Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019209 (hepatomegaly)
 5,798 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of ciprofibrate, a potent oxyisobutyrate derivative, on several hepatic enzyme parameters was studied in five rat strains following a 14-day treatment period. Ciprofibrate-dependent hepatomegaly was observed at two dose levels (2 and 20 mg/kg) in all rat strains examined. A 10- to 15-fold induction in the 12-hydroxylation of lauric acid with a less marked 1.5- to 5-fold induction of 11-hydroxylation was observed in treated animals. This dose-dependent increase in fatty acid hydroxylase activity was associated with a maximal 10-fold increase in the specific content of cytochrome P-450 IVA1 isoenzyme apoprotein, as assessed immunochemically using an ELISA technique. The activities of the cytochrome P-450 I (IA1 and IA2) and II (IIB1 and IIB2) families, as measured by ethoxyresorufin-O-deethylase and benzphetamine-N-demethylase activities respectively, were decreased on treatment. In the mitochondria, monoamine oxidase activity was significantly decreased at the higher dose level whereas alpha-glycerophosphate dehydrogenase activity was elevated. Total carnitine acetyltransferase activity (mitochondrial and peroxisomal) and peroxisomal beta-oxidation were markedly increased at both dose levels in all strains examined. Cytosolic glutathione peroxidase activity, measured using both t-butylhydroperoxide and hydrogen peroxide as substrates, was decreased on treatment to approximately 50% of the control value. In treated animals, a marked increase in mRNA levels coding for cytochrome P-450 IVA1 and the peroxisomal bifunctional protein of the fatty acid beta-oxidation spiral was observed. However, mRNA levels coding for glutathione peroxidase appeared unchanged following ciprofibrate administration, in contrast to the above-noted decrease of glutathione peroxidase enzyme activity. Taken collectively, our results have further substantiated a close association between the induction of microsomal cytochrome P-450 IVA1, peroxisomal beta-oxidation and total carnitine acetyltransferase activity in rat liver, and have performed a conceptual basis for the rationalization of the chronic toxicity of peroxisome proliferators in this species.
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PMID:Characterization of the hepatic responses to the short-term administration of ciprofibrate in several rat strain. Co-induction of microsomal cytochrome P-450 IVA1 and peroxisome proliferation. 239 Jan 5

1. The inducing effect of hypolipidaemic compounds containing arylcarboxylic structure (fenofibrate, bezafibrate, ciprofibrate) on drug-metabolizing enzymes was compared with that of other chemically different molecules (probucol, 1-benzylimidazole) in rat liver. 2. Hepatomegaly was closely associated to the decrease in triglycerides and cholesterol contents in plasma. 3. Lauric acid hydroxylation and hydratation of trans-stilbene oxide by the cytosolic epoxide hydrolase were markedly increased by the arylcarboxylic acids (fenofibrate, bezafibrate and ciprofibrate). The determination of the concentration in microsomal epoxide hydrolase by immunoassay revealed no change in the protein amount within the membrane; only the specific activity was enhanced by bezafibrate and 1-benzylimidazole, suggesting an activation process. 4. Bilirubin glucuronidation was increased by the arylcarboxylic structures and by 1-benzylimidazole; by contrast probucol decreased this activity.
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PMID:Comparative induction of drug-metabolizing enzymes by hypolipidaemic compounds. 250 68

The influence of 1-benzylimidazole on the activities of hepatic monooxygenases cytochromes P-450 dependent, epoxide hydrolases and UDP-glucuronosyltransferases was investigated in male Wistar rats. Several doses (25, 75 and 100 mg/kg/day) were administered gastrically during 5 days in order to evaluate the dose-related induction. The treatment caused a dose-dependent hepatomegaly. 1-Benzylimidazole decreased the plasma level in triglycerides by 60-70%; by contrast the cholesterol content was not changed during the time course of the experiment. Lauric acid hydroxylase, benzphentamine N-demethylase, 7-ethoxyresorufin O-deethylase, 7-ethoxycoumarin O-deethylase activities were increased 3.5-, 4-, 13- and 46-fold, respectively with the highest dose. By immunoblotting, an enhancement in the protein bands corresponding to cytochromes P-450c and P-450b could be simultaneously observed, whatever the dose administered, thus suggesting an induction process. However, 1-benzylimidazole failed to bind with high affinity to the cytosolic Ah receptor. On the other hand, measurement of the activity of the microsomal epoxide hydrolase with benzo(a)pyrene-4,5-oxide as substrate and quantitation of the enzyme protein by immunoassay revealed that the increase in the activity after treatment with the compound was the result of enzyme activation only. By contrast, cytosolic epoxide hydrolase was not affected by 1-benzylimidazole. This compound also stimulated three distinct forms of UDP-glucuronosyltransferase. The activities towards 4-methylumbelliferone, 1-naphthol, morphine or a monoterpenoid alcohol, nopol, supported by two different isozymes were significantly increased only with the highest dose; meanwhile bilirubin glucuronidation was 2-fold enhanced, whatever the dose used. These observations emphasize the variety of the effects of 1-benzylimidazole on drug-metabolizing enzymes.
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PMID:Effect of 1-benzylimidazole on cytochromes P-450 induction and on the activities of epoxide hydrolases and UDP-glucuronosyltransferases in rat liver. 284 Sep 13

