The role of the sphingosine axis in immune regulation: A dichotomy in the anti-inflammatory effects between sphingosine kinase 1 and sphingosine kinase 2-dependent pathways

Background: Sphingosine kinase has been identified as playing a central role in the immune cascade, being a common mediator in the cellular response to a variety of signals. The different effects of sphingosine kinase 1 and 2 (SphK1 and SphK2, respectively) activity have not been completely characterized. Aim: To determine the different roles played by SphK1 and SphK2 in the regulation of immune-mediated disorders. Methods: Nine groups of mice were studied. Concanavalin A (ConA) injection was used to induce immune-mediated hepatitis. Mice were treated with SphK1 inhibitor (termed SphK-I) and SphK2 inhibitor (termed ABC294640), prior to ConA injection, and effects of treatment on liver enzymes, subsets of T lymphocytes, and serum levels of cytokines were observed. Results: While liver enzyme elevation was ameliorated by administration of SphK1 inhibitor, SphK2 inhibitor-treated mice did not show this tendency. A marked decrease in expression of CD25+ T-cells and Foxp+ T-cells was observed in mice treated with a high dose of SphK1 inhibitor. Alleviation of liver damage was associated with a statistically significant reduction of serum IFNγ levels in mice treated with SphK1 inhibitor and not in those treated with SphK2 inhibitor. Conclusions: Early administration of SphK1 inhibitor in a murine model of immune-mediated hepatitis alleviated liver damage and inflammation with a statistically significant reduction in IFN-γ levels. The data support a dichotomy in the anti-inflammatory effects of SphK1 and SphK2, and suggests that isoenzyme-directed therapies can improve the effect of targeting these pathways.

Development, validation, and application of a liquid chromatography-tandem mass spectrometry method for quantitative determination of trans-4-hydroxy-l-proline concentration in the serum of dogs with chronic hepatitis

OBJECTIVE

To develop and analytically validate a liquid chromatography-tandem mass spectrometry method for measurement of endogenous trans-4-hydroxy-l-proline concentrations in canine serum and to assess serum trans-4-hydroxy-l-proline concentrations in dogs with chronic hepatitis.

SAMPLE

Serum samples obtained from 20 dogs with histopathologically confirmed chronic hepatitis and 20 healthy control dogs.

PROCEDURES

A liquid chromatography-tandem mass spectrometry method for quantification of trans-4-hydroxy-l-proline concentration was developed and assessed for analytic sensitivity, linearity, accuracy, precision, and reproducibility. Serum concentration of trans-4-hydroxy-l-proline in dogs with chronic hepatitis and healthy control dogs was measured.

RESULTS

Observed-to-expected ratios for dilutional parallelism ranged from 72.7% to 111.5% (mean ± SD, 91.3 ± 19.6%). Intra-assay and interassay coefficients of variation ranged from 2.1% to 3.0% and 3.2% to 5.3%, respectively. Relative error ranged from -2.3% to 7.8%. Trans-4-hydroxy-l-proline concentrations were significantly lower in serum obtained from dogs with chronic hepatitis (median, 0.24 ng/mL; range, 0.06 to 1.84 ng/mL) than in serum obtained from healthy control dogs (median, 0.78 ng/mL; range, 0.14 to 4.90 ng/mL).

CONCLUSIONS AND CLINICAL RELEVANCE

The method described here for the quantification of trans-4-hydroxy-l-proline concentration in canine serum was found to be sensitive, specific, precise, accurate, and reproducible. Dogs with chronic hepatitis had significantly lower serum trans-4-hydroxy-l-proline concentrations than did healthy control dogs, possibly as a result of altered hepatic metabolism of amino acids.

Presence of Systemic Inflammatory Response Syndrome Predicts a Poor Clinical Outcome in Dogs with a Primary Hepatitis

Primary hepatopathies are a common cause of morbidity and mortality in dogs. The underlying aetiology of most cases of canine hepatitis is unknown. Consequently, treatments are typically palliative and it is difficult to provide accurate prognostic information to owners. In human hepatology there is accumulating data which indicates that the presence of systemic inflammatory response syndrome (SIRS) is a common and debilitating event in patients with liver diseases. For example, the presence of SIRS has been linked to the development of complications such as hepatic encephalopathy (HE) and is associated with a poor clinical outcome in humans with liver diseases. In contrast, the relationship between SIRS and clinical outcome in dogs with a primary hepatitis is unknown. Seventy dogs with histologically confirmed primary hepatitis were enrolled into the study. Additional clinical and clinicopathological information including respiratory rate, heart rate, temperature, white blood cell count, sodium, potassium, sex, presence of ascites, HE score, alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin and red blood cell concentration were available in all cases. The median survival of dogs with a SIRS score of 0 or 1 (SIRS low) was 231 days compared to a median survival of 7 days for dogs with a SIRS score of 2, 3 or 4 (SIRS high) (p<0.001). A Cox proportional hazard model, which included all other co-variables, revealed that a SIRS high score was an independent predictor of a poor clinical outcome. The effect of modulating inflammation on treatment outcomes in dogs with a primary hepatitis is deserving of further study.

Evidence for novel hepaciviruses in rodents

Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent rodent hepacivirus clades were detected in 27 (1.8%) of 1,465 European bank voles (Myodes glareolus) and 10 (1.9%) of 518 South African four-striped mice (Rhabdomys pumilio). Bats showed anti-HCV immunoblot reactivities but no virus detection, although the genetic relatedness suggested by the serologic results should have enabled RNA detection using the broadly reactive PCR assays developed for this study. 210 horses and 858 cats and dogs were tested, yielding further horse-associated hepaciviruses but none in dogs or cats. The rodent viruses were equidistant to HCV, exceeding by far the diversity of HCV and the canine/equine hepaciviruses taken together. Five full genomes were sequenced, representing all viral lineages. Salient genome features and distance criteria supported classification of all viruses as hepaciviruses. Quantitative RT-PCR, RNA in-situ hybridisation, and histopathology suggested hepatic tropism with liver inflammation resembling hepatitis C. Recombinant serology for two distinct hepacivirus lineages in 97 bank voles identified seroprevalence rates of 8.3 and 12.4%, respectively. Antibodies in bank vole sera neither cross-reacted with HCV, nor the heterologous bank vole hepacivirus. Co-occurrence of RNA and antibodies was found in 3 of 57 PCR-positive bank vole sera (5.3%). Our data enable new hypotheses regarding HCV evolution and encourage efforts to develop rodent surrogate models for HCV.

Endosulfan induced early pathological changes in vital organs of rat: a biochemical approach

AIM

To evaluate the pathogenesis in heart and liver by the early induction of biochemical and antioxidant derangements in rats exposed to endosulfan.

