Effects of ethanol feeding on collagen synthesizing and degrading enzymes in rat pancreas.

Collagen metabolism in the pancreas was investigated in male Wistar strain rats after 7 weeks of ethanol feeding. Compared with control rats, the ethanol-fed rats had a normal hydroxyproline content in the pancreas. However, prolyl hydroxylase activity and collagenolytic cathepsin activity were increased, though collagenase activity did not change. Both prolyl hydroxylase activity and collagenolytic cathepsin activity were inversely correlated with amylase activities. These findings were also confirmed in ethanol-pyrazole treated rats. These results suggest that the ethanol-induced pancreatic injury, even at an early stage, accelerates the collagen metabolism in the pancreas.

Free and small peptide-bound [14C]hydroxyproline synthesis in vitro in ethanol-induced hepatic injury in the rat liver.

To clarify the significance of free and small peptide-bound hydroxyproline synthesis in ethanol-induced liver injury, we measured the in vitro synthesis of [14C]hydroxyproline in the 67% ethanol-soluble fraction in rat liver slices, together with hepatic protein-bound [14C]hydroxyproline synthesis. The synthesis of free and small peptide-bound [14C]hydroxyproline was 11.1 +/- 2.0 dpm x 10(-4)/g liver/3 hr and the synthesis of protein-bound [14C]hydroxyproline was 10.1 +/- 3.3 dpm x 10(-4)/g liver/3 hr in control rat liver. In the ethanol-fed rat liver, the synthesis of free and small peptide-bound [14C]hydroxyproline significantly increased 1.5-fold and the synthesis of protein-bound [14C]hydroxyproline significantly increased 1.6-fold, while the hepatic collagen content did not change. There was a significant correlation between free and small peptide-bound [14C]hydroxyproline synthesis and protein-bound [14C]hydroxyproline synthesis. These results suggest that free and small peptide-bound hydroxyproline synthesis plays an important role in regulating the content of hepatic collagens.

Preventive effect of gomisin A, a lignan component of shizandra fruits, on acetaminophen-induced hepatotoxicity in rats.

The preventive effect of gomisin A, a lignan component of shizandra fruits, on acetaminophen-induced hepatotoxicity in rats was examined by histological and biochemical analysis. Acetaminophen at a dose of 750 mg/kg was administered to male Wistar rats with or without pretreatment with 50 mg/kg of gomisin A. Gomisin A inhibited not only the elevation of serum aminotransferase activity and hepatic lipoperoxides content, characteristic of acetaminophen administration, but also the appearance of histological changes such as degeneration and necrosis of hepatocytes. However, gomisin A did not affect the decrease in liver glutathione content. These results suggest that gomisin A protects the liver from injury after administration of acetaminophen through the suppression of lipid peroxidation.

Mechanism of the protective action of thiol compounds in ethanol-induced liver injury.

The protective action of cysteine or mercaptopropionylglycine (MPG) in acute ethanol-induced liver injury has been investigated in the rat. Cysteine accelerated clearance of ethanol and acetaldehyde from blood and liver and prevented an increase in hepatic content of triglyceride and serum ornithine carbamoyl transferase activity. MPG accelerated clearance of ethanol and acetaldehyde less efficiently but prevented an increase in these variables to the same degree. The mode of action of thiol compounds in acute ethanol-induced liver injury has been discussed.

Increase in lipoperoxides and prolyl hydroxylase activity in rat liver following chronic ethanol feeding.

The effect of lipid peroxidation on hepatic collagen synthesis was investigated in male Wistar strain rats after 7 weeks of ethanol feeding. Compared with control rats, the ethanol-fed rats had a significantly higher lipoperoxide content and a significantly lower reduced glutathione content al all times following ethanol treatment. Except for the earliest time (2 days), hepatic prolyl hydroxylase activity was also significantly increased and finally reached up to 214% of the control level. Hepatic hydroxyproline content was slightly increased, but not statistically significant. The lipoperoxides content was significantly correlated with prolyl hydroxylase activity and inversely correlated with reduced glutathione content. These findings were also confirmed in ethanol-pyrazole-treated rats. These results suggest that elevated lipoperoxides mediate an acceleration of collagen synthesis, even at an early stage, in ethanol-induced hepatic injury.

