Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the determinants of hepatic clearance functions in a rat model of liver cirrhosis induced by phenobarbital/CCl4. Aminopyrine N-demethylation (ABT), galactose elimination (GBT), and serum bile acids (SBA) were determined in vivo. The livers were then characterized hemodynamically: intrahepatic shunting (IHS) was determined by microspheres and sinusoidal capillarization by measuring the extravascular albumin space (EVA) by a multiple indicator dilution technique. The intrinsic clearance was determined by assaying the activity of the rate-limiting enzymes in vitro. Hepatocellular volume (HCV) was measured by morphometry. ABT and SBA, but not GBT, differentiated cirrhotic from normal liver. IHS ranged from normal to 10%; all cirrhotic livers showed evidence of sinusoidal capillarization (reduced EVA). The cirrhotic livers showed a bimodal distribution of HCV, HCV being decreased in 50% of the cirrhotic livers. Multivariate analysis showed EVA and portal flow to be the main determinants of microsomal (ABT) and cytosolic (GBT) clearance function; SBA, by contrast, were determined solely by IHS. We conclude that sinusoidal capillarization is the main determinant of hepatic clearance, while serum bile acids reflect intrahepatic shunting. These findings emphasize the importance of alterations of hepatic nutritional flow to explain reduced clearance function in cirrhosis of the liver.
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PMID:Determinants of hepatic function in liver cirrhosis in the rat. Multivariate analysis. 319 65

The detection of circulating serum antibodies that react with various nuclear or cytoplasmic antigens of cell substrates has become an established investigation in the diagnosis of autoimmune diseases. Antinuclear antibodies as well as some non-organ-specific anticytoplasmic autoantibodies might be of diagnostic significance. Some examples are anti-mitochondrial antibodies in autoimmune liver diseases, anti-cytoskeletal antibodies in chronic active hepatitis, polymyositis and infectious diseases and microsomal antibodies in juvenile cryptogenic liver cirrhosis. New techniques and methods such as indirect immunofluorescence on tissue culture substrates, enzymelinked immunoassays and immunoblotting tests now form the basis of further studies. These tests allow a more sensitive and specific assay for lysosomal and Golgi apparatus antigens. It may be possible to more precisely associate particular anti-cytoplasmic antibodies that react with autoimmune diseases.
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PMID:[Non-organ specific anticytoplasmic autoantibodies. Immunoserologic detection and diagnostic relevance]. 330 68

Total microsomal cytochrome P-450 levels were decreased, to about 50% of control, in liver of male rats made cirrhotic by the prolonged intake of a choline-deficient diet. We have suggested previously that this decrease in cytochrome P-450 levels is not a generalized one, but is selective for certain forms of the enzyme. In the present study, levels of six cytochrome P-450 forms including the sex-specific cytochrome P-450 forms, P-450UT-A, P-450PCN-E, and P-450UT-l, were quantitated immunochemically in hepatic microsomes prepared from control and cirrhotic male rats and were related to changes in the regioselectivity of cytochrome P-450-mediated androst-4-ene-3,17-dione hydroxylation in these fractions. The principal finding of this study was that the male-specific androst-4-ene-3,17-dione 16 alpha-hydroxylase was decreased in cirrhotic microsomes to about 20% of control. The content of P-450UT-A decreased concurrently from about 0.40 to less than 0.01 nmol/mg of microsomal protein. Other pathways of androst-4-ene-3,17-dione hydroxylation were also affected, but to different extents than the 16 alpha-hydroxylase. 6 beta-Hydroxylation decreased in cirrhotic microsomes to about 45% of control, despite a marked decrease in P-450PCN-E from 0.27 to less than 0.002 nmol/mg of microsomal protein. The rate of androst-4-ene-3,17-dione 7 alpha-hydroxylation underwent a less pronounced reduction in cirrhosis to about two-thirds of control microsomal activity, and levels of the cytochrome P-450 associated with this activity, P-450UT-F, were decreased in proportion with the decrease in total microsomal cytochrome P-450. 16 beta-Hydroxylase activity was unaffected by the cirrhotogenic process. From spectral binding studies it was apparent that androst-4-ene-3,17-dione elicited a high affinity type I interaction in control microsomal fractions (Ks = 4.5 microM), whereas no interaction was apparent in cirrhotic liver microsomes. Levels of three other forms of cytochrome P-450--P-450PB-C (a constitutive form inducible by phenobarbital), P-450ISF-G (a major isosafrole-inducible form), and P-450UT-I (the major female sexually-differentiated isozyme)--were apparently unaltered in cirrhosis. These findings are consistent with the assertion that specific forms of cytochrome P-450 are subject to altered regulation in hepatic cirrhosis.
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PMID:Altered regulation of cytochrome P-450 enzymes in choline-deficient cirrhotic male rat liver: impaired regulation and activity of the male-specific androst-4-ene-3,17-dione 16 alpha-hydroxylase, cytochrome P-450UT-A, in hepatic cirrhosis. 354 47