MATERIALS AND METHODS

Wistar rats were gavaged with endosulfan (0.5, 1 and 1.5 mg/kg body weight in sunflower oil) for a period of 21 days (single dose at 24 h interval). Control and sunflower oil control groups were also maintained simultaneously. Rats were sacrificed on the 22(nd) day posttreatment. Blood samples, heart and liver were collected and different biochemical parameters such as total protein, cholesterol, triglycerides, amino acids and antioxidant and lipid peroxidation level were measured. Statistical analysis was carried out by one way ANOVA, followed by Bonferroni' post-hoc test.

RESULTS

Endosulfan induced a significant increase in the serum levels of total protein, amino acids, triglyceride, total cholesterol, free fatty acid and phospholipid levels in a dose-dependent manner. In the heart and liver, lipid peroxidation was increased significantly in a dose-dependent manner and the antioxidant levels such as superoxide dismutase (SOD), glutathione S-transferase, glutathione peroxidase, and catalase were significantly decreased in a dose-dependent pattern.

CONCLUSION

Exposure to endosulfan results in a significant derangement in the biochemical parameters with a decrease in antioxidant levels in the heart and liver. This is an early indication of pathogenesis in the vital organs of rats.

[Platelet functions in acute and chronic experimentally induced hepatopathia]

It's well known the coagulation damage in chronic hepatitis and hepatic cirrhosis. The aim of our study was to quantify platelet dysfunction in acute and chronic toxic hepatitis.

MATERIAL AND METHOD

We determined adhesivity, aggregability and icosanoids production in rats with acute and chronic hepatopathia induced by CCl4 administration.

RESULTS

Our data shows that platelet adhesivity and aggregability are affected in chronic toxic affectation but also in acute intoxication (p < 0.05). Icosanoids production (expressed like MDA levels are significantly decreased only in chronic CCl4 intoxication (p < 0.001). Significantly correlation appears between aggregability and adhesivity in control group (r = 0.66) and between aggregability and MDA (r = -0.78) and adhesivity and MDA (r = -0.57) in lot C.

CONCLUSION

Primary haemostasis and platelet dysfunction are involved in coagulation dysfunction in hepatic diseases and the modifications of platelet parameters also appeared in acute hepatic affectation.

Co-appearance of autoantibody-producing B220(low) B cells with NKT cells in the course of hepatic injury

Severe hepatic injury is induced by Concanavalin A (Con A) administration in mice, the major effector cells being CD4(+) T cells, NKT cells and macrophages. Since autologous lymphocyte subsets are associated with tissue damage, Con A-induced hepatic injury is considered to be autoimmune hepatitis. However, it has remained to be investigated how autoantibodies and B-1 cells are responsible for this phenomenon. In this study, it was demonstrated that autoantibodies which were detected using Hep-2 cells in immunofluorescence tests and using double-strand (ds) DNA in the ELISA method, appeared after Con A administration (a peak at day 14). Moreover, autoantibody-producing B220(low) cells (i.e., B-1 cells) also appeared at this time. Purified B220(low) cells were found to have a potential to produce autoantibodies. These results suggest that Con A-induced hepatic injury indeed includes the mechanism of autoimmune hepatitis.

Intestinal, adipose, and liver inflammation in diet-induced obese mice

Chronic inflammation and increased visceral adipose tissue (VAT) are key elements of the metabolic syndrome. Both are considered to play a pathogenic role in the development of liver steatosis and insulin resistance. The aim of the present study was to investigate the hypothesis that an inflamed intestine, induced both by diet and chemical irritation, could induce persistent inflammation in VAT. Female C57BL/6JOlaHsd mice were used. In study I, groups of mice (n = 6 per group) were given an obesity-inducing cafeteria diet (diet-induced obesity) or regular chow only (control) for 14 weeks. In study II, colitis in mice (n = 8) was induced by 3% dextran sulfate sodium in tap water for 5 days followed by 21 days of tap water alone. Healthy control mice (n = 8) had tap water only. At the end of the studies, all mice were killed; and blood and tissues were sampled and processed for analysis. Body weight of diet-induced obese mice was greatly increased, with evidence of systemic inflammation, insulin resistance, and liver steatosis. Tissue inflammation indexed by proinflammatory cytokine expression was recorded in liver, mesenteric fat, and proximal colon/distal ileum, but not in subcutaneous or perigonadal fat. In dextran sulfate sodium-induced colitis mice, mesenteric fat was even more inflamed than the colon, whereas a much milder inflammation was seen in liver and subcutaneous fat. The studies showed both diet- and colitis-initiated inflammation in mesenteric fat. Fat depots contiguous with intestine and their capacity for exaggerated inflammatory responses to conditions of impaired gut barrier function may account for the particularly pathogenic role of VAT in obesity-induced metabolic disorders.

Hepatic 64Cu excretion in Dobermanns with subclinical hepatitis

To investigate whether Dobermanns have impaired copper excretion an intravenous radioactive copper isotope ((64)Cu) was used as a tracer. Five patients and eight normal dogs (5 normal Dobermanns and 3 Beagles) were studied. The five female Dobermann patients had a subclinical hepatitis and an increased hepatic copper concentration (median 822mg/kg, range 690-1380mg/kg dry matter). The normal dogs, five Dobermanns and three Beagles, had no abnormal liver histopathology and hepatic copper concentrations were considered normal (Dobermanns; median 118mg/kg, range 50-242mg/kg dry matter; Beagles; median 82mg/kg, range 50-88mg/kg dry matter). Cholestasis was excluded in all dogs by means of a (99m)Tc-Bis-IDA hepatobiliary scintigraphy. Plasma clearance of (64)Cu was comparable in all dogs with no statistically significant differences. The excretion of (64)Cu into the bile, although not statistically significant, was less for the Dobermanns with subclinical hepatitis compared to the normal dogs. The findings suggest that impaired copper excretion may play a role in the aetiology of chronic hepatitis in the Dobermann.

Diminished lifespan and acute stress-induced death in DNA-PKcs-deficient mice with limiting telomeres

An adequate and appropriate response to physiological and pathophysiological stresses is critical for long-term homeostasis and viability of the aging organism. Previous work has pointed to the immune system, telomeres and DNA repair pathways as important and distinct determinants of a normal healthy lifespan. In this study, we explored the genetic interactions of telomeres and DNA-PKcs, a protein involved in non-homologous end-joining (NHEJ) and immune responses, in the context of a key aspect of aging and lifespan--the capacity to mount an acute and appropriate immune-mediated stress response. We observed that the combination of DNA-PKcs deficiency and telomere dysfunction resulted in a shortened lifespan that was reduced further following viral infection or experimental activation of the innate immune response. Analysis of the innate immune response in the DNA-PKcs-deficient mice with short dysfunctional telomeres revealed high basal serum levels of tumor necrosis factor alpha (TNFalpha) and hyper-active cytokine responses upon challenge with polyinosinic-polycytidylic acid (poly-IC). We further show that serum cytokine levels become elevated in telomere dysfunctional mice as a function of age. These results raise speculation that these genetic factors may contribute to misdirected immune responses of the aged under conditions of acute and chronic stress.

