liver

    PubMed Central

    Rao, Rohit; Yang, Qian; Orman, Mehmet A; Berthiaume, Francois; Ierapetritou, Marianthi G; Androulakis, Ioannis P

    2016-01-01

    Circadian rhythms play an important role in maintaining homeostasis and solid organ function. The purpose of this study is to assess the implications of burn injury in rats on the underlying circadian patterns of gene expression in liver. Circadian-regulated genes and burn-induced genes were identified by applying consensus clustering methodology to temporally differentially expressed probe sets obtained from burn and sham-burn data sets. Of the liver specific genes which we hypothesize that exhibit circadian rhythmicity, 88% are not differentially expressed following the burn injury. Specifically, the vast majority of the circadian regulated-genes representing central carbon and nitrogen metabolism are “up-regulated” after the burn injury, indicating the onset of hypermetabolism. In addition, cell-cell junction and membrane structure related genes showing rhythmic behavior in the control group were not differentially expressed across time in the burn group, which could be an indication of hepatic damage due to the burn. Finally, the suppression of the immune function related genes is observed in the postburn phase, implying the severe “immunosuppression”. Our results demonstrated that the short term response (24-h post injury) manifests a loss of circadian variability possibly compromising the host in terms of subsequent challenges. PMID:27335693

  4. The isolation and properties of phenylalanine hydroxylase from rat liver

    PubMed Central

    Gillam, Shirley Su; Woo, Savio L. C.; Woolf, Louis I.

    1974-01-01

    Phenylalanine hydroxylase was prepared from rat liver and purified 200-fold to about 90% purity. All the enzymic activity of the liver appeared in a single protein of mol.wt. approx. 110000, but omission of dithiothreitol and of a preliminary filtration step to remove lipids resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. The Km and Vmax. values of the enzyme for phenylalanine, p-fluorophenylalanine and dimethyltetrahydropterin were measured; p-chlorophenylalanine inhibited the enzyme by competing with phenylalanine. Disc gel electrophoresis at pH7.2 showed a single protein band containing all the enzymic activity, but at pH8.7 the enzyme dissociated into two inactive fragments of similar but not identical molecular weight. The molecule of phenylalanine hydroxylase contained two atoms of iron, one atom of copper and one molecule of FAD; molybdenum was absent. Treatment with chelating agents showed that both non-haem iron and copper were necessary for enzymic activity. The molecule contained five thiol groups, and thiol-binding reagents inhibited the enzyme. Catalase or peroxidase enhanced enzymic activity fivefold; it is postulated that catalase (or other peroxidase) plays a part in the hydroxylation reaction independent of the protection by catalase of enzyme and cofactor from inactivation by a hydroperoxide. PMID:4854920

  5. Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver.

    PubMed

    Wack, K E; Ross, M A; Zegarra, V; Sysko, L R; Watkins, S C; Stolz, D B

    2001-02-01

    Sinusoidal endothelial cell (SEC) porosities were compared between the periportal (zone 1) and pericentral (zone 3) regions of the rat liver during regeneration following partial hepatectomy (PHx). SEC porosities and fenestration diameters were measured in control livers, as well as at 5 minutes, 24, 48, 72, 96, 120 hours, and 14 days following PHx. Bimodal maximums in both porosity and fenestration diameters were observed in both zones at 5 minutes and 5 days following PHx. SEC porosities increased significantly in both zones 1 and 3 within 5 minutes following PHx, but the increase was maintained only in zone 1 at 24 hours after resection. Following the initial rise, both zones displayed a gradual decrease to less than half their porosity values at 72 hr post-PHx. After 72 hours, porosities increased to over control levels and remained elevated until 14 days after PHx. The decrease in porosity at 72 hr post-PHx is accompanied by ultrastructural changes within the sinusoid at this time. Vascular corrosion casting and transmission electron microscopy (TEM) show sinusoid compression resulting from increased hepatic plate widths due to hepatocyte proliferation in the absence of SEC proliferation. Also at this time, we observed many SEC completely enveloped by stellate cells. The zonal variations observed for porosities throughout regeneration did not correlate with changes in laminin, collagen I and IV, or fibronectin deposition within the space of Disse. Taken together, the data reveal that SEC are dynamic regulators of porosity that respond rapidly and locally to environmental zonal stimuli during liver regeneration. PMID:11172338

  6. Interaction of human lactoferrin with the rat liver

    SciTech Connect

    Debanne, M.T.; Regoeczi, E.; Sweeney, G.D.; Krestynski, F.

    1985-04-01

    Binding of human lactoferrin (hLf) by purified rat liver plasma membranes was studied to clarify whether the liver possesses specific hLf receptors. The binding was rapid between 4 degrees and 37 degrees C, with a pH optimum close to 5.0. At 22 degrees C and in glycine-NaOH (5 mM, pH 7.4) containing 150 mM NaCl and 0.5% albumin, 1 microgram of membrane bound a maximum of 11.8 ng hLf. The dissociation constant of the interaction was 1.6 X 10(-7) M. Other proteins of high isoelectric points (lactoperoxidase, lysozyme, and particularly salmine sulfate) and a piperazine derivative inhibited hLf binding in a concentration- dependent manner. In contrast, monosaccharides (galactose, N- acetylgalactosamine, mannose, and fucose) were ineffective. By omitting NaCl from the incubation buffer, binding was increased 3.6-fold. Erythrocyte ghosts bound hLf less firmly and alveolar macrophages more firmly than hepatic plasma membranes. Liver cell fractionations performed after the intravenous injection of labeled hLf showed that approximately 88% of the hepatic radioligand was associated with parenchymal cells. When binding was expressed per unit of cell volume, however, more hLf was present in nonparenchymal than in parenchymal cells, implying that the above value was determined by the relative cell masses rather than affinities alone. It is concluded that the binding of hLf by hepatic plasma membranes is electrostatic, i.e., is mediated by the cationic nature of the ligand, and that it is explicable in terms of a ''specific nonreceptor interaction'' of the generalized type proposed by Cuatrecasas and Hollenberg.

  7. Prolonged exposure of cholestatic rats to complete dark inhibits biliary hyperplasia and liver fibrosis.

    PubMed

    Han, Yuyan; Onori, Paolo; Meng, Fanyin; DeMorrow, Sharon; Venter, Julie; Francis, Heather; Franchitto, Antonio; Ray, Debolina; Kennedy, Lindsey; Greene, John; Renzi, Anastasia; Mancinelli, Romina; Gaudio, Eugenio; Glaser, Shannon; Alpini, Gianfranco

    2014-11-01

    Biliary hyperplasia and liver fibrosis are common features in cholestatic liver disease. Melatonin is synthesized by the pineal gland as well as the liver. Melatonin inhibits biliary hyperplasia of bile duct-ligated (BDL) rats. Since melatonin synthesis (by the enzyme serotonin N-acetyltransferase, AANAT) from the pineal gland increases after dark exposure, we hypothesized that biliary hyperplasia and liver fibrosis are diminished by continuous darkness via increased melatonin synthesis from the pineal gland. Normal or BDL rats (immediately after surgery) were housed with light-dark cycles or complete dark for 1 wk before evaluation of 1) the expression of AANAT in the pineal gland and melatonin levels in pineal gland tissue supernatants and serum; 2) biliary proliferation and intrahepatic bile duct mass, liver histology, and serum chemistry; 3) secretin-stimulated ductal secretion (functional index of biliary growth); 4) collagen deposition, liver fibrosis markers in liver sections, total liver, and cholangiocytes; and 5) expression of clock genes in cholangiocytes. In BDL rats exposed to dark there was 1) enhanced AANAT expression/melatonin secretion in pineal gland and melatonin serum levels; 2) improved liver morphology, serum chemistry and decreased biliary proliferation and secretin-stimulated choleresis; and 4) decreased fibrosis and expression of fibrosis markers in liver sections, total liver and cholangiocytes and reduced biliary expression of the clock genes PER1, BMAL1, CLOCK, and Cry1. Thus prolonged dark exposure may be a beneficial noninvasive therapeutic approach for the management of biliary disorders. PMID:25214401

  8. Oxidative conversion of isothiocyanates to isocyanates by rat liver.

    PubMed Central

    Lee, M S

    1994-01-01

    This report describes the oxidative metabolism of isothiocyanates to isocyanates catalyzed by rat liver microsomes. Incubation of 2-naphthylisothiocyanate, microsomes, and NADPH yielded either N,N'-di-naphthylurea or, on inclusion of 2-aminofluorene in the incubations, N-2-naphthyl-N'-2-fluorenylurea. These ureas were formed by the production of the known genotoxicant, 2-naphthylisocyanate, which reacted with its hydrolysis product, 2-aminonaphthalene, to yield the symmetrical urea, or with 2-aminofluorene to form the mixed urea. Formation of N,N'-di-2-naphthylthiourea was also observed because 2-aminonaphthalene reacted with the substrate. Urea formation was dependent on the microsomes, NADPH, and oxygen. Use of microsomes from rats previously treated with Aroclor 1254 increased urea formation greater than 10-fold. The enzyme activity was inhibited by alpha-napthoflavone, flavone, or CO, and slightly inhibited by metyrapone, 7-ethoxycoumarin, or SKF-525A. It was not inhibited by methimazole or paraoxon, suggesting that neither flavin-containing monooxygenase nor hydrolytic enzyme was involved. These data are consistent with a cytochrome P450-dependent, oxidative desulfuration of 2-naphthylisothiocyanate to yield 2-naphthylisocyanate. Further studies with the isomeric 1-naphthylisothiocyanate and the dietary benzylisothiocyanate showed that they can also be metabolized to their isocyanates, as evidenced by the trapping of isocyanates with 2-aminofluorene to form the mixed ureas. PMID:7889832

  9. Etoxazole is Metabolized Enantioselectively in Liver Microsomes of Rat and Human in Vitro.

    PubMed

    Yao, Zhoulin; Qian, Mingrong; Zhang, Hu; Nie, Jing; Ye, Jingqing; Li, Zuguang

    2016-09-01

    Acaricide etoxazole belongs to the ovicides/miticides diphenyloxazole class, affecting adults to lay sterile eggs by inhibiting chitin biosynthesis possibly. The reverse-phase HPLC-MS/MS method was used to determine the etoxazole enantiomers. The enantioselective degradation behavior of rac-etoxazole in liver microsomes of rat and human in vitro with NADPH was dramatically different. The t1/2 of (R)-etoxazole was 15.23 min in rat liver microsomes and 30.54 min in human liver microsomes, while 21.73 and 23.50 min were obtained for (S)-etoxazole, respectively. The Vmax of (R)-etoxazole was almost 5-fold of (S)-etoxazole in liver microsomes of rat in vitro. However, the Vmax of (S)-etoxazole was almost 2-fold of (R)-etoxazole in liver microsomes of human in vitro. The CLint of etoxazole was also shown the enantioselectivity on the contrary in liver microsomes of rat and human. These results indicated that the metabolism of two etoxazole enantiomers was selective in liver microsomes of rat and human in vitro, and enantioselectivity in the two kinds of liver microsomes was in the difference in degradation performance. The reason might be related to the composition and content involved in the enzyme system. PMID:27479246

  10. Changes in liver uptake of a radioiodinated triglyceride analog in ethanol-fed rats

    SciTech Connect

    Schwendner, S.W.; Skinner, R.S.W.; Gross, M.; Ruyan, M.; Counsell, R.E. VA Medical Center, Ann Arbor, MI )

    1991-03-11

    A radioiodinated triglyceride (TG) analog, ({sup 125}I)-glycerol-2-palmitoyl-1,3-di-15-(p-iodophenyl)pentadecanoate (DPPG) has been synthesized and shown to accumulate within the liver of normal rats within 15 min of i.v. administration. With time, the radioactivity clears and more activity appears as the fatty acid metabolite than as parent compound. In this study, rats were fed a commercial liquid diet containing 36% of the calories either as ethanol (ET) or sucrose (CON). After six weeks, the ET rats had significantly higher plasma and liver TG levels than CON rats. In addition, the ET rats showed fatty infiltration of the liver by histopathologic examination. DPPG formulated in a detergent-saline vehicle was administered and different patterns of both uptake and clearance were seen in these groups of rats. The CON rats showed greater uptake and more rapid clearance of radioactivity than ET rats. A similar pattern was observed noninvasively by gamma camera scintigraphy. In addition, PAGE analysis of the plasma revealed that 90% of the radioactivity in the plasma was associated with plasma lipoproteins within 5 m. By 120 m 40% of the plasma activity in CON rats was associated with albumin, indicating hydrolysis to the free fatty acid. In the ET rats only 22% was albumin bound at this time. Thus, DPPG shows promise as an agent to diagnose changes in liver lipid metabolism in such disease states as alcoholism.

  11. Effect of Phenobarbital on Chloramphonicol-Induced Toxicity in Rat Liver and Small Intestine

    PubMed Central

    Ahmadizadeh, Massumeh; Esmailpoor, Masood; Goodarzi, Zahra

    2013-01-01

    Objective(s): The aim of the present study is to determine the effect of Chloramphenicol (CAP) on rat liver and small intestine. Effect of phenobarbital (PB) on CAP toxicity was also investigated. Materials and Methods: Rats were received CAP at doses of 0, 200, 400 and 600 mg/kg. Another group was pretreated with 80 mg/kg PB 30 min prior to administration of various doses of CAP. The experiment was repeated for seven consecutive days. Blood was collected for determination of serum aspartate aminotransferase (AST) alanine aminotransferase (ALT). The liver and small intestine tissues were processed for light microscopy. Results: CAP induced a dose dependent elevation of AST and ALT and produced injury in the liver and small intestine when compared to control animals. PB markedly decreased AST and ALT levels and protected liver and small intestine against CAP-induced toxicity. Conclusion : This study suggested rat liver and small intestine have potential to bioactivate CAP. PMID:24570836

  12. Citrulline synthesis in rat tissues and liver content of carbamoyl phosphate and ornithine

    PubMed Central

    Raijman, Luisa

    1974-01-01

    Rat liver ornithine carbamoyltransferase appears to be located exclusively in the mitochondria; the activity that is found in the soluble fraction is indistinguishable from mitochondrial ornithine carbamoyltransferase by simple kinetic criteria, and seems to result from breakage of mitochondria during homogenization. Of several rat tissues studied, only the liver and the mucosa of small intestine contain significant amounts of ornithine carbamoyltransferase; the activity in intestinal mucosa is less than one thousandth of that in liver. Qualitatively, this distribution coincides with that of carbamoyl phosphate synthetase I and its cofactor, acetylglutamate. The rat liver contents of carbamoyl phosphate and ornithine were 0.1 and 0.15μmol/g wet wt. of tissue respectively. On the basis of these values, it is proposed that in vivo the ornithine carbamoyltransferase activity of liver may be much lower than its maximal activity in vitro might suggest. PMID:4822731

  13. Sex differences in rats in the metabolism of phenytoin to 5-(3,4-dihydroxyphenyl)-5-phenylhydantoin.

    PubMed

    Billings, R E

    1983-06-01

    Phenytoin (DPH) is metabolized in isolated hepatocytes from male rats by hydroxylation to 5-(4-hydroxyphenyl)-5-phenylhydantoin, 5-(3,4-dihydroxy-1,5-cyclohexadien-1-yl)-5-phenylhydantoin (dihydrodiol) and a catecholic metabolite, 5-(3,4-dihydroxyphenyl)-5-phenylhydantoin, which is further metabolized by methylation of one of the phenolic hydroxyl groups. Isolated hepatocytes from female rats convert DPH to the initial metabolites, but only trace amounts of the catechol are formed. Similar results were obtained in vivo and with liver homogenate preparations. Incubation of possible precursor metabolites to the catechol indicate that the sex difference in catechol formation is due to differences in 5-(4-hydroxyphenyl)-5-phenylhydantoin hydroxylation rather than to differences in oxidation of the dihydrodiol metabolite. It is postulated that different isozymes of cytochrome P-450 catalyze the hydroxylation of DPH and its p-phenol metabolite because sex differences are observed only in the second hydroxylation step. Furthermore, the sex difference may be due to lower activity of one or more cytochrome P-450 isozymes in female rats than in male rats. These results may have important implications in the pharmacological activity and toxicity of DPH. PMID:6864524

  14. Polyploidization delay in rat hepatocytes under liver growth inhibition by hypokinesia

    NASA Technical Reports Server (NTRS)

    Faktor, V. M.; Malyutin, V. F.; Li, S. Y.; Brodskiy, V. Y.

    1981-01-01

    A study of young rats, weighing 55 to 59 g, after being for 10 days in conditions of limited mobility, shows a retardation of body growth as well as that of liver growth. The decrease in the rate of growth is accompanied by a reduction of cell proliferation and by delay polyploidization of hepatocytes in the liver of experimental rats. The materials, methods, and results of research are discussed.

  15. Effect of Dietary Vitamin E Supplementation on Liver Oxidative Damage in Rats with Water-Immersion Restraint Stress.

    PubMed

    Ohta, Yoshiji; Yashiro, Koji; Ohashi, Koji; Horikoshi, Yosuke; Kusumoto, Chiaki; Matsura, Tatsuya; Fukuzawa, Kenji

    2015-01-01

    We examined how dietary supplementation of vitamin E protects against liver oxidative damage in rats with water-immersion restraint stress (WIRS). Before WIRS exposure, rats received a normal diet (ND) or vitamin E-supplemented diet (VESD) (500 IU α-tocopherol/kg diet) at a mean dose of 15 g/animal/d for 4 wk. The two diet groups had serum transaminases and lactate dehydrogenase activities and adrenocorticotropic hormone, corticosterone, and glucose levels to a similar extent. VESD-fed rats had higher liver α-tocopherol concentrations and lower liver ascorbic acid, total coenzyme Q9 (CoQ9), reduced CoQ9, reduced CoQ10, and lipid peroxide (LPO) concentrations than ND-fed rats. When the two diet groups were exposed to 6 h of WIRS, the serum liver cell damage index enzyme activities increased more greatly in ND-fed rats than in VESD-fed rats but the serum stress marker levels increased to a similar extent. The WIRS exposure caused no change in liver LPO concentration with the further increase in liver α-tocopherol concentration in VESD-fed rats but increased liver LPO concentration without changing liver α-tocopherol concentration in ND-fed rats. Upon the WIRS exposure, liver reduced glutathione concentration decreased with the further decrease in liver ascorbic acid concentration in VESD-fed rats and those concentrations decreased in ND-fed rats. The WIRS exposure recovered the decreased liver total CoQ9 and reduced CoQ9 concentrations in VESD-fed rats but decreased liver total CoQ9, reduced CoQ9, and reduced CoQ10 concentrations in ND-fed rats. These results indicate that dietary vitamin E supplementation protects against liver oxidative damage without affecting the stress response in rats with WIRS. PMID:26052141

  16. Medium chain triglycerides dose-dependently prevent liver pathology in a rat model of non-alcoholic fatty liver disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolic syndrome is often accompanied by development of hepatic steatosis and less frequently by nonalcoholic fatty liver disease (NAFLD) leading to nonalcoholic steatohepatitis (NASH). Replacement of corn oil with medium chain triacylglycerols (MCT) in the diets of alcohol-fed rats has been show...

  17. PPAR{alpha} agonists up-regulate organic cation transporters in rat liver cells

    SciTech Connect

    Luci, Sebastian; Geissler, Stefanie; Koenig, Bettina; Koch, Alexander; Stangl, Gabriele I.; Hirche, Frank; Eder, Klaus . E-mail: klaus.eder@landw.uni-halle.de

    2006-11-24

    It has been shown that clofibrate treatment increases the carnitine concentration in the liver of rats. However, the molecular mechanism is still unknown. In this study, we observed for the first time that treatment of rats with the peroxisome proliferator activated receptor (PPAR)-{alpha} agonist clofibrate increases hepatic mRNA concentrations of organic cation transporters (OCTNs)-1 and -2 which act as transporters of carnitine into the cell. In rat hepatoma (Fao) cells, treatment with WY-14,643 also increased the mRNA concentration of OCTN-2. mRNA concentrations of enzymes involved in carnitine biosynthesis were not altered by treatment with the PPAR{alpha} agonists in livers of rats and in Fao cells. We conclude that PPAR{alpha} agonists increase carnitine concentrations in livers of rats and cells by an increased uptake of carnitine into the cell but not by an increased carnitine biosynthesis.

  18. Chronic ethanol inhibits receptor-stimulated phosphoinositide hydrolysis in rat liver slices

    SciTech Connect

    Gonzales, R.A.; Crews, F.T. )

    1991-03-01

    The effects of chronic ethanol feeding on norepinephrine (NE)- and arginine-vasopressin (AVP)-stimulated phosphoinositide (PI) hydrolysis in rat liver slices was determined. The maximum NE-stimulated PI response was significantly reduced by 40% in liver slices from 8-month-old rats which had been treated for 5 months with a liquid diet containing ethanol compared to pair-fed controls. The maximum AVP-stimulated PI response was decreased by 39% in liver slices from the ethanol-fed rats compared to control. EC50 values for NE- and AVP-stimulated PI hydrolysis in liver slices were not affected by the chronic ethanol treatment. Similar reductions in the maximal NE- and AVP-stimulated PI hydrolysis (28% and 27%, respectively) were found in 22-month-old rats which had been maintained on an ethanol containing diet for 5 months compared to pair-fed controls. The binding of (3H)prazosin and (3H)AVP to liver plasma membranes from 8-month-old ethanol-fed rats was not significantly different from binding to liver membranes from sucrose-fed controls. Our data suggest that chronic ethanol ingestion may lead to a reduction in PI-linked signal transduction in liver.

  19. Changing Interdigestive Migrating Motor Complex in Rats under Acute Liver Injury

    PubMed Central

    Zheng, Su-Jun; Xu, Weihong; Zhang, Jianying; Chen, Yu; Duan, Zhongping

    2014-01-01

    Gastrointestinal motility disorder is a major clinical manifestation of acute liver injury, and interdigestive migrating motor complex (MMC) is an important indicator. We investigated the changes and characteristics of MMC in rats with acute liver injury. Acute liver injury was created by d-galactosamine, and we recorded the interdigestive MMC using a multichannel physiological recorder and compared the indexes of interdigestive MMC. Compared with normal controls, antral MMC Phase I duration was significantly prolonged and MMC Phase III duration was significantly shortened in the rats with acute liver injury. The duodenal MMC cycle and MMC Phases I and IV duration were significantly prolonged and MMC Phase III duration was significantly shortened in the rats with acute liver injury. The jejunal MMC cycle and MMC Phases I and IV duration were significantly prolonged and MMC Phase III duration was significantly shortened in the rats with acute liver injury compared with normal controls. Compared with the normal controls, rats with acute liver injury had a significantly prolonged interdigestive MMC cycle, related mainly to longer MMC Phases I and IV, shortened MMC Phase III, and MMC Phase II characterized by increased migrating clustered contractions, which were probably major contributors to the gastrointestinal motility disorders. PMID:25544942

  20. Conversion of 5-aminolaevulinate into haem by homogenates of human liver. Comparison with rat and chick-embryo liver homogenates.