The widely used broad leaf herbicide, dicamba, or Banvel, is similar in structure to xenobiotics which induce hepatic drug metabolism or proliferation of hepatic peroxisomes in rodents. The ability of xenobiotics to effect these hepatic changes often portends their positive outcomes in chronic bioassays. Dicamba's ability to induce hepatomegaly and peroxisome proliferation was studied in male and female Sprague-Dawley rats. Rats were placed on feed containing 0, 0.001, 0.01, 0.1, or 1% dicamba or 0.01% ciprofibrate for 3 weeks. Dicamba had no effect on relative liver weights or feed efficiency in either female or male rats at all doses tested. Dicamba, however, caused a statistically significant increase in peroxisomal beta-oxidation activity in liver homogenates from rats of both sexes fed 1% dicamba. Fatty acyl CoA-oxidase activity was increased in male rats fed 1% dicamba. A protein of M(r) 80 kDa was visible when liver homogenates of female or male rats fed 1% dicamba were subjected to SDS-PAGE. Lauric acid hydroxylase activity and CYP4A-reactive protein were increased in microsomes from male rats fed the highest level of dicamba. Moreover, dicamba was observed to transcriptionally upregulate the peroxisome proliferator-activated receptor (PPAR), a peroxisome proliferator sensitive receptor previously shown to be linked to the transcriptional regulation of a variety of peroxisome-specific enzymes. These studies show that dicamba is a peroxisome proliferator in rats. Although dicamba was not an efficacious inducer of peroxisomal enzymes in these rats, dicamba's ability to transcriptionally activate the PPAR and induce peroxisomal and related enzymes must be considered in the safety evaluation of this herbicide.
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PMID:The herbicide dicamba (2-methoxy-3,6-dichlorobenzoic acid) is a peroxisome proliferator in rats. 765 66

Male Wistar rats and male Duncan Hartley guinea pigs were treated with one i.p. dose of perfluorodecanoic acid (PFDA) resulting in pronounced hepatomegaly in the rat but not the guinea pig. PFDA treatment also resulted in a 4-fold induction of lauric acid 12-hydroxylase activity in the rat but not the guinea pig, indicating induction of the CYP4A subfamily of isoenzymes. Consistent with this latter conclusion, Western blot analysis of rat liver microsomes using an antibody to CYP4A1 and Northern blot analysis of RNA extracts using a CYP4A1 cDNA probe, revealed PFDA-dependent induction of the CYP4A subfamily in the rat but not the guinea pig. Taken collectively, our data has demonstrated that PFDA, like other peroxisome proliferators, is also a CYP4A inducer and conforms to the well-documented species specificity in induction for this class of compound.
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PMID:Induction of the CYP4A subfamily by perfluorodecanoic acid: the rat and the guinea pig as susceptible and non-susceptible species. 814 May 91

Male Wistar albino rats were treated for a 7 day period with equimolar doses of the trimer and tetramer oligomers of chlorotrifluoroethylene (CTFE), resulting in significant hepatomegaly for both compounds. In addition, both trimer and tetramer significantly induced the peroxisomal beta-oxidation of fatty acids as assessed by increases in palmitoyl-coenzyme A (CoA) oxidation, thus confirming these oligomers as peroxisome proliferators. Consistent with these conclusions, both trimer and tetramer increased the hydroxylation of lauric acid indicating that the CTFEs were inducers of the CYP4A subfamily, a conclusion further supported by substantial increases in the steady-state levels of the cognate CYP4A1 mRNA as determined by northern blotting. The liver appeared to be more susceptible to induction than the kidney and the CTFE tetramer was more potent than the trimer. These results are discussed with respect to both the differential hepatotoxicity, and biotransformation/disposition of the two polyhalogenated oligomers.
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PMID:Chlorotrifluoroethylene trimer and tetramer are inducers of the CYP4A subfamily. 821 51

The effects of zileuton, a 5-lipoxygenase inhibitor, on hepatic peroxisomal enzyme activity as well as hepatic drug metabolizing activity in male and female CD-1 mice were assessed after oral administration of the drug (50, 150, or 450 mg/kg/day) for 14 days. The effects were compared to those in mice receiving clofibrate (CLOF;462 mg/kg/day, po) or sodium phenobarbital (PB; 50 mg/kg/day, po). Zileuton pretreatment caused hepatomegaly and elevated liver peroxisomal KCN-insensitive palmitoyl CoA oxidase activity in a dose-dependent manner. However, these changes were marginal (< or = 121% increase), when compared to those elicited by CLOF (approximately 370% increase). In both sexes, zileuton pretreatment also caused a dose-dependent increase in the levels of liver microsomal cytochrome P450 2B and cytochrome P450 4A (CYP4A) proteins, and their associated monoxygenase activity. In the case of CYP4A, the induction of lauric acid 12-hydroxylase activity by zileuton was more pronounced in female (maximal 851% increase) than in male mice (maximal 111% increase). Based on the dose normalized response observed in CD-1 mice, zileuton can be considered a relatively weak inducer of peroxisome enzyme activities (cf.CLOF) and a moderate inducer of cytochromes P450. Moreover, zileuton exhibits characteristics of both a PB- and a CLOF-type hepatic enzyme inducer, especially in the female mice.
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PMID:Hepatic peroxisomal and drug metabolizing activity in CD-1 mice after oral treatment with a novel 5-lipoxygenase inhibitor. 866 44