Effect of diphenyl dimethyl bicarboxylate on concanavalin A-induced liver injury in mice

Diphenyl dimethyl bicarboxylate (DDB) is a hepatoprotectant and used in the treatment of chronic viral hepatitis patients in China. The aim of the present paper was to investigate the effect of DDB on liver injury mediated by immune response in concanavalin A (Con A)-treated mice. A dose of Con A 30 mg/kg was injected via the tailvein to induce liver injury in mice. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), total bilirubin (TBIL) and tumor necrosis factor alpha (TNF-alpha) level as well as liver TNF-alpha mRNA expression were determined. The following results were obtained: (1) Prior oral administration of DDB 150 mg/kg markedly reduced the elevated serum ALT, TBA and TBIL levels, and the liver lesions in Con A-treated mice; (2) DDB significantly inhibited the elevation of serum TNF-alpha and liver TNF-alpha mRNA expression 2 h after Con A injection; (3) DDB significantly inhibited hepatocyte nuclear DNA fragmentation 12 h after Con A injection; (4) DDB dose-dependently prevented the direct DNA damage induced by CuSO(4)-Phen-Vit C-H(2)O(2) system in vitro, and the ex vivo experiment also showed that the administration of DDB reduced the susceptibility of mouse liver nuclei DNA to CuSO(4)-Phen-Vit C-H(2)O(2) system. These results suggest that DDB could directly protect hepatocyte DNA from oxidative damage, and inhibit TNF-alpha mRNA expression in liver tissue, which resulted in prevention of liver damage induced by Con A in mice.

Mechanism of protective action of bicyclol against CCl-induced liver injury in mice

Bicyclol is a novel synthetic drug for the treatment of chronic viral hepatitis in China. This paper reports the protective action of bicyclol against experimental liver injury in mice and its mechanism of action. Oral administration of bicyclol markedly reduced the elevated serum transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) and the hepatic morphologic changes induced by CCl(4) in mice. Mechanistic studies demonstrated that bicyclol significantly inhibited CCl(4)-induced lipid peroxidation of liver microsomes and (14)CCl(4) covalent binding to microsomal lipids and proteins in vitro, and decreased the level of the trichloromethyl free radical (*CCl(3)) generated from CCl(4) metabolism by NADPH-reduced liver microsomes. On the other hand, bicyclol neither directly inhibited the activity of ALT or AST in vitro nor affected hepatic ALT protein content in mice. These results suggest that bicyclol has remarkable hepatoprotective effects and its mechanism of action may be related to a decrease in free radical-induced damage to hepatocytes.

Improvement in liver pathology after 4 months of D-penicillamine in 5 doberman pinschers with subclinical hepatitis

Five female Doberman Pinschers with increased hepatic copper concentrations and persistent (3-4 years) subclinical hepatitis were treated with D-penicillamine for 4 months. Before and after treatment, the dogs underwent clinical, hematologic (red blood cell, white blood cell, and differential and thrombocyte counts), and clinical chemistry (creatinine, alkaline phosphatase, alanine aminotransferase, and total bile acid concentrations) examinations, and liver biopsies were examined histologically and their copper content measured quantitatively. No adverse effects were observed during treatment, and CBC and serum chemistry test results did not change. The mean liver copper concentration was 1,036 mg/kg dry matter before treatment and decreased to 407 mg/kg after treatment (P = .03). The copper concentrations had decreased (by between 134 and 1,135 mg/kg dry matter) in all of the dogs. The histopathologic appearance had improved or returned to normal in all 5 dogs. We conclude that D-penicillamine effectively reduced copper retention in these dogs and improved the histopathologic appearance of the lesions. However, because D-penicillamine has both copper-chelating and anti-inflammatory properties, it is not possible to draw conclusions on the etiology of this disease.

Serum hepatitis associated with commercial plasma transfusion in horses

This report describes 4 fatal cases of serum hepatitis associated with the administration of commercial plasma in the horse. Serum hepatitis in the horse is characterized by acute hepatic central lobular necrosis, and it has been associated with the administration of biological products of equine origin. None of these horses had a recent history of equine biologic-origin vaccination; however, they had received 1.5-5 L of commercial plasma, and in I horse, an additional 8 L of fresh blood. Acute, severe colic unresponsive to medical therapy, lethargy, or sudden death developed in these 4 horses 41 to 60 days later. Two of the horses developed encephalopathy, confirmed in 1 horse by the presence of severe diffuse Alzheimer type II astrocytes in the brain. Although the prevalence of serum hepatitis associated with the administration of commercial plasma appears to be low in the horse, it should be considered an uncommon but potentially fatal risk factor.

Association between liver copper concentration and subclinical hepatitis in Doberman Pinschers

The prevalence of subclinical hepatitis was investigated in a group of 106 randomly selected 3-year-old Doberman Pinschers. Histopathologic examination of liver samples from 65 dogs (52 dogs with high bile acids, alkaline phosphatase activity, or alanine aminotransferase activity or with copper granules in hepatocytes in a liver aspirate and 13 normal dogs) revealed subclinical hepatitis in 22 dogs (19 females and 3 males). Liver copper concentrations measured by instrumental neutron activation analysis was significantly higher (mean +/- SD; 419 +/- 414 microg/g dry matter) in dogs with hepatitis than those without liver disease (197 +/- 113 microg/g; P = .0008). At 2.6 +/- 0.6 years hepatitis persisted in 5 of 16 dogs available for examination. One dog with a high copper concentration but normal liver subsequently developed subclinical hepatitis after 3 years. During the follow-up period, the average copper concentration of the 6 dogs with persistent subclinical hepatitis was 939 +/- 299 microg/g and had continued to rise significantly (P = .02). The hepatitis in these dogs was associated with apoptotic hepatocytes and copper-laden Kupffer cells in centrolobular regions. The results of this study suggest that there is a relationship among copper storage, hepatocellular damage, and hepatitis in Doberman Pinschers.

[Correction of immune and hematopoietic system disorders in experimental toxic hepatitis with Lacto Flor]

Reduction in cells quantity of thymus, lymphatic nodes, bone marrow and rosette formation cells, decrease in erythrocytes and leucocytes number, suppression of antibody production are seen in experimentally developed acute toxic hepatitis (ATH). Lacto Flor preparation was established to have potential properties to restore different immune and hematological systems disorders observed in mice with ATH.

Accelerated neutrophil apoptosis in 2 canine cases of hepatic disorder

Accelerated neutrophil apoptosis was confirmed by TUNEL assay in two canine cases of hepatic disorder. One dog was diagnosed as having lymphocytic hepatitis and the other lymphocytic cholangitis by histopathology of liver biopsy specimen.

Effect of oxymatrine on murine fulminant hepatitis and hepatocyte apoptosis

OBJECTIVE

To evaluate the protective effects and mechanism of action of oxymatrine (OM) on the experimental fulminant hepatitis (FH) and early hepatocyte apoptosis in murine liver tissue.