    PubMed

    Bonkovsky, H L; Healey, J F; Sinclair, P R; Sinclair, J F

    1985-05-01

    To assess whether the synthesis of haem can be studied in small amounts of human liver, we measured kinetics of the conversion of 5-aminolaevulinate into haem and haem precursors in homogenates of human livers. We used methods previously developed in our laboratory for studies of rat and chick-embryo livers [Healey, Bonkowsky, Sinclair & Sinclair (1981) Biochem. J. 198, 595-604]. The maximal rate at which homogenates of human livers converted 5-aminolaevulinate into protoporphyrin was only 26% of that for rat, and 58% of that for chick embryo. In the absence of added Fe2+, homogenates of fresh human liver resembled those of chick embryos in that protoporphyrin and haem accumulated in similar amounts, whereas fresh rat liver homogenate accumulated about twice as much haem as protoporphyrin. However, when Fe2+ (0.25 mM) was added to human liver homogenates, mainly haem accumulated, indicating that the supply of reduced iron limited the activity of haem synthase, the final enzyme in the haem-biosynthesis pathway. Addition of the potent iron chelator desferrioxamine after 30 min of incubation with 5-amino[14C]laevulinate stopped further haem synthesis without affecting synthesis of protoporphyrin. Thus the prelabelled haem was stable after addition of desferrioxamine. Since the conversion of 5-amino[14C]laevulinate into haem and protoporphyrin was carried out at pH 7.4, whereas the pH optimum for rat or bovine hepatic 5-aminolaevulinate dehydratase is about 6.3, we determined kinetic parameters of the human hepatic dehydrase at both pH values. The Vmax was the same at both pH values, whereas the Km was slightly higher at the lower pH. Our results indicate that the synthesis of porphyrins and haem from 5-aminolaevulinate can be studied with the small amounts of human liver obtainable by percutaneous needle biopsy. We discuss the implications of our results in relation to use of rat or chick-embryo livers as experimental models for the biochemical features of human acute

  1. DEVELOPMENT OF A TOXICITY TEST SYSTEM USING PRIMARY RAT LIVER CELLS

    EPA Science Inventory

    A model in vitro rat liver parenchymal cellular toxicity system employing cells obtained by the in situ collagenase perfusion technique has been developed to detect potential liver toxicants. The initial evaluation of this test system was accomplished using cadmium chloride, chro...

  2. High affinity binding of (/sup 3/H)cocaine to rat liver microsomes

    SciTech Connect

    El-Maghrabi, E.A.; Calligaro, D.O.; Eldefrawi, M.E.

    1988-01-01

    )/sup 3/H)cocaine bound reversible, with high affinity and stereospecificity to rat liver microsomes. Little binding was detected in the lysosomal, mitochondrial and nuclear fractions. The binding kinetics were slow and the kinetically calculated K/sub D/ was 2 nM. Induction of mixed function oxidases by phenobarbital did not produce significant change in (/sup 3/H)cocaine binding. On the other hand, chronic administration of cocaine reduced (/sup 3/H)cocaine binding drastically. Neither treatment affected the affinity of the liver binding protein for cocaine. Microsomes from mouse and human livers had less cocaine-binding protein and lower affinity for cocaine than those from rat liver. Binding of (/sup 3/H)cocaine to rat liver microsomes was insensitive to monovalent cations and > 10 fold less sensitive to biogenic amines than the cocaine receptor in rat striatum. However, the liver protein had higher affinity for cocaine and metabolites except for norcocaine. Amine uptake inhibitors displaced (/sup 3/H)cocaine binding to liver with a different rank order of potency than their displacement of (/sup 3/H)cocaine binding to striatum. This high affinity (/sup 3/H)cocaine binding protein in liver is not likely to be monooxygenase, but may have a role in cocaine-induced hepatotoxicity

  3. Actions of juglone on energy metabolism in the rat liver

    SciTech Connect

    Saling, Simoni Cristina; Comar, Jurandir Fernando; Mito, Marcio Shigueaki; Peralta, Rosane Marina; Bracht, Adelar

    2011-12-15

    Juglone is a phenolic compound used in popular medicine as a phytotherapic to treat inflammatory and infectious diseases. However, it also acts as an uncoupler of oxidative phosphorylation in isolated liver mitochondria and, thus, may interfere with the hepatic energy metabolism. The purpose of this work was to evaluate the effect of juglone on several metabolic parameters in the isolated perfused rat liver. Juglone, in the concentration range of 5 to 50 {mu}M, stimulated glycogenolysis, glycolysis and oxygen uptake. Gluconeogenesis from both lactate and alanine was inhibited with half-maximal effects at the concentrations of 14.9 and 15.7 {mu}M, respectively. The overall alanine transformation was increased by juglone, as indicated by the stimulated release of ammonia, urea, L-glutamate, lactate and pyruvate. A great increase (9-fold) in the tissue content of {alpha}-ketoglutarate was found, without a similar change in the L-glutamate content. The tissue contents of ATP were decreased, but those of ADP and AMP were increased. Experiments with isolated mitochondria fully confirmed previous notions about the uncoupling action of juglone. It can be concluded that juglone is active on metabolism at relatively low concentrations. In this particular it resembles more closely the classical uncoupler 2,4-dinitrophenol. Ingestion of high doses of juglone, thus, presents the same risks as the ingestion of 2,4-dinitrophenol which comprise excessive compromising of ATP production, hyperthermia and even death. Low doses, i.e., moderate consumption of natural products containing juglone, however, could be beneficial to health if one considers recent reports about the consequences of chronic mild uncoupling. -- Highlights: Black-Right-Pointing-Pointer We investigated how juglone acts on liver metabolism. Black-Right-Pointing-Pointer The actions on hepatic gluconeogenesis, glycolysis and ureogenesis. Black-Right-Pointing-Pointer Juglone stimulates glycolysis and ureagenesis and

  4. Influence of diabetes on liver injury induced by antitubercular drugs and on silymarin hepatoprotection in rats.

    PubMed

    Srivastava, R K; Sharma, S; Verma, S; Arora, B; Lal, H

    2008-12-01

    Isoniazid, rifampicin and pyrazinamide during short-course chemotherapy for tuberculosis can result in liver injury. The coexistence of tuberculosis and diabetes is common in patients who receive inadequate treatment. The risk of hepatotoxicity from many toxicants is increased in diabetic rats. Silymarin provides protection against liver injury caused by many hepatotoxicants, including antitubercular drugs (ATDs). In the wake of increased severity of ATD-induced hepatotoxicity in diabetes we report here the results of a study on the influence of diabetes on silymarin hepatoprotection in rats. Rats with diabetes induced via intraperitoneally injected streptozotocin (50 mg/kg), nondiabetic rats and insulin-treated diabetic rats received isoniazid (7.5 mg/kg/day), rifampicin (10 mg/kg/day) and pyrazinamide (35 mg/kg/day) orally (p.o.) with or without silymarin (100 mg/kg/day p.o.) treatment for 45 days. Compared to nondiabetic rats, liver function tests and histological changes of liver revealed exaggerated liver injury in diabetic rats caused by ATDs which was evident by 5- to 8-fold increases in serum levels of marker enzymes (aspartate and alanine aminotransferase, alkaline phosphatase and gamma-glutamyltranspeptidase) and 1- to 2-fold increases in bilirubin accompanied by a 2-fold decrease in total serum proteins, intense fatty and inflammatory infiltrations, necrosis and fibrosis. Coadministration of silymarin provided protection against ATD hepatotoxicity in all animals. However, insulin-treated diabetic animals showed greater silymarin-induced hepatoprotection against ATD-induced liver injury, which was characterized by near normal levels of marker enzymes, an increase in total proteins and normal hepatic structure. These results thus indicate that diabetes exaggerates ATD-induced liver injury and attenuates silymarin-induced hepatoprotection. However, insulin treatment for diabetes offers greater silymarin-induced hepatoprotection against ATD-induced liver

  5. Protective effects of hydroxysafflor yellow A (HSYA) on alcohol-induced liver injury in rats.

    PubMed

    He, Yanhao; Liu, Qiang; Li, Yanxiang; Yang, Xiaofeng; Wang, Weirong; Li, Tingting; Zhang, Wei; Cui, Yuexin; Wang, Chaoyun; Lin, Rong

    2015-03-01

    Hydroxysafflor yellow A (HSYA), the main active natural constituent extracted from Carthamus tinctorius L., has been widely used for the treatment of cerebrovascular and cardiovascular diseases. The aim of this study is to explore the effect of HSYA on alcohol-induced liver injury and the underlying mechanism. Male Sprague-Dawley rats were used to establish the liver injury model induced by alcohol. HSYA treatment ameliorated serum biochemical indicators by reducing the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronan (HA), laminin (LN), and type III precollagen (III-C) in rats. HSYA efficiently increased the activity and messenger RNA (mRNA) of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in rat liver tissue compared with those of model group, which was obviously reduced by alcohol. HSYA also apparently decreased the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in rat liver tissue compared with those of model group, which was obviously enhanced by alcohol. Histological studies demonstrated that HSYA substantially reduced the number of macro- and micro-vesicular steatosis, suppressed hepatic fibrogenesis and shrunk ballooning degeneration areas, ameliorated the severity of liver damage induced by long-term drinking, and finally improved the liver architecture. In addition, immunohistochemistry study indicated that the activation of transforming growth factor β1 (TGF-β1) stimulated by alcohol in rat liver tissue was significantly blocked by HSYA. Collectively, these data demonstrated that HSYA can effectively protect the liver of rats from long-term alcohol injury, which relates with the enhanced antioxidant capacity of liver tissues and inhibition of TGF-β1 expression. PMID:25626885

  6. Triglyceride kinetics, tissue lipoprotein lipase, and liver lipogenesis in septic rats

    SciTech Connect

    Lanza-Jacoby, S.; Tabares, A. )

    1990-04-01

    The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studied by examining liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant iv infusion of (2-3H)glycerol-labeled VLDL. Clearance of VLDL-TG was also evaluated by measuring activities of lipoprotein lipase (LPL) in heart, soleus muscle, and adipose tissue from fasted control, fasted E. coli-treated, fed control, and fed E. coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 x 10(7) live E. coli colonies per 100 g body wt. Twenty-four hours after E. coli injection, serum TG, free fatty acids (FFA), and cholesterol of fasted E. coli-treated rats were elevated by 170, 76, and 16%, respectively. The elevation of serum TG may be attributed to the 67% decrease in clearance rate of VLDL-TG in fasted E. coli-treated rats compared with their fasted controls. The suppressed activities of LPL in adipose tissue, skeletal muscle, and heart were consistent with reduced clearance of TG. Secretion of VLDL-TG declined by 31% in livers of fasted E. coli-treated rats, which was accompanied by a twofold increase in the composition of liver TG. Rates of in vivo TG synthesis in livers of the fasted E. coli-treated rats were twofold higher than in those of fasted control rats. Decreased rate of TG appearance along with the increase in liver synthesis of TG contributed to the elevation of liver lipids in the fasted E. coli-treated rats.

  7. Protective effects of vitamin D3 against d-galactosamine-induced liver injury in rats.

    PubMed

    Colakoglu, Neriman; Kuloglu, Tuncay; Ozan, Enver; Kocaman, Nevin; Dabak, Durrin Ozlem; Parlak, Gozde

    2016-08-01

    In this study, we examined liver damage induced by d-galactosamine (d-GaIN) and the protective effects of vitamin D3 in relation to d-GaIN toxicity. Twenty Wistar albino rats were used in this study. The rats were divided into four groups. Group I rats were used as the control group. Group II rats were given a single intraperitoneal injection of d-GaIN. Group III rats were given a single intraperitoneal injection of d-GaIN, intramuscular vitamin D3 for five days. Group IV rats were given intramuscular vitamin D3 for five days. All of rats were euthanized by cervical decapitation on the fifth day of experiment. Upon completion of the experiment, a midsaggital incision was performed, and the livers of all rats were removed and fixed. The livers were processed to perform TUNEL technique and histochemical staining. During the microscope examination, we observed inflamatory cell infiltration, sinusoidal dilatation, and apoptotic bodies due to d-GaIN exposure. In addition, glycogen content of the group II hepatocytes was significantly decreased. Vitamin D3 treatment provided better structural apperance of the livers in group III. TUNEL positive cells were extremly pervasive in the group II livers. The study found group III TUNEL positive cells at a reduced rate in relation to group II due to vitamin D3 treatment. This findings indicate that d-GaIN causes inflamation in the liver. This inflamation triggers the apoptotic process gradually. Vitamin D3 has potency to decrease the severity of d-GaIN-caused structural liver damage. PMID:27291692

  8. METABOLOMIC EVALUATION OF RAT LIVER AND TESTIS TO CHARACTERIZE THE TOXICITY OF TRIAZOLE FUNGICIDES

    EPA Science Inventory

    The effects of two triazole fungicides, myclobutanil and triadimefon, on endogenous rat metabolite profiles in blood serum, liver, and testis was assessed using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Adult male Sprague-Dawley rats were dosed daily by gavage for...

  9. Beneficial Effects of Ocimum gratissimum Aqueous Extract on Rats with CCl4-Induced Acute Liver Injury

    PubMed Central

    Chiu, Chun-Ching; Huang, Chih-Yang; Chen, Tzy-Yen; Kao, Shao-Hsuan; Liu, Jer-Yuh; Wang, Yi-Wen; Tzang, Bor-Show; Hsu, Tsai-Ching

    2012-01-01

    Ocimum gratissimum (OG) is known as a food spice and traditional herb, which has been recommended for the treatment of various diseases. To investigate the hepatoprotective effect of OG aqueous extract (OGAE), male Wistar rats challenged by carbon tetrachloride (CCl4) were used as the animal model of chronic hepatic injury. Significantly increased serum catalase and DPPH levels were detected in CCl4-administrated rats that were treated with OGAE or silymarin as compared to those rats that were treated with saline or CCl4. In contrast, significantly decreased stress proteins including HSP70 and iNOS were observed in livers of CCl4-administrated rats that were treated with OGAE or sylimarin as compared to those rats that were treated with saline or CCl4. Moreover, significant decreases of MMP-9/MMP-2 ratio, uPA, phosphorylated ERK (p-ERK) and NF-κB (p-P65) were detected in livers of CCl4-administrated rats that were treated with OGAE or sylimarin as compared to those rats that were treated with saline or CCl4. These findings imply that OGAE can efficiently inhibit CCl4-induced liver injuries in rats and may therefore be a potential food or herb for preventing liver injuries. PMID:22792126

  10. Reconstitution of rat liver vasopressin receptors into phospholipid vesicles

    SciTech Connect

    Dickey, B.; Navarro, J.; Fishman, J.; Fine, R.

    1986-05-01

    Isolation and characterization of the hepatic vasopressin (V1) receptor has been hampered by the loss of vasopressin binding when the receptor is solubilized. An alternative to a soluble binding assay is reconstitution of solubilized receptors into phospholipid vesicles. They report here the initial reconstitution of solubilized vasopressin receptors. Rat liver microsomes were solubilized with 3% 3-((3-cholamido-propyl)dimethyl-ammonio)-1-propanesulfonate (CHAPS) in 20mM HEPES (pH 7.4). The solubilized protein was combined with an equal volume of 7% soybean phospholipids dissolved in 3% CHAPS. This solution was passed over a column of Sephadex G50 equilibrated with 30 mM HEPES, 5mM MgCl/sub 2/ (pH 7.4). Reconstituted vesicles containing the microsomal proteins were recovered in the void volume. Binding of (/sup 3/H)-Vasopressin to the reconstituted vesicles at pH 7.4 was 80% specific, saturable, reversible and required magnesium. Solubilization of microsomes in the presence of glycerol, prebound ligand, phospholipids or magnesium did not improve subsequent binding. This reconstitution procedure will allow examination of signal transduction mechanisms and may be used as a functional assay in isolating the receptor.

  11. Stimulation of rat liver beta-galactosidase activity by ions.

    PubMed Central

    Baccino, F M; Zuretti, M F; Pernigotti, L

    1975-01-01

    1. The p-nitrophenyl beta-D-galactosidase asctivity in rat liver homogenates of lysosome-rich fractions was shown to be markedly affected by the ionic composition of the medium. A stimulation of the reaction rate at pH 5 was produced by most of the salts tested, which contained anions such as acetate, SO4(2-) and Cl-, and cations such as Na+, K= and Mg2+. The most pronounced effect was observed with MgCl2. Only potassium glutamate was inhibitory. 2. Five peaks of beta-galactosidase activity obtained by DEAE-cellulose chromatography were equally sensitive to changes in the ionic composition of the medium. In the presence of added NaC1, the whole rate-pH curve was displaced towards higher pH values, the optimum being shifted from 2.0-2.5 to 3.5. The stimulation at pH 5.0 appeared to be mainly due to changes in Vmax., whereas the apparent Km was slightly modified. 3. Unlike the total, the free beta-galactosidase activity remained unchanged or even declined when KC1 was added to the reaction medium. PMID:3174

  12. Lysosomal phospholipids from rat liver after treatment with different drugs.

    PubMed

    Tjiong, H B; Lepthin, J; Debuch, H

    1978-01-01

    Rats were treated with 5 different drugs p-ethoxyacetanilide (I), indometacin (II) and nor-amidopyrine-methanesulfonate (III), O,O'-bis(diethylaminoethyl)hexestrol(IV) and choloroquine (V) for 3 - 4 weeks. Liver cell fractions were isolated by discontinuous gradient centrifugation and the specific activity of acid phosphatase was determined in each. Lysosomal fractions contained widely varying amounts of this marker enzyme, indicating that the concentration of lysosomes within these fractions differed. The amounts and patterns of phospholipids reflected this fact. Since we assumed bis(monoacylglycero)phosphate [(MAG)2-P; synonym:lysobisphosphatidic acid] is a marker lipid for secondary lysosomes, we expected and found significant quantities of this acidic phospholipid only in those lysosomal fractions which were also rich in acid phosphatase activity. 12% of the lysosomal phospholipids from animals receiving the hexestrol derivative (IV), and 19% of those from the chloroquine (V) experiment were present as (MAG)2P. The fatty acid compositions of this lysosomal phospholipid were not the same in all lysosome fractions. The more (MAG)2P present in the lysosomes, the more unsaturated are the fatty acids. Thus, after treatment with chloroquine, more than 90% of the fatty acids from (MAG)2P are unsaturated; C22:6 represents about 70% of the total. PMID:627402

  13. Uncouplers of rat-liver mitochondrial oxidative phosphorylation

    PubMed Central

    Parker, V. H.

