Time- and Concentration-Dependent Induction of CYP1A1 and CYP1A2 in Precision-Cut Rat Liver Slices Incubated in Dynamic Organ Culture in the Presence of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin

Drahushuk, Adam T.; McGarrigle, Barbara P.; Slezak, Brian P.; Stegeman, John J.; Olson, James R.

doi:10.1006/taap.1998.8578

Cited by 21 publications

(7 citation statements)

References 34 publications

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“…In one study, where different incubation time points were employed, all longer than 24 h, level of induction by TCDD was found to increase with time of incubation being highest after 96 h of incubation (Drahushuk et al, 1999), in contrast to the present study where maximum induction was noted after a 24-h exposure to benzo[a]pyrene. In the study of Drahushuk et al (1999), however, the dynamic organ culture system was employed, whereas in the present study the multiwell plate system was used and this may have influenced the uptake of the inducing agent. Alternatively, induction profile may be dependent on the nature of the inducing agent.…”

Section: Discussioncontrasting

confidence: 85%

“…A rise in this activity in rat slices has already been reported following incubation with other CYP1A1 inducers such as ␤-naphthoflavone (Müller et al, 1996), TCDD (Drahushuk et al, 1996) and Aroclor 1254 (Price et al, 2004). In one study, where different incubation time points were employed, all longer than 24 h, level of induction by TCDD was found to increase with time of incubation being highest after 96 h of incubation (Drahushuk et al, 1999), in contrast to the present study where maximum induction was noted after a 24-h exposure to benzo[a]pyrene. In the study of Drahushuk et al (1999), however, the dynamic organ culture system was employed, whereas in the present study the multiwell plate system was used and this may have influenced the uptake of the inducing agent.…”

Section: Discussionmentioning

confidence: 81%

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Evaluation of the precision-cut liver and lung slice systems for the study of induction of CYP1, epoxide hydrolase and glutathione S-transferase activities

et al. 2007

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Section: Discussioncontrasting

confidence: 85%

Section: Discussionmentioning

confidence: 81%

Evaluation of the precision-cut liver and lung slice systems for the study of induction of CYP1, epoxide hydrolase and glutathione S-transferase activities

et al. 2007

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“…Thus, 10 nM TCDD was used in all other experiments in this report. A dose-dependent induction of CYP1A1 was also observed in rat and human liver slices maintained in dynamic organ culture, with 10 nM TCDD producing maximal induction (Drahushuk et al 1998(Drahushuk et al , 1999. Bruner-Tran et al (1999) also used 10 nM TCDD in a study in which proliferative phase human endometrial explants were cultured for 24 h with or without TCDD exposure in the presence of hormones, then injected into nude mice.…”

Section: Discussionmentioning

confidence: 93%

“…CYP1A1 protein was localized by a modification of the above CYP1B1 procedure and the procedure described by Drahushuk et al (1999). The antigen retrieval step and preceding PBS wash step were eliminated, primary antibody was replaced with Mab 1-12-3 (Drahushuk et al, 1999), and negative-control antibody was replaced with mouse myeloma protein IgG 2A (Organo Teknik, Durham, NC). Primary and control antibody incubation was for 180 min.…”

Section: Morphology and Immunohistochemistrymentioning

confidence: 99%

Effect of TCDD Exposure on CYP1A1 and CYP1B1 Expression in Explant Cultures of Human Endometrium

Bofinger

Li²,

Chi³

et al. 2001

Toxicological Sciences

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Endometriosis is a debilitating disease estimated to affect 10% of reproductive-age women and characterized by the growth of endometrial tissue outside of the uterus. The present study characterizes a human endometrial explant culture model for studying the direct effects of TCDD exposure by assessing the expression of CYP1A1 and CYP1B1 mRNA (Northern blotting), protein (Western blotting), and activity (7-ethoxyresorufin-O-deethylase; EROD) in explants cultured with and without TCDD. Explants were obtained at laparoscopy or laparotomy from women undergoing surgery for tubal ligation, endometriosis, or pelvic pain unrelated to endometriosis. The explants were cultured with 10 nM estradiol (E(2)) or 1 nM E(2) plus 500 nM progesterone (P(4)) with or without TCDD (first 24 h). The expression of CYP1A1 and CYP1B1 mRNA was greatest with 10 nM TCDD and increased up to 72 h after initial exposure. EROD activity increased up to 120 h. Explants from a secretory phase biopsy became reorganized in culture and formed a new epithelial membrane, while maintaining basic endometrial morphology and viability for up to 120 h. At 24 h, TCDD significantly increased CYP1A1 and CYP1B1 mRNA, and at 72 h, TCDD significantly increased EROD activity and CYP1B1 protein compared to explants cultured without TCDD for similar times. CYP1B1 protein also exhibited substantial constitutive expression that was similar in uncultured biopsies, where CYP1B1 protein was immunolocalized in the cytoplasm of epithelial glands, with only occasional patches of protein in the surface epithelial membrane. In explants cultured with and without TCDD exposure, CYP1B1 protein was localized in the cytoplasm of the new surface epithelial membrane and glands closest to the surface. CYP1A1 protein was not detected in uncultured biopsies or explants. Both younger age (age 30 and under) and proliferative phase were associated with higher TCDD-induced EROD activity in specimens treated with E(2):P(4). No significant endometriosis-related differences were observed for any of the biomarkers, but the detection of disease-specific change was limited by small sample size and variability in tissue-cycle phase. The human endometrial explant culture model will be useful for future studies of the effects of dioxin-like compounds on human endometrium in relationship to cycle phase and hormonal exposure.