METHODS

Fulminant hepatitis mice were induced by injecting lipopolysaccharide (LPS) intraperitoneally (ip) in galactosamine (GalN) sensitized mice. Two separate experiments were designed, including saline control group, fulminant hepatitis group and oxymatrine pretreated group (50 mg/kg, intraperitoneally, bid x 3 days). The levels of serum tumor necrosis factor alpha (TNFa) in mice from two experiments were determined at 5-hour and 7.5-hour after injecting galactosamine/lipopolysaccharide. Mouse liver samples at 5-hour time point were obtained for in situ end labeling (ISEL) staining and ultrastructural observation of apoptotic cells under transmission electron microscope (TEM). Liver samples at 7.5-hour time point were taken for hematoxylin-eosin (HE) staining and immunohistochemical staining of Fas and its ligand (FasL).

RESULTS

As compared with the fulminant hepatitis group, the levels of serum tumor necrosis factor alpha in mice from the OM pretreated group at 5-hour and 7.5-hour time point were all significantly decreased (P < 0.05 and P < 0.01 respectively). Hepatocyte apoptosis in mice at 5-hour time point was significantly inhibited (P < 0.01). Both the degree of liver injury and the degree of Fas and Fas ligand expression in the OM pretreated group were reduced remarkably (P < 0.01 and 0.05 respectively) when compared with the saline control group.

CONCLUSIONS

Oxymatrine protects mice from fulminant hepatitis induced by GalN/LPS and may block hepatocyte apoptosis and subsequent necrosis through downregulating the production of serum tumor necrosis factor alpha and the expression of Fas and Fas ligand in liver tissue.

[Use of dietary fiber in experimental hepatitis in rats]

Hepatitis is most widespread form of a lesion of a liver taking an essential place among the causes of invalidity of the population. In present work the created food fibres allocated from various vegetative raw material are described. Is shown the food fibres of bean crops and secondary resources of processing of a grapes improve a general condition of laboratory animals with a liver struck by hepatitis.

Effects of CH-100, a chinese herbal medicine, on acute concanavalin A-mediated hepatitis in control and alcohol-fed rats

BACKGROUND

Administration of concanavalin A (Con A) leads to acute hepatitis that involves T-cell activation and inflammatory mediator production in mice and rats. We examined the role of CH-100, a Chinese herbal medicine previously trialed in human hepatitis C, in the prevention of Con A-related, T-cell-mediated, acute liver injury in rats.

METHODS

Female Wistar rats were fed 40% ethanol, 2% sucrose, or isocaloric sucrose for 8 weeks. At the same time, these animals were fed either the Chinese herbal medicine CH-100 (4 tablets/kg body weight/ day) or placebo in chow daily. Blood from the tail vein was collected for endotoxin (lipopolysaccharide) assay at 0, 4, and 8 weeks of ethanol consumption. Twenty-four hours after injection of Con A (20 mg/kg body weight) or phosphate-buffered saline, blood from the tail vein was collected for alanine aminotransferase and tumor necrosis factor (TNF)-alpha assays. Liver-associated CD4+ T cells were isolated from liver perfusates and then cultured with Con A (5 microg/ml) at 37 degrees C for 24 hr. Supernatants were harvested for TNF-alpha assay. The proportion of CD4+ T cells in blood and liver perfusates was measured. Liver samples were collected for histopathological analysis.

RESULTS

Lipopolysaccharide levels were significantly reduced in CH-100-treated ethanol-fed rats compared with placebo-treated rats. After Con A injection, alanine aminotransferase levels were lower at 12 and 24 hr in herb-treated rats compared with placebo-treated rats. Furthermore, serum TNF-alpha levels were lower in ethanol-fed rats on herbal treatment. A significant decrease in TNF-alpha production by liver-associated CD4+ T cells in culture was observed in CH-100-treated ethanol-fed rats. CH-100 treatment was associated with a decreased percentage of CD4+ cells in both blood and liver perfusate in all groups. Herb-treated rats displayed markedly less hepatic necrosis and a reduced CD4+ T-cell infiltrate in portal areas than did placebo-fed rats.

CONCLUSIONS

The results demonstrate that CH-100 modified the T-cell response to Con A injection. The effect was more marked in ethanol-fed rats, which suggests a possible role for CH-100 in treating alcoholic liver disease.

Glycyrrhizin protects mice from concanavalin A-induced hepatitis without affecting cytokine expression

The administration of concanavalin A (Con A) to mice induces cytokine-dependent hepatitis. In the present study, the effect of glycyrrhizin on Con A-induced hepatitis was examined. Treatment of mice with Con A (0.2 mg/mouse, i.v.) induced elevation of the plasma transaminase activities at 24 h. Mice were treated with glycyrrhizin (100, 200 and 400 mg/kg, i.p.), and glycyrrhizin at the doses of 200 and 400 mg/kg inhibited the Con A-induced elevation of the plasma transaminase activities. At 1 h after Con A treatment, interferon-gamma, tumor necrosis factor-alpha, interleukin-2 and interleukin-6 proteins were released into the plasma. Although treatment with glycyrrhizin at 200 mg/kg inhibited Con A-induced hepatitis, it did not affect the release of any of these Con A-induced cytokines into the plasma. The present results clearly show that glycyrrhizin inhibited Con A-induced hepatitis without affecting cytokine expression.

Clinical features of inflammatory liver disease in cats: 41 cases (1983-1993)

OBJECTIVE

To compare the clinical and clinicopathologic findings in and prognosis for cats with lymphocytic portal hepatitis (LPH) versus cats with acute or chronic cholangiohepatitis (CH).

DESIGN

Retrospective study.

ANIMALS

25 cats with LPH; 16 cats with CH (7 acute, 9 chronic).

PROCEDURE

Cats with LPH and CH were selected by evaluating records from liver biopsy specimens submitted to the University of Minnesota Veterinary Teaching Hospital during a 10-year period. Clinical and clinicopathologic data were retrieved.

RESULTS

Cats with CH had higher segmented and band neutrophil counts, alanine aminotransferase activities, and total bilirubin concentrations than did cats with LPH. Cats with acute CH had higher segmented and band neutrophil counts and lower serum alkaline phosphatase activities and total bilirubin concentrations than did cats with chronic CH. Twelve of 14 cats with LPH or CH had coarse or nodular texture to the liver on ultrasonography, with loss of portal vein wall clarity noticed in 4 of 8 cats with LPH. Sixteen of 23 cats with LPH and 8 of 15 cats with CH survived > 1 year. Of those cats living < 1 year, all cats with LPH and 5 of 7 cats with CH had a serious concurrent illness that may have been responsible for their deaths.

CLINICAL IMPLICATIONS

LPH and CH can be detected and tentatively differentiated through evaluation of clinical laboratory test results, but histologic evaluation of liver specimens is necessary for definitive differentiation. Survival time was good regardless of the type of inflammatory liver disease.