    1965-01-01

    1. The ability of a series of compounds to uncouple oxidative phosphorylation of rat-liver mitochondria has been investigated. 2. The compounds were: 2-amino-1,1,3-tricyanopropene; carbonyl cyanide phenylhydrazone and its m-chloro and p-trifluoromethoxy derivatives; 4,5,6,7-tetrachloro-, 5-chloro-4-nitro-, 5-nitro-and 4,5,6,7-tetrachloro-1-methyl-benzotriazole; 4-hydroxy-3,5-di-iodo-, 3,5-di-bromo-4-hydroxy- and 3,5-dichloro-4-hydroxy-benzonitrile; and pentafluorophenol. 3. In a medium the components and physical condition of which were, as far as possible, kept constant, each compound was tested for ability to stimulate adenosine triphosphatase, to stimulate respiration in the presence of pyruvate as substrate, to inhibit phosphate uptake and to prevent swelling by trimethyltin. 4. Each compound was also examined with respect to its ability to produce rapid rigor mortis in mice. 5. The biological properties were compared with the dissociation constant and the hexane–water partition coefficient for each compound. 6. With the exception of 4,5,6,7-tetrachloro-1-methylbenzotriazole, all the compounds behaved qualitatively as 2,4-dinitrophenol. 7. Within each class of compound there is a relation between biological activity and the physical attributes measured. 8. The most efficient uncouplers were the most acidic and the most hydrophobic. PMID:5881655

  14. Effects of Stevia rebaudiana natural products on rat liver mitochondria.

    PubMed

    Kelmer Bracht, A; Alvarez, M; Bracht, A

    1985-03-15

    The effects of several natural products extracted from the leaves of Stevia rebaudiana on rat liver mitochondria were investigated. The compounds used were stevioside (a non-caloric sweetener), steviolbioside, isosteviol and steviol. Total aqueous extracts of the leaves were also investigated. S. rebaudiana natural products inhibited oxidative phosphorylation, ATPase activity NADH-oxidase activity, succinate-oxidase activity, succinate dehydrogenase, and L-glutamate dehydrogenase. The ADP/O ratio was decreased. Substrate respiration (state II respiration) was increased at low concentrations (up to 0.5 mM) and inhibited at higher concentrations (1 mM or more). In uncoupled mitochondria, inhibition of substrate respiration was the only effect observed. Net proton ejection induced by succinate and swelling induced by several substrates were inhibited. Of the compounds investigated, the sweet principle stevioside was less active. It was concluded that, in addition to the inhibitory effects, S. rebaudiana natural products may also act as uncouplers of oxidative phosphorylation. The possible physiologic consequences of the ingestion of stevioside and S. rebaudiana aqueous extracts are discussed. PMID:2858211

  15. Intracellular localization of aldehyde dehydrogenase in rat liver

    PubMed Central

    Marjanen, Leo

    1972-01-01

    1. Distribution of aldehyde dehydrogenase activity in rat liver was studied by measuring the rate of disappearance of acetaldehyde in the presence of each of the subcellular fractions. These were obtained by rough separation of particulate fractions from the soluble portion of the cell, by differential centrifugation, and by isopycnic gradient centrifugation. 2. The maximal rate of acetaldehyde oxidation was 3.7 μmol/min per g, with an apparent Km value below 10−5m. The highest rate of activity was observed in phosphate buffers of high Pi concentration (above 60mm). 3. The activity measured was completely dependent on NAD+. 4. The microsomal fraction and the nuclei were inactive in the assay. Of the total activity 80% was found in the mitochondrial fraction and the remaining 20% in the cytoplasm. 5. The distribution pattern is important from the point of view of acetaldehyde oxidation during ethanol metabolism. The apparent discrepancy of the results obtained by different workers and the localization of acetaldehyde oxidation in vivo is discussed. PMID:4346744

  16. The riboflavin/FAD cycle in rat liver mitochondria.

    PubMed

    Barile, M; Brizio, C; Valenti, D; De Virgilio, C; Passarella, S

    2000-08-01

    Here we provide evidence that mitochondria isolated from rat liver can synthesize FAD from riboflavin that has been taken up and from endogenous ATP. Riboflavin uptake takes place via a carrier-mediated process, as shown by the inverse relationship between fold accumulation and riboflavin concentration, the saturation kinetics [riboflavin Km and Vmax values were 4.4+/-1.3 microM and 35+/-5 pmol x min(-1) (mg protein)(-1), respectively] and the inhibition shown by the thiol reagent mersalyl, which cannot enter the mitochondria. FAD synthesis is due to the existence of FAD synthetase (EC 2.7.7.2), localized in the matrix, which has as a substrate pair mitochondrial ATP and FMN synthesized from taken up riboflavin via the putative mitochondrial riboflavin kinase. In the light of certain features, including the protein thermal stability and molecular mass, mitochondrial FAD synthetase differs from the cytosolic isoenzyme. Apparent Km and apparent Vmax values for FMN were 5.4+/-0.9 microM and 22.9+/-1.4 pmol x min(-1) x (mg matrix protein)(-1), respectively. Newly synthesized FAD inside the mitochondria can be exported from the mitochondria in a manner sensitive to atractyloside but insensitive to mersalyl. The occurrence of the riboflavin/FAD cycle is proposed to account for riboflavin uptake in mitochondria biogenesis and riboflavin recovery in mitochondrial flavoprotein degradation; both are prerequisites for the synthesis of mitochondrial flavin cofactors. PMID:10903524

  17. Regulation of phosphatidylcholine synthesis in rat liver endoplasmic reticulum.

    PubMed Central

    Sribney, M; Knowles, C L; Lyman, E M

    1976-01-01

    The biosynthesis of phosphatidylcholine in rat liver microsomal preparations catalysed by CDP-choline-1,2-diacylglycerol cholinephosphotransferase (EC 2.7.8.2) was inhibited by a combination of ATP and CoA or ATP and pantetheine. ATP alone at high concentrations (20 mM) inhibits phosphatidylcholine formation to the extent of 70%. In the presence of 0.1 mM-CoA, ATP (2 mM) inhibits to the extent of 80% and in the presence of 1 mM-pantetheine to the extent of 90%. ADP and other nucleotide triphosphates in combination with either CoA or pantetheine are only 10-30% as effective in inhibiting phosphatidylcholine synthesis. AMP(CH2)PP [adenosine 5'-(alphabeta-methylene)triphosphate] together with CoA inhibits to the extent of 59% and with pantetheine by 48%. AMP-P(CH2)P [adenosine 5'-(betagamma-methylene)triphosphate] together with either CoA or pantetheine had no significant effect on phosphatidylcholine formation. Other closely related derivatives of pantothenic acid were without effect either alone or in the presence of ATP, as were thiol compounds such as cysteine, homocysteine, cysteamine, dithiothreitol and glutathione. Several mechanisms by which this inhibition might take place were ruled out and it is concluded that ATP together with either CoA or pantetheine interacts reversibly with phosphatidylcholine synthetase to cause temporarily the inhibition of phosphatidylcholine formation. PMID:182154

  18. Different tumours induced by benzo(a)pyrene and its 7,8-dihydrodiol injected into adult mouse salivary gland.

    PubMed Central

    Wigley, C. B.; Amos, J.; Brookes, P.

    1978-01-01

    A comparison has been made between the carcinogenic activities of benzo(a)pyrene and the proposed proximate carcinogen, benzo(a)pyrene 7,8-dihydrodiol, in the adult C57BL mouse submandibular salivary gland. In preliminary studies using a range of doses, the dihydrodiol was slightly less active than the parent hydrocarbon in this system. There was a difference in the type of tumour induced by the 2 compounds. Benzo(a)pyrene induced tumours of the salivary glands at the site of injection, whereas the dihydrodiol induced malignant lymphosarcomas, particularly of the thymus, which were often metastatic to other orgnas. Possible reasons for the different sites of action of the 2 compounds are discussed. PMID:580763

  19. Liver gluconeogenic metabolites in young and old rats during septic shock.

    PubMed

    Schumer, W

    1988-07-01

    Aged individuals have diminished resistance to severe sepsis and septic shock. Previous studies in young animals showed that the liver's gluconeogenic capacity was an important determinant of survival in shock states. This study compared hepatic carbohydrate intermediates from young rats and old rats to correlate changes during peritonitis septic shock with known differences in survival times. Old control rats had glucose 6-phosphate (G6P) concentrations two-fold higher than young controls, 354 +/- 49 nanomole/g wet liver vs 180 +/- 41, suggesting a reduced ability to convert hexose monophosphate precursor into blood sugar. There was a 53% increase in G6P levels in the peritonitis livers, to 540 +/- 155 nanomole/g liver while in young septic rats the G6P decreased 33 per cent. These opposite, highly significant changes in shock (P = 0.01) show the reduced ability of old animals to mobilize gluconeogenic precursors. Fructose 1,6-biphosphate (FBP) in old control liver was 14 +/- 3 nanomole/g liver and did not change in shock; in young rats, FBP was 7.0 +/- 3 nanomole and increased 230 per cent in shock, showing a different metabolic response in young and old animals. These data suggest older animals may be more vulnerable to shock because of lower gluconeogenic potential. PMID:3389597

  20. Toward the identification of liver toxicity markers: a proteome study in human cell culture and rats.

    PubMed

    Thome-Kromer, Birgit; Bonk, Ines; Klatt, Mathias; Nebrich, Grit; Taufmann, Marion; Bryant, Stewart; Wacker, Ulrich; Köpke, Andreas

    2003-10-01

    The effects of toxic and nontoxic compound treatments were investigated by high resolution custom developed 2-11 pH gradient NEPHGE (non equilibrium pH gradient electrophoresis) two-dimensional electrophoresis. Two models were compared: (i) in vivo rat and (ii) the human cell line HepG2, to test their suitability in a proteomics based approach to identify a toxicity marker. 163 and 321 proteins were identified from the rat liver and the HepG2 proteome. These represent various isoforms of 113 and 194 different NCBI annotated gene sequences, respectively. Nine compounds were selected to induce proteome variations associated with liver toxicity and metabolism. The rat liver proteome database consists of 78 gels, the HepG2 database of 52 gels. Variant proteins were assessed regarding their usefulness as a toxicity marker by evaluating their treatment specificity against multiple control treatments. Thirteen potential toxicity marker proteins were found in rat liver and eight in HepG2. Catalase and carbamoylphosphate synthetase-1 isoforms were found to be significantly changed after treatment by 4/4 and 3/4 toxic compounds in rat liver, respectively. Aldo-keto-reductase family 1, member C1 was implicated for 3/4 liver cell toxic compounds in HepG2. Our approach was able to differentiate the quality of potential toxicity markers and provided useful information for an ongoing characterization of more compounds in a wider number of toxicity classes. PMID:14625847

  1. Therapeutic Effects of Melatonin On Liver And Kidney Damages In Intensive Exercise Model of Rats.

    PubMed

    Gedikli, Semin; Gelen, Volkan; Sengul, Emin; Ozkanlar, Seckin; Gur, Cihan; Agırbas, Ozturk; Cakmak, Fatih; Kara, Adem

    2015-01-01

    Extensive exercise induces inflammatory reactions together with high production of free radicals and subsequent liver and kidney tissues damage. This study was designed to investigate for effects of melatonin on liver and kidney tissues in the extensive exercise exposed rats and non-exercised rats. In this research, 24-male Sprague-Dawley rats were divided into four groups. For exercise rat model, the rats were exposed to slow pace running with the velocity of 10 m/min for 5 minutes for five days just before the study. And for last ten days after adaptation period, the exercise was improved as 15 min with the speed of 20 m/min and intra-peritoneal melatonin injection has been performed to the melatonin treated groups with the dose of 10 mg/kg. Biochemical results revealed a decrease in the parameters of kidney and liver enzymes in exercise-group and an increase in the parameters of serum, liver and kidney enzymes in the group that melatonin-exercise-group. As for histological analysis, while it is observed that there are cellular degenerations in the liver and kidney tissues with exercise application, a decrease has been observed in these degenerations in the group that melatonin was applied. At the end of the research, it has been determined that exercise application causes some damages on liver and kidney, and these damages were ameliorated with melatonin treatment. PMID:26310355

  2. [Mutagenic Activity of Four Aminoazo Compounds with Different Carcinogenicity for Rat Liver in the Ames Test].

    PubMed

    Frolova, T S; Sinitsyna, O I; Kaledin, V I

    2015-01-01

    In this paper in the bacterial Ames test we compared the mutagenicity of four aminoazo compounds, previously studied by other researchers and used for activation of rat liver enzymes, with the carcinogenicity in the rat liver. It was found that in the Ames test they have mutagenic activity, however, this activity does not correlate quantitatively with rat sensitivity to their hepatocarcinogenic action. Thus, the most active carcinogen 3'-methyl-4-dimethylaminoazobenzene causes mutations almost 2.5 times less than weakly carcinogenic ortho-aminoazotoluene, and exactly the same number of mutations as non-carcinogenic N,N-diethyl-4-aminoazobenzene. PMID:26591610

  3. Inhibition of diethylnitrosamine-induced liver cancer in rats by Rhizoma paridis saponin.

    PubMed

    Liu, Jing; Man, Shuli; Li, Jing; Zhang, Yang; Meng, Xin; Gao, Wenyuan

    2016-09-01

    Rhizoma Paridis saponin (RPS) had been regarded as the main active components responsible for the anti-tumor effects of the herb Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. In the present research, we set up a rat model of diethylnitrosamine (DEN) induced hepatoma to evaluate antitumor effect of RPS. After 20 weeks treatment, rats were sacrificed to perform histopathological examinations, liver function tests, oxidative stress assays and so forth. As a result, DEN-induced hepatoma formation. RPS alleviated levels of liver injury through inhibiting liver tissues of malondialdehyde (MDA) and nitric oxide (NO) formation, increasing superoxide dismutases (SOD) production, and up-regulating expression of GST-α/μ/π in DEN-induced rats. All in all, RPS would be a potent agent inhibiting chemically induced liver cancer in the prospective application. PMID:27451357

  4. Dietary Supplementation of Blueberry Juice Enhances Hepatic Expression of Metallothionein and Attenuates Liver Fibrosis in Rats

    PubMed Central

    Wang, Yuping; Cheng, Mingliang; Zhang, Baofang; Nie, Fei; Jiang, Hongmei

    2013-01-01

    Aim To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense. Methods Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX) was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl4 and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA) and collagen III (Col III) were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenates were determined. Metallothionein (MT) expression was detected by real-time RT-PCR and immunohistochemical techniques. Results Blueberry juice consumption significantly attenuates CCl4-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT), increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver. Conclusion Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis. PMID:23554912

  5. Oxidative stress associated with pathological lesions in the liver of rats experimentally infected by Fasciola hepatica.

    PubMed

    Bottari, Nathieli B; Mendes, Ricardo E; Lucca, Neuber J; Schwertz, Claiton I; Henker, Luan C; Olsson, Débora C; Piva, Manoela M; Sangoi, Manuela; Campos, Luízi P; Moresco, Rafael N; Jaques, Jeandre A; Da silva, Aleksandro S

    2015-12-01

    The aim of this study was to analyze the antioxidant status and oxidative profile in serum and liver of rats experimentally infected with Fasciola hepatica and its relationship with pathological findings. Twenty-four rats were divided into two groups: group A consisted of 12 healthy rats and group B of 12 rats infected orally with 20 metacercaria of F. hepatica. At days 20 and 150 post-infection (PI), blood and liver samples of six animals from each group were collected. The protein oxidation (AOPP technique: advanced oxidation protein products) and antioxidants (FRAP technique: ferric reducing antioxidant power) levels were measured in serum and liver. Furthermore, nitrite/nitrate (NOx) levels and lipid peroxidation (TBARS technique: thiobarbituric acid reactive substances) were measured in liver. AOPP and FRAP levels were increased (P < 0.05) in serum and liver of infected animals in acute and chronic infection when compared with healthy animals. The same occurred with TBARS and NOx levels in the liver (P < 0.05). Histopathology revealed periportal fibrous hepatitis, composed of an abundant inflammatory infiltrate in portal spaces on infected animals, as well as bile duct hyperplasia. The results found seem to be related to the host free radical production demonstrated in serum samples and liver due to the parasite infection. PMID:26311170

  6. Therapeutic effect of Pleurotus eryngii cellulose on experimental fatty liver in rats.

    PubMed

    Huang, J F; Zhan, T; Yu, X L; He, Q A; Huang, W J; Lin, L Z; Du, Y T; Pan, Y T

    2016-01-01

    The aim of this study was to explore the therapeutic effect of Pleurotus eryngii cellulose on experimental fatty liver in rats. Rats were fed high-fat fodder to establish a rat fatty liver model, and were then fed different concentrations of Pleurotus eryngii cellulose for six weeks. Lipitor was used as a positive control. Measured levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), and total triglyceride (TG); the activity of malondialdehyde (MDA), superoxide dismutase (SOD), hepatic lipase (HL), and lipoprotein lipase; and liver histopathological changes. Successfully established rat fatty liver model after feeding high-fat fodder for one week. A diet of P. eryngii cellulose for six weeks significantly reduced ALT, AST, TC, and TG levels in rat serum (P < 0.01); TC and AST levels in P. eryngii cellulose high-dose group and Lipitor group were not significantly different from those of the control (P > 0.05). SOD activity increased significantly, while MDA and HL activity decreased (P < 0.05); fatty degeneration and fat accumulation both decreased in hepatic tissue. Hepatic protection of P. eryngii cellulose showed dose-related effect. P. eryngii cellulose can affect lipid metabolism, having therapeutic effects on fatty liver in rats. PMID:26985922

  7. EVALUATION OF BENZO[C]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T1/2CL8 CELLS

    EPA Science Inventory

    EVALUATION OF BENZO[c]CHRYSENE DIHYDRODIOLS IN THE MORPHOLOGICAL CELL TRANSFORMATION OF MOUSE EMBRYO FIBROBLAST C3H10T?CL8 CELLS

    Abstract The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans-B[c]C-7,8-diol, trans-B[c]C-9...

  8. Expression patterns and action analysis of genes associated with drug-induced liver diseases during rat liver regeneration

    PubMed Central

    Ning, Qian-Ji; Qin, Shao-Wei; Xu, Cun-Shuan

    2006-01-01

    AIM: To study the action of the genes associated with drug-induced liver diseases at the gene transcriptional level during liver regeneration (LR) in rats. METHODS: The genes associated with drug-induced liver diseases were obtained by collecting the data from databases and literature, and the gene expression changes in the regenerating liver were checked by the Rat Genome 230 2.0 array. RESULTS: The initial and total expression numbers of genes occurring in phases of 0.5-4 h after partial hepatectomy (PH), 4-6 h after PH (G0/G1 transition), 6-66 h after PH (cell proliferation), 66-168 h after PH (cell differentiation and structure-function reconstruction) were 21, 3, 9, 2 and 21, 9, 19, 18, respectively. It is illustrated that the associated genes were mainly triggered at the initial stage of LR and worked at different phases. According to their expression similarity, these genes were classified into 5 types: only up-regulated (12 genes), predominantly up-regulated (4 genes), only down-regulated (11 genes), predominantly down-regulated (3 genes), and approximately up-/down-regulated (2 genes). The total times of their up- and down-expression were 130 and 79, respectively, demonstrating that expression of most of the genes was increased during LR, while a few decreased. The cell physiological and biochemical activities during LR were staggered according to the time relevance and were diverse and complicated in gene expression patterns. CONCLUSION: Drug metabolic capacity in regenerating liver was enhanced. Thirty-two genes play important roles during liver regeneration in rats. PMID:17109518

  9. Effects of ventromedial and lateral hypothalamic stimulation on chemically-induced liver injury in rats

    SciTech Connect

    Iwai, M.; Shimazu, T.

    1988-01-01

    The effects of hypothalamic stimulation on experimental liver injury induced by carbon tetrachloride (CCL/sub 4/) or dimethylnitrosamine (DMN) were studied in rats, by measuring plasma alanine amino-transferase (ALT) activity as an index of acute liver injury. Electrical stimulation of the ventromedial hypothalamus (VHM) in CCl/sub 4/-treated rats caused a marked increase in plasma ALT activity, accompanied by a significant decrease in ALT activity in the liver, although CCl4 treatment alone had no significant effect on plasma ALT activity. A similar effect of VHM stimulation on plasma ALT activity was observed in rats treated with DMN, another hepatotoxic chemical. No such exaggerated effect of VMH stimulation on plasma ALT activity was observed after stimulation of the lateral hypothalamic area (LH). Surgical sympathetic denervation of the liver greatly suppressed the increase in plasma ALT activity after CCl/sub 4/ injection and VMH stimulation. Measurement of regional blood flow indicated that VMH stimulation did not produce a significant change in blood flow to the liver. These results suggest that the VMH is involved in the progress of chemically-induced liver injury through activation of the sympathetic nerve, possibly by affecting liver metabolism more than the blood flow change to the liver.

  10. [Mitochondrial dysfunction and compensatory mechanisms in liver cells during acute carbon tetrachloride-induced rat intoxication].

    PubMed

    Zavodnik, I B

    2015-01-01

    Electron-transport chain and redox-balance of mitochondria are important targets that are damaged during intoxication. The aim of the present work was to estimate the role of impairments in cellular bioenergetic function in the development of liver damage during acute carbon tetrachloride intoxication in rats and to elucidate possible compensatory mechanisms. Acute CCl4-induced rat intoxication (0.8 g/kg or 4 g/kg) resulted in considerable impairments of respiratory and synthetic mitochondrial functions; their manifestations depended on the dose of the toxic agent and the duration of the intoxication increased and accompanied by complete uncoupling of oxidation and phosphorylation processes in liver mitochondria. The intoxication induced considerable liver damage and accumulation of NO in blood plasma and liver tissue. The changes of some parameters of liver mitochondrial functional activity demonstrate an oscillative pattern, reflecting compensatory mechanisms during intoxication that involved increased reduced glutathione level and enhanced succinate dehydrogenase activity. PMID:26716745

  11. The characteristic gene expressions of MAPK phosphatases 1 and 2 in hepatocarcinogenesis, rat ascites hepatoma cells, and regenerating rat liver.

    PubMed

    Yokoyama, A; Karasaki, H; Urushibara, N; Nomoto, K; Imai, Y; Nakamura, K; Mizuno, Y; Ogawa, K; Kikuchi, K

    1997-10-29

    mRNA levels of mitogen-activated protein kinase phosphatases, MKP-1 and MKP-2, were determined during chemical hepatocarcinogenesis and during regeneration of rat liver. In chemical hepatocarcinogenesis, the mRNA levels of MKP-1 were increased in primary hepatomas but decreased in rat ascites hepatomas as compared with normal liver. MKP-2 was undetectable in normal liver but strongly expressed in hepatomas. The MKP-2 mRNA level was increased with expression of malignant phenotypes in hepatomas. In regenerating liver, the mRNA level of MKP-1 increased immediately but transiently after partial hepatectomy, and peaked again on day 10, the time when hepatocytes cease proliferation. The elevated expression of MKP-1 on day 10 suggests some roles of MKP-1 as a negative regulator in hepatocyte proliferation. PMID:9367840

  12. Repeated Treatment with Furazolidone Induces Multiple Cytochrome P450-Related Activities in Chicken Liver, but Not in Rat Liver

    PubMed Central

    SASAKI, Nobuo; MATUMOTO, Tomoyuki; IKENAKA, Yoshinori; NAKAYAMA, Shouta M. M.; ISHIZUKA, Mayumi; KAZUSAKA, Akio; FUJITA, Shoichi

    2013-01-01

    ABSTRACT The nitrofuran antimicrobial agent, furazolidone (FZ), is still used in veterinary medicine in some countries in the Middle and Far Eastern countries. The present study aimed to investigate the effects of successive bolus doses of FZ and its metabolite 3-amino-2-oxazolidinone (AOZ) on cytochrome P450 (CYP)-related activities in the livers of rats and chickens. Female Wistar rats and white Leghorn chickens were orally administered FZ once a day for 4 consecutive days. FZ-treated chickens showed an increase in multiple CYP-related activities, however, rats treated with FZ did not show these changes. In chickens, treatment with FZ also induced production of microsomal CYP2C6-like apoprotein. The present study demonstrated that FZ caused a multiple-type induction of CYP-related activities in chickens, but not in rats. PMID:23774039

  13. Effect of Azadirachta indica (Neem) leaf aqueous extract on paracetamol-induced liver damage in rats.

    PubMed

    Bhanwra, S; Singh, J; Khosla, P

    2000-01-01

    The effect of aqueous leaf extract of Azadirachta indica (A. indica) was evaluated in paracetamol induced hepatotoxicity in rats. Liver necrosis was produced by administering single dose of paracetamol (2 g/kg, p.o.). The liver damage was evidenced by elevated levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transpeptidase (gamma-GT) and by histopathological observations of liver sections. Aqueous A. indica leaf extract (500 mg/kg, p.o.) significantly (P < 0.01) reduced these elevated levels of AST, ALT and gamma-GT. Paracetamol induced liver necrosis was also found to be reduced as observed macroscopically and histologically. PMID:10919097

  14. The Mechanisms Underlying the Hypolipidaemic Effects of Grifola frondosa in the Liver of Rats.

    PubMed

    Ding, Yinrun; Xiao, Chun; Wu, Qingping; Xie, Yizhen; Li, Xiangmin; Hu, Huiping; Li, Liangqiu

