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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
|
| pubmed:dateCreated |
1994-7-12
|
| pubmed:abstractText |
The role of oxygen tension, insulin, and glucagon on the preservation and induction of cytochrome P450 isoenzyme activities and contents was investigated in rat hepatocytes cultured for 4 days on crude liver membrane fractions at 4 or 13% O2. At 13% O2, three out of six immunochemically analyzed P450 isoenzymes were significantly higher than in 4% O2. Exposure to phenobarbital (PB) from Days 1 to 4 dose dependently increased the protein content and decreased the albumin secretion in 13% O2 cultures only. The maximal induction of P450 isoenzymes CYP2B1/2B2 (20- to 25-fold) and CYP2C6 (6-fold) were found at 0.75 mM PB at both oxygen tensions. In contrast, the highest induction of CYP1A1/1A2 (3-fold), of CYP3A (2-fold), and EROD activity were found with 3 mM PB in 4% O2 cultures. CYP2B-dependent testosterone hydroxylation at positions 16 alpha/beta was elevated to a greater extent in 13% O2 cultures (96-fold at 0.75 mM PB) compared to 4% O2 cultures (42-fold). This activity was affected by the insulin concentrations and the insulin:glucagon ratio. With decreasing insulin concentration (100 to 1 nM) or with increasing insulin:glucagon ratios (1:100-1:0.1), the enzyme activity increased preferentially in 4% O2 cultures. The results of these investigations demonstrate that different tissue oxygen tension modulates the responsiveness of the cultured hepatocytes to the glucoregulatory hormones insulin and glucagon and this modulation results in a altered activity of cytochrome P450 isoforms.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Albumins,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP1A1,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System,
http://linkedlifedata.com/resource/pubmed/chemical/Glucagon,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin,
http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes,
http://linkedlifedata.com/resource/pubmed/chemical/L-Lactate Dehydrogenase,
http://linkedlifedata.com/resource/pubmed/chemical/Oxidoreductases,
http://linkedlifedata.com/resource/pubmed/chemical/Oxygen,
http://linkedlifedata.com/resource/pubmed/chemical/Testosterone
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0041-008X
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
126
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
372-9
|
| pubmed:dateRevised |
2011-11-17
|
| pubmed:meshHeading |
pubmed-meshheading:8209390-Albumins,
pubmed-meshheading:8209390-Animals,
pubmed-meshheading:8209390-Cells, Cultured,
pubmed-meshheading:8209390-Cytochrome P-450 CYP1A1,
pubmed-meshheading:8209390-Cytochrome P-450 Enzyme System,
pubmed-meshheading:8209390-Enzyme Induction,
pubmed-meshheading:8209390-Enzyme-Linked Immunosorbent Assay,
pubmed-meshheading:8209390-Glucagon,
pubmed-meshheading:8209390-Hydroxylation,
pubmed-meshheading:8209390-Insulin,
pubmed-meshheading:8209390-Isoenzymes,
pubmed-meshheading:8209390-L-Lactate Dehydrogenase,
pubmed-meshheading:8209390-Liver,
pubmed-meshheading:8209390-Male,
pubmed-meshheading:8209390-Oxidoreductases,
pubmed-meshheading:8209390-Oxygen,
pubmed-meshheading:8209390-Rats,
pubmed-meshheading:8209390-Rats, Sprague-Dawley,
pubmed-meshheading:8209390-Testosterone
|
| pubmed:year |
1994
|
| pubmed:articleTitle |
Oxygen tension, insulin, and glucagon affect the preservation and induction of cytochrome P450 isoforms in cultured rat hepatocytes.
|
| pubmed:affiliation |
Institute of Toxicology, Swiss Federal Institute of Technology, Schwerzenbach.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|