Copper increases in both plasma and red blood cells at the onset of acute hepatitis in LEC rats

Ceruloplasmin is excreted mostly in the apo-form in Wilson's disease patients and Long-Evans rats with a cinnamon-like coat color (LEC rats), an animal model for Wilson's disease, and hence the concentration of Cu in the plasma is low. However, it increases toward and at the onset of acute hepatitis in LEC rats, the increased Cu in the plasma being bound to ceruloplasmin, metallothionein and albumin. Changes in the concentration of Cu in red blood cells (RBCs) were monitored with age for the first time together with that in the plasma in LEC rats. Cu in the RBCs was found to increase to a 5-7 times higher level than that in the plasma toward the onset and peaked at the onset, the pattern being similar to that in the plasma. The source of the Cu increase in the RBCs was discussed, and it was assumed that the so-called free Cu ions that leak from the damaged hepatocytes are bound to albumin and/or taken up by the RBCs.

Carcinoembryonic antigen-related cell-cell adhesion molecule C-CAM is greatly increased in serum and urine of rats with liver diseases

C-CAM (rat cell CAM/human CD66a) is ubiquitous and multifunctional. It is involved in intercellular adhesion, signal transduction and cell growth inhibition. Structurally, it is related to the carcinoembryonic antigen. In the present study serum, bile and urine of rats with liver diseases were analyzed for the presence of cell CAM. After bile duct ligation and during galactosamine (GalN) hepatitis we found that large amounts of liver membrane-bound C-CAM are secreted or shed into blood. The serum level of another liver membrane-bound protein, LI-cadherin, is not increased. It was shown that C-CAM is also present in bile fluid, and for the first time that C-CAM is present in the urine of rats with liver diseases. A particularly high concentration was measured in the urine of rats suffering from GalN hepatitis.

Induction of Fas ligand and Fas antigen mRNA expressions in interferon-gamma transgenic mouse liver

The interferon-gamma (IFN-gamma) transgenic mouse develops chronic hepatitis. In the present study, lymphoid cell infiltration and expression of the Fas system were studied in the transgenic mouse liver. Morphological analysis showed the infiltration of lymphoid cells at the portal area and necro-inflammation in the lobules. Furthermore, the infiltrating lymphoid cells were found to be present in the areas of piecemeal necrosis and the intralobular region. The polymerase chain reaction revealed induction of Fas antigen and Fas ligand mRNA expressions. The chronic hepatitis in this mouse reflects the profiles of human chronic hepatitis.

Pentoxifylline prevents concanavalin A-induced hepatitis by reducing tumor necrosis factor alpha levels and inhibiting adhesion of T lymphocytes to extracellular matrix

BACKGROUND/AIMS

Concanavalin A activates T lymphocytes and causes T cell-mediated hepatic injury in mice. Tumor necrosis factor alpha is a critical mediator in this experimental model. T-cell-mediated liver injury involves the migration of immune cells, notably CD4+ T lymphocytes, into liver tissue. Pentoxifylline is a strong suppressor of tumor necrosis factor alpha release and prevents leukocyte adherence to vascular endothelium and down-regulates the expression of intercellular adhesion molecule-1 in monocytes. In this study, we examined the efficacy of pentoxifylline as a potential therapeutic compound for the treatment of concanavalin A hepatitis.

METHODS

Balb/c mice were injected with 12 mg/kg concanavalin A with or without a single injection of pentoxifylline (5-300 mg/kg), 2 h prior to concanavalin A administration. Liver damage was evaluated by determining serum levels of liver enzymes and tumor necrosis factor alpha, and hepatic histopathology compared to mice treated with concanavalin A only. We also assessed the effects of pentoxifylline on the adhesive properties of T lymphocytes to fibronectin, as a paradigm for immune cell-extracellular matrix interactions required for migration. Pretreatment with pentoxifylline significantly reduced serum levels of liver enzymes (3800+/-650 vs 150+/-28 IU/l) and tumor necrosis factor alpha (710+/-105 vs 113+/-15 pg/ml) with no evidence of inflammation in histopathologic examination compared to control mice treated with concanavalin A. Pentoxifylline also inhibited the binding of murine T cells to fibronectin. All the effects of pentoxifylline were dose-dependent.

CONCLUSIONS

These results indicate that high doses of pentoxifylline can prevent concanavalin A hepatitis by suppression of tumor necrosis factor alpha release and inhibition of T cells adhesion to extracellular matrix.

Use of ursodeoxycholic acids in a dog with chronic hepatitis: effects on serum hepatic tests and endogenous bile acid composition

A dog with severe cholestasis secondary to chronic hepatitis was treated with ursodeoxycholic acid (UDCA) PO. After 2 weeks of daily treatment, the dog was more active and had an improved appetite. Monthly serum biochemical determinations and analysis of individual bile acid profiles documented improvement in hepatobiliary tests and a marked reduction in the concentrations of potentially hepatotoxic endogenous bile acids. These effects were maintained for approximately 6 months. The findings in this dog are similar to those reported for human patients treated with UDCA and provide preliminary evidence in support of its continued evaluation in the treatment of cholestatic liver disease in the dog.

Subclinical versus clinical hepatitis in the dobermann: evaluation of changes in blood parameters

Concentrations of the enzymes alanine aminotransferase (ALT) and alkaline phosphatase (AP) were determined in blood samples from 626 randomly selected clinically healthy dobermann. ALT levels greater than three times the normal upper value were detected in 55 dogs. These dogs were selected for further investigation; the owners of 23 of the dogs allowed a liver biopsy to be performed. Histopathological examination revealed various degrees of hepatitis and excessive amounts of copper in 21 of the dogs. These cases, referred to as subclinical dobermann hepatitis (DH), were selected for a follow-up investigation in which the clinical signs and serum parameters (ALT, AP and bilirubin) were studied for a period of three to 48 months. Serum parameters of those with subclinical DH were compared with blood samples collected from 22 dogs with clinical DH. Individual dogs showed great variation in the levels of ALT and AP between consecutive serum samples. These enzyme levels never, however, fell to the normal range. During the subclinical stage no statistically significant (P > 0.05) change occurred in the concentrations of ALT or AP. When dogs with subclinical DH were compared with dogs with clinical DH, there was no statistically significant (P > 0.05) difference in ALT levels, whereas AP concentrations were significantly (P < 0.001) higher among clinically affected dogs. Elevated levels of bilirubin were detected almost exclusively in dogs with clinical DH. After the onset of clinical signs there was a decrease in the ALT levels and an increase in AP concentrations as the disease progressed, but the changes were not statistically significant (P > 0.05).