The aim of this study was to determine the prognostic significance of functional changes in the liver during progression of cirrhosis. Liver function was quantitated weekly by the aminopyrine breath test (measuring microsomal function) and the galactose breath test (measuring cytosolic function) in rats made cirrhotic by bile duct ligation (n = 14) and in sham-surgery controls (n = 9). Nine rats died spontaneously of cirrhosis. Both the aminopyrine breath test and galactose breath test were sensitive (89%) predictors of death within 1 week, but the galactose breath test was more specific (83%). Morphometric measurements of livers from surviving cirrhotic animals and controls (n = 5 each) showed that mean hepatocyte mass was maintained in the cirrhotic livers [cirrhosis (17.0 +/- 2.0) vs. controls (13.9 +/- 0.9 gm)]. The galactose breath test was also maintained, whereas the aminopyrine breath test was significantly decreased in the surviving cirrhotics. The galactose breath test, but not the aminopyrine breath test, correlated with hepatocyte mass (r = 0.67). The aminopyrine breath test correlated with microsomal aminopyrine N-demethylase activity (r = 0.78). Serial use of quantitative liver tests allows prediction of time of death from cirrhosis in this model.
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PMID:The evolution of changes in quantitative liver function tests in a rat model of biliary cirrhosis: correlation with morphometric measurement of hepatocyte mass. 357 Jan 57

To determine whether the aminopyrine breath test can be used to document the presence of cirrhosis in patients with cholestatic liver disease, 19 patients (13 primary biliary cirrhosis, 4 sclerosing cholangitis and 2 chronic extrahepatic bile duct obstruction) underwent clinical and biochemical evaluations, liver biopsies and an aminopyrine breath test. Results were compared with those in 10 patients with biopsy-proven chronic active hepatitis with bridging and/or cirrhosis and in 22 healthy subjects. The aminopyrine breath test results in the 10 cholestatic patients with cirrhosis were not significantly different from the results in precirrhotic cholestatic patients (mean +/- S.D., 11.2 +/- 5.0 vs. 11.6 +/- 2.8% dose per 2 hr, p greater than 0.05) or healthy subjects (11.5 +/- 2.9% dose per 2 hr). In contrast, the results in the patients with chronic hepatitis were markedly depressed (3.2 +/- 1.9% dose per 2 hr, p less than 0.05). The aminopyrine breath test results did not correlate with results of conventional liver function tests in the cholestatic patients. These results demonstrate that the aminopyrine breath test is not clinically useful in identifying the presence of cirrhosis in patients with cholestatic liver disease, and provide further evidence that decreased microsomal enzyme function is a late feature of cholestatic liver disease.
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PMID:The aminopyrine breath test does not correlate with histologic disease severity in patients with cholestasis. 357 Jan 58

Hepatic cirrhosis produced by repeated inhalation of carbon tetrachloride is associated with reduced levels of microsomal cytochrome P450. In this study the C19-steroids androstenedione and testosterone were used as specific probes of the functional activity of several forms of cytochrome P450 in microsomal fractions from control and cirrhotic rat liver. The principal finding, that androstenedione 16 alpha-hydroxylation and testosterone 2 alpha-, 16 alpha-, and 17 alpha-hydroxylation were reduced to 14%-38% of control activity, strongly suggests that levels of the male sexually differentiated cytochrome P450 (P(450)16 alpha) are decreased in hepatic cirrhosis. The activity of other cytochrome P450-mediated C19-steroid hydroxylases, with the exception of androstenedione 6 beta-hydroxylase, appeared essentially unaltered in microsomes from cirrhotic rats. Cirrhosis induced by carbon tetrachloride was also associated with greatly decreased activity of the microsomal cytochrome P450-independent 17 beta-oxidoreductase, an enzyme that catalyzes the conversion of androstenedione to testosterone. Consequently, and in view of the impaired activity of cytochrome P450-mediated testosterone 17 alpha-hydroxylation, the capacity of cirrhotic microsomes to catalyze the interconversion of androstenedione and testosterone was much lower than that of control microsomes. The present data confirm and extend earlier observations that selective impairment of drug oxidation pathways occurs in hepatic cirrhosis. These changes are unrelated to the acute toxicity produced by carbon tetrachloride exposure. The available evidence supports the assertion that specific forms of cytochrome P450 are subject to altered regulation in cirrhosis.
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PMID:Impaired androgen 16 alpha-hydroxylation in hepatic microsomes from carbon tetrachloride-cirrhotic male rats. 358 1