    2016-01-01

    The present study investigated the hypolipidaemic effects of Grifola frondosa and its regulation mechanism involved in lipid metabolism in liver of rats fed a high-cholesterol diet. The body weights and serum lipid levels of control rats, of hyperlipidaemic rats, and of hyperlipidaemic rats treated with oral G. frondosa were determined. mRNA expression and concentration of key lipid metabolism enzymes were investigated. Serum cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels were markedly decreased in hyperlipidaemic rats treated with G. frondosa compared with untreated hyperlipidaemic rats. mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), acyl-coenzyme A: cholesterol acyltransferase (ACAT2), apolipoprotein B (ApoB), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC1) were significantly down-regulated, while expression of cholesterol 7-alpha-hydroxylase (CYP7A1) was significantly up-regulated in the livers of treated rats compared with untreated hyperlipidaemic rats. The concentrations of these enzymes also paralleled the observed changes in mRNA expression. Two-dimensional polyacrylamide gel electrophoresis (2-DE) and Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) were used to identify 20 proteins differentially expressed in livers of rats treated with G. frondosa compared with untreated hyperlipidemic rats. Of these 20 proteins, seven proteins were down-regulated, and 13 proteins were up-regulated. These findings indicate that the hypolipidaemic effects of G. frondosa reflected its modulation of key enzymes involved in cholesterol and triacylglycerol biosynthesis, absorption, and catabolic pathways. G. frondosa may exert anti-atherosclerotic effects by inhibiting LDL oxidation through down-regulation and up-regulating proteins expression in the liver of rats. Therefore, G. frondosa may produce both hypolipidaemic and anti-atherosclerotic effects, and potentially

  15. The Mechanisms Underlying the Hypolipidaemic Effects of Grifola frondosa in the Liver of Rats

    PubMed Central

    Ding, Yinrun; Xiao, Chun; Wu, Qingping; Xie, Yizhen; Li, Xiangmin; Hu, Huiping; Li, Liangqiu

    2016-01-01

    The present study investigated the hypolipidaemic effects of Grifola frondosa and its regulation mechanism involved in lipid metabolism in liver of rats fed a high-cholesterol diet. The body weights and serum lipid levels of control rats, of hyperlipidaemic rats, and of hyperlipidaemic rats treated with oral G. frondosa were determined. mRNA expression and concentration of key lipid metabolism enzymes were investigated. Serum cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels were markedly decreased in hyperlipidaemic rats treated with G. frondosa compared with untreated hyperlipidaemic rats. mRNA expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), acyl-coenzyme A: cholesterol acyltransferase (ACAT2), apolipoprotein B (ApoB), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC1) were significantly down-regulated, while expression of cholesterol 7-alpha-hydroxylase (CYP7A1) was significantly up-regulated in the livers of treated rats compared with untreated hyperlipidaemic rats. The concentrations of these enzymes also paralleled the observed changes in mRNA expression. Two-dimensional polyacrylamide gel electrophoresis (2-DE) and Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) were used to identify 20 proteins differentially expressed in livers of rats treated with G. frondosa compared with untreated hyperlipidemic rats. Of these 20 proteins, seven proteins were down-regulated, and 13 proteins were up-regulated. These findings indicate that the hypolipidaemic effects of G. frondosa reflected its modulation of key enzymes involved in cholesterol and triacylglycerol biosynthesis, absorption, and catabolic pathways. G. frondosa may exert anti-atherosclerotic effects by inhibiting LDL oxidation through down-regulation and up-regulating proteins expression in the liver of rats. Therefore, G. frondosa may produce both hypolipidaemic and anti-atherosclerotic effects, and potentially

  16. Normothermic machine perfusion reduces bile duct injury and improves biliary epithelial function in rat donor livers.

    PubMed

    Op den Dries, Sanna; Karimian, Negin; Westerkamp, Andrie C; Sutton, Michael E; Kuipers, Michiel; Wiersema-Buist, Janneke; Ottens, Petra J; Kuipers, Jeroen; Giepmans, Ben N; Leuvenink, Henri G D; Lisman, Ton; Porte, Robert J

    2016-07-01

    Bile duct injury may occur during liver procurement and transplantation, especially in livers from donation after circulatory death (DCD) donors. Normothermic machine perfusion (NMP) has been shown to reduce hepatic injury compared to static cold storage (SCS). However, it is unknown whether NMP provides better preservation of bile ducts. The aim of this study was to determine the impact of NMP on bile duct preservation in both DCD and non-DCD livers. DCD and non-DCD livers obtained from Lewis rats were preserved for 3 hours using either SCS or NMP, followed by 2 hours ex vivo reperfusion. Biomarkers of bile duct injury (gamma-glutamyltransferase and lactate dehydrogenase in bile) were lower in NMP-preserved livers compared to SCS-preserved livers. Biliary bicarbonate concentration, reflecting biliary epithelial function, was 2-fold higher in NMP-preserved livers (P < 0.01). In parallel with this, the pH of the bile was significantly higher in NMP-preserved livers (7.63 ± 0.02 and 7.74 ± 0.05 for non-DCD and DCD livers, respectively) compared with SCS-preserved livers (7.46 ± 0.02 and 7.49 ± 0.04 for non-DCD and DCD livers, respectively). Scanning and transmission electron microscopy of donor extrahepatic bile ducts demonstrated significantly decreased injury of the biliary epithelium of NMP-preserved donor livers (including the loss of lateral interdigitations and mitochondrial injury). Differences between NMP and SCS were most prominent in DCD livers. Compared to conventional SCS, NMP provides superior preservation of bile duct epithelial cell function and morphology, especially in DCD donor livers. By reducing biliary injury, NMP could have an important impact on the utilization of DCD livers and outcome after transplantation. Liver Transplantation 22 994-1005 2016 AASLD. PMID:26946466

  17. Metabolism of aildenafil in vivo in rats and in vitro in mouse, rat, dog, and human liver microsomes.

    PubMed

    Li, Yan; Wu, Linan; Gu, Yuan; Si, Duanyun; Liu, Changxiao

    2014-06-01

    Aildenafil, 1-{[3-(6, 7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4, 3-d] primidin-5-yl)-4-ethoxyphenyl] sulfonyl}-cis-3, 5-dimethylpiperazine, a phosphodiesterase type V enzyme inhibitor (PDE5I), is under development for treatment of erectile dysfunction (ED). The purpose of this study was to elucidate metabolism of aildenafil in vivo in rats and in vitro in mouse, rat, dog, and human liver microsomes. Thirty-one phase I metabolites have been found by LTQ/Orbitrap hybrid mass spectrometry in rat urine, faeces, and bile after oral administration. Major biotransformation pathways of aildenafil included N-dealkylation of the piperazine ring, hydroxylation and dehydrogenation, aliphatic hydroxylation and loss of alkyl group of piperazine ring. Minor pathways involved hydroxylation on the phenyl ring, pyrazole N-demethylation, O-deethylation, loss of piperazine ring (cleavage of N-S bond) and dehydrogenation on the piperazine ring. Similar metabolic pathways of aildenafil were observed in the incubations of liver microsomes from mouse, rat, and dog as well as from human. The depletion rate of parent drug in mouse and rat liver microsomes was significantly different from that in human liver microsomes. The cytochrome P450 reaction phenotyping analysis was conducted using isozyme-specific inhibitors. The results indicated that CYP3A was the main isoenzyme involved in oxidative metabolism of aildenafil. Overall, these in vitro and in vivo findings should provide valuable information on possible metabolic behaviours of aildenafil in humans. PMID:24311535

  18. Ameliorative effect of Partysmart in rat model of alcoholic liver disease.

    PubMed

    Gopumadhavan, S; Rafiq, Mohammed; Azeemuddin, M; Mitra, S K

    2008-02-01

    Present study was designed to investigate the effect of polyherbal formulation PartySmart in experimental model of alcoholic liver disease in male Wistar strain rats. Alcohol plus fish oil were administered to animals for 8 weeks to induce liver injury. PartySmart was administered at doses of 250 and 500 mg/kg body weight. After 8 weeks, parameters such as liver weight, liver function serum markers alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) and lipid peroxidation were studied. Livers from all the groups were subjected for histological evaluation. Treatment with PartySmart at the dose of 500 mg/kg body weight showed significant reduction in the levels of serum ALT, AST and ALP with a decrease in liver weight as compared to ethanol-fed rats. A significant decrease was also observed in malondialdehyde levels following treatment with PartySmart at 500 mg/kg body weight. Histological profile of liver tissue in PartySmart-treated animals showed lesser vacuolar degeneration and intactness of hepatic architecture along with improved glycogen deposition as demonstrated by PAS staining. PartySmart ameliorated alcohol-induced liver injury by preventing cell membrane disturbances, reduction of oxidative stress by free radical scavenging and antioxidant activity and normalization of altered intracellular redox status. Thus, PartySmart can be beneficial in the treatment of alcohol-induced liver damage. PMID:18335812

  19. Silymarin's Protective Effects and Possible Mechanisms on Alcoholic Fatty Liver for Rats.

    PubMed

    Zhang, Wei; Hong, Rutao; Tian, Tulei

    2013-07-30

    Silymarin has been introduced fairly recently as a hepatoprotective agent. But its mechanisms of action still have not been well established. The aim of this study was to make alcoholic fatty liver model of rats in a short time and investigate silymarin's protective effects and possible mechanisms on alcoholic fatty liver for rats. The model of rat's alcoholic fatty liver was induced by intragastric infusion of ethanol and high-fat diet for six weeks. Histopathological changes were assessed by hematoxylin and eosin staining (HE). The activities of alanine transarninase (ALT) and aspartate aminotransferase (AST), the levels of total bilirubin (TBIL), total cholesterol (TC) and triglyceride (TG) in serum were detected with routine laboratory methods using an autoanalyzer. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and the level of malondialdehyde (MDA) in liver homogenates were measured by spectrophotometry. The TG content in liver tissue was determined by spectrophotometry. The expression of nuclear factor-κB (NF-κB), intercellular adhesion molecule-1 (ICAM-1) and interleukin-6 (IL-6) in the liver were analyzed by immunohistochemistry. Silymarin effectively protected liver from alcohol-induced injury as evidenced by improving histological damage situation, reducing ALT and AST activities and TBIL level in serum, increasing SOD and GPx activities and decreasing MDA content in liver homogenates and reducing TG content in liver tissue. Additionally, silymarin markedly downregulated the expression of NF-κB p65, ICAM-1 and IL-6 in liver tissue. In conclusion, Silymarin could protect against the liver injury caused by ethanol administration. The effect may be related to alleviating lipid peroxidation and inhibiting the expression of NF-κB. PMID:24244810

  20. D-Lactate transport and metabolism in rat liver mitochondria.

    PubMed Central

    de Bari, Lidia; Atlante, Anna; Guaragnella, Nicoletta; Principato, Giovanni; Passarella, Salvatore

    2002-01-01

    In the present study we investigated whether isolated rat liver mitochondria can take up and metabolize D-lactate. We found the following: (1) externally added D-lactate causes oxygen uptake by mitochondria [P/O ratio (the ratio of mol of ATP synthesized to mol of oxygen atoms reduced to water during oxidative phosphorylation)=2] and membrane potential (Delta(psi)) generation in processes that are rotenone-insensitive, but inhibited by antimycin A and cyanide, and proton release from coupled mitochondria inhibited by alpha-cyanocinnamate, but not by phenylsuccinate; (2) the activity of the putative flavoprotein (D-lactate dehydrogenase) was detected in inside-out submitochondrial particles, but not in mitochondria and mitoplasts, as it is localized in the matrix phase of the mitochondrial inner membrane; (3) three novel separate translocators exist to mediate D-lactate traffic across the mitochondrial inner membrane: the D-lactate/H(+) symporter, which was investigated by measuring fluorimetrically the rate of endogenous flavin reduction, the D-lactate/oxoacid antiporter (which mediates both the D-lactate/pyruvate and D-lactate/oxaloacetate exchanges) and D-lactate/malate antiporter studied by monitoring photometrically the appearance of the D-lactate counteranions outside mitochondria. The D-lactate translocators, in the light of their different inhibition profiles separate from the monocarboxylate carrier, were found to differ from each other in the V(max) values and in the inhibition and pH profiles and were shown to regulate mitochondrial D-lactate metabolism in vitro. The D-lactate translocators and the D-lactate dehydrogenase could account for the removal of the toxic methylglyoxal from cytosol, as well as for D-lactate-dependent gluconeogenesis. PMID:11955284

  1. Subpopulations of proteasomes in rat liver nuclei, microsomes and cytosol.

    PubMed Central

    Palmer, A; Rivett, A J; Thomson, S; Hendil, K B; Butcher, G W; Fuertes, G; Knecht, E

    1996-01-01

    Mammalian proteasomes are composed of 14-17 different types of subunits, some of which, including major-histocompatibility-complex-encoded subunits LMP2 and LMP7, are non-essential and present in variable amounts. We have investigated the distribution of total proteasomes and some individual subunits in rat liver by quantitative immunoblot analysis of purified subcellular fractions (nuclei, mitochondria, microsomes and cytosol). Proteasomes were mainly found in the cytosol but were also present in the purified nuclear and microsomal fractions. In the nuclei, proteasomes were soluble or loosely attached to the chromatin, since they could be easily extracted by treatment with nucleases or high concentrations of salt. In the microsomes, proteasomes were on the outside of the membranes. Further subfractionation of the microsomes showed that the proteasomes in this fraction were associated with the smooth endoplasmic reticulum and with the cis-Golgi but were practically absent from the rough endoplasmic reticulum. Using monospecific antibodies for some proteasomal subunits (C8, C9, LMP2 and Z), the composition of proteasomes in nuclei, microsomes and cytosol was investigated. Although there appear not to be differences in proteasome composition in the alpha subunits (C8 and C9) in the different locations, the relative amounts of some beta subunits varied. Subunit Z was enriched in nuclear proteasomes but low in microsome-associated proteasomes, whereas LMP2, which was relatively low in nuclei, showed a small enrichment in the microsomes. These differences in subunit composition of proteasomes probably reflect differences in the function of proteasomes in distinct cell compartments. PMID:8687380

  2. Protective effect of potato peel extract against carbon tetrachloride-induced liver injury in rats.

    PubMed

    Singh, Nandita; Kamath, Vasudeva; Narasimhamurthy, K; Rajini, P S

    2008-09-01

    Our earlier studies have shown that extracts derived from potato peel (PPE) are rich in polyphenols and possess strong antioxidant activity both in vitro and in vivo. The objective of the present study was to investigate its potential to offer protection against acute liver injury in rats. Rats pretreated with PPE (oral, 100mg/kgb.w./day for 7 days) were administered a single oral dose carbon tetrachloride (CCl(4), 3ml/kg b.w., 1:1 in groundnut oil) and sacrificed 8h of post-treatment. Hepatic damage was assessed by employing biochemical parameters (transaminase enzyme levels in plasma and liver [AST-aspartate transaminase; ALT-alanine transaminase, LDH-lactate dehydrogenase]). Further, markers of hepatic oxidative damage were measured in terms of malondialdehyde (MDA), enzymic antioxidants (CAT, SOT, GST, GPX) and GSH (reduced glutathione) levels. In addition, the CCl(4)-induced pathological changes in liver were evaluated by histopathological studies. Our results demonstrated that pretreatment of rats with PPE significantly prevented the increased activities of AST and ALT in serum, prevented the elevation of hepatic MDA formation as well as protected the liver from GSH depletion. PPE pretreatment also restored CCl(4)-induced altered antioxidant enzyme activities to control levels. The protective effect of PPE was further evident through the decreased histological alterations in liver. Our findings provide evidences to demonstrate that PPE pretreatment significantly offsets CCl(4)-induced liver injury in rats, which may be attributable to its strong antioxidant propensity. PMID:21791371

  3. Dietary nucleotides protect against alcoholic liver injury by attenuating inflammation and regulating gut microbiota in rats.

    PubMed

    Cai, Xiaxia; Bao, Lei; Wang, Nan; Ren, Jinwei; Chen, Qihe; Xu, Meihong; Li, Di; Mao, Ruixue; Li, Yong

    2016-06-15

    Nucleotides have been reported to be effective in attenuating liver damage and regulating gut microbiota. However, the protective effect of nucleotides against alcoholic liver injury remains unknown. The present study aims to investigate whether nucleotides ameliorate alcoholic liver injury and explores the possible mechanism. Male Wistar rats were given alcohol, equivalent distilled water or an isocaloric amount of dextrose intragastrically twice daily for up to 6 weeks respectively. Two subgroups of alcohol-treated rats were fed with a nucleotide-supplemented AIN-93G rodent diet. Serum enzymes, inflammatory cytokines and microbiota composition of the caecum content were evaluated. We found that nucleotides could significantly decrease serum alanine aminotransferase and aspartate aminotransferase, plasma lipopolysaccharide and inflammatory cytokine levels. Sequencing of 16S rRNA genes revealed that nucleotide-treated rats showed a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than alcohol-treated rats. Moreover, nucleotide treatment inhibited the protein expression of toll-like receptor 4, CD14 and repressed the phosphorylation of inhibitor kappa Bα and nuclear factor-κB p65 in the liver. These results suggested that nucleotides suppressed the inflammatory response and regulated gut microbiota in alcoholic liver injury. The partial inhibition of lipopolysaccharide - toll-like receptor 4-nuclear factor-κB p65 signaling in the liver may be attributed to this mechanism. PMID:27247978

  4. Expression of liver carnitine palmitoyltransferase I and II genes during development in the rat.

    PubMed Central

    Thumelin, S; Esser, V; Charvy, D; Kolodziej, M; Zammit, V A; McGarry, D; Girard, J; Pegorier, J P

    1994-01-01

    The enzyme activity and the expression (protein and mRNA concentrations) of genes encoding for hepatic carnitine palmitoyl-transferases (CPT) I and II were studied during neonatal development, in response to nutritional state at weaning and during the fed-starved transition in adult rats. The activity, the protein concentration and the level of mRNA encoding CPT I are low in foetal-rat liver and increase 5-fold during the first day of extra-uterine life. The activity and gene expression of CPT I are high during the entire suckling period, in the liver of 30-day-old rats weaned at 20 days on to a high-fat diet and in the liver of 48 h-starved adult rats. The activity and CPT I gene expression are markedly decreased in the liver of rats weaned on to a high-carbohydrate diet. By contrast, the activity, the protein concentration and the level of mRNA encoding CPT II are already high in the liver of term foetuses and remain at this level throughout the suckling period, irrespective of the nutritional state of the animals either at weaning or in the adult. Images Figure 1 Figure 2 PMID:8002965

  5. Bisphenol A glucuronide/sulfate diconjugate in perfused liver of rats

    PubMed Central

    INOUE, Hiroki; KEMANAI, Shino; SANO, Chie; KATO, Seiyu; YOKOTA, Hiroshi; IWANO, Hidetomo

    2016-01-01

    In isolated hepatocytes, the environmental estrogen bisphenol A (BPA) is metabolized into a mono-glucuronide and a glucuronide/sulfate diconjugate. Little is known about the fate of the diconjugate in the liver. The present study focused on the metabolism and dispostion of BPA diconjugate in the liver using a perfusion method. In Sprague-Dawley rats, BPA (15,150 or 1,500 nmol) was applied into the liver. In male rats, the infused BPA was conjugated to both glucuronide and a diconjugate during passage through the liver. The diconjugate was observed at high-dose application of the substrate. In female rats, the chemical was conjugated almost exclusively to the glucuronide in all doses utilized in this study. In both the male and female rats, the resultant metabolites were preferentially excreted into the bile. These results suggest that BPA is conjugated primarily to mono-glucuronide in rat liver; and that in males, diconjugate production occurs under conditions of high-dose exposure to BPA. PMID:26782136

  6. Lack of significant promoting activity by benzene in the rat liver model of carcinogenesis

    SciTech Connect

    Taningher, M.; Perrotta, A.; Malacarne, D.

    1995-08-01

    The promoting activity of benzene on rat liver carcinogenesis was investigated. The chemical was tested for its ability to enhance the growth of preneoplastic foci, as detected by gamma-glutamyl transpeptidase (GGT) staining in diethylnitrosamine (DENA) initiated hepatocytes. Two weeks after receiving a single ip dose of 200 mg/kg DENA, F344 rats were given daily oral doses of 400 mg/kg benzene (5 d/wk) for 6 wk. At wk 3 after the experiment began, all animals underwent partial hepatectomy, and at wk 8 were sacrificed. Following benzene treatment, no variation in the liver/body weight ratio was observed. After scoring of foci in liver slides, no significant difference in foci number and area could be observed between rats treated with DENA plus benzene and rats treated with DENA alone. Practically no foci were observed in the liver of rats treated only with benzene. The lack of benzene promoting activity in the liver model is discussed. 28 refs., 1 fig., 1 tab.

  7. Bisphenol A glucuronide/sulfate diconjugate in perfused liver of rats.

    PubMed

    Inoue, Hiroki; Kemanai, Shino; Sano, Chie; Kato, Seiyu; Yokota, Hiroshi; Iwano, Hidetomo

    2016-06-01

    In isolated hepatocytes, the environmental estrogen bisphenol A (BPA) is metabolized into a mono-glucuronide and a glucuronide/sulfate diconjugate. Little is known about the fate of the diconjugate in the liver. The present study focused on the metabolism and dispostion of BPA diconjugate in the liver using a perfusion method. In Sprague-Dawley rats, BPA (15,150 or 1,500 nmol) was applied into the liver. In male rats, the infused BPA was conjugated to both glucuronide and a diconjugate during passage through the liver. The diconjugate was observed at high-dose application of the substrate. In female rats, the chemical was conjugated almost exclusively to the glucuronide in all doses utilized in this study. In both the male and female rats, the resultant metabolites were preferentially excreted into the bile. These results suggest that BPA is conjugated primarily to mono-glucuronide in rat liver; and that in males, diconjugate production occurs under conditions of high-dose exposure to BPA. PMID:26782136

  8. Vitamin K1 attenuates bile duct ligation-induced liver fibrosis in rats.

    PubMed

    Jiao, Kun; Sun, Quan; Chen, Baian; Li, Shengli; Lu, Jing

    2014-06-01

    Vitamin K1 is used as a liver protection drug for cholestasis-induced liver fibrosis in China, but the mechanism of vitamin K1's action in liver fibrosis is unclear. In this study, a model of liver fibrosis was achieved via bile duct ligation in rats. The rats were then injected with vitamin K1, and the levels of serum aspartate aminotransferase, alanine transaminase, total bilirubin and the fibrotic grade score, collagen content, the expressions of α-smooth muscle actin (SMA) and cytokeratin 19 (CK19) were measured on day 28 after ligation. The levels of the biochemical parameters, fibrotic score and collagen content were significantly reduced by treatment with vitamin K1 in bile duct-ligated rats. In addition, α-SMA and CK19 expression was significantly reduced by vitamin K1 treatment in bile duct-ligated rats. These results suggested that vitamin K1 may attenuate liver fibrosis by inhibiting hepatic stellate cell activation in bile duct-ligated rats. PMID:24742111

  9. Inhibition of cyclooxygenase-2 alleviates liver cirrhosis via improvement of the dysfunctional gut-liver axis in rats.

