Naphthoflavone
Mostrando 13-24 de 35 artigos, teses e dissertações.
-
13. Cloning of a cDNA coding for P-450 LM3c from rabbit liver microsomes and regulation of its expression.
Liver cytochromes P-450 LM3c in the rabbit and P-450p in the rat are two related forms, inducible by macrolide antibiotics such as triacetyloleandomycin (TAO) and glucocorticoids such as dexamethasone. We prepared a cDNA library from TAO induced rabbit liver mRNA and characterized a cDNA (pLM3c-4.1) that hybridized to pDex 3.22, a cDNA complementary to cytoc
-
14. The Ah Phenotype. Survey of Forty-Eight Rat Strains and Twenty Inbred Mouse Strains
Forty-four inbred and four randombred rat strains and 20 inbred mouse strains were examined for their Ah phenotype by determining the induction of liver microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity (EC 1.14.14.1) by intraperitoneal treatment with either β-naphthoflavone or 3-methylcholanthrene. All 48 rat strains were found to be Ah-res
-
15. On the mechanisms of induction of cancer-protective enzymes: a unifying proposal.
Induction of detoxification enzymes is a major mechanism whereby a wide variety of chemical agents protect rodents against neoplastic, mutagenic, and other toxicities of carcinogens. The enzyme NAD(P)H:(quinone acceptor) oxidoreductase (EC 1.6.99.2) can protect against the toxicities of quinones and is a useful marker for protective enzyme induction. Quinone
-
16. Overexpression of apolipoprotein CII causes hypertriglyceridemia in transgenic mice.
We have generated transgenic mice expressing the human apolipoprotein CII (apoCII) gene under the transcriptional control of the human cytochrome P-450 IA1 (CYPIA1) promoter. Human apoCII transgenic (HuCIITg) mice exhibited significant basal expression of the transgene (plasma apoCII level = 26.1 +/- 4 mg/dl) and showed further induction of transgene express
-
17. Liver cells contain constitutive DNase I-hypersensitive sites at the xenobiotic response elements 1 and 2 (XRE1 and -2) of the rat cytochrome P-450IA1 gene and a constitutive, nuclear XRE-binding factor that is distinct from the dioxin receptor.
Dioxin stimulates transcription from the cytochrome P-450IA1 promoter by interaction with the intracellular dioxin receptor. Upon binding of ligand, the receptor is converted to a form which specifically interacts in vitro with two dioxin-responsive positive control elements located in close proximity to each other about 1 kb upstream of the rat cytochrome P
-
18. Regulation of glutathione S-transferase Ya subunit gene expression: identification of a unique xenobiotic-responsive element controlling inducible expression by planar aromatic compounds.
We have identified a region in the 5' flanking sequence of the glutathione S-transferase (RX:glutathione R-transferase, EC 2.5.1.18) Ya subunit gene that contains a unique xenobiotic-responsive element (XRE). The regulatory region spans nucleotides -722 to -682 of the 5' flanking sequence and is responsible for part of the basal level as well as inducible ex
-
19. Cytochrome P450 1A1 promoter as a genetic switch for the regulatable and physiological expression of a plasma protein in transgenic mice.
Transgenic and gene knockout techniques allow for in vivo study of the consequences of adding or subtracting specific genes. However, in some instances, such as the study of lethal mutations or of the physiological consequences of changing gene expression, turning on and off an introduced gene at will would be advantageous. We have used cytochrome p450 1A1 p
-
20. Leukotriene B4 omega-hydroxylase in human polymorphonuclear leukocytes. Partial purification and identification as a cytochrome P-450.
Human polymorphonuclear leukocytes (PMN) not only synthesize and respond to leukotriene B4 (LTB4), but also catabolize this mediator of inflammation rapidly and specifically by omega-oxidation. To characterize the enzyme(s) responsible for omega-oxidation of LTB4, human PMN were disrupted by sonication and subjected to differential centrifugation to yield me
-
21. Regulation of the antioxidant response element by protein kinase C-mediated phosphorylation of NF-E2-related factor 2
A coordinated cellular response to oxidative stress occurs in part through transcriptional regulation via a cis-acting sequence known as the antioxidant response element (ARE). NF-E2-related factor 2 (Nrf2), a member of the Cap'n'Collar family of basic region-leucine zipper (bZIP) transcription factors, has been implicated as an essential component of a
The National Academy of Sciences.
-
22. Nrf1 and Nrf2 positively and c-Fos and Fra1 negatively regulate the human antioxidant response element-mediated expression of NAD(P)H:quinone oxidoreductase1 gene
Twenty-four base pairs of the human antioxidant response element (hARE) are required for high basal transcription of the NAD(P)H:quinone oxidoreductase1 (NQO1) gene and its induction in response to xenobiotics and antioxidants. hARE is a unique cis-element that contains one perfect and one imperfect AP1 element arranged as inverse repeats separated by 3
The National Academy of Sciences of the USA.
-
23. Analysis of human cytochrome P450 3A4 cooperativity: Construction and characterization of a site-directed mutant that displays hyperbolic steroid hydroxylation kinetics
Cytochrome P450 3A4 is generally considered to be the most important human drug-metabolizing enzyme and is known to catalyze the oxidation of a number of substrates in a cooperative manner. An allosteric mechanism is usually invoked to explain the cooperativity. Based on a structure–activity study from another laboratory using various effector–substrate
The National Academy of Sciences.
-
24. On the amino acid sequence of cytochrome P-450 isozyme 4 from rabbit liver microsomes.
Isozyme 4 of rabbit liver microsomal cytochrome P-450 was shown earlier in this laboratory to contain multiple NH2-terminal residues, whereas isozymes 2, 3a, 3b, and 3c have single, unique NH2-terminal sequences. Similar results were obtained with isozyme 4 obtained from animals that were untreated, treated with phenobarbital (which does not induce this isoz