Diagnosis and prognosis of chronic hepatitis and cirrhosis in dogs

The purpose of this investigation was to evaluate the significance of enzymatic and biochemical analyses in the classification of chronic inflammatory liver disease and to evaluate the prognosis of these diseases. Chronic hepatitis and cirrhosis were diagnosed by histopathological examination in 79 dogs. Decreased appetite and lethargy were the most common owner complaints (46/79). Vomiting and, or, diarrhoea were reported in 27/79 dogs. Ascites was the most common clinical sign (43/79), whereas icterus was a more unusual finding demonstrated in 16/79 dogs. Liver cirrhosis was diagnosed most frequently, in 33/79 dogs, followed by chronic progressive hepatitis (22/79), chronic cholangiohepatitis (13/79), and chronic non-specific hepatitis (11/79). Hypoalbuminaemia was the most consistent biochemical aberration in liver cirrhosis (25/26) and in chronic progressive hepatitis (13/18). These diseases also showed normal to mildly increased concentrations of serum alanine aminotransferase (ALT) and serum gamma-glutamyl transferase (GGT) and a moderate to marked increase of serum alkaline phosphatase (ALP) and fasting serum bile acid (SBA) concentrations. As expected, icterus and markedly elevated ALT, ALP, GGT and SBA levels were demonstrated in chronic cholangiohepatitis. In this disease hypoalbuminaemia was shown in 6/12 dogs, whereas in dogs with chronic non-specific hepatitis, mean SBA and albumin concentrations were normal. In liver cirrhosis the prognosis was poor, with 94 per cent of the dogs dead within one week of established diagnosis. For dogs with the other types of chronic hepatitis the prognosis was more favourable with the mean survival time ranging from 21.1 to 36.4 months.

Hepatic disease associated with administration of tetanus antitoxin in eight horses

Seven horses developed clinical or subclinical hepatitis 48 to 87 days after administration of tetanus antitoxin. One horse had mildly high hepatic enzyme activity 120 days after inoculation with tetanus antitoxin. The first horse developed signs of depression, lethargy, and anorexia. During hospitalization, signs of hepatoencephalopathy were noticed, and laboratory data were consistent with hepatic disease. Another horse that was found dead had gross and histologic lesions compatible with serum hepatitis. Screening of serum gamma-glutamyltransferase (GGT) and aspartate transaminase activities were used to investigate the remaining horses in the herd. High GGT activities (71 to 206 IU/L) were detected in 5 additional herd members. These horses appeared clinically normal, apart from 2 reports of nasal photosensitization and an aborted fetus. In 3 horses, high serum GGT activity persisted over a 44-day testing period. All affected horses had been given tetanus antitoxin within 12 hours of parturition, and a common source of vaccine was identified for 7 horses. Findings in this group of horses indicate that clinical and subclinical serum hepatitis can develop after administration of tetanus antitoxin.

Occurrence of autoimmune antibodies to liver microsomal proteins associated with lethal hepatitis in LEC rats: effects of TJN-101 ((+)-(6S,7S,R-biar)- 5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy-6,7-dimethyl-10,11- methylenedioxy-6-dibenzo[a,c]cyclooctenol) on the development of hepatitis and the autoantibodies

Long Evans Cinnamon (LEC) rats, that spontaneously develop hepatitis, were found to possess autoantibodies to liver microsomal proteins (anti-LM) before the development of hepatitis. Anti-LM antibody was assumed to appear in association with the lethal hepatitis in the LEC rats. Thus, the purpose of this study was to investigate the effects of an anti-hepatitis drug on the development of hepatitis and the occurrence of the antibody in LEC rats. Mortality, blood biochemical parameters and the titer of serum anti-LM antibody were measured. In control LEC rats, 4 of 8 rats died before 20 weeks of age. In rats treated with TJN-101 ((+)-(6S,7S,R-biar)-5,6,7,8-tetrahydro-1,2,3,12-tetramethoxy -6,7-dimethyl-10,11 - methylenedioxy-6-dibenzo[a,c]cyclooctenol), 4 of 7 rats died of hepatitis, but the time of death was delayed by 7-10 weeks compared to the control rats. The titer of the anti-LM antibody increased 3-7 weeks before death in the non-survivors in control and TJN-101-treated rats, supporting the idea that anti-LM antibody occurs in association with acute lethal hepatitis.

Protection by sinomenine against endotoxin-induced fulminant hepatitis in galactosamine-sensitized mice

Sinomenine, an epimorphinan alkaloid, was tested for protecting hepatitis induced by lipopolysaccharide (LPS) in galactosamine (GalN)-sensitized mice. Sinomenine protected against the hepatic injuries in the dose range of 10-100 mg/kg in a dose-dependent manner and suppressed the production of tumor necrosis factor (TNF), which appeared in serum earlier than aminotransferases in GalN/LPS-treated mice. Sinomenine significantly suppressed the in vitro production of superoxide anion and hydrogen peroxide in the macrophage cultures stimulated with phorbol 12-myristate acetate. It is discussed that sinomenine prevents GalN/LPS-treated hepatic failure by suppressing TNF production and/or reactive oxygen generation.

Effects of cyclosporin-A and D-penicillamine on the development of hepatitis and the production of antibody to protein disulfide isomerase in LEC rats

Long Evans Cinnamon (LEC) rats, which spontaneously develop hepatitis, produce an autoantibody to protein disulfide isomerase (PDI) before the development of clinical signs of hepatitis. Anti-PDI antibody may be associated with immunological hepatitis. Thus, the purpose of this study was to investigate the effects of some drugs on the development of hepatitis and the occurrence of the antibody in LEC rats. Cyclosporin-A, an immunosuppressant, and D-penicillamine, which promotes copper excretion, were orally administered to LEC rats for 23 weeks. Mortality, blood biochemical parameters and the titer of serum anti-PDI antibody were measured. In control LEC rats, four of eight rats died before 20-weeks-old. Only one of seven rats in the cyclosporin-A-treated group died at the age of 20 weeks. When rats were treated with D-penicillamine, the development of clinical signs of hepatitis was inhibited, and all rats survived. Cyclosporin-A-treated rats showed increases in blood biochemical parameters similar to those in control rats. The titer of anti-PDI antibody in control rats was higher the non-survivors than survivors. These findings suggest the association of the anti-PDI antibody with lethality, but not with the apparent development and progression of hepatitis as measured by blood biochemical parameters in LEC rats.

Serum hepatocyte growth factor activity and hepatocyte proliferation in Long-Evans with a cinnamon-like coat color rats with hepatic lesions

We classified hepatic lesions spontaneously developed by Long-Evans with a cinnamon-like coat color (LEC) rats into the following four stages: Normal liver, acute hepatitis, chronic hepatitis, and hepatoma, by biochemical tests of the sera, and anatomical and histopathological examination of the livers. Hepatocyte growth factor (HGF) activity in the sera of LEC rats which developed acute hepatitis, chronic hepatitis, and hepatoma was higher than that of normal LEC rats. In particular, HGF activity in the sera of the LEC rats with acute hepatitis was about 70-fold that of normal LEC rats. However, primary cultured hepatocytes of LEC rats with hepatic lesions were hardly proliferated by stimulation with EGF and insulin in vitro or with increased HGF in vivo. These results suggest that the hepatocytes of LEC rats with hepatic lesions disorder the signal transduction of growth factors.