In anesthetized rats, a marked decrease in CCK-OP activity and, to a far lesser extent, in the pancreatic secretory effect of CCK-33 were found after portal administration, compared to the femoral route. Changes in the biological activity of CCK-OP were further investigated after 30 min incubation with different subcellular liver fractions (1000 X g, 12,000 X g, microsomal fraction with or without NADPH). All the subcellular liver fractions caused an approximately 70% decrease in the CCK-effect, as calculated from dose-response relationships. The inactivation of CCK-OP after incubation with microsomal fractions of thioacetamide (TAA)-induced cirrhotic liver did not differ from that of control rats. The CCK-OP dose-response curves were similar in cirrhotic and control rats, but the pancreatic secretion was sustained to a greater extent and the inhibitory effect of supramaximal stimulation was delayed in cirrhotic rats. It was concluded that CCK-OP can be inactivated by liver proteins present in microsomal fractions, by a NADPH-independent mechanism. This inactivation did not diminish in liver cirrhosis. There were no changes in CCK-OP elimination in cirrhotic rats in vivo, thus pancreatic hypertrophy in experimental cirrhosis must be explained by other mechanisms.
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PMID:Inactivation of cholecystokinin octapeptide by normal and cirrhotic liver in rats. 368 Oct 28

The effect of a choline-deficient diet on microsomal cytochrome P-450 and mixed-function oxidase (MFO) activity was investigated in relation to the development of nutritional cirrhosis. In rats that received the choline-deficient diet for 28 weeks cirrhosis was evident macroscopically and histologically; control rats that received an identical diet supplemented with choline had normal livers. Microsomal cytochrome P-450 and cytochrome b5 were reduced in cirrhotic liver to 50% of control levels. Three MFO activities (ethylmorphine N-demethylase, aryl hydrocarbon hydroxylase and 7-ethoxycoumarin O-deethylase) were also reduced to 40-70% of control levels. However, the turnover number for the O-deethylation of 7-ethoxycoumarin was not reduced in cirrhotic liver. This finding suggested that certain drug oxidations may be selectively depressed in nutritional cirrhosis. To examine the possibility that selective changes in MFO activity may reflect the suppression of certain cytochrome P-450 isozymes, partially purified fractions of the cytochrome were prepared after solubilisation and hydrophobic affinity chromatography (on n-octylamino-Sepharose 4B) of cirrhotic and control liver microsomes. Analysis of these fractions by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and laser densitometry indicated that a protein band of apparent minimum molecular weight 50.5 kD was primarily affected in cirrhotic rat liver microsomes. Levels of two other bands (apparent minimum molecular weight 48 and 52.5 kD) appeared essentially unaltered. Additional electrophoretic studies, conducted under non-reduced conditions, indicated the haemoprotein nature of protein bands in the 48-55 kD region. These data strongly suggest that cirrhosis produced in rats by a choline-deficient diet is associated with selective decreases in oxidative drug metabolism and individual cytochrome P-450 isozymes.
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PMID:Drug metabolism in cirrhosis. Selective changes in cytochrome P-450 isozymes in the choline-deficient rat model. 371 30

The effects of verapamil on portal pressure, microsomal liver function and extravascular albumin space were investigated in rats rendered cirrhotic by chronic exposure to phenobarbital and carbon tetrachloride. Verapamil significantly decreased splenic pulp pressure by 28% (P less than 0.05). In cirrhotic animals it improved liver function, measured by the aminopyrine and caffeine breath tests, by 36% (P less than 0.025) and 53% (P less than 0.05), respectively. The extravascular albumin space, an important determinant of drug clearance, was measured by a multiple indicator dilution technique. It was significantly larger in verapamil treated than in untreated cirrhotics (4.41 +/- 1.06 vs 2.73 +/- 0.79 ml/g; P less than 0.01). We conclude that verapamil has significant potential as a portal antihypertensive agent and its value in treating cirrhosis in man should be explored by controlled studies.
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PMID:Chronic verapamil administration lowers portal pressure and improves hepatic function in rats with liver cirrhosis. 374 84

We report the findings in two sisters with active cirrhosis and an anti-liver-kidney microsomal antibody (anti-LKM) of the autoimmune type. This unusual disease is characterized by the presence of high levels of antibodies that react with the smooth and rough endoplasmic reticulum of the liver and other tissues. Our patients had the usual features of chronic hepatitis associated with presence of antibodies: they were young girls, they had anti-LKM antibodies of autoimmune type persisting at a high titer during the whole course of the disease, but with no smooth muscle antibodies; one had a low level of IgA. The occurrence of two cases in the same family has not yet been reported and is probably not coincidental because of the rare occurrence of this disease.
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PMID:Chronic active hepatitis associated with liver-kidney microsomal antibody of an autoimmune type. Two familial cases. 376 10


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