Differential alteration of cytochrome P450 isoenzymes in two experimental models of cirrhosis
Bibliographic record
Abstract
Liver diseases are associated with a decrease in hepatic drug elimination, but there is evidence that cirrhosis does not result in uniform changes of cytochrome P450 (CYP) isoenzymes. The objective of this study was to determine the content and activity of four CYP isoenzymes in the bile duct ligation and carbon tetrachloride (CCl 4 )-induced models of cirrhosis. The hepatic content of CYP1A, CYP2C, CYP2E1, and CYP3A was measured by Western blot analysis. CYP activity in vivo was evaluated with breath tests using substrates specific for different isoenzymes: caffeine (CYP1A2), aminopyrine (CYP2C11), nitrosodimethylamine (CYP2E1), and erythromycin (CYP3A). Bile duct ligation resulted in biliary cirrhosis; CYP1A, CYP2C and CYP3A content was decreased and the caffeine, aminopyrine, and erythromycin breath tests were reduced whereas CYP2E1 content and the nitrosodimethylamine breath test were unchanged compared with controls. CCl 4 treatment resulted in cirrhosis of varying severity as assessed from the decrease in liver weight and serum albumin. In rats with mild cirrhosis, CYP content was comparable with controls except for a decrease in CYP2C. The activity of CYPs was also unchanged except for an increase in CYP2E1 activity. In rats with more severe cirrhosis, the content of all four CYP isoenzymes and the caffeine, aminopyrine, and erythromycin breath tests were reduced whereas the nitrosodimethylamine breath test was unchanged. In both models of cirrhosis, there was a significant correlation between the breath tests results and the severity of cirrhosis as assessed from serum albumin levels. These results indicate that content and the catalytic activity of individual CYP enzymes are differentially altered by cirrhosis in the rat and also suggest that drug probes could be useful to assess hepatic functional reserve.Key words: breath test, cirrhosis, cytochrome P450, bile duct ligation, carbon tetrachloride.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.016 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".