Sympathetic nerves, but not the adrenal gland, contribute to elevated plasma levels of met-enkephalin in rats with acute cholestatic hepatitis

Met-enkephalin is known to circulate in human and animal plasma in low levels. However, the source(s) of plasma met-enkephalin have not been completely elucidated. It has been proposed that the adrenal gland, sympathetic nerves, pancreas and the gut might be implicated. Recently, markedly elevated levels of met-enkephalin have been documented in the presence of liver disease. To investigate potential sources of met-enkephalin in liver disease, rats with acute cholestatic hepatitis 24 h after gavage with alpha naphthylisothiocyanate (ANIT) 100 mg/kg were studied. Plasma met-enkephalin levels were determined by radioimmunoassay in plasma samples from normal, adrenalectomized, or chemically sympathectomized animals. In control rats, ANIT treatment resulted in a striking 8.7-fold increase in systemic venous met-enkephalin levels (inferior vena cava) (P < or = 0.0005) and a significant increase in peptidase-derived met-enkephalin levels (determined after trypsin/carboxypeptidase B digestion of plasma samples) (P < or = 0.05). ANIT-treatment also resulted in a 5.6-fold increase in portal vein met-enkephalin levels (P < or = 0.005). Portal vein met-enkephalin levels were only 1.2-fold higher than IVC levels in ANIT-treated rats (P < or = 0.05). Plasma activities of the two main enkephalin degrading enzymes, aminopeptidase and enkephalinase, were similar in control and ANIT-treated rats. Chemical sympathectomy, prior to ANIT treatment, decreased the elevation in inferior vena caval met-enkephalin levels by 35% (P < or = 0.005). Adrenalectomy did not alter ANIT-induced increases in circulating met-enkephalin levels (pNS).(ABSTRACT TRUNCATED AT 250 WORDS)

The origins and kinetics of bilirubin in dogs with hepatobiliary and haemolytic diseases

In 35 dogs with spontaneous hepatobiliary liver disease the kinetics and the sources of bilirubin were quantified. The disorders were extrahepatic bile duct obstruction (n = 4), fulminant hepatitis (n = 2), (sub)acute hepatitis (n = 5), chronic active hepatitis (CAH) with cirrhosis (n = 6), hepatic lymphosarcoma (n = 5), centrizonal necrosis secondary to haemolytic anaemia (n = 6) and other (n = 2). The plasma disappearance of [3H]bilirubin was analyzed with a two-compartment model in all dogs. The ratio early labeled/late labeled bilirubin was determined by measuring the incorporation of [14C]glycine into erythrocyte haem and faecal stercobilin. By introducing this relation in the model analysis the bilirubin production rates from erythrocyte destruction (PE), ineffective erythropoiesis (PI) and hepatic haemoprotein (PL) could be quantified. Total bilirubin turnover was increased in both primary haemolytic disease and most cases of hepatobiliary disease. Erythrocyte survival was reduced in all cases but one. The bilirubin clearance was impaired to 30-50% of the normal value in most cases of hepatobiliary disease and also in primary haemolysis. In dogs with fulminant hepatitis, and cirrhosis with or without CAH, the clearance rates were reduced to values below 15% of normal. In these dogs both an impaired clearance and an increased production were important determinants of hyperbilirubinaemia. In other cases plasma bilirubin was primarily determined by increased production. These clearances and production rates were similar in haemolysis and in many cases of primary hepatobiliary disease. The hepatic haemoprotein turnover was quite variable in all subgroups, ranging from 1-74% of the total bilirubin turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Laboratory assessment of chronic hepatitis in Syrian hamsters

Clinical chemistry studies in the diagnosis of hamster diseases have received little attention. Although normal values exist for serum constituents, the effects of disease on these values are not well documented. Chronic hepatitis is endemic in several Syrian hamster (Mesocricetus auratus) colonies and is reported mainly through routine histologic examination. We investigated whether any differences in serum clinical chemistries were present in animals with hepatobiliary disease versus unaffected hamsters. Only serum alanine aminotransferase (ALT) and bile acids were significantly elevated in hamsters with chronic hepatitis only. In hamsters that had both chronic hepatitis and biliary disease, the serum ALT, alkaline phosphatase, cholesterol, and bile acids were significantly elevated. The results of this study indicated that serum clinical chemistries may be a useful antemortem diagnostic test for chronic hepatobiliary disease in hamsters.

Hereditary low level of plasma ceruloplasmin in LEC rats associated with spontaneous development of hepatitis and liver cancer

Both young (5 weeks old) and old (61-100 weeks old) hereditary hepatitis LEC rats showed a markedly low level of plasma ceruloplasmin (Cp) ferroxidase activity as compared with that of age-matched LEA and BN strain rats. This trait was genetically examined by the use of (BN x LEC) F1 hybrid and (F1 x LEC) backcross rats. The F1 hybrids never developed hepatitis and showed a similar level of Cp to that found in the parental BN rats. Among the backcross rats with about 1:1 segregation rate for hepatitis, affected rats had a remarkably decreased level of Cp, as found in LEC rats, whereas unaffected rats exhibited a similar level of Cp to that of BN, F1 and LEA rats. These results indicate that the low level of Cp is heritable in a single autosomal recessive mode in LEC rats. The observed tight link between the low Cp level and the hepatitis in LEC rats suggests that defective copper metabolism may be associated with the occurrence of hepatitis in LEC rats, since Cp is a copper-binding protein primarily involved in copper transport from the liver.

Clinico-pathological studies of LEC rats with hereditary hepatitis and hepatoma in the acute phase of hepatitis

The LEC rat, which suffers from hereditary hepatitis, was examined for elucidation of its clinicopathological characteristics during development of the acute phase of hepatitis by quantitative analyses of histological observations of the liver in combination with laboratory data on various serum enzymes. The progression of acute hepatitis in the LEC rat was observed to begin insidiously early in life, i.e., a few enlarged hepatocytes and Councilman bodies appeared at around 8 weeks of age without clinical signs. Furthermore, it was revealed that the acute phase of hepatitis started with a remarkable increase of Councilman bodies, large nuclei and hepatocytes in mitosis in the liver 3 to 4 weeks before the onset of fulminant hepatitis, which is characterized by the elevation of serum enzyme activities such as GOT, GPT and gamma-GTP, and the onset of jaundice. From those observations, three stages were proposed for the progression of acute hepatitis in the LEC rat.

[Morphofunctional status of blood and bone marrow cells in acute experimental hepatitis induced by allyl alcohol]

Acute experimental hepatitis was induced by a single injection of 1% water solution of allyl spirit in a dose of 100 mg/kg. Morphofunctional state of peripheral blood and bone marrow cells was studied with the use of hematological and cytochemical methods. Specific changes were detected in the peripheral blood and bone marrow cell parameters in the early (6 and 12 h) and late (24h--10 days) periods after the injection. Changes in the liver and in the blood and bone marrow cells were irreversible. Most of the parameters studied returned to normal 22 days after the injection of allyl spirit.

