Urinary metabonomics characterization of liver fibrosis induced by CCl₄ in rats and intervention effects of Xia Yu Xue Decoction

Xia Yu Xue Decoction (XYXD) is a traditional Chinese medicine which has been widely used in clinic practice for treating liver disease. However, its mechanism of action remains unknown. In this study, a urinary metabonomic method, based on gas chromatography coupled with mass spectrometry (GC/MS), was developed to investigate the effect of XYXD on liver fibrosis. Pattern recognition analysis, including principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA), showed that metabolic perturbations induced by CCl(4) were restored after treatment with XYXD. Ten potential biomarkers associated with modulation of energy metabolism, microflora metabolism, amino acid and fatty acid metabolism were identified, suggesting that the mechanism of action of XYXD may involve these processes. Our findings indicate that metabonomic methods based on GC/MS may provide a useful means of exploring biomarkers involved in liver fibrosis and for elucidating the mechanisms of action of therapies used in traditional Chinese medicine.

Hepatotoxin-induced hypertaurinuria: a proton NMR study

The urinary excretion of taurine by rats after dosing with various hepatotoxins has been investigated by 1H NMR spectroscopy. After single hepatotoxic doses of hydrazine, carbon tetrachloride, 1-naphthylisothiocyanate, or thioacetamide there was biochemical and histopathological evidence of hepatic damage. Proton NMR spectroscopy of the urine collected for 24 h after dosing from these animals revealed a marked elevation in taurine (control 11.9 mumole/h/kg) after dosing with thioacetamide (42.2 mumole/h/kg), carbon tetrachloride (52.5 mumole/h/kg), 1-naphthyl-isothiocyanate (80.4 mumole/h/kg) and hydrazine (52.9 mumole/h/kg). After allyl alcohol administration there was no increase in taurine excretion (7.5 mumol/h/kg). The excretion of taurine after hydrazine administration was dose related. High resolution proton NMR spectroscopic analysis of urine also revealed resonances from several metabolites of hydrazine, an N-acetylcysteine conjugate of allyl alcohol, and acetamide as a metabolite of thioacetamide after dosing with the respective compounds. Changes in endogenous substances that may be related to the pathological events were also detected, such as a decrease in the excretion of 2-oxoglutarate and citrate after both hydrazine and carbon tetrachloride administration. The results confirm that proton NMR spectroscopic analysis of urine is a powerful analytical tool for the evaluation and study of toxic substances. Furthermore, measurement of urinary taurine may provide a non-invasive indicator of acute hepatic damage with certain classes of hepatotoxins.

[125I-n-iodophenamine as a prototype compound for the study of microsomal oxidation]

Dynamics of distribution and excretion with urine of 125I-p-iodophenamine were studied impairment of rat liver tissue microsomal oxidation by means of CC14 treatment. This poison inhibited distinctly metabolism and excretion of the labelled compound in rats but not in rabbits, which was due to difference in the mechanisms of the compound biotransformation. The requirements for compounds suitable for studies of microsomal oxidation by means of excretory test were not met by 125I-p-iodophenamine.

Urinary polyamine excretion as related to cell death and cell proliferation induced by carbon tetrachloride intoxication

This study addresses the question whether urinary polyamine excretion is related to cell death or cell proliferation. CCl4 intoxication of the rat was used as the experimental model. Treatment with CCl4, a hepatotoxic haloalkane, produces an initial phase of liver cell death succeeded by a regenerative phase of growth, during which the liver is restored. The highest rate of putrescine (and spermidine) excretion occurred during the first 24 hr of CCl4 intoxication and coincided with the period of maximum liver damage. During subsequent liver regeneration the rate of excretion of both polyamines decreased.

The excretion of ascorbic acid and hippuric acid in the urine of rats with liver injury

The excretion of ascorbic acid and hippuric acid in the urine as liver function tests has no marked advantages when compared with other tests (activities of serum enzymes glutamate dehydrogenase and L-alanine: 2-oxoglutarate aminotransferase, hexobarbital sleeping time).

[The excretion of hippuric acid and ascorbic acid in the urine of liver-damaged rats (author's transl]

The authors investigated the effects of the administration of thioacetamide, carbon tetrachloride and aminophenazone on the excretion of ascorbic acid and hippuric acid in adult male and female Wistar rats. After a single application of thioacetamide and aminophenazone, the ascorbic acid content in the urine showed a dose-dependent increase, whereas that in the liver had decreased. This increase in the urinary ascorbic acid might be due to a release of stored ascorbic acid from the liver cells. When thioacetamide was given for a prolonged period, the ascorbic acid content in the urine increased at the beginning; later one, at the end of three weeks, it was slightly inferior to the control value. Both single and repeated applications of thioacetamide led to a decrease in the excretion of hippuric acid in the urine, which is attributed to an impairment of the mitochondrial hippuric acid synthesis. Long-term treatment with aminophenazone resulted in an increase of ascorbic acid in the urine, which is indicative of an induction effect, whereas the ascorbic acid content in the liver remained unchanged. There was no effect on the excretion of hippuric acid. In regard to their use in the toxicological evaluation of drugs, these two metabolic effects offer no decisive advantage over current liver function tests.

Urinary excretion of alpha-fetoprotein in rats on a cirrhogenic carbon tetrachloride regimen

Alpha-fetoprotein was detected in the serum and urine of 2- to 9-mth-old rats subjected to protracted CCl4 poisoning. During the first 3 mth of the experiment, urinary excretion of AFP was found in 30-40 per cent. of the animals, increasing to 70 per cent. thereafter. The liver lesions progressed from acute parenchymal necrosis to cirrhosis, but hepatocellular carcinomas did not develop. Uptake of tritiated thymidine by the hepatocytes increased significantly but was constant throughout the experimental period. The findings are compared to the observations made during 3mDAB-induced hepatocarcinogenesis in the rat.

Structural and functional changes in rat kidney during CCl4 intoxication

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