    PubMed

    Gao, Jin-Hang; Wen, Shi-Lei; Tong, Huan; Wang, Chun-Hui; Yang, Wen-Juan; Tang, Shi-Hang; Yan, Zhao-Ping; Tai, Yang; Ye, Cheng; Liu, Rui; Huang, Zhi-Yin; Tang, Ying-Mei; Yang, Jin-Hui; Tang, Cheng-Wei

    2016-06-01

    Inflammatory transport through the gut-liver axis may facilitate liver cirrhosis. Cyclooxygenase-2 (COX-2) has been considered as one of the important molecules that regulates intestinal epithelial barrier function. This study was aimed to test the hypothesis that inhibition of COX-2 by celecoxib might alleviate liver cirrhosis via reduction of intestinal inflammatory transport in thiacetamide (TAA) rat model. COX-2/prostaglandin E2 (PGE2)/EP-2/p-ERK integrated signal pathways regulated the expressions of intestinal zonula occludens-1 (ZO-1) and E-cadherin, which maintain the function of intestinal epithelial barrier. Celecoxib not only decreased the intestinal permeability to a 4-kDa FITC-dextran but also significantly increased expressions of ZO-1 and E-cadherin. When celecoxib greatly decreased intestinal levels of LPS, TNF-α, and IL-6, it significantly enhanced T cell subsets reduced by TAA. As a result, liver fibrosis induced by TAA was significantly alleviated in the celecoxib group. These data indicated that celecoxib improved the integrity of intestinal epithelial barrier, blocked inflammatory transport through the dysfunctional gut-liver axis, and ameliorated the progress of liver cirrhosis. PMID:27056726

  10. Carcinogenic risk of copper gluconate evaluated by a rat medium-term liver carcinogenicity bioassay protocol.

    PubMed

    Abe, Masayoshi; Usuda, Koji; Hayashi, Seigo; Ogawa, Izumi; Furukawa, Satoshi; Igarashi, Maki; Nakae, Dai

    2008-08-01

    Carcinogenic risk and molecular mechanisms underlying the liver tumor-promoting activity of copper gluconate, an additive of functional foods, were investigated using a rat medium-term liver carcinogenicity bioassay protocol (Ito test) and a 2-week short-term administration experiment. In the medium-term liver bioassay, Fischer 344 male rats were given a single i.p. injection of N-nitrosodiethylamine at a dose of 200 mg/kg b.w. as a carcinogenic initiator. Starting 2 weeks thereafter, rats received 0, 10, 300 or 6,000 ppm of copper gluconate in diet for 6 weeks. All rats underwent 2/3 partial hepatectomy at the end of week 3, and all surviving rats were killed at the end of week 8. In the short-term experiment, rats were given 0, 10, 300 or 6,000 ppm of copper gluconate for 2 weeks. Numbers of glutathione S-transferase placental form (GST-P) positive lesions, single GST-P-positive hepatocytes and 8-oxoguanine-positive hepatocytes, and levels of cell proliferation and apoptosis in the liver were significantly increased by 6,000 ppm of copper gluconate in the medium-term liver bioassay. Furthermore, hepatic mRNA expression of genes relating to the metal metabolism, inflammation and apoptosis were elevated by 6,000 ppm of copper gluconate both in the medium-term liver bioassay and the short-term experiments. These results indicate that copper gluconate possesses carcinogenic risk toward the liver at the high dose level, and that oxidative stress and inflammatory and pro-apoptotic signaling statuses may participate in its underlying mechanisms. PMID:18350280

  11. Kupffer cell-mediated exacerbation of methimazole-induced acute liver injury in rats.

    PubMed

    Akai, Sho; Uematsu, Yasuaki; Tsuneyama, Koichi; Oda, Shingo; Yokoi, Tsuyoshi

    2016-05-01

    Methimazole (MTZ), an anti-thyroid drug, is known to cause liver injury in humans. It has been demonstrated that MTZ-induced liver injury in Balb/c mice is accompanied by T helper (Th) 2 cytokine-mediated immune responses; however, there is little evidence for immune responses associated with MTZ-induced liver injury in rats. To investigate species differences in MTZ-induced liver injury, we administered MTZ with a glutathione biosynthesis inhibitor, L-buthionine-S,R-sulfoximine (BSO), to F344 rats and subsequently observed an increase in plasma alanine aminotransferase (ALT) and high-mobility group box 1 (HMGB1), which are associated with hepatic lesions. The hepatic mRNA expression of innate immune-related genes significantly increased in BSO- and MTZ-treated rats, but the change in Th2-related genes was not much greater than the change observed in the previous mouse study. Moreover, an increase in Kupffer cells and an induction of the phosphorylation of extracellular signal-regulated kinase (ERK)/c-Jun N-terminal kinase (JNK) proteins were accompanied by an increase in Toll-like receptor 4 (TLR4) expression, indicating that Kupffer cell activation occurs through HMGB1-TLR4 signaling. To elucidate the mechanism of liver injury in rats, gadolinium chloride, which inactivates the function of Kupffer cells, was administered before BSO and MTZ administration. The gadolinium chloride treatment significantly suppressed the increased ALT, which was accompanied by decreased hepatic mRNA expression related to innate immune responses and ERK/JNK phosphorylation. In conclusion, Kupffer cell-mediated immune responses are crucial factors for the exacerbation of MTZ-induced liver injury in rats, indicating apparent species differences in the immune-mediated exacerbation of liver injury between mice and rats. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26177832

  12. Species differences in the handling of lysosomotropic metals and Triton WR 1339 by rat and Chinese hamster liver.

    PubMed

    Seidel, A; Heumann, H G; Sütterlin, U; Wiener, M; Haffner, H

    1985-05-01

    The study was undertaken in order to understand the reasons for the distinct differences in the elimination rate of lanthanides and transuranium elements from the liver of different mammalian species. The binding of monomeric 239Pu in livers of rats and Chinese hamsters was analyzed by density gradient centrifugation and electrophoresis. It was concluded that this nuclide is initially bound to lysosomes in liver of rats and Chinese hamsters. The influence of Triton WR 1339 (TWR) on the density of lysosomal marker enzymes from rat and Chinese hamster liver at day 4 was very similar for both animal species but the TWR induced shift persisted in Chinese hamsters up to day 60 whereas in rat liver the lysosomal density increased again with time. Electron microscopic inspection confirmed the similarity of the initial reaction of hepatocyte lysosomes. However, after 60 to 70 days typical TWR induced "tritosomes" were absent from rat hepatocytes but could be found regularly in hepatocytes from Chinese hamsters. The elimination rate of 3H-activity from liver injection of 3H-TWR was lower in Chinese hamsters than in rats. It was concluded that the differences in elimination rate of lanthanides and transuranium elements from liver of various mammalian species and the differences observed after TWR injection might reflect differences in the composition or function of the lysosomal system in the livers of different mammalian species. With respect to the transport of certain heavy metals the rat liver is not a reliable model for human liver. PMID:4029172

  13. Near-Infrared Fluorescence Imaging of Liver Metastases in Rats using Indocyanine Green

    PubMed Central

    van der Vorst, Joost R.; Hutteman, Merlijn; Mieog, Sven D.; de Rooij, Karien E.; Kaijzel, Eric L.; Löwik, Clemens W.G.M.; Putter, Hein; Kuppen, Peter J.K.; Frangioni, John V.; van de Velde, Cornelis J.H.; Vahrmeijer, Alexander L.

    2011-01-01

    Background Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is a promising technique to obtain real-time assessment of the extent and number of colorectal liver metastases during surgery. The current study aims to optimize dosage and timing of ICG administration. Materials and methods Liver tumors were induced in 18 male WAG/Rij rats by subcapsular inoculation of CC531 rat colorectal cancer cells into three distinct liver lobes. Rats were divided in 2 groups: imaging after 24 and 48 hours or 72 and 96 hours after intravenous ICG administration. In each time group, rats were allocated to three dose groups: 0.04, 0.08, or 0.16 mg ICG. Intraoperative imaging and ex vivo measurements were performed using Mini-FLARE™ and confirmed by fluorescence microscopy. Fluorescence intensity was quantified using the Mini-FLARE software and the difference between tumor signal and liver signal (tumor-to-liver ratio; TLR) was calculated. Results In all 18 rats, all colorectal liver metastases (N = 34), some as small as 1.2 mm, were identified using ICG and the Mini-FLARE™ imaging system. Average tumor-to-liver ratio (TLR) over all groups was 3.0 ± 1.2. TLR was significantly higher in the 72 h time group compared to other time points. ICG dose did not significantly influence TLR, but a trend was found favoring the 0.08 mg dose group. Fluorescence microscopy demonstrated a clear fluorescent rim around the tumor. Conclusions This study demonstrates that colorectal cancer liver metastases can be clearly identified during surgery using ICG and the Mini-FLARE™ imaging system, with optimal timing of 72 h post-injection and an optimal dose of 0.08 mg (0.25 mg/kg) ICG. NIR fluorescence imaging has the potential to improve intraoperative detection of micrometastases and thus the completeness of resection. PMID:21396660

  14. Effect of the Human Amniotic Membrane on Liver Regeneration in Rats

    PubMed Central

    Sipahi, Mesut; Şahin, Sevinç; Arslan, Ergin; Börekci, Hasan; Metin, Bayram; Cantürk, Nuh Zafer

    2015-01-01

    Introduction. Operations are performed for broader liver surgery indications for a better understanding of hepatic anatomy/physiology and developments in operation technology. Surgery can cure some patients with liver metastasis of some tumors. Nevertheless, postoperative liver failure is the most feared complication causing mortality in patients who have undergone excision of a large liver mass. The human amniotic membrane has regenerative effects. Thus, we investigated the effects of the human amniotic membrane on regeneration of the resected liver. Methods. Twenty female Wistar albino rats were divided into control and experimental groups and underwent a 70% hepatectomy. The human amniotic membrane was placed over the residual liver in the experimental group. Relative liver weight, histopathological features, and biochemical parameters were assessed on postoperative day 3. Results. Total protein and albumin levels were significantly lower in the experimental group than in the control group. No difference in relative liver weight was observed between the groups. Hepatocyte mitotic count was significantly higher in the experimental group than in the control group. Hepatic steatosis was detected in the experimental group. Conclusion. Applying the amniotic membrane to residual liver adversely affected liver regeneration. However, mesenchymal stem cell research has the potential to accelerate liver regeneration investigations. PMID:26457000

  15. A mode of action for induction of liver tumors by Pyrethrins in the rat

    SciTech Connect

    Price, Roger J.; Walters, David G.; Finch, John M.; Gabriel, Karl L.; Capen, Charles C.; Osimitz, Thomas G. . E-mail: tom@sciencestrategies.com; Lake, Brian G.

    2007-01-15

    High doses of Pyrethrins produce liver tumors in female rats. To elucidate the mode of action for tumor formation, the hepatic effects of Pyrethrins have been investigated. Male Sprague-Dawley CD rats were fed diets containing 0 (control) and 8000 ppm Pyrethrins and female rats' diets containing 0, 100, 3000 and 8000 ppm Pyrethrins for periods of 7, 14 and 42 days and 42 days followed by 42 days of reversal. As a positive control, rats were also fed diets containing 1200-1558 ppm sodium Phenobarbital (NaPB) for 7 and 14 days. The treatment of male rats with 8000 ppm Pyrethrins, female rats with 3000 and 8000 ppm Pyrethrins and both sexes with NaPB resulted in increased liver weights, which were associated with hepatocyte hypertrophy. Hepatocyte replicative DNA synthesis was also increased by treatment with Pyrethrins and NaPB. The treatment of male and female rats with Pyrethrins and NaPB produced significant increases in hepatic microsomal cytochrome P450 (CYP) content and a marked induction of CYP2B-dependent 7-pentoxyresorufin O-depentylase and testosterone 16{beta}-hydroxylase activities. Significant increases were also observed in CYP3A-dependent testosterone 6{beta}-hydroxylase activity. The hepatic effects of Pyrethrins were dose-dependent in female rats with 100 ppm being a no effect level and on cessation of treatment were reversible in both sexes. This study demonstrates that Pyrethrins are mitogenic CYP2B form inducers in rat liver. The mode of action for Pyrethrins-induced rat liver tumor formation appears to be similar to that of NaPB and some other non-genotoxic CYP2B inducers of hepatic xenobiotic metabolism.

  16. Metabolism of hyperpolarized [1-(13) C]pyruvate through alternate pathways in rat liver.

    PubMed

    Jin, Eunsook S; Moreno, Karlos X; Wang, Jian-Xiong; Fidelino, Leila; Merritt, Matthew E; Sherry, A Dean; Malloy, Craig R

    2016-04-01

    The source of hyperpolarized (HP) [(13) C]bicarbonate in the liver during metabolism of HP [1-(13) C]pyruvate is uncertain and likely changes with physiology. Multiple processes including decarboxylation through pyruvate dehydrogenase or pyruvate carboxylase followed by subsequent decarboxylation via phosphoenolpyruvate carboxykinase (gluconeogenesis) could play a role. Here we tested which metabolic fate of pyruvate contributed to the appearance of HP [(13) C]bicarbonate during metabolism of HP [1-(13) C]pyruvate by the liver in rats after 21 h of fasting compared to rats with free access to food. The (13) C NMR of HP [(13) C]bicarbonate was observed in the liver of fed rats, but not in fasted rats where pyruvate carboxylation and gluconeogenesis was active. To further explore the relative fluxes through pyruvate carboxylase versus pyruvate dehydrogenase in the liver under typical conditions of hyperpolarization studies, separate parallel experiments were performed with rats given non-hyperpolarized [2,3-(13) C]pyruvate. (13) C NMR analysis of glutamate isolated from the liver of rats revealed that flux from injected pyruvate through pyruvate dehydrogenase was dominant under fed conditions whereas flux through pyruvate carboxylase dominated under fasted conditions. The NMR signal of HP [(13) C]bicarbonate does not parallel pyruvate carboxylase activity followed by subsequent decarboxylation reaction leading to glucose production. In the liver of healthy well-fed rats, the appearance of HP [(13) C]bicarbonate exclusively reflects decarboxylation of HP [1-(13) C]pyruvate via pyruvate dehydrogenase. © 2016 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26836042

  17. Sipa1l1 is an early biomarker of liver fibrosis in CCl4-treated rats

    PubMed Central

    Marfà, Santiago; Morales-Ruiz, Manuel; Oró, Denise; Ribera, Jordi; Fernández-Varo, Guillermo; Jiménez, Wladimiro

    2016-01-01

    ABSTRACT At present, several procedures are used for staging liver fibrosis. However, these methods may involve clinical complications and/or present diagnostic uncertainty mainly in the early stages of the disease. Thus, this study was designed to unveil new non-invasive biomarkers of liver fibrosis in an in vivo model of fibrosis/cirrhosis induction by CCl4 inhalation by using a label-free quantitative LC-MS/MS approach. We analyzed 94 serum samples from adult Wistar rats with different degrees of liver fibrosis and 36 control rats. Firstly, serum samples from 18 CCl4-treated rats were clustered into three different groups according to the severity of hepatic and the serum proteome was characterized by label-free LC-MS/MS. Furthermore, three different pooled serum samples obtained from 16 control Wistar rats were also analyzed. Based on the proteomic data obtained, we performed a multivariate analysis which displayed three main cell signaling pathways altered in fibrosis. In cirrhosis, more biological imbalances were detected as well as multi-organ alterations. In addition, hemopexin and signal-induced proliferation-associated 1 like 1 (SIPA1L1) were selected as potential serum markers of liver fibrogenesis among all the analyzed proteins. The results were validated by ELISA in an independent group of 76 fibrotic/cirrhotic rats and 20 controls which confirmed SIPA1L1 as a potential non-invasive biomarker of liver fibrosis. In particular, SIPA1L1 showed a clear diminution in serum samples from fibrotic/cirrhotic rats and a great accuracy at identifying early fibrotic stages. In conclusion, the proteomic analysis of serum samples from CCl4-treated rats has enabled the identification of SIPA1L1 as a non-invasive marker of early liver fibrosis. PMID:27230648

  18. Ameliorative Effects of Pomegranate Peel Extract against Dietary-Induced Nonalcoholic Fatty Liver in Rats.

    PubMed

    Al-Shaaibi, Siham N K; Waly, Mostafa I; Al-Subhi, Lyutha; Tageldin, Mohamed H; Al-Balushi, Nada M; Rahman, Mohammad S

    2016-03-01

    Non-alcoholic fatty liver disease (NAFLD) is caused by fat accumulation and is associated with oxidative stress. In this study, we investigated the potential protective effect of pomegranate (Punica granatum L.) peel extract (PPE) against oxidative stress in the liver of rats with NAFLD. Sprague-Dawley rats were fed a high fat diet (HFD), 20% corn oil, or palm oil for 8 weeks in the presence or absence of PPE. The control group was fed a basal diet. The progression of NAFLD was evaluated histologically and by measuring liver enzymes (alanine transaminase and aspartate transaminase), serum lipids (triglycerides and total cholesterol), and oxidative stress markers. The HFD feeding increased the body weight and caused NAFLD, liver steatosis, hyperlipidemia, oxidative stress, and elevated liver enzymes. Administration of PPE ameliorated the hepatic morphology, reduced body weight, improved liver enzymes, and inhibited lipogenesis. Furthermore, PPE enhanced the cellular redox status in the liver tissue of rats with NAFLD. Our findings suggest that PPE could improve HFD-induced NAFLD via abolishment of hepatic oxidative damage and hyperlipidemia. PPE might be considered as a potential lead material in the treatment of NAFLD and obesity through the modulation of lipid metabolism. PMID:27069901

  19. Methanobactin reverses acute liver failure in a rat model of Wilson disease.

    PubMed

    Lichtmannegger, Josef; Leitzinger, Christin; Wimmer, Ralf; Schmitt, Sabine; Schulz, Sabine; Kabiri, Yaschar; Eberhagen, Carola; Rieder, Tamara; Janik, Dirk; Neff, Frauke; Straub, Beate K; Schirmacher, Peter; DiSpirito, Alan A; Bandow, Nathan; Baral, Bipin S; Flatley, Andrew; Kremmer, Elisabeth; Denk, Gerald; Reiter, Florian P; Hohenester, Simon; Eckardt-Schupp, Friedericke; Dencher, Norbert A; Adamski, Jerzy; Sauer, Vanessa; Niemietz, Christoph; Schmidt, Hartmut H J; Merle, Uta; Gotthardt, Daniel Nils; Kroemer, Guido; Weiss, Karl Heinz; Zischka, Hans

    2016-07-01

    In Wilson disease (WD), functional loss of ATPase copper-transporting β (ATP7B) impairs biliary copper excretion, leading to excessive copper accumulation in the liver and fulminant hepatitis. Current US Food and Drug Administration- and European Medicines Agency-approved pharmacological treatments usually fail to restore copper homeostasis in patients with WD who have progressed to acute liver failure, leaving liver transplantation as the only viable treatment option. Here, we investigated the therapeutic utility of methanobactin (MB), a peptide produced by Methylosinus trichosporium OB3b, which has an exceptionally high affinity for copper. We demonstrated that ATP7B-deficient rats recapitulate WD-associated phenotypes, including hepatic copper accumulation, liver damage, and mitochondrial impairment. Short-term treatment of these rats with MB efficiently reversed mitochondrial impairment and liver damage in the acute stages of liver copper accumulation compared with that seen in untreated ATP7B-deficient rats. This beneficial effect was associated with depletion of copper from hepatocyte mitochondria. Moreover, MB treatment prevented hepatocyte death, subsequent liver failure, and death in the rodent model. These results suggest that MB has potential as a therapeutic agent for the treatment of acute WD. PMID:27322060

  20. The effect of sorafenib on liver regeneration and angiogenesis after partial hepatectomy in rats

    PubMed Central

    Kiroplastis, K; Fouzas, I; Katsiki, E; Patsiaoura, K; Daoudaki, M; Komninou, A; Xolongitas, E; Katsika, E; Kaidoglou, K; Papanikolaou, V

    2015-01-01

    Background Liver regeneration is vital for the survival of patients submitted to extensive liver resection as a treatment of hepatocellular carcinoma (HCC). Sorafenib is a multikinase inhibitor of angiogenesis and cell division, both of which are integral components of liver regeneration. We investigated the effect of preoperative treatment with sorafenib, a drug used for the treatment of HCC, on liver regeneration and angiogenesis in healthy rats, after two-thirds partial hepatectomy (PH2/3). Methods In total 48 Wistar rats received intragastric injections of sorafenib (30 mg/kg/d) or vehicle, underwent PH2/3, and were sacrificed at 48, 96 or 168 hours after that. The regenerative index of the liver remnant was studied, as well as the mitotic index. DNA synthesis and angiogenesis were estimated by immunohistochemistry for the Ki-67 and CD34 antigens, respectively. Results Sorafenib reduced significantly the regenerative index at all time points but not the mitotic index at 48, 96 or 168 hours. Deoxyribonucleic acid (DNA) synthesis and angiogenesis were not affected significantly either. Conclusions Sorafenib, when administered preoperatively, reduces incompletely and transiently the regeneration of the liver after PH2/3 in rats. This could mean that sorafenib can be used as neoadjuvant treatment of patients with HCC prior to liver resection, but further experimental and clinical studies are needed to establish the safety of this treatment. Hippokratia 2015; 19 (3): 249-255. PMID:27418785

  1. Effect of chronic carbon monoxide exposure on experimental alcoholic liver injury in rats

    SciTech Connect

    Nanji, A.A. ); Jui, L.T.; French, S.W. )

    1989-01-01

    Two groups of experimental animals with pair-fed controls were studied to evaluate the effect of chronic carbon monoxide (CO) exposure on progression of experimental alcoholic liver injury. Eight pairs of male Wistar rats were continuously infused liquid diet and ethanol or isocaloric dextrose for four months. Four pairs were also exposed to CO. Liver damage was followed monthly by serum ALT and morphologic assessment of liver biopsy. Serum levels of ALT were significantly higher in the CO-ethanol group compared to other groups. Electron microscopy revealed a greater degree of cell necrosis in the CO exposed group which explained the significantly higher ALT activity in these animals. Both experimental groups had significantly greater liver damage than controls. Carboxyhemoglobin levels were not different in the ethanol-fed and control group. Our results show that chronic CO exposure enhances liver cell necrosis in ethanol-fed rats thereby lending support to the hypothesis that ethanol and hypoxia enhance cellular disruption in the liver which could be important in the pathogenesis of alcoholic liver disease in rats.