Effects of long-term administration of sulindac on APC mRNA and apoptosis in colons of rats treated with azoxymethane.

PURPOSE: Non-steroidal anti-inflammatory drugs, including sulindac, have been shown to exhibit anti-colon cancer activity; however, the detailed mechanisms concerning continuous long-term administration are still unclear. Therefore, we examined the anti-colon carcinogenesis effects of sulindac after prolonged administration. METHODS: Administration of AOM, a colon-specific carcinogen, induced colonic preneoplastic lesions, which can progress to carcinomas about 40-50 weeks after AOM administration. We studied the effects of sulindac on the incidence of preneoplastic lesions, proliferative activity of colonic cells (AgNORs), tumor suppressor adenomatous polyposis coli (APC) gene expression, and apoptosis using AOM-treated rat colon mucosa at 4 weeks and 40 weeks (early and late stage of colon carcinogenesis, respectively). RESULTS: Sulindac suppressed the development of preneoplastic lesions induced by AOM at 4 weeks and 40 weeks by about 50% ( P<0.01); the proliferative activity of colonic cells increased by AOM was suppressed almost completely. Furthermore, APC expression was significantly increased by sulindac at both the early and late stages ( P<0.01). However, apoptosis was clearly increased at the early stage ( P<0.01), but not at the late stage. CONCLUSIONS: APC overexpression induced by sulindac can suppress colon carcinogenesis at both the early and late stages, but apoptosis might work as one of anti-cancer mechanisms at the early stage of colon carcinogenesis.

Collagenase and collagenolytic cathepsin in normal and fibrotic rat liver.

Collagenase and collagenolytic cathepsin activities in normal and carbon tetrachloride-induced fibrotic livers of rats were simultaneously determined at 35 and 25 degrees C for 18 h, using the same 14C-labeled neutral soluble collagen as a substrate. Collagenolytic cathepsin had higher activity under the assay conditions at both 35 and 25 degrees C than collagenase in normal and fibrotic livers. On sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis, the collagen was visibly degraded by collagenolytic cathepsin, but not by collagenase. These results indicate that, unlike collagenase, collagenolytic cathepsins exist as active forms in the rat liver, and can participate in the degradation of collagens, especially of soluble collagens including procollagens.

Diagnostic value of serum markers of connective tissue turnover for predicting histological staging and grading in patients with chronic hepatitis C.

PURPOSE: Chronic hepatitis C is an insidiously progressive disease, in which repeated assessment of liver histology is required. Various serum fibrotic markers have now been introduced. Our present aim was to assess, by receiver operating characteristic analysis, the usefulness of serum fibrotic markers for diagnosing fibrotic staging and necroinflammatory grading in chronic hepatitis C. METHODS: Serum levels of procollagen type III N-terminal peptide (PIIINP), 7S fragment of type IV collagen (PIVNP), hyaluronan (HA), matrix metalloproteinase (MMP)-1, MMP-2, and tissue inhibitor of metalloproteinases (TIMP)-1 were measured in 169 patients with chronic hepatitis C. RESULTS: The accuracy of these tests for discriminating stages greater than F2 from stages less than F1 was superior to that for discriminating stage F3 from stages less than F2. The most useful test for predicting stages greater than F2 was the serum HA test (cutoff value, 50 ng/ml; sensitivity, 75%; specificity, 80%), and the next-most useful was the serum MMP-2 test (cutoff value, 550 ng/ml; sensitivity, 75%; specificity, 70%). The usefulness of these tests for discriminating moderate grade from grades less than mild was superior to that for discriminating grades more than mild from minimal grade. The most useful test for predicting moderate grade was the serum HA test (cutoff value, 60 ng/ml; sensitivity, 77%; specificity, 74%), and the second-most useful was the serum PIVNP test (cutoff value, 6.5 ng/ml: sensitivity, 74%; specificity, 75%). The combination of the most useful and next-most useful test results increased the accuracy of the diagnosis of staging and grading. CONCLUSIONS: These serum fibrotic markers, especially the serum HA test, would be clinically useful for assessing staging and grading in patients with chronic hepatitis C.

