Are Bile Acids Involved in the Renal Dysfunction of Obstructive Jaundice? An Experimental Study in Bile Duct Ligated Rats
Bibliographic record
Abstract
BACKGROUND: Surgery on patients with obstructive jaundice is associated with a significant risk of postoperative renal failure. Bile acids are implicated as nephrotoxins because they accumulate in the plasma and the kidney becomes their only excretory route in cholestasis. The experimental evidence favoring this proposal is inadequate and unconvincing. Therefore, we designed an animal experiment involving bile duct ligated (BDL) rats in which we could correlate variations in serum and urine bile acids with indices of nephrotoxicity and renal function. HYPOTHESIS: Bile acids are putative nephrotoxins. MATERIALS AND METHODS: Total serum and urine bile acid concentrations and profiles were determined using liquid chromatography/gas chromatography/mass spectrometry selected ion monitoring. Nephrotoxicity was assessed by renal histopathology and by determination of the urinary activities of the following enzymes: muramidase, glutamate dehydrogenase, alkaline phosphatase, N-acetyl-beta-D-glucosaminidase, and lactate dehydrogenase. Renal function was assessed by measuring urine osmolality, daily osmolar excretion, sodium excretion (U(Na)V), potassium excretion (U(K)V), and total protein and albumin excretion. RESULTS: Maximum plasma concentrations and renal clearance of bile acids occurred between the third or fourth postoperative day following BDL. This peak coincided with maximal disruption of proximal convoluted tubule architecture and postoperative changes in renal function-increased urine flow rate and decreases in urine osmolality and sodium excretion. Thereafter, 1) plasma levels of bile acids returned toward normal levels, 2) urinary bile acid clearance declined, 3) normal renal histology was restored, and 4) normal renal function was reestablished. Throughout this period, fluctuations in enzymuria were evident. However, these shifts did not coincide with plasma and urine bile acid concentrations and histological and functional changes. DISCUSSION AND CONCLUSIONS: Transient functional impairment of renal cation and water transport and nonspecific morphological changes in the proximal convoluted tubule occur 3 to 4 days following bile duct ligation in rats. These functional and morphological changes occurred when plasma total and urinary bile acids were at their peaks. Although it is tempting to equate association with causality, we cannot implicate bile acids as being responsible for the aberrations in renal function and structure following BDL. Accordingly, we have concluded that elevated plasma concentrations of bile acids are renal exacerbates acting in concert with other factors, be they prerenal or renal in origin to precipitate a cascade of events leading to postoperative renal failure in cholestasis.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".