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“…4 Previous studies have demonstrated that the activities of certain phase I and phase II xenobiotic-metabolizing enzymes remained stable in both fresh and cryopreserved liver slices, [5][6][7] and that xenobiotic-metabolizing cytochrome P450 (CYP) isoforms are inducible by exposure of the slices in vitro to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), b-naphthoflavone (b-NF), phenobarbital (PB), 16a-carbonitrile (PCN) [8][9][10] and other so-called inducers. On the basis of those studies, PCLS have been used widely to study biotransformation and toxicology of xenobiotics, including metabolic pathways, metabolites, drug interaction and drug toxicity.…”

Section: Introductionmentioning

confidence: 99%

Establishment of Rat Precision‐cut Fibrotic Liver Slice Technique and Its Application in Verapamil Metabolism

Guo

Wang

Zhang

2007

Clin Exp Pharma Physio

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1. Liver fibrosis is the compensatory state of cirrhosis. In the long asymptomatic period, it is imperative to select a proper dosing regimen for drugs that are applicable to hepatic fibrosis. Otherwise, progressive deterioration to uncompensated cirrhosis may occur. The present study explored the characteristics of drug metabolism in fibrotic liver. 2. A rat precision-cut fibrotic liver slice (PCFLS) technique was established and the metabolism of verapamil was studied employing this technique. A rat hepatic fibrosis model was successfully induced integrating complex factors that included a high-fat diet, alcohol and CCl4. The PCFLS were incubated under different conditions and lactate dehydrogenase leakage, glutathione S-transferase activity and 3[4,5-dimethythiazole-2-yl]-2,5-diphenyltetrazolium bromide reduction were used as indices to assess PCFLS viability. Activities of phase I and phase II metabolizing enzymes were monitored following treatment with cytochrome P450 (CYP) inducers. Normal and fibrotic liver slices were incubated individually with 10 micromol/L verapamil. The concentration of verapamil in the medium was determined by high-performance liquid chromatography and intrinsic clearance (Cl(int)) was calculated on the basis of the concentration-time curve. 3. The results showed that the PCFLS viability remained steady throughout the 6 h of culture when the thickness of slices was 300 microm and pH of the medium was 7.0; CYP inducers (phenobarbital and ethanol) enhanced CYP2E1, CYP3A1/2 and uridine diphosphate-glucuronate transferase (UDPGT) activities, respectively, in a time-dependent manner. The Cl(int) (microL/min per mg) values differed significantly between normal (9.7 +/- 1.8) and fibrotic (5.6 +/- 1.4) liver slices (P < 0.01). 4. These results suggested that the PCFLS could remain viable for 2-6 h under appropriate conditions. The stability and inducibility of drug-metabolizing enzymes of PCFLS were also demonstrated. Furthermore, the metabolic rate of verapamil in PCFLS was decreased. These findings add further support to the use of PCFLS as a tool to study drug metabolism and to guide clinical medication.

show abstract

Time- and Concentration-Dependent Induction of CYP1A1 and CYP1A2 in Precision-Cut Rat Liver Slices Incubated in Dynamic Organ Culture in the Presence of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin

Cited by 21 publications

References 34 publications

Evaluation of the precision-cut liver and lung slice systems for the study of induction of CYP1, epoxide hydrolase and glutathione S-transferase activities

Evaluation of the precision-cut liver and lung slice systems for the study of induction of CYP1, epoxide hydrolase and glutathione S-transferase activities

Effect of TCDD Exposure on CYP1A1 and CYP1B1 Expression in Explant Cultures of Human Endometrium

Establishment of Rat Precision‐cut Fibrotic Liver Slice Technique and Its Application in Verapamil Metabolism

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