Hepatic collagenolytic cathepsin in patients with chronic liver disease.

Human hepatic collagenolytic cathepsin consisted of a major component having a molecular weight of 25 000 and a minor one of 35 000; the former is indistinguishable for cathepsin B in its enzymatic properties. Hepatic collagenolytic cathepsin increased in chronic active liver disease in proportion to hepatic hydroxyproline content. The ratio of collagenolytic cathepsin to hepatic hydroxyproline content remained within the normal range in chronic hepatitis, but decreased significantly in cirrhosis. These results suggest that collagenolytic cathepsin participates, at least partly, in the progress of hepatic fibrosis.

Clinical usefulness of serum tissue inhibitor of metalloproteinases (TIMP)-2 assay in patients with chronic liver disease in comparison with serum TIMP-1.

Tissue inhibitors of metalloproteinases (TIMPs) are involved in liver fibrosis through impaired matrix degradation. Previous studies showed that the serum level of TIMP-1 was increased in patients with chronic liver disease, reflecting the liver TIMP-1 level, and that it is useful for assessing liver fibrosis. An enzyme immunoassay for TIMP-2 is now available. In this study, we examined the clinical usefulness of this serum TIMP-2 test for liver fibrosis in patients with chronic liver disease, in comparison with the serum TIMP-1 test. The serum TIMP-2 concentration was 61 +/- 13 ng/ml in healthy controls (n = 32), and 18% higher in the group of chronic active hepatitis (CAH) patients (n = 34), 64% higher in the liver cirrhosis (LC) group (n = 33) and 44% higher in the hepatocellular carcinoma (HCC) group (n = 61), and similar to the control level in the chronic persistent hepatitis (CPH) group (n = 23). In contrast, the serum TIMP-1 concentration was 155 +/- 17 ng/ml in the healthy controls, 18% higher in CPH, 35% in CAH, 63% higher in LC and 92% higher in HCC. The serum TIMP-2 level was related to the histological degrees of both periportal necrosis and liver fibrosis, as well as to the serum TIMP-1 level. However, the relationships for TIMP-2 were weaker compared to those of serum TIMP-1. These results suggest that compared to the serum TIMP-1 level, changes in the serum TIMP-2 level in chronic liver disease are less liver-specific, and the serum TIMP-2 level is less useful in the assessment of liver fibrosis in chronic liver disease.

Collagenase activity in the granulocytes of patients with various liver diseases.

Studies were conducted on collagenase activity on peripheral granulocytes of patients with various liver diseases. Total collagenase activity increased significantly in chronic active hepatitis (CAH) and in liver cirrhosis (LC), and, in these disorders, it correlated with the extent to which hepatic fibrosis has progressed. Active collagenase activity increased in CAH, but no differences from normal controls were found in other liver diseases. These results suggest that total collagenase may reflect the degree of hepatic fibrosis, and that active collagenase may be related to chronic active hepatitis lesions.

Serum tissue inhibitor of metalloproteinases in patients with chronic liver disease and with hepatocellular carcinoma.

To examine the clinical significance of serum level of tissue inhibitor of metalloproteinases (TIMP) in chronic liver disease and in hepatocellular carcinoma, we measured serum TIMP concentration by a sandwich enzyme immunoassay in 79 patients with chronic liver disease and 49 patients with hepatocellular carcinoma. Serum TIMP concentration was 164 +/- 20 ng/ml in healthy controls, and was 10% higher than control in chronic persistent hepatitis, 36% higher in chronic active hepatitis, 62% higher in liver cirrhosis and 30% higher in primary biliary cirrhosis. Serum TIMP level was closely correlated with serum level of type IV collagen 75 domain and with the histological degree of liver fibrosis in chronic liver disease. Serum TIMP level in hepatocellular carcinoma was increased 2.3-fold compared with that in controls, and was significantly higher than in liver cirrhosis. Serum TIMP level increased with tumor size, and significantly correlated with serum alpha-fetoprotein level. Gel filtration on Sephadex G-75 showed that the TIMP in serum was present as an enzyme-complexed form. These results suggest that the measurement of serum TIMP concentration is useful in the clinical assessment of liver fibrosis in chronic liver disease and of the development of hepatocellular carcinoma.