  2. Ameliorative Effects of Pomegranate Peel Extract against Dietary-Induced Nonalcoholic Fatty Liver in Rats

    PubMed Central

    Al-Shaaibi, Siham N. K.; Waly, Mostafa I.; Al-Subhi, Lyutha; Tageldin, Mohamed H.; Al-Balushi, Nada M.; Rahman, Mohammad S.

    2016-01-01

    Non-alcoholic fatty liver disease (NAFLD) is caused by fat accumulation and is associated with oxidative stress. In this study, we investigated the potential protective effect of pomegranate (Punica granatum L.) peel extract (PPE) against oxidative stress in the liver of rats with NAFLD. Sprague-Dawley rats were fed a high fat diet (HFD), 20% corn oil, or palm oil for 8 weeks in the presence or absence of PPE. The control group was fed a basal diet. The progression of NAFLD was evaluated histologically and by measuring liver enzymes (alanine transaminase and aspartate transaminase), serum lipids (triglycerides and total cholesterol), and oxidative stress markers. The HFD feeding increased the body weight and caused NAFLD, liver steatosis, hyperlipidemia, oxidative stress, and elevated liver enzymes. Administration of PPE ameliorated the hepatic morphology, reduced body weight, improved liver enzymes, and inhibited lipogenesis. Furthermore, PPE enhanced the cellular redox status in the liver tissue of rats with NAFLD. Our findings suggest that PPE could improve HFD-induced NAFLD via abolishment of hepatic oxidative damage and hyperlipidemia. PPE might be considered as a potential lead material in the treatment of NAFLD and obesity through the modulation of lipid metabolism. PMID:27069901

  3. Data on differentially expressed microRNAs in the liver between nonalcoholic fatty liver disease and normal Wistar rat using Solexa sequencing.

    PubMed

    Zhang, Deqing; Wang, Yuqian; Ji, Zhibin; Wang, Zhonghua

    2016-09-01

    The dataset includes data from the Solexa sequencing reported in our paper: "Identification and differential expression of microRNAs associated with fat deposition in the liver of Wistar rats with nonalcoholic fatty liver disease" [1]. The data collected include small RNAs and microRNAs in liver tissue from high glucose-induced NAFLD Wistar rats, using normal Wistar rats as their negative controls. 6 small RNA libraries were constructed and the expression profiles were compared between the two groups. Here we describe in detail how the data, deposited in the Gene Expression Omnibus (GEO) with the accession number GEO: GSE68411, was generated including the basic analysis. PMID:27331102

  4. Lysosomal acid lipase deficiency in rats: Lipid analyses and lipase activities in liver and spleen

    SciTech Connect

    Kuriyama, M.; Yoshida, H.; Suzuki, M.; Fujiyama, J.; Igata, A. )

    1990-09-01

    We report the biological characterization of an animal model of a genetic lipid storage disease analogous to human Wolman's disease. Affected rats accumulated cholesteryl esters (13.3-fold), free cholesterol (2.8-fold), and triglycerides (5.4-fold) in the liver, as well as cholesteryl esters (2.5-fold) and free cholesterol (1.33-fold) in the spleen. Triglycerides did not accumulate, and the levels actually decreased in the spleen. Analysis of the fatty acid composition of the cholesteryl esters and triglycerides showed high percentages of linoleic acid (18:2) and arachidonic acid (20:4) in both organs, especially in the liver. No accumulation of phospholipids, neutral glycosphingolipids, or gangliosides was found in the affected rats. Acid lipase activity for (14C)triolein, (14C)cholesteryl oleate, and 4-methyl-umbelliferyl oleate was deficient in both the liver and spleen of affected rats. Lipase activity at neutral pH was normal in both liver and spleen. Heterozygous rats showed intermediate utilization of these substrates in both organs at levels between those for affected rats and those for normal controls, although they did not accumulate any lipids. These data suggest that these rats represent an animal counterpart of Wolman's disease in humans.

  5. Chronic Arsenic Exposure-Induced Oxidative Stress is Mediated by Decreased Mitochondrial Biogenesis in Rat Liver.

    PubMed

    Prakash, Chandra; Kumar, Vijay

    2016-09-01

    The present study was executed to study the effect of chronic arsenic exposure on generation of mitochondrial oxidative stress and biogenesis in rat liver. Chronic sodium arsenite treatment (25 ppm for 12 weeks) decreased mitochondrial complexes activity in rat liver. There was a decrease in mitochondrial superoxide dismutase (MnSOD) activity in arsenic-treated rats that might be responsible for increased protein and lipid oxidation as observed in our study. The messenger RNA (mRNA) expression of mitochondrial and nuclear-encoded subunits of complexes I (ND1 and ND2) and IV (COX I and COX IV) was downregulated in arsenic-treated rats only. The protein and mRNA expression of MnSOD was reduced suggesting increased mitochondrial oxidative damage after arsenic treatment. There was activation of Bax and caspase-3 followed by release of cytochrome c from mitochondria suggesting induction of apoptotic pathway under oxidative stress. The entire phenomenon was associated with decrease in mitochondrial biogenesis as evident by decreased protein and mRNA expression of nuclear respiratory factor 1 (NRF-1), nuclear respiratory factor 2 (NRF-2), peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), and mitochondrial transcription factor A (Tfam) in arsenic-treated rat liver. The results of the present study indicate that arsenic-induced mitochondrial oxidative stress is associated with decreased mitochondrial biogenesis in rat liver that may present one of the mechanisms for arsenic-induced hepatotoxicity. PMID:26767369

  6. Enhanced expression of glucose-regulated protein 78 correlates with malondialdehyde levels during the formation of liver cirrhosis in rats

    PubMed Central

    ZHANG, YUN; ZHANG, HUIYING; ZHAO, ZHONGFU; LV, MINLI; JIA, JIANTAO; ZHANG, LILI; TIAN, XIAOXIA; CHEN, YUNXIA; LI, BAOHONG; LIU, MINGSHE; HAN, DEWU; JI, CHENG

    2015-01-01

    The aim of the present study was to explore the role of glucose-regulated protein 78 (GRP78) in the development of liver cirrhosis promoted by intestinal endotoxemia in rats. Fifty-one male Wistar rats were randomly divided into the liver cirrhosis 4-week, 6-week and 8-week groups and the normal control group at each time point. Liver cirrhosis was induced by employing multiple pathogenic factors in the rats. Blood and liver tissues were collected. The levels of alanine aminotransferase (ALT), homocysteine, endotoxin and tumor necrosis factor-α (TNF-α) in the plasma, and TNF-α, malondialdehyde (MDA) and procollagen type III peptide (PIIIP) in the liver tissues were determined. The mRNA and protein expression levels of GRP78 in the liver were detected using reverse transcription-quantitative polymerase chain reaction and immunohistochemistry. Morphological changes were observed through hematoxylin and eosin and van Gieson staining of the liver. Liver cirrhosis caused marked histopathological changes to the livers of the rats. Following significant increases in the levels of ALT, homocysteine, endotoxin and TNF-α in the plasma, and TNF-α, MDA and PIIIP in the liver tissues of all experimental groups with the progression of liver cirrhosis, the mRNA and protein expression levels of GRP78 also gradually increased. In addition, correlation analysis indicated that the enhanced expression of GRP78 correlated with the MDA levels of the rats during the formation of liver cirrhosis. PMID:26668603

  7. Nonalcoholic Fatty Liver Disease Progression in Rats is Accelerated by Splenic Regulation of Liver PTEN/AKT

    PubMed Central

    Wang, Ziming; Li, Naishu; Wang, Biao; Lin, Jianhua

    2015-01-01

    Background/Aim: The spleen has been reported to participate in the development of nonalcoholic fatty liver disease (NAFLD), but the mechanism has not been fully characterized. This study aims to elucidate how the spleen affects the development of NAFLD in a rat model. Materials and Methods: Following either splenectomy or sham operation, male Sprague–Dawley (SD) rats were fed a high-fat diet to drive the development of NAFLD; animals fed a normal diet were used as controls. Two months after surgery, livers and blood samples were collected. Serum lipids were measured; liver histology, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) gene expression, and the ratio of pAkt/Akt were determined. Results: Splenectomy increased serum lipids, except triglyceride (TG) and high-density lipoprotein (HDL), in animals fed either a high-fat or normal diet. Furthermore, splenectomy significantly accelerated hepatic steatosis. Western blot analysis and real-time polymerase chain reaction showed splenectomy induced significant downregulation of PTEN expression and a high ratio of pAkt/Akt in the livers. Conclusions: The spleen appears to play a role in the development of NAFLD, via a mechanism involving downregulation of hepatic PTEN expression. PMID:26228367

  8. Correlation between liver cell necrosis and circulating alanine aminotransferase after ischaemia/reperfusion injuries in the rat liver.

    PubMed

    Knudsen, Anders R; Andersen, Kasper J; Hamilton-Dutoit, Stephen; Nyengaard, Jens R; Mortensen, Frank V

    2016-04-01

    Circulating liver enzymes such as alanine transaminase are often used as markers of hepatocellular damage. Ischaemia/reperfusion (I/R) injury is an inevitable consequence of prolonged liver ischaemia. The aim of this study was to examine the correlation between liver enzymes and volume of liver cell necrosis after ischaemia/reperfusion injuries, using design-unbiased stereological methods. Forty-seven male Wistar rats were subjected to 1 h of partial liver ischaemia, followed by either 4 or 24 h of reperfusion. Within each group, one-third of animals were subjected to ischaemic preconditioning and one-third to ischaemic postconditioning. At the end of reperfusion, blood and liver samples were collected for analysis. The volume of necrotic liver tissue was subsequently correlated to circulating markers of I/R injury. Correlation between histological findings and circulating markers was performed using Pearson's correlation coefficient. Alanine transferase peaked after 4 h of reperfusion; however, at this time-point, only mild necrosis was observed, with a Pearson's correlation coefficient of 0.663 (P = 0.001). After 24 h of reperfusion, alanine aminotransferase was found to be highly correlated to the degree of hepatocellular necrosis R = 0.836 (P = 0.000). Furthermore, alkaline phosphatase (R = 0.806) and α-2-macroglobulin (R = 0.655) levels were also correlated with the degree of necrosis. We show for the first time that there is a close correlation between the volume of hepatocellular necrosis and alanine aminotransferase levels in a model of I/R injury. This is especially apparent after 24 h of reperfusion. Similarly, increased levels of alkaline phosphatase and α-2-macroglobulin are correlated to the volume of liver necrosis. PMID:27292534

  9. The role of the liver in non-shivering thermogenesis in the rat

    PubMed Central

    Stoner, H. B.

    1973-01-01

    1. The temperatures of the liver and afferent aortic and portal blood were measured in 20° C acclimated rats at different environmental temperatures (Ta) between 20 and 37° C. The heated-thermocouple technique was used to measure the metabolic heat production of the liver, its blood flow, and to correct the temperature difference between it and the reference junction for blood flow. 2. The temperature of the liver was higher than that of the afferent blood. On raising Ta from 20 to 30° C the liver temperature fell and the temperature difference between the liver and the aortic blood was reduced despite the decrease in the thermal gradient between the liver and the exterior and a small reduction in hepatic blood flow. A further rise in Ta to 37° C led to an increase in the liver and blood temperatures. The same pattern was seen when the temperature differences were corrected for blood flow. 3. Metabolic heat production in the liver decreased when Ta was raised from 20 to 30° C. 4. In a 20° C environment inhibition of non-shivering thermogenesis with propranolol HCl (10 mg/kg body wt. I.V.) led to a fall in the temperature of the liver and its metabolic heat production towards levels found in untreated rats at Ta = 30° C. Consequently, in treated rats the change in metabolic heat production on raising Ta to 30° C was less than in untreated ones. 5. These results are interpreted as evidence for the participation of the liver in thermoregulatory non-shivering thermogenesis. ImagesFig. 3 PMID:4727083

  10. Effect of detergents on in vitro 7 alpha-hydroxycholesterol formation by rat liver microsomes.

    PubMed

    Sanghvi, A; Grassi, E; Bartman, C; Diven, W F

    1982-09-01

    Formation of 7 alpha-hydroxycholesterol by rat liver microsomes was quantitated using a gas chromatograph-mass spectrometer (GC/MS) operated in selected ion monitoring (SIM) mode. Microsomes from normal rat livers incubated for different periods were found to yield increased 7 alpha-hydroxycholesterol with time. This was also true when incubations contained Tween-80, but in this instance, the rate of 7 alpha-hydroxycholesterol production was lower and dependent on the concentration of Tween used. Similarly, Triton X-100, Renex-30, Kyro EOB, Cutscum, and Emulgen 911 all lowered the formation of 7 alpha-hydroxycholesterol by rat liver microsomes, whereas Triton WR-1339 stimulated its production. Analysis of data obtained from following the enzyme reaction over an extended period using an integrated Michaelis-Menten equation indicated the enzyme possesses a very significant affinity for the product (Ks greater than Kp). Similar analysis shows that Tween-80 is a noncompetitive inhibitor of the enzyme. PMID:7144453

  11. Molecular mechanism of null expression of aldehyde dehydrogenase-1 in rat liver

    SciTech Connect

    Chen, J.; Yoshida, Akira; Yanagawa, Yuchio

    1996-04-01

    In isozyme systems in general, the pattern of tissue-dependent expression of a given type of isozyme is uniform in various mammalian species. In contrast, a major cytosolic aldehyde dehydrogenase isozyme, termed ALDH1, which is strongly expressed in the livers of humans and other mammals, is hardly detectable in rat liver. Thirteen nucleotides existing in the 5{prime}-promoter region of human, marmoset, and mouse ALDH1 genes are absent in the four rat strains examined. When the 13 nucleotides were deleted from a chloramphenicol acetyltransferase expression construct, which contained the 5{prime} promoter region of the human ALDH1 gene and a low-background promoterless chloramphenicol acetyltransferase expression vector, the expression activity was severely diminished in human hepatic cells. Thus, deletion of the 13 nucleotides in the promoter region of the gene can account for the lack of ALDH1 expression in rat liver. 16 refs., 3 figs.

  12. The removal of partially metabolized very-low-density lipoproteins by the perfused rat liver.

    PubMed Central

    Suri, B S; Targ, M E; Robinson, D S

    1981-01-01

    1. Donor perfused rat livers were used to prepare VLD (very-low-density) lipoproteins, labelled in their triacylglycerol and protein components with [1-14C]oleic acid and L-[4,5-3H]leucine respectively. Partially metabolized VLD lipoproteins, similarly labelled, were obtained from supradiaphragmatic rats injected with the parent VLD lipoproteins. 2. The triacylglycerol and protein components of the partially metabolized VLD lipoproteins were removed by recipient perfused rat livers at rates much higher than those of the parent VLD lipoproteins. No degradation of the partially metabolized VLD lipoproteins to LD (low-density) lipoproteins occurred during the perfusions. 3. Removal of hepatic lipase from the livers did not significantly affect the rate of removal of the partially metabolized VLD lipoproteins. PMID:7317016

  13. Selective permeability of rat liver mitochondria to purified aspartate aminotransferases in vitro.

    PubMed Central

    Marra, E; Doonan, S; Saccone, C; Quagliariello, E

    1977-01-01

    1. A method was devised to allow determination of intramitochondrial aspartate amino-transferase activity in suspensions of intact mitochondria. 2. Addition of purified rat liver mitochondrial aspartate aminotransferase to suspensions of rat liver mitochondria caused an apparent increase in the intramitochondrial enzyme activity. No increase was observed when the mitochondria were preincubated with the purified cytoplasmic isoenzyme. 3. These results suggest that mitochondrial aspartate aminotransferase, but not the cytoplasmic isoenzyme, is able to pass from solution into the matrix of intact rat liver mitochondria in vitro. 4. This system may provide a model for studies of the little-understood processes by which cytoplasmically synthesized components are incorporated into mitochondria in vivo. PMID:883959

  14. The synthesis of glycosaminoglycans in aging rat liver. A brief note.

    PubMed

    Gressner, A M; Schulz, W; Greiling, H

    1979-07-01

    The synthesis of glycosaminoglycans (GAG) was studied in liver slices from postnatal (9 days), young (140 days), adult (490 days) and senescent (940 days) rats. It was found that the rate of synthesis was highest in postnatal rat liver and decreased to about half in young rats with no further reduction in adult and senescent age groups. The specific radioactivity of the precursors of GAG synthesis did not change with age. The synthesis pattern of specific types of GAG in postnatal liver was characterized by a significant higher percentage of chondroitin sulfate and hyaluronic acid. In the following age classes the profile of specific GAG synthesis did not change significantly (heparin sulfate: chondroitin sulfate" hyaluronic acid: "keratin sulfate" = 84%:8.3%:1.5%:1.6%). PMID:470468

  15. Umbilical cord-derived mesenchymal stem cells alleviate liver fibrosis in rats

    PubMed Central

    Chai, Ning-Li; Zhang, Xiao-Bin; Chen, Si-Wen; Fan, Ke-Xing; Linghu, En-Qiang

    2016-01-01

    AIM: To evaluate the efficacy of umbilical cord-derived mesenchymal stem cells (UC-MSCs) transplantation in the treatment of liver fibrosis. METHODS: Cultured human UC-MSCs were isolated and transfused into rats with liver fibrosis induced by dimethylnitrosamine (DMN). The effects of UC-MSCs transfusion on liver fibrosis were then evaluated by histopathology; serum interleukin (IL)-4 and IL-10 levels were also measured. Furthermore, Kupffer cells (KCs) in fibrotic livers were isolated and cultured to analyze their phenotype. Moreover, UC-MSCs were co-cultured with KCs in vitro to assess the effects of UC-MSCs on KCs’ phenotype, and IL-4 and IL-10 levels were measured in cell culture supernatants. Finally, UC-MSCs and KCs were cultured in the presence of IL-4 antibodies to block the effects of this cytokine, followed by phenotypical analysis of KCs. RESULTS: UC-MSCs transfused into rats were recruited by the injured liver and alleviated liver fibrosis, increasing serum IL-4 and IL-10 levels. Interestingly, UC-MSCs promoted mobilization of KCs not only in fibrotic livers, but also in vitro. Co-culture of UC-MSCs with KCs resulted in increased production of IL-4 and IL-10. The addition of IL-4 antibodies into the co-culture system resulted in decreased KC mobilization. CONCLUSION: UC-MSCs could increase IL-4 and promote mobilization of KCs both in vitro and in vivo, subsequently alleviating the liver fibrosis induced by DMN. PMID:27468195

  16. Microvesicular fatty liver in rats with resembling Reye's syndrome induced by 4-pentenoic acid.

    PubMed

    Sakaida, N; Senzaki, H; Shikata, N; Morii, S

    1990-09-01

    To produce an animal model of Reye's syndrome (RS), 20 adult male Wistar rats were given 10 repeated i.p. injections of 50 mg/kg 4-pentenoic acid (PA) each separated by an 8-h interval. Then, 90 min after the tenth dose, they were given a final i.p. injection of 150 mg/kg PA. Thirteen control animals were injected with vehicle only using the same time schedule. More than half the animals in each group were fed a common diet, but the others were fasted during the terminal 10-h stage. All rats were sacrificed 30 min after the last injection. At the terminal stage, in comparison with the vehicle-injected controls, hypolipemia, hypoglycemia and high titers of serum ammonia and urea N were estimated significantly in the PA-treated rats fed throughout the whole period. Hypolipemia and hypoglycemia were more prominent in the terminally fasted group than the group fed continuously. Only in the PA-treated rats fed throughout the whole period moderate morphological signs of microvesicular fatty liver were exhibited. Ultracytochemical findings and biochemical determinations showed that the major lipids in the microvesicular fatty livers were triglycerides. Morphometric analysis revealed distinct hepatic mitochondrial swelling in the PA-treated rats. Therefore, the above treatment with PA was able to induce microvesicular fatty liver in rats with resembling RS, which were fed throughout the treatment procedure, but not in the terminally fasted rats. PMID:2260472

  17. Hepatoprotective activity of bacoside A against N-nitrosodiethylamine-induced liver toxicity in adult rats.

    PubMed

    Janani, Panneerselvam; Sivakumari, Kanakarajan; Parthasarathy, Chandrakesan

    2009-10-01

    N-Nitrosodiethylamine (DEN) is a notorious carcinogen, present in many environmental factors. DEN induces oxidative stress and cellular injury due to enhanced generation of reactive oxygen species; free radical scavengers protect the membranes from DEN-induced damage. The present study was designed to evaluate the protective effect of bacoside A (the active principle isolated from Bacopa monniera Linn.) on carcinogen-induced damage in rat liver. Adult male albino rats were pretreated with 15 mg/kg body weight/day of bacoside A orally (for 14 days) and then intoxicated with single necrogenic dose of N-nitrosodiethylamine (200 mg/kg bodyweight, intraperitonially) and maintained for 7 days. The liver weight, lipid peroxidation (LPO), and activity of serum marker enzymes (aspartate transaminases, alanine transaminases, lactate dehydrogenase, alkaline phosphatase, and gamma-glutamyl transpeptidase) were markedly increased in carcinogen-administered rats, whereas the activities of marker enzymes were near normal in bacoside A-pretreated rats. Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutatione-S-transferase, and reduced glutathione) in liver also decreased in carcinogen-administered rats, which were significantly elevated in bacoside A-pretreated rats. It is concluded that pretreatment of bacoside A prevents the elevation of LPO and activity of serum marker enzymes and maintains the antioxidant system and thus protects the rats from DEN-induced hepatotoxicity. PMID:18679812