We used reverse transcriptase polymerase chain reaction (RT-PCR) assays to examine primary leukemic cells in on-study diagnostic bone marrow specimens from 642 children with newly diagnosed acute lymphoblastic leukemia (ALL) for the expression of MLL-AF4, E2A-PBX1, and BCR-ABL fusion transcripts. All PCR assays were performed centrally in the Children's Cancer Group ALL Biology Reference Laboratory. MLL-AF4 transcript was found in only 0.7% of the study population which excluded infants. E2A-PBX1 transcript was found in 2.5% of the study population and 3.3% of B-precursor cases. Expression was associated with massive hepatomegaly. BCR-ABL transcript was found in 2.3% of cases and correlated with older age, induction failure, and inferior event-free survival (EFS). RT-PCR assays allow rapid identification of patients with MLL-AF4 and BCR-ABL positive ALL. These patients have a poor outcome with contemporary therapy and rapid identification facilitates timely allocation to innovative treatment programs.
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PMID:Expression of BCR-ABL, E2A-PBX1, and MLL-AF4 fusion transcripts in newly diagnosed children with acute lymphoblastic leukemia: a Children's Cancer Group initiative. 925 Jul 88

Allogeneic bone marrow transplantation is the only curative treatment for patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML); however, recurrence of disease remains a major cause of treatment failure. A 26-year-old man with chronic myeloid leukemia who had a cytogenetic relapse 49 months after his first syngeneic bone marrow transplant (BMT) and hematologic relapse 23 months thereafter progressed to blast crisis despite treatment with IFN-alpha for 15 months. He underwent a second transplantation in early second blast crisis, 92 months after the first BMT with PBPC from his previous donor. Successful hematological reconstitution occurred. On day 50 after the second transplantation the patient developed a generalized rash, hepatomegaly, and cholestatic signs. Skin and liver biopsy revealed changes compatible with acute graft-versus-host disease (GVHD). Treatment with cyclosporin A (CSA) and prednisone was started, and the GVHD resolved. Fifteen months after PBPC transplantation he had a molecular relapse. Despite discontinuation of CSA, the patient progressed into blast crisis 7 months later. The occurrence of GVHD and disappearance of the BCR-ABL-positive clone suggest that a graft-versus-leukemia (GVL) effect may have been operative for 15 months in a patient given a second syngeneic BMT in blast crisis.
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PMID:Graft-versus-host disease following second syngeneic stem cell transplantation for relapsed chronic myeloid leukemia. 987 66

The SCID mouse represents a valuable tool for assessing growth characteristics and drug sensitivity of human leukemic cells. We have examined differences in the engraftment patterns in SCID mice of primary human leukemic cells isolated from children (< 21 years old) with either t(1;19)+/E2A-PBX1+ or t(9;22)+/BCR-ABL+ acute lymphoblastic leukemia. Leukemic cells from 13/24 t(1;19)+/E2A-PBX1+ patients caused overt leukemia in SCID mice. Macroscopic lesions were evident in 6/13 cases, with multiple sites involved in some mice: hepatomegaly,(3) splenomegaly(4), thymic enlargement; liver tumors(1), kidney tumors(1), abdominal tumors(1). Microscopic lesions in SCID mouse organs were present in all 13 cases and involved the bone marrow, brain, heart, gut, liver, kidney, lung, ovary, pancreas, skeletal muscle, spleen, and thymus. Leukemic cells from 5/20 t(9;22)+/BCR-ABL+ patients caused overt leukemia in SCID mice. Notably, macroscopic lesions (splenomegaly; leukemic bones; hepatic tumors) were observed in only 1 case. In all 5 cases, microscopic lesions were found in the mouse bone marrow. Additional microscopic lesions were restricted to skeletal muscle, spleen, and mesentery (1 case) or thymus (1 case). These findings differ markedly from those of t(1;19)+/E2A-PBX1+ leukemic cells due to the lack of involvement of major organs such as liver, pancreas, kidney, skin, or brain. These data illustrate the biological heterogeneity of childhood ALL and suggest that the differential risks associated with t(1;19)+/E2A-PBX1+ and t(9;22)+/BCR-ABL ALL might arise from unique engraftment and proliferation capabilities of the respective leukemic cell populations.
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PMID:Distinct in vivo engraftment and growth patterns of t(1;19)+/E2A-PBX1+ and t(9;22)+/BCR-ABL+ human leukemia cells in SCID mice. 1003 3


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