Serum carbohydrate-deficient transferrin in patients with nonalcoholic liver disease and with hepatocellular carcinoma.

Serum carbohydrate-deficient transferrin (CDT) is used as a reliable and specific marker of alcohol consumption. However, recent studies have shown false-positive CDT test results in nonalcoholic liver disease. We examined the clinical significance of serum CDT in nonalcoholic liver disease, especially hepatocellular carcinoma. Serum CDT was measured in 23 teetotallers, 56 patients with alcoholic liver disease, 84 patients with viral liver disease and 67 patients with hepatocellular carcinoma, with an Axis %CDT radioimmunoassay kit, and the results were expressed as percentages of the total transferrin (%CDT). The mean serum %CDT value was increased 1.8-fold in alcoholic liver fibrosis and 3.8-fold in alcoholic liver cirrhosis compared with the teetotallers. The serum %CDT values in viral chronic hepatitis were similar to those of the teetotallers, and were increased 2.0-fold in viral liver cirrhosis. False-positive results were found in 10 (37%) of the 27 patients with viral liver cirrhosis. The mean serum %CDT value was increased 2.5-fold in hepatocellular carcinoma, and false-positive results were found in 31 (46%) of the 67 patients. The serum %CDT value was related to the severity of Child grade, the size of tumor and the grade of histological differentiation. These results suggest that the ability of serum CDT test to detect chronic alcoholism may be reduced in patients with nonalcoholic liver cirrhosis and those with hepatocellular carcinoma.

Collagen-binding activity of plasma vitronectin in chronic liver disease.

The collagen-binding activity of plasma vitronectin was measured in 15 control subjects and 64 subjects with chronic liver disease. The assay of collagen-binding vitronectin was performed by an enzyme immunoassay using a monoclonal antibody to human vitronectin and type I collagen from human placenta. The plasma collagen-binding vitronectin concentration (mean +/- S.D.) was 5.6 +/- 1.9 micrograms/ml in the controls, 8.3 +/- 1.1 micrograms/ml in chronic persistent hepatitis, 8.3 +/- 2.9 micrograms/ml in chronic active hepatitis, 7.8 +/- 2.9 micrograms/ml in liver cirrhosis and 8.2 +/- 2.1 micrograms/ml in hepatocellular carcinoma with cirrhosis. The percent collagen-binding vitronectin to total plasma vitronectin was 2.2 +/- 0.8% in the controls, 3.9 +/- 2.2% in chronic persistent hepatitis, 3.9 +/- 1.2% in chronic active hepatitis, 5.8 +/- 3.3% in liver cirrhosis and 4.1 +/- 1.2% in hepatocellular carcinoma with cirrhosis. The plasma collagen-binding vitronectin also correlated with the serum levels of 7S collagen and hyaluronic acid. These findings suggest that vitronectin may play an important role in the progression of liver disease and/or in hepatic fibrosis through its collagen-binding domain.

A simple and rapid microdiffusion method for blood ammonia using a reflectance meter and a reagent plate, and its clinical evaluation for liver diseases.

A simple and rapid procedure using 20 microliters of whole blood is described for estimating blood ammonia by means of a reflectance meter using a reagent plate, which operates by the principle of microdiffusion. The most suitable condition for microdiffusion was at 37 degrees C for 15 min, in which the standard curve was linear, and reproducibility and recovery were sastisfactory. Blood ammonia levels by this method correlate significantly with the values by an ion exchange method in 72 patients with liver disease (r = + 0.970, y = 1.13x - 11). The method has a distinct advantage in sensitivity, simplicity, and rapidity for blood ammonia determination.

Clinical evaluation of a monoclonal antibody to serum KM01 for the diagnosis of hepatocellular carcinoma.