  18. Effects of Neurolytic Celiac Plexus Block on Liver Regeneration in Rats with Partial Hepatectomy

    PubMed Central

    Li, Jun; Yan, Hong-Tao; Che, Jian-Xiang; Bai, Shu-Rong; Qiu, Qing-Ming; Ren, Ling; Pan, Fan; Sun, Xiao-Qin; Tian, Fu-Zhou; Li, Dong-Xuan; Tang, Li-Jun

    2013-01-01

    Liver regeneration is the basic physiological process after partial hepatectomy (PH), and is important for the functional rehabilitation of the liver after acute hepatic injury. This study was designed to explore the effects of neurolytic celiac plexus block (NCPB) on liver regeneration after PH. We established a model of PH in rats, assessing hepatic blood flow, liver function, and serum CRP, TNF-α, IL-1β and IL-6 concentrations of the residuary liver after PH. Additionally, histopathological studies, immunohistochemistry, and western blotting were also performed. Our results indicated that NCPB treatment after PH improved liver regeneration and survival rates, increased hepatic blood flow, reduced hepatocyte damage, decreased the secretion and release of inflammatory cytokines, increased the expression of B cell lymphoma/leukemia-2 (Bcl-2), and decreased the expression of Bcl-2 associated X protein (Bax). Additionally, Western blotting revealed that the expression of NF-κB p65 and c-Jun were decreased in liver after NCPB. In conclusion, the results of our present study indicate that NCPB treatment has a favorable effect on liver regeneration after PH. We suggest that NCPB can be utilized as an effective therapeutic method to help the functional rehabilitation of the liver after acute hepatic injury or liver cancer surgery. PMID:24039865

  19. Exercises in Hot and Humid Environment Caused Liver Injury in a Rat Model

    PubMed Central

    Liu, Bang; Liu, YuZheng; Zeng, ZhiYu; Lu, LingLing; Zheng, ZhiYong; Li, Bing; Zheng, ZongFu

    2014-01-01

    Objective To investigate injury pattern during intense exercises in hot and humid environment particularly on liver in a rat exertional heat stroke model. Methods We randomly divided 30 rats into a control group (CG), a normal temperature (25±2°C, 60%±5% humidity) exercise group (NTEG) and a high temperature and high humidity (35±2°C, 80%±10% humidity) exercising group (HTEG), each comprising 10 animals. The NTEG and HTEG rats were forced to run in a treadmill for 1 hour maximum at 20 rpm. We analyzed liver cells of all three groups with JC-1 dye and flow cytometry for apoptosis rates in addition to liver tissue 8 - hydroxy deoxyguanosine (8 - OhdG) and blood serum IL–6, tumor necrosis factor alpha (TNF-α), alanine aminotransferase ALT, aspartate amino transferase (AST), serum creatinine (CREA), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), creatine phosphate kinase (CK) concentrations. Result Compared with NTEG rats, beside reduced exercise tolerance (60±5 vs. 15±3 minutes) (p = 0.002) the 8-OhdG liver tissue concentrations were significantly higher (p = 0.040) in the HTEG rats. The HTEG developed more organ tissue damage and cellular fragmentations of liver cells. In both exercise groups TNF-α and IL-6 serum concentrations were enhanced significantly (p<0.001) being highest in the HTEG animals. Serum ALT, AST, LDH, CREA, BUN and CK concentrations were significantly enhance in both exercise groups. Conclusion In our exertional heat stroke rat model, we found tissue damage particularly in livers during exercises in hot and humid environment that was related to inflammation, oxidative stress and apoptosis. PMID:25548911

  20. Developmental variation of the diaphragm and liver in Fischer 344 rats.

    PubMed

    Lu, C C; Mull, R L; Lochry, E A; Christian, M S

    1988-06-01

    The nature and frequency of a developmental variation of the diaphragm and liver in Fischer 344 rats are described. Totals of 20, 98 and 55 (25 for caesarean-sectioning and 30 for natural delivery) mated female rats were used for Experiments 1, 2, and 3, respectively. Each rat was intubated (gavage) with either an aqueous suspension of 0.2% METHOCEL, 0.25% methyl cellulose, or distilled water as a single daily dose from days 6 through 15 (inclusive) of gestation. On the 20th day of gestation, a caesarean-section was performed, and the uterine contents of each rat were examined. A gross necropsy was performed on the pups of 30 mated female rats on day 21 postpartum. The visceral examinations conducted on these fetuses and pups included an evaluation of a developmental variation in the diaphragm and liver. The variation consisted of a thin fibrous central tendon of the diaphragm with an area of liver (0.5-3 mm diameter) that protruded within the thin central tendon of the diaphragm. The incidence (mean % of fetuses affected per litter) of the diaphragm/liver developmental variation was 9% and 11% for METHOCEL- and water-treated groups, respectively. A thin central tendon was present in the diaphragm of all fetuses of methyl cellulose-treated dams; these fetuses did not have a raised area of the liver present within the diaphragm's central tendon. However, in a few weaned pups of the Fischer 344 rats in this study, liver protruded within the central tendon of the diaphragm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3400072

  1. METABOLISM OF BENZ(J)ACEANTHRYLENE (CHOLANTHRYLENE) AND BENZ(L)ACEANTHRYLENE BY INDUCED RAT LIVER S9 (JOURNAL VERSION)

    EPA Science Inventory

    The metabolites of benz(j)aceanthrylene (B(j)A) and benz(l)aceanthrylene (B(l)A) produced by incubation with liver S9 proteins from rats induced with Aroclor-1254 and phenobarbital have been studied. Aroclor-1254 and phenobarbital induced rat liver S9 each metabolized B(j)A to tr...

  2. INITIATION/PROMOTION BIOASSAY IN RAT LIVER: USE OF GAMMA GLUTAMYLTRANSPEPTIDASE-POSITIVE FOCI TO INDICATE CARCINOGENIC ACTIVITY

    EPA Science Inventory

    Gamma Glutamyltranspeptidase (GGTase)-positive foci have been used to indicate activity in an initiation/promotion bioassay in rat liver. This rat liver foci bioassay has been proposed for inclusion in tier 2 of a three tier decision tree approach to carcinogenesis testing where ...

  3. Lipidomic changes in rat liver after long-term exposure to ethanol

    SciTech Connect

    Fernando, Harshica; Bhopale, Kamlesh K.; Kondraganti, Shakuntala; Kaphalia, Bhupendra S.; Shakeel Ansari, G.A.

    2011-09-01

    Alcoholic liver disease (ALD) is a serious health problem with significant morbidity and mortality. In this study we examined the progression of ALD along with lipidomic changes in rats fed ethanol for 2 and 3 months to understand the mechanism, and identify possible biomarkers. Male Fischer 344 rats were fed 5% ethanol or caloric equivalent of maltose-dextrin in a Lieber-DeCarli diet. Animals were killed at the end of 2 and 3 months and plasma and livers were collected. Portions of the liver were fixed for histological and immunohistological studies. Plasma and the liver lipids were extracted and analyzed by nuclear magnetic resonance (NMR) spectroscopy. A time dependent fatty infiltration was observed in the livers of ethanol-fed rats. Mild inflammation and oxidative stress were observed in some ethanol-fed rats at 3 months. The multivariate and principal component analysis of proton and phosphorus NMR spectroscopy data of extracted lipids from the plasma and livers showed segregation of ethanol-fed groups from the pair-fed controls. Significant hepatic lipids that were increased by ethanol exposure included fatty acids and triglycerides, whereas phosphatidylcholine (PC) decreased. However, both free fatty acids and PC decreased in the plasma. In liver lipids unsaturation of fatty acyl chains increased, contrary to plasma, where it decreased. Our studies confirm that over-accumulation of lipids in ethanol-induced liver steatosis accompanied by mild inflammation on long duration of ethanol exposure. Identified metabolic profile using NMR lipidomics could be further explored to establish biomarker signatures representing the etiopathogenesis, progression and/or severity of ALD. - Highlights: > Long term exposure to ethanol was studied. > A nuclear magnetic resonance (NMR) spectroscopy based lipidomic approach was used. > We examined the clustering pattern of the NMR data with principal component analysis. > NMR data were compared with histology and

  4. Decreased synthesis of DNA in regenerating rat liver after the administration of reserpine

    PubMed Central

    Ćihák, A.; Vaptzarova, K.

    1973-01-01

    1. Reserpine given to rats before the enhanced synthesis of DNA begins 14h after partial hepatectomy markedly depresses thymidine uptake into DNA at 24 hours. 2. At this time decreased activity of liver thymidine kinase but unchanged thymidine 5′-nucleotidase were observed. 3. Reserpine has no effect on DNA synthesis when administered simultaneously with the labelled thymidine 2 h before killing. 4. With depressed DNA synthesis after reserpine administration there is no significant decrease of liver RNA synthesis. PMID:4793440

  5. Aloe vera gel protects liver from oxidative stress-induced damage in experimental rat model.

    PubMed

    Nahar, Taslima; Uddin, Borhan; Hossain, Shahdat; Sikder, Abdul Mannan; Ahmed, Sohel

    2013-01-01

    Aloe vera is a semi-tropical plant of Liliaceae family which has a wide range of applications in traditional medicine. In the present study, we sought to investigate the heptaoprotective potential of Aloe vera gel as a diet supplement. To achieve this goal, we have designed in vitro and in vivo experimental models of chemical-induced liver damage using male Sprague-Dawley rat. In the in vitro model, its effect was evaluated on Fenton's reaction-induced liver lipid peroxidation. Co-incubation with gel significantly reduced the generation of liver lipid peroxide (LPO). Next, to see the similar effect in vivo, gel was orally administered to rats once daily for 21 successive days. Following 1 hour of the last administration of gel, rats were treated with intra-peritoneal injection of CCl4. Dietary gel showed significant hepatoprotection against CCl4-induced damage as evident by restoration of liver LPO, serum transaminases, alkaline phosphatase, and total bilirubin towards near normal. The beneficial effects were pronounced with the doses used (400 and 800 mg/kg body weight). Besides, we did not observe any significant drop in serum albumin, globulin as well as total protein levels of gel-administered rats. Histopathology of the liver tissue further supported the biochemical findings confirming the hepatoprotective potential of dietary gel. PMID:23652643

  6. TRANEXAMIC ACID ACTION ON LIVER REGENERATION AFTER PARTIAL HEPATECTOMY: EXPERIMENTAL MODEL IN RATS

    PubMed Central

    SOBRAL, Felipe Antonio; DAGA, Henrique; RASERA, Henrique Nogueira; PINHEIRO, Matheus da Rocha; CELLA, Igor Furlan; MORAIS, Igor Henrique; MARQUES, Luciana de Oliveira; COLLAÇO, Luiz Martins

    2016-01-01

    ABSTRACT Background: Different lesions may affect the liver resulting in harmful stimuli. Some therapeutic procedures to treat those injuries depend on liver regeneration to increase functional capacity of this organ. Aim: Evaluate the effects of tranexamic acid on liver regeneration after partial hepatectomy in rats. Method: 40 rats (Rattus norvegicus albinus, Rodentia mammalia) of Wistar-UP lineage were randomly divided into two groups named control (CT) and tranexamic acid (ATX), with 20 rats in each. Both groups were subdivided, according to liver regeneration time of 32 h or seven days after the rats had been operated. The organ regeneration was evaluated through weight and histology, stained with HE and PCNA. Results: The average animal weight of ATX and CT 7 days groups before surgery were 411.2 g and 432.7 g, and 371.3 g and 392.9 g after the regeneration time, respectively. The average number of mitotic cells stained with HE for the ATX and CT 7 days groups were 33.7 and 32.6 mitosis, and 14.5 and 14.9 for the ATX and CT 32 h groups, respectively. When stained with proliferating cell nuclear antigen, the numbers of mitotic cells counted were 849.7 for the ATX 7 days, 301.8 for the CT 7 days groups, 814.2 for the ATX 32 hand 848.1 for the CT 32 h groups. Conclusion: Tranexamic acid was effective in liver regeneration, but in longer period after partial hepatectomy.

  7. Characterization of CC-531 as a Rat Model of Colorectal Liver Metastases

    PubMed Central

    White, Sarah Beth; Procissi, Daniele; Chen, Jeane; Gogineni, Venkateswara Rao; Tyler, Patrick; Yang, Yihe; Omary, Reed A.; Larson, Andrew C.

    2016-01-01

    Purpose Surgical resection of colorectal liver metastases is not achievable in more than 70% of the cases. Although the liver directed therapies have become a part of the stand of care, lack of a preclinical model impedes the assessment of toxicity and therapeutic benefits attributed several candidate drugs or treatment regimens that can be designed. In the present study we aim develop and characterize a rat colorectal liver metastasis model. Materials and Methods Growth characteristics of CC-531 cells were determined in vitro followed by subcapsular liver implantation in syngeneic WAG/Rij rats. Tumor growth progression was followed over 3 weeks by ultrasound (US) and magnetic resonance imaging (MRI). Growth characteristics were also assessed by histopathology and immunohistochemistry in harvested tumor tissues. Results The doubling time of CC-531 cells was found be under 24hrs and all the implanted rats grew tumors. US imaging showed hypoechoic masses and MRI showed contrast enhancement representing complex tumor microenvironments. Hematoxylin and Eosin staining confirmed tumor growth and uniform CD31 staining in tumor confirmed even vessel density. Conclusion CC-531 can be used as a metastatic rat tumor colorectal liver metastases model with well-defined characteristics that can be readily followed by imaging whilst having a therapeutic window for interventions. PMID:27171151

  8. Altered feeding differentially regulates circadian rhythms and energy metabolism in liver and muscle of rats.

    PubMed

    Reznick, Jane; Preston, Elaine; Wilks, Donna L; Beale, Susan M; Turner, Nigel; Cooney, Gregory J

    2013-01-01

    Energy metabolism follows a diurnal pattern responding to the light/dark cycle and food availability. This study investigated the impact of restricting feeding to the daylight hours and feeding a high fat diet on circadian clock (bmal1, dbp, tef and e4bp4) and metabolic (pepck, fas, ucp3, pdk4) gene expression and markers of energy metabolism in muscle and liver of rats. The results show that in chow-fed rats switched to daylight feeding, the peak diurnal expression of genes in liver was shifted by 6-12h while expression of these genes in muscle remained in a similar phase to rats feeding ad libitum. High fat feeding during the daylight hours had limited effect on clock gene expression in liver or muscle but shifted the peak expression of metabolic genes (pepck, fas) in liver by 6-12h. The differential effects of daylight feeding on gene and protein expression in muscle and liver were accompanied by an 8% reduction in whole body energy expenditure, a 20-30% increased glycogen content during the light phase in muscle of day-fed rats and increased adipose tissue deposition per gram food consumed. These data demonstrate that a mismatch of feeding and light/dark cycle disrupts tissue metabolism in muscle with significant consequences for whole body energy homeostasis. PMID:22952003

  9. [Effect of Fuzheng Huayu recipe on CYP450 isozymes in normal and liver fibrosis rats].

    PubMed

    Zheng, Tian-hui; Liu, Wei; Li, Shu-ping; Yang, Tao; Wang, Chang-hong; Liu, Cheng-hai

    2015-03-01

    To study the effect of Fuzheng Huayu recipe (FZHY) on five types of isozymes of cytochrome P450 (CYP450) of normal and liver fibrosis rats by using the cocktail probe method. Dimethylnitrosamine ( DMN) was injected to induce the liver fibrosis model. After the tail vein injection with Cocktail probe solutions prepared with five CYP450s probe substrates (phenacetin-CYP1A2, omeprazole-CYP2C9, tolbutamide-CYP2C19, dextromethorphan-CYP2D6, midazolam-CYP3A4), the plasma concentrations of the five probe substrates were determined by LC-MS/MS, and the pharmacokinetic parameters were calculated by PK solutions 2. After the oral administration with FZHY, normal rats given phenacetin, omeprazole, tolbutamide and dextromethorphan showed increase in AUC(0-t) and decrease in CL to varying degrees, indicating that FZHY obviously inhibited the activities of CYP1A2, CYP2C9, CYP2C19 and CYP2D6 in normal rats, but with no obvious effect on the activity of CYP3A4. After the oral administration with FZHY, liver fibrosis rats treated with CYP2C9 showed the significant increase in AUC(0-t) and significant decrease in Vd, hut with no obvious changes in the pharmacokinetic parameters of other four types of prove substances, suggesting that FZHY could significantly inhibit the activity of CYP2C9 in rats but had no effect on the activities of CYP1A2, CYP2C19, CYP2D6 and CYP3A4. The changes in the activity of CYP450 isozymes in liver fibrosis rats may be the reason for FZHY's different effects on CYP450 isozymes in normal and liver fibrosis rats. PMID:26226765

  10. An assessment of the calcium content of rat liver mitochondria in vivo.

    PubMed Central

    Reinhart, P H; van de Pol, E; Taylor, W M; Bygrave, F L

    1984-01-01

    The effect of systematically altering the isolation conditions on the total calcium content of mitochondria isolated from perfused rat liver was examined. We showed that, under most isolation conditions, significant redistributions of mitochondrial calcium occurred resulting in up to 5-fold changes of the total calcium content. Mitochondrial Ca2+ flux inhibitors such as Ruthenium Red and nupercaine were only partially effective in inhibiting such redistributions. We present evidence indicating that the total calcium content of rat liver mitochondria in situ may approximate 2 nmol X (mg of protein)-1. PMID:6201164

  11. Effect of low temperature on metabolism of rat liver slices and epididymal fat pads.

    NASA Technical Reports Server (NTRS)

    Hillyard, L. A.; Entenman, C.

    1973-01-01

    Study of low temperature effects on the metabolism of radioisotope-tagged glucose and palmitate in rat liver slices and epididymal fat pads. The obtained data suggest that the oxidative capacity of rat liver and adipose tissue is maintained at low temperatures to a greater degree than the synthetic capacity. It was concluded that sufficient energy can be produced at 17 C for maintenance of essential tissue functions by these two tissues but that the energy requirements may not be met at 7 C.

  12. Metabonomic evaluation of idiosyncrasy-like liver injury in rats cotreated with ranitidine and lipopolysaccharide

    SciTech Connect

    Maddox, Jane F. . E-mail: maddox@msu.edu; Luyendyk, James P.; Cosma, Gregory N.; Breau, Alan P.; Bible, Roy H.; Harrigan, George G.; Goodacre, Royston; Ganey, Patricia E.; Cantor, Glenn H.; Cockerell, Gary L.; Roth, Robert A. . E-mail: rothr@msu.edu

    2006-04-01

    Idiosyncratic liver injury occurs in a small fraction of people on certain drug regimens. The cause of idiosyncratic hepatotoxicity is not known; however, it has been proposed that environmental factors such as concurrent inflammation initiated by bacterial lipopolysaccharide (LPS) increase an individual's susceptibility to drug toxicity. Ranitidine (RAN), a histamine-2 receptor antagonist, causes idiosyncratic liver injury in humans. In a previous report, idiosyncrasy-like liver toxicity was created in rats by cotreating them with LPS and RAN. In the present study, the ability of metabonomic techniques to distinguish animals cotreated with LPS and RAN from those treated with each agent individually was investigated. Rats were treated with LPS or its vehicle and with RAN or its vehicle, and urine was collected for nuclear magnetic resonance (NMR)- and mass spectroscopy-based metabonomic analyses. Blood and liver samples were also collected to compare metabonomic results with clinical chemistry and histopathology. NMR metabonomic analysis indicated changes in the pattern of metabolites consistent with liver damage that occurred only in the LPS/RAN cotreated group. Principal component analysis of urine spectra by either NMR or mass spectroscopy produced a clear separation of the rats treated with LPS/RAN from the other three groups. Clinical chemistry (serum alanine aminotransferase and aspartate aminotransferase activities) and histopathology corroborated these results. These findings support the potential use of a noninvasive metabonomic approach to identify drug candidates with potential to cause idiosyncratic liver toxicity with inflammagen coexposure.

  13. RNA Interference against Discoidin Domain Receptor 2 Ameliorates Alcoholic Liver Disease in Rats

    PubMed Central

    Luo, Zheng; Liu, Huimin; Sun, Xiaomeng; Guo, Rong; Cui, Ruibing; Ma, Xiangxing; Yan, Ming

    2013-01-01

    Discoidin domain receptor 2 (DDR2) is involved in fibrotic disease. However, the exact pathogenic implications of the receptor in early alcoholic liver disease are still controversial. We constructed plasmid vectors encoding short-hairpin RNA against DDR2 to investigate its role in alcoholic liver disease in an immortalized rat hepatic stellate cell line, HSC-T6, and in rats by MTT, RT-PCR and western blot analyses; immunohistochemistry and electron microscopy. Alcohol-induced upregulation of DDR2 was associated with the expression of matrix metalloproteinase 2, the transforming growth factor β1 signaling pathway and tissue inhibitor of metalloproteinase 1; collagen deposition; and extracellular matrix remodeling. Inhibition of DDR2 decreased HSC-T6 cell proliferation and liver injury in rats with 10-week-induced alcoholic liver disease. DDR2 may have an important role in the pathogenesis of early-stage alcoholic liver disease. Silencing DDR2 may be effective in preventing early-stage alcoholic liver disease. PMID:23409069

  14. Kinetics and control of oxidative phosphorylation in rat liver mitochondria after dexamethasone treatment

    PubMed Central

    2004-01-01

    The present investigation was undertaken in order to evaluate the contributions of ATP synthesis and proton leak reactions to the rate of active respiration of liver mitochondria, which is altered following dexamethasone treatment (1.5 mg/kg per day for 5 days). We applied top-down metabolic control analysis and its extension, elasticity analysis, to gain insight into the mechanisms of glucocorticoid regulation of mitochondrial bioenergetics. Liver mitochondria were isolated from dexamethasone-treated, pair-fed and control rats when in a fed or overnight fasted state. Injection of dexamethasone for 5 days resulted in an increase in the fraction of the proton cycle of phosphorylating liver mitochondria, which was associated with a decrease in the efficiency of the mitochondrial oxidative phosphorylation process in liver. This increase in proton leak activity occurred with little change in the mitochondrial membrane potential, despite a significant decrease in the rate of oxidative phosphorylation. Regulation analysis indicates that mitochondrial membrane potential homoeostasis is achieved by equal inhibition of the mitochondrial substrate oxidation and phosphorylation reactions in rats given dexamethasone. Our results also suggest that active liver mitochondria from dexamethasone-treated rats are capable of maintaining phosphorylation flux for cellular purposes, despite an increase in the energetic cost of mitochondrial ATP production due to increased basal proton permeability of the inner membrane. They also provide a complete description of the effects of dexamethasone treatment on liver mitochondrial bioenergetics. PMID:15175015

  15. Bees' Honey Protects the Liver of Male Rats against Melamine Toxicity

    PubMed Central

    El Rabey, Haddad A.; Al-Seeni, Madeha N.; Al-Solamy, Suad M.

