Search results for: Rabbit Anti-Human CYP1A1 Antibodies
#21458012 
2011/03/31
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Cross-sectional study of hepatic CYP1A and CYP3A enzymes in hybrid striped bass, channel catfish and Nile tilapia following oxytetracycline treatment.
Terramycin for Fish® (oxytetracycline, OTC) is one of three approved drugs for therapeutic treatment of fish in the United States. Nothing is known, however, of the effects of this therapeutic on drug metabolizing enzymes in fish post-treatment. The main purpose of the study was to examine whether the fish CYP1A and CYP3A enzymes would cross-react with antibodies to known mammalian cytochrome P-450 forms (CYP1A1 and CYP3A). Observational feeding studies of OTC effects were conducted in hybrid striped bass, channel catfish and Nile tilapia. Oxytetracycline was mixed into the feed to achieve a daily dose of 82.8 mg per kg body weight at a feeding rate of 1% body weight per day. Hepatic microsomes of each fish were prepared and Western blotting of CYP1A1 and CYP3A4 and enzyme assays of CYP1A2 and CYP3A4 were performed prior to OTC treatment and on post-treatment days 1, 6, 11 and 21. Both goat anti-rat CYP1A1 and rabbit anti-human CYP3A4 showed good cross-reactivity with all three species in this study. All three species exhibited distinct perturbations in one or more of the variables examined on day 1 post-treatment. Immediately following the 10-day medication period, relative liver weight (RLW) of hybrid striped bass was increased 44% and remained elevated through post-treatment day 21. Increased CYP3A4 enzyme activity and protein abundance were noted in channel catfish and Nile tilapia, respectively. This observational approach demonstrated species differences both in control activities and in the timing and extent of hepatic responses to OTC. The unique perturbations of hepatic CYP450 enzymes in different fish species to OTC treatment observed in this study may have relevance for the use of additional antibiotics or other therapeutics used in aquaculture.N Topic Popovic, T Howell, J G Babish, P R Bowser
2925 related Products with: Cross-sectional study of hepatic CYP1A and CYP3A enzymes in hybrid striped bass, channel catfish and Nile tilapia following oxytetracycline treatment.
25 mg1 Product tipe: Instrumen1000 TESTS/0.65ml10 mg100ug200 500 mg25 mg 5 G 5 G100ul1 g
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#17728539 2007/08/29
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Observational study of hepatic cytochrome P-450 protein expression and activity in summer flounder (Paralichtys dentatus) after combination ormetoprim-sulfadimethoxine treatment.
The metabolism of aquaculture antibiotics on the piscine, hepatic cytochrome P-450 (CYP) system has not yet been defined. Fifty summer flounder, maintained at 20 degrees C, were fed ormetoprim-sulfadimethoxine (Romet-30(R)) at 1% body weight daily and were randomly sampled before treatment and on days 1, 6, 10 and 21 after treatment. Western blotting of hepatic microsomes included goat antirat CYP1A1 and rabbit antihuman CYP3A4 serum. Catalytic activities comprised: 3-cyano-7-ethoxycoumarin (CEC), 7-benzyloxy-4-trifluoromethylcoumarin (BFC), resorufin benzyl ether (BzRes). Treatment induced CYP1A1 and CYP3A4 expression. Dealkylation of CEC (CYP1A2) was increased after treatment. Romet-30 inhibited CYP3A4 activity measured by BFC, but induced BzRes CYP3A4. The usefulness of mammalian antibodies for piscine P-450 Western blotting was demonstrated. The hepatic P-450 1A2 and 3A4 metabolism was quantifiable by kits developed for mammalian microsomes.Natalija Topic Popovic, John G Babish, Paul R Bowser
2749 related Products with: Observational study of hepatic cytochrome P-450 protein expression and activity in summer flounder (Paralichtys dentatus) after combination ormetoprim-sulfadimethoxine treatment.
1 Set100ug Lyophilized1 Set1001 Set50 1 Set1 mg1mg1 Set1 Set1 Set
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#15210296 //
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Characterization and profiling of hepatic cytochromes P450 and phase II xenobiotic-metabolizing enzymes in beluga whales (Delphinapterus leucas) from the St. Lawrence River Estuary and the Canadian Arctic.