In order to evaluate a monoclonal antibody KM01 which was developed in mice immunized against a human colon carcinoma cell line, serum levels of KM01 and other tumor markers were studied in patients with both hepatocellular carcinoma and liver cirrhosis and in patients with liver cirrhosis alone. The KM01 levels in the sera of 50 patients with hepatocellular carcinoma plus liver cirrhosis and 50 patients with liver cirrhosis were measured using an enzyme immunoassay method and compared with various tumor markers including alpha-fetoprotein (AFP), DUPAN-2, and protein induced vitamin K absence or antagonist-II (PIVKA-II). The mean serum level (+/- S.D.) and sensitivity of KM01 in patients with hepatocellular carcinoma plus liver cirrhosis were 734 (+/- 716) units/ml and 64%, respectively, and they were significantly higher than those of liver cirrhosis patients (P < 0.001). Three out of 9 cases showing negative serum AFP levels had positive serum KM01 levels. Although the sensitivity of serum KM01 level for hepatocellular carcinoma was inferior to serum AFP and plasma PIVKA-II values, the sensitivity of a combination assay of serum KM01 or AFP was increased to 88%. Clinical data of the patients with markedly elevated serum KM01 levels (more than 1000 units/ml) were compared with patients with moderately elevated levels (530-1000 units/ml); serum bilirubin and alkaline-phosphatase were statistically higher in the former group (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of clinical laboratory liver tests between asymptomatic HBV and HCV carriers with persistently normal aminotransferase serum levels.

We examined the clinicopathological state in asymptomatic hepatitis C virus (HCV) carriers with persistently normal aminotransferase serum levels in comparison with asymptomatic hepatitis B virus (HBV) carriers. The findings showed that the thymol turbidity test (TTT) values and zinc sulfate turbidity test (ZTT) values were significantly higher in asymptomatic HCV carriers than in asymptomatic HBV carriers, whose values were within the normal limits. Multivariate analysis showed that the independent predictor of serum TTT and ZTT levels was the HCV infection. In clinical state, simple and cheap tests such as TTT and ZTT are useful for mass screening to detect HCV carriers in medical check-ups of healthy workers.

Serum collagenase activity in chronic liver diseases.

To examine whether serum collagenase activity reflects the amount of hepatic collagenase in the fibrotic liver, we measured serum collagenase activity in 67 patients with chronic liver disease and in 26 healthy controls. Collagenase activity in serum was measured after reactivation by denaturing and dissociating the inhibitors with 3 M KSCN and 1 mM aminophenylmercuric acetate. Serum collagenase activity was 35% lower than control in chronic persistent hepatitis, 48% lower in chronic active hepatitis, 56% lower in liver cirrhosis and 68% lower in hepatocellular carcinoma. To interpret this finding of low serum collagenase activity, we measured serum concentration of TIMP (Tissue Inhibitor of Metallo-Proteinases). Serum TIMP concentration was increased as liver disease developed, and it was inversely correlated with serum collagenase activity. These results suggest that in this assay condition serum collagenase activity is influenced by TIMP, and thus may not reflect the amount of hepatic collagenase in patients with chronic liver disease.

Effects of canrenoate potassium, an aldosterone antagonist on portal hemodynamics in patients with compensated liver cirrhosis.

BACKGROUND/AIMS: Long-term administration of spironolactone is reported to reduce portal pressure in cirrhotic patients. We examined the effects of acute administration of canrenoate potassium, an aldosterone antagonist, on portal hemodynamics in compensated cirrhotic patients using noninvasive duplex Doppler ultrasonography. MATERIALS AND METHODS: Baseline values were obtained in the fasting state, and then 200mg of canrenoate potassium in 10ml of saline solution was intravenously administered to 22 patients, whereas 10ml of saline solution was administered as a placebo to 8 patients. RESULTS: The portal cross-sectional area, portal blood velocity and portal blood flow decreased by 5.3 +/- 9.2, 10.4 +/- 8.7% and 13.0 +/- 12.4%, respectively at the nadir 60min after administration and these decreases persisted until 120min. Placebo did not affect these parameters of portal hemodynamics. Eleven responders, who had a more than 10% drop in portal blood flow 60min after administration, had significantly higher levels of plasma aldosterone than 8 non responders who had less than 10% drop. The reduction rate of portal blood flow was closely correlated with plasma aldosterone level. CONCLUSIONS: These findings suggest that aldosterone antagonist directly causes a reduction in portal blood flow, probably through inhibition of aldosterone-induced vasoconstrictive action.