    2013-01-01

    The protective effect of natural bees' honey to the liver of male albino rats against melamine toxicity was studied. Melamine supplementation at a dose of 20000 ppm in the diet for 28 days induced adverse effects on the liver, decreased serum total protein and increased liver enzyme: alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. Histological changes of the melamine supplemented group showed necrosis in the hepatic tissues around the central veins of the liver and precipitation of melamine crystals. Treating the male albino rats (that were presupplemented regularly with 20000 ppm melamine) with natural bees' honey at a dose of 2.5 g/kg body weight for 28 days improved both liver functions and increased serum protein. In addition, a positive impact on the shape of the cells after treatment with honey compared to the positive melamine supplemented group was observed. In conclusion, the results of this study revealed that the use of natural bees' honey has the ability to protect the liver of rats against the toxic effects of melamine. PMID:23971045

  16. Peroxisome proliferator-activated receptor-alpha expression in rat liver during postnatal development.

    PubMed

    Panadero, M; Herrera, E; Bocos, C

    2000-08-01

    The expression of the peroxisome proliferator-activated receptor-alpha (PPARalpha) as well as of some related genes was studied in rat liver at different stages of development (from 19-day-old fetuses to 1 month-old rats). The level of PPARalpha mRNA appeared higher in neonates than in fetuses or 1 month-old rats. Whereas the pattern for phosphoenolpyruvate carboxykinase (PEPCK) mRNA level was similar to that of PPARalpha, the mRNA level of both acyl-CoA oxidase (ACO) and apolipoprotein CIII (apo CIII) showed diverse profiles. Western blotting analysis also revealed an increased level of PPARalpha protein in liver of suckling rats. Similarities of mRNA PEPCK and PPARalpha expression indicate a common control mechanism, where both nutritional and hormonal factors may be involved. PMID:11018288

  17. PASS-Predicted Hepatoprotective Activity of Caesalpinia sappan in Thioacetamide-Induced Liver Fibrosis in Rats

    PubMed Central

    Kadir, Farkaad A.; Kassim, Normadiah M.; Abdulla, Mahmood Ameen; Ahmadipour, Fatemeh; Yehye, Wageeh A.

    2014-01-01

    The antifibrotic effects of traditional medicinal herb Caesalpinia sappan (CS) extract on liver fibrosis induced by thioacetamide (TAA) and the expression of transforming growth factor β1 (TGF-β1), α-smooth muscle actin (αSMA), and proliferating cell nuclear antigen (PCNA) in rats were studied. A computer-aided prediction of antioxidant and hepatoprotective activities was primarily performed with the Prediction Activity Spectra of the Substance (PASS) Program. Liver fibrosis was induced in male Sprague Dawley rats by TAA administration (0.03% w/v) in drinking water for a period of 12 weeks. Rats were divided into seven groups: control, TAA, Silymarin (SY), and CS 300 mg/kg body weight and 100 mg/kg groups. The effect of CS on liver fibrogenesis was determined by Masson's trichrome staining, immunohistochemical analysis, and western blotting. In vivo determination of hepatic antioxidant activities, cytochrome P450 2E1 (CYP2E1), and matrix metalloproteinases (MPPS) was employed. CS treatment had significantly increased hepatic antioxidant enzymes activity in the TAA-treated rats. Liver fibrosis was greatly alleviated in rats when treated with CS extract. CS treatment was noted to normalize the expression of TGF-β1, αSMA, PCNA, MMPs, and TIMP1 proteins. PASS-predicted plant activity could efficiently guide in selecting a promising pharmaceutical lead with high accuracy and required antioxidant and hepatoprotective properties. PMID:24701154

  18. Medium chain triglycerides dose-dependently prevent liver pathology in a rat model of non-alcoholic fatty liver disease.

    PubMed

    Ronis, Martin J J; Baumgardner, January N; Sharma, Neha; Vantrease, Jamie; Ferguson, Matthew; Tong, Yudong; Wu, Xianli; Cleves, Mario A; Badger, Thomas M

    2013-02-01

    Metabolic syndrome is often accompanied by development of hepatic steatosis and less frequently by non-alcoholic fatty liver disease (NAFLD) leading to non-alcoholic steatohepatitis (NASH). Replacement of corn oil with medium chain triacylglycerols (MCT) in the diets of alcohol-fed rats has been shown to protect against steatosis and alcoholic liver injury. The current study was designed to determine if a similar beneficial effect of MCT occurs in a rat model of NAFLD. Groups of male rats were isocalorically overfed diets containing 10%, 35% or 70% total energy as corn oil or a 70% fat diet in which corn oil was replaced with increasing concentrations of saturated fat (18:82, beef tallow:MCT oil) from 20% to 65% for 21 days using total enteral nutrition (TEN). As dietary content of corn oil increased, hepatic steatosis and serum alanine amino transferases were elevated (P < 0.05). This was accompanied by greater expression of cytochrome P450 enzyme CYP2E1 (P < 0.05) and higher concentrations of polyunsaturated 18:2 and 20:4 fatty acids (FA) in the hepatic lipid fractions (P < 0.05). Keeping the total dietary fat at 70%, but increasing the proportion of MCT-enriched saturated fat resulted in a dose-dependent reduction in steatosis and necrosis without affecting CYP2E1 induction. There was no incorporation of C8-C10 FAs into liver lipids, but increasing the ratio of MCT to corn oil: reduced liver lipid 18:2 and 20:4 concentrations; reduced membrane susceptibility to radical attack; stimulated FA β- and ω-oxidation as a result of activation of peroxisomal proliferator activated receptor (PPAR)α, and appeared to increase mitochondrial respiration through complex III. These data suggest that replacing unsaturated fats like corn oil with MCT oil in the diet could be utilized as a potential treatment for NAFLD. PMID:23576797

  19. Clock gene expression in the liver of streptozotocin-induced and spontaneous type 1 diabetic rats.

    PubMed

    Hofmann, K; Schönerstedt, U; Mühlbauer, E; Wedekind, D; Peschke, E

    2013-09-01

    Several investigations have shown a relation between diabetes and alterations of the liver circadian clock. We investigated the diurnal expression of clock genes and clock-controlled genes (CCGs) in 3-hour intervals for a 24-h period in the livers of male streptozotocin (STZ)-treated rats, male spontaneous type 1 diabetic LEW.1AR1-iddm (Iddm) rats, and Iddm rats treated for 10 days with insulin. Hepatic mRNA was extracted, and the relative expression of clock genes (Per1, Per2, Bmal1, Clock, Cry1), as well as CCGs (Dbp, E4bp4, RevErbα, Rorα, Pparγ), was analyzed by reverse transcription followed by real-time polymerase chain reaction. Diabetic STZ and Iddm rats, as well as insulin-substituted Iddm rats, exhibited a significant diurnal expression pattern of clock genes as determined by Cosinor analysis; however, the MESOR (midline estimating statistic of rhythm) of Bmal1, Per2, and Clock transcript expression was altered in Iddm and insulin-substituted Iddm rats. The hepatic expression of the CCGs Dbp and RevErbα revealed a diurnal rhythm in all investigated groups. Insulin administration to Iddm rats normalized the enhanced MESOR in the expression of Dbp, RevErbα, and E4bp4 to the levels of normoglycemic controls. Cosinor analysis indicated no diurnal rhythm of Pparγ expression in the livers of diabetic STZ or Iddm rats or in those of insulin-substituted Iddm rats. Also, insulin substitution could not reverse the decreased MESOR of Pparγ expression in Iddm rats. In consequence of the diabetic disease, changes in the expression of clock genes and CCGs suggest alterations in the hepatic peripheral clock mechanism. PMID:23632905

  20. Ring-Oxidative Biotransformation and Drug Interactions of Propofol in the Livers of Rats

    PubMed Central

    Tai, Yu-Ting; Lin, Yi-Ling; Chang, Chia-Chen; Cherng, Yih-Giun; Don, Ming-Jaw; Chen, Ruei-Ming

    2015-01-01

    Propofol, an intravenous anesthetic agent, is widely used for inducing and maintaining anesthesia during surgical procedures and for sedating intensive care unit patients. In the clinic, rapid elimination is one of the major advantages of propofol. Meanwhile, the biotransformation and drug interactions of propofol in rat livers are still little known. In this study, we evaluated the ring-oxidative metabolism of propofol in phenobarbital-treated rat livers and possible drug interactions. Administration of phenobarbital to male Wistar rats significantly increased levels of hepatic cytochrome P450 (CYP) 2B1/2 and microsomal pentoxyresorufin O-dealkylase (PROD) activity. Analyses by high-performance liquid chromatography and liquid chromatography mass spectroscopy revealed that propofol was metabolized by phenobarbital-treated rat liver microsomes into 4-hydroxypropofol. In comparison, PROD activity and 4-hydroxy-propofol production from propofol metabolism were suppressed by orphenodrine, an inhibitor of CYP2B1/2, and a polyclonal antibody against rat CYP2B1/2 protein. Furthermore, exposure of rats to propofol did not affect the basal or phenobarbital-enhanced levels of hepatic CYP2B1/2 protein. Meanwhile, propofol decreased the dealkylation of pentoxyresorufin by phenobarbital-treated rat liver microsomes in a concentration-dependent manner. Taken together, this study shows that rat hepatic CYP2B1/2 plays a critical role in the ring-oxidative metabolism of propofol into 4-hydroxypropofol, and this anesthetic agent can inhibit CYP2B1/2 activity without affecting protein synthesis. PMID:25710017

  1. Cholinesterase activity in rat liver and serum during experimentally induced inflammation.

    PubMed

    Simon, G; Budavári, I

    1977-01-01

    Cholinesterase activity of albino rats with acute local oedematous inflammation induced by turpentine, croton oil or Freund's adjuvant was elevated in the liver homogenate but decreased in the serum. Aprotinin administration prevented the decrease of serum activity. In the oedema fluid of rats treated with croton oil an enzyme with cholinester splitting activity was detected and it was shown to be identical with serum cholinesterase (EC 3. 1. 1. 8.). PMID:311577

  2. [Levels of glutathione and anaerobic glycolysis in the kidney and liver of rats treated with chloroethanol].

    PubMed

    Rinaudo, M T; Curto, M; Bruno, R

    1983-11-30

    Chloroethanol administration produces in rats a strong fall of glutathione levels in liver and kidney tissues. In liver, such a modification does not imply alterations in the levels of glucose, glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-biphosphate, lactate and pyruvate and in the glycolytic activity. In kidney, the glycolytic activity does not result modified, while it appears a reduction in levels of glucose, glucose-6-phosphate, fructose-1,6-biphosphate and triose phosphates and a remarkable increase of pyruvate. The administration of chloroethanol produces a strong fall of glutathione in the soluble and nuclear fractions of liver and in the soluble and mitochondrial fractions of kidney. PMID:6230087

  3. Effect of flavonoid compounds extracted from Iris species in prevention of carbon tetrachloride-induced liver fibrosis in rats.

    PubMed

    Wang, Y L; Lv, H Y; Zhang, Q

    2015-01-01

    We investigated the effect of flavonoid compounds extracted from species of genus Iris L. on carbon tetrachloride (CCl4)-induced rat liver fibrosis. Thirty Sprague-Dawley rats were randomly divided into normal control group, liver fibrosis model group, and drug treatment group (N = 10 each). Next, 0.2 mL/100 g CCl4 was subcutaneously injected for 6 weeks in both model and treatment rats to generate the liver fibrosis model. In the control group, an equal volume of castor oil was injected subcutaneously. Rats in the treatment group also received 100 mg·kg(-1)·day(-1) flavonoid compounds via gastric tubes. After 6 weeks, rats were sacrificed, and their liver tissues were examined for pathological changes, including alanine aminotransferase, aspartate aminotransferase, total bilirubin, hyaluronic acid, laminin, and procollagen type-3. Liver tissues from control rats showed no significant pathological changes, while model animals showed significant liver fibrosis. In the treatment group, liver fibrosis significantly decreased compared to the model group (P < 0.05). Liver fibrotic indices, including hyaluronic acid, laminin, and procollagen type-3, in treatment rats were all significantly lower than those in the model group (P < 0.05), but not significantly different compared to the normal group (P > 0.05). Other liver function indices, including alanine aminotransferase, aspartate aminotransferase, and total bilirubin, in treatment rats were also significantly lower than those in model rats (P < 0.01) but higher than those in control animals (P < 0.05). Flavonoid compounds extracted from Iris plants showed significant inhibitory effects on CCl4-induced rat liver fibrosis. PMID:26400326

  4. Bioimaging of DsRed fluorescence in the transgenic rat liver

    NASA Astrophysics Data System (ADS)

    Arao, Yukitomo; Hakamata, Yoji; Igarashi, Yuka; Sato, Yuki; Murakami, Takashi; Kobayashi, Eiji

    2006-02-01

    We developed the Alb-DsRed2 transgenic (Tg) rat designed with liver-specific expression of the red fluorescent protein, DsRed2. Herein, we report high expression of DsRed2 in neonate liver of both sexes, although they were sexually dimorphic and exhibited a male-specific pattern in adult rats. In an effort to examine the expression in each animal under development, we employed an in vivo Bio-imaging system to quantitatively estimate hepatic DsRed2 expression levels. The temporal profiles pertaining to DsRed expression were similar in male and female Tg rats until 28 days old. The levels in both sexes decreased gradually following birth, and were not detectable at 21 days. Subsequently, expression in males increased again at 35 days and was maintained at a persistently high level thereafter. On the other hand, expression in females disappeared steadily. Although hepatic DsRed expression levels in gonadectomized Tg rats was not significantly different, DsRed expression in hypophysectomized female Tg rats appeared dramatically 72 hr following operation. Hepatocytes were collected from adult Tg rats and cultured in conditioning medium. DsRed expression in female hepatocytes could be detected 72 hr following culturing. These results suggest that hepatic DsRed expression in female rats is regulated in vivo by the pituitary. This report is shows use of Alb-DsRed2 Tg rats in conjunction with a novel bio-imaging system represents a powerful experimental system.

  5. Pathogenesis of Lactobacillus casei-induced polyarthritis in Lewis rats: 2. Time related changes in organ weights and liver enzymes.

    PubMed

    Wilson, D; O'Byrne, E M; Blancuzzi, V; Schlosser, M; Borman, C H; DiPasquale, G

    1993-01-01

    Hepatic enzymes and organ weights were measured in LEW/N female rats during the acute and the chronic phases of L. casei-induced arthritis on day 3 and days 30 and 59, respectively. In the acute phase, day 3, adrenal and spleen weights were increased and thymus weights were decreased in L. casei arthritic rats as compared to normal control rats. Adrenal, liver, kidney, spleen and thymus weights of arthritic rats were in the normal range on days 30 and 59. Liver cytochrome P450, aminopyrine N-demethylase and analine hydroxylase were reduced in livers of L. casei-treated rats on day 3 as compared to normal controls. On days 30 and 59 hepatic enzymes in L. casei-arthritic rats were in the normal range. Unlike adjuvant arthritis in which changes in liver enzymes alter drug metabolism; after the acute onset of L. casei-induced arthritis, hepatic enzymes return to the normal range. PMID:8273567

  6. GH binding to liver in young and old female rats: relation to somatomedin-C secretion

    SciTech Connect

    Takahashi, S.; Meites, J.

    1987-11-01

    Age-related changes in binding of /sup 125/I-bovine GH to liver membrane fractions were measured in female Long-Evans rats 2, 6, 12, and 20 months of age. Specific GH binding did not change between 2 and 6 months of age but increased significantly at 12 and 20 months of age. Scatchard analyses showed that the plots were curvilinear and consisted of high- and low-affinity binding sites. The age-related increases in binding sites were mainly due to an increase in number of low-affinity binding sites. Serum somatomedim-C (SM-C) levels in 20-month-old rats were about half those in the 6-month-old rats. Twice daily injections of ovine GH (2 mg/kg body wt) for 7 days depressed liver GH binding and increased serum SM-C levels in 19-month-old female rats, but had no effect on GH binding in 2-month-old female rats. These results suggest that the increase in liver GH binding sites and the decrease in SM-C secretion are associated with our previously reported decrease in GH secretion in old female rats.

  7. Hepatoprotective and antioxidant effect of tender coconut water on carbon tetrachloride induced liver injury in rats.

    PubMed

    Loki, Anthony Loperito; Rajamohan, T

    2003-10-01

    Hepatoprotective and antioxidant effects of tender coconut water (TCW) were investigated in carbon tetrachloride (CCl4)-intoxicated female rats. Liver damage was evidenced by the increased levels of serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) and decreased levels of serum proteins and by histopathological studies in CCl4-intoxicated rats. Increased lipid peroxidation was evidenced by elevated levels of thiobarbituric acid reactive substance (TBARS) viz, malondialdehyde (MDA), hydroperoxides (HP) and conjugated dienes (CD), and also by significant decrease in antioxidant enzymes activities, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (Gpx) and glutathione reductase (GR) and also reduced glutathione (GSH) content in liver. On the other hand, CCl4-intoxicated rats treated with TCW retained almost normal levels of these constituents. Decreased activities of antioxidant enzymes in CCl4-intoxicated rats and their reversal of antioxidant enzyme activities in TCW treated rats, shows the effectiveness of TCW in combating CCl4-induced oxidative stress. Hepatoprotective effect of TCW is also evidenced from the histopathological studies of liver, which did not show any fatty infiltration or necrosis, as observed in CCl4-intoxicated rats. PMID:22900330

  8. Food-anticipatory activity and liver per1-luc activity in diabetic transgenic rats

    NASA Technical Reports Server (NTRS)

    Davidson, Alec J.; Stokkan, Karl-Arne; Yamazaki, Shin; Menaker, Michael

    2002-01-01

    The mammalian Per1 gene is an important component of the core cellular clock mechanism responsible for circadian rhythms. The rodent liver and other tissues rhythmically express Per1 in vitro but typically damp out within a few cycles. In the liver, the peak of this rhythm occurs in the late subjective night in an ad lib-fed rat, but will show a large phase advance in response to restricted availability of food during the day. The relationship between this shift in the liver clock and food-anticipatory activity (FAA), the circadian behavior entrained by daily feeding, is currently unknown. Insulin is released during feeding in mammals and could serve as an entraining signal to the liver. To test the role of insulin in the shift in liver Per1 expression and the generation of FAA, per-luciferase transgenic rats were made diabetic with a single injection of streptozotocine. Following 1 week of restricted feeding and locomotor activity monitoring, liver was collected for per-luc recording. In two separate experiments, FAA emerged and liver Per1 phase-shifted in response to daytime 8-h food restriction. The results rule out insulin as a necessary component of this system.

  9. Caffeic acid attenuates rat liver reperfusion injury through sirtuin 3-dependent regulation of mitochondrial respiratory chain.

    PubMed

    Mu, Hong-Na; Li, Quan; Pan, Chun-Shui; Liu, Yu-Ying; Yan, Li; Hu, Bai-He; Sun, Kai; Chang, Xin; Zhao, Xin-Rong; Fan, Jing-Yu; Han, Jing-Yan

    2015-08-01

    Sirtuin 3 (Sirt3) plays critical roles in regulating mitochondrial oxidative metabolism. However, whether Sirt3 is involved in liver ischemia and reperfusion (I/R) injury remains elusive. Caffeic acid (CA) is a natural antioxidant derived from Salvia miltiorrhiza. Whether CA protects against liver I/R injury through regulating Sirt3 and the mitochondrial respiratory chain (MRC) is unclear. This study investigated the effect of CA on liver I/R injury, microcirculatory disturbance, and potential mechanisms, particularly focusing on Sirt3-dependent MRC. Liver I/R of male Sprague-Dawley rats was established by occlusion of portal area vessels for 30 min followed by 120 min of reperfusion. CA (15 mg/kg/h) was continuously infused via the femoral vein starting 30 min before ischemia. After I/R, Sirt3 expression, and MRC activity decreased, acetylation of NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 9 and succinate dehydrogenase complex, subunit A, flavoprotein variant provoked, and the liver microcirculatory disturbance and injury were observed. Treatment with CA attenuated liver injury, inhibited Sirt3 down-expression, and up-regulated MRC activity. CA attenuated rat liver microcirculatory disturbance and oxidative injury through regulation of Sirt3 and the mitochondrial respiratory chain. PMID:25960048

  10. Simple steatosis sensitizes cholestatic rats to liver injury and dysregulates bile salt synthesis and transport

    PubMed Central

    Lionarons, Daniël A.; Heger, Michal; van Golen, Rowan F.; Alles, Lindy K.; van der Mark, Vincent A.; Kloek, Jaap J.; de Waart, Dirk R.; Marsman, Hendrik A.; Rusch, Henny; Verheij, Joanne; Beuers, Ulrich; Paulusma, Coen C.; van Gulik, Thomas M.

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. It is uncertain if simple steatosis, the initial and prevailing form of NAFLD, sensitizes the liver to cholestasis. Here, we compared the effects of obstructive cholestasis in rats with a normal liver versus rats with simple steatosis induced by a methionine/choline-deficient diet. We found that plasma liver enzymes were higher and hepatic neutrophil influx, inflammation, and fibrosis were more pronounced in animals with combined steatosis and cholestasis compared to cholestasis alone. Circulating bile salt levels were markedly increased and hepatic bile salt composition shifted from hydrophilic tauro-β-muricholate to hydrophobic taurocholate. This shift was cytotoxic for HepG2 hepatoma cells. Gene expression analysis revealed induction of the rate-limiting enzyme in bile salt synthesis, cytochrome P450 7a1 (CYP7A1), and modulation of the hepatic bile salt transport system. In conclusion, simple steatosis sensitizes the liver to cholestatic injury, inflammation, and fibrosis in part due to a cytotoxic shift in bile salt composition. Plasma bile salt levels were elevated, linked to dysregulation of bile salt synthesis and enhanced trafficking of bile salts from the liver to the systemic circulation. PMID:27535001