[Dipeptidyl aminopeptidase IV in hospitalized patients and in galactosamine hepatitis of the rat: Activity and lectin affinity chromatography in serum and hepatic plasma membranes]

The activity of dipeptidyl aminopeptidase IV was studied in the sera of 378 hospitalized patients. The mean activity of dipeptidyl aminopeptidase IV was elevated significantly in patients with neoplasmata and hepatitis, but not in patients with liver cirrhosis. Significant correlations (p less than 0.001) existed with gamma-glutamyl transferase, glutamate dehydrogenase, alkaline phosphatase and leucine aminopeptidase. A significant correlation with lactate dehydrogenase existed only in patients with neoplasmata. Principal component analysis, performed with aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, leucine aminopeptidase, lactate dehydrogenase and dipeptidyl aminopeptidase IV, revealed correlations between the activities of aspartate aminotransferase and alanine aminotransferase, and between alkaline phosphatase and leucine aminopeptidase, but neither dipeptidyl aminopeptidase IV nor lactate dehydrogenase showed any correlation with either of these two groups. In lectin affinity chromatography with concanavalin A and wheat germ lectin sepharose, serum dipeptidyl aminopeptidase IV from liver cirrhosis patients showed the same binding pattern as that from healthy subjects. The activity and glycosylation of dipeptidyl aminopeptidase IV in serum and hepatic plasma membranes was investigated in rats, following the induction of hepatitis with galactosamine. In the serum, dipeptidyl aminopeptidase IV activity was elevated as early as 6 h after galactosamine injection, and the elevated activity persisted until the 7th day. At the same time dipeptidyl aminopeptidase IV activity was also elevated in the hepatic plasma membrane. Ninety eight percent of hepatic dipeptidyl aminopeptidase IV bound to concanavalin A as well as to wheat germ lectin and this value was unchanged during hepatitis. In the serum of control rats, 90% of dipeptidyl aminopeptidase IV bound to concanavalin A but only 39% to wheat germ lectin.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous hepatitis in Long-Evans rats. A potential animal model for fulminant hepatitis in man

Spontaneous hepatitis associated with severe jaundice occurred in 90% of an inbred strain of Long-Evans rats. The rapidly progressive syndrome was characterized by abrupt onset, hyperbilirubinemia and increased serum levels of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, associated with massive and multifocal necrosis of the liver. This strain should provide a useful animal model for analysis of the pathogenesis of fulminant hepatitis in humans.

Elevation of serum alpha-fetoprotein and proliferation of oval cells in the livers of LEC rats

Alpha-fetoprotein (AFP) in the sera of 35 LEC (Long-Evans with a cinnamon-like coat color) rats between 7 and 25 weeks of age was evaluated by enzyme-linked immunosorbent assay (ELISA). Elevation of serum AFP and proliferation of oval cells in the liver were observed in most LEC rats, which suffered from acute hepatitis. On the other hand, the serum AFP level was within the normal range before the onset of hepatitis. Immunohistochemical staining for AFP revealed that some of the proliferating oval cells produced AFP. Morphometric analysis of AFP-positive cells and ELISA for serum AFP demonstrated that there was a statistically significant correlation between the number of AFP-positive cells in the liver and the concentration of AFP in the serum. Histological examination revealed the transition and differentiation of the oval cells to small hepatocytes. These results suggested that the phenomena which occurred in LEC rats suffering from acute hepatitis were similar to those that occurred during the early stage of azo dye hepatocarcinogenesis, although the extent of the oval cell proliferation and the elevation of serum AFP in LEC rats were not as great as those in rats treated with azo dye. This is the first report on a rat strain with proliferation of AFP-producing oval cells during its natural history.

Hepatitis in vervet monkeys caused by Fusarium moniliforme

The fungus Fusarium moniliforme Sheldon is a common contaminant of maize (Zea mays L.) intended for human and animal consumption throughout the world. Culture material of F. moniliforme MRC 826, isolated from home-grown maize in an area in Transkei, southern Africa, with a high rate of human oesophageal cancer, was highly toxic to vervet monkeys (Cercopithecus pygerythrus). Ten monkeys were fed a standard primate diet which contained various amounts of culture material for 180 days. Two control monkeys received the standard diet without culture material. Pathological changes observed in liver biopsies taken by laparotomy were characterized by focal disturbance of the trabecular structure, degeneration and necrosis of hepatocytes, mononuclear infiltration, and in severe cases by cirrhosis. Biochemical changes, particularly increases in liver enzyme activities in serum, paralleled the liver damage seen by light microscopy. The acute, subacute and chronic toxic hepatitis induced in various degrees in all the monkeys fed fungal culture material showed close similarity with human viral hepatitis. The lesions also have some similarities to those induced in primates by aflatoxin, but differ in several respects. Ultrastructural nuclear and nucleolar changes caused by F. moniliforme, i.e. marginal clumping of chromatin and large nucleoli with segregation of fibrillar and granular components, suggested some similarity with the changes reported to be caused by aflatoxin and some other hepatocarcinogens. A long-term feeding experiment in vervet monkeys with F. moniliforme MRC 826 and attempts to isolate and chemically characterise the hepatotoxic metabolite(s) produced by this fungus are being continued.

Circulating thyroid hormones in primates with mild or severe hepatitis following liver transplantation

In order to study the effects of acute immunologically mediated liver disease on circulating thyroid hormones, serum levels of thyroxine (T4, total and free) and triiodothyronine (T3) were measured in 8 baboons before and for 60 days after allogeneic liver transplantation. In 3 animals early rejection and jaundice developed; T4 levels declined as liver function deteriorated. In the 5 tolerant animals liver function was only temporarily deranged without jaundice and there was a consistent early rise in T4 (P less than 0.01) followed by a later fall. T3 concentrations were relatively normal in both groups. The T3 resin uptake test remained virtually unchanged in all animals. Serum T4 and T3 responses to exogenously administered bovine thyrotropin (TSH) were similar in the jaundiced and anicteric animals. We conclude that the early rise in T4 in the tolerant animals was caused by transient increases in thyroid binding globulin in (TBG) while the fall in thyroid hormones in these and in the jaundiced animals was related to a decline in TBG levels. Thyroid responsiveness to TSH is not disturbed by moderately deranged liver function.

Effect of experimental duck virus hepatitis infection on some biochemical constituents and enzymes in the serum of white Pekin ducklings

Experimental duck virus hepatitis infection of 11-day-old white Pekin ducklings having specific maternal antibodies revealed significant changes in some biochemical constituents and enzymes of the serum during the 3 weeks following exposure. These changes included a marked decrease in the total proteins and the albumin fraction, together with a significant elevation in levels of alkaline phosphatase, glutamic pyruvic transaminase, bilirubin, and creatinine. Most of these changes were attributed primarily to a deranged liver function associated with duck virus hepatitis infection.