Cytochromes P450 (CYP, phase I) and conjugating (phase II) enzymes can be induced by and influence the toxicokinetics (metabolism) and toxicity of xenobiotic contaminants in exposed organisms. Beluga whale (Delphinapterus leucas) from the endangered St. Lawrence (SL) River Estuary population exhibit deleterious health effects and various severe pathologies that have been associated with contaminant exposure. In contrast, such effects (e.g. reproductive and immunological impairment) are generally less frequent in less exposed populations in the Canadian Arctic (CA). In the present study, opportunistic sampling resulted in the collection immediately after death of liver tissue from a single female neonate SL beluga (SL6) and male and female CA beluga (n=10) from the Arviat region of western Hudson Bay, in addition to sampling of stranded carcasses of male and female SL beluga (n=5) at least 12 h postmortem. We immunologically characterized cross-reactive proteins of hepatic microsomal CYP1A, CYP2B, CYP3A, CYP2E, epoxide hydrolase (EH) and uridine diphosphoglucuronosyl transferase (UDPGT) isozymes. Cross-reactive proteins were found in all SL and CA beluga using anti-rat CYP1A1, anti-rainbow trout CYP3A, anti-human CYP2E1, anti-rabbit EH and anti-human UDPGT1A1 polyclonal antibodies (Abs), whereas faintly cross-reactive CYP2B proteins were only found in SL6 and the CA samples using an anti-rabbit CYP2B1 Ab. In corresponding catalytic activity assessments, only SL6 and all CA beluga microsomal samples exhibited CYP1A-mediated 7-ethoxyresorufin O-deethylase (EROD) activity (51-260 pmol/mg/min), CYP3A-mediated activity (113-899 pmol/mg/min) based on the formation of 6beta-hydroxytestosterone using a testosterone hydroxylase assay, and UDPGT activity (830-4956 pmol/mg/min) based on 1-naphthylglucuronide formation. The marginal cross-reactivity with the anti-CYP2B1 Ab and lack of catalytically measurable hydroxytestosterone isomers associated with CYP2B-type activity in all the SL and CA animals is suggestive of low CYP2B-type enzyme expression in beluga. The absence of measurable total P450 enzyme levels and catalytic activities in samples from the stranded SL belugas suggested catalytically inactive enzymes as a consequence of tissue degradation related due to the time delay of sample collection after death. However, all SL and CA animals demonstrated similar, immunologically cross-reactive phase I and II hepatic enzyme profiles, which is suggestive of the importance of metabolism in the toxicokinetics and fate of xenobiotics in animals from both populationsMelissa A McKinney, Augustine Arukwe, Sylvain De Guise, Daniel Martineau, Pierre Béland, André Dallaire, Stéphane Lair, Michel Lebeuf, Robert J Letcher
1834 related Products with: Characterization and profiling of hepatic cytochromes P450 and phase II xenobiotic-metabolizing enzymes in beluga whales (Delphinapterus leucas) from the St. Lawrence River Estuary and the Canadian Arctic.
100ug10 mg 5 G2.5 mg1,000 tests100ul1 mg100ug100 mg1000
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#11370663 //
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Induction of CYP1A by benzo[k]fluoranthene in human hepatocytes: CYP1A1 or CYP1A2?
While fresh human hepatocyte cultures are widely used to model hepatic cytochrome P450 (CYP) regulation and activity, their CYP1A subfamily composition induced by, e.g., polycyclic aromatic hydrocarbons is ambiguous. CYP1A1, CYP1A2, or both have been reported to be expressed, and their varied roles in chemical carcinogenesis makes resolution of which CYPs are expressed essential. We have used an immunoblot system with Bis-Tris-HCl-buffered polyacrylamide gel, which clearly resolves human CYP1A1 and CYP1A2, and polyclonal goat anti-human CYP1A1/CYP1A2 and rabbit anti-human CYP1A2 antibodies to probe the expressed CYP1A1 and CYP1A2 composition of seven individual human hepatocyte cultures induced with 5 microM benzo[k]fluoranthene (BKF) for 24 h. In six of the cultures only CYP1A1 was detected, and in the seventh both CYPs were detected. In most vehicle-treated hepatocyte cultures, neither CYP1A1 nor CYP1A2 was detected. In three additional hepatocyte cultures treated individually with BKF and 2,3,7,8,-tetrachlorodibenzo-p-dioxin (TCDD), the resultant induced CYP1A1/1A2 profiles were essentially not influenced by the nature of the inducing agents. To develop an activity-based assay to differentiate between CYP1A1 and CYP1A2 expression in human hepatocytes, our previously published R warfarin assay (Drug Metab. Disp. (1995) 23, 1339-1345) was applied to TCDD (10 nM)-treated hepatocyte culture. The low concentration of TCDD did not produce inhibition of the warfarin metabolism-such inhibition could confound the results. Based on the ratios of 6- to 8-hydroxywarfarin formed in two cultures, the ratios of CYP1A1/CYP1A2 expressed in these cultures were determined and they agreed with the ratios determined by immunoblot analysis. Thus each individual human hepatocyte culture must be characterized for induced CYP1A1 and CYP1A2 expression in studies of CYP1A activity. The warfarin assay provides a means of characterizing the cultures.N Liu, Q Y Zhang, D Vakharia, D Dunbar, L S Kaminsky