Effect of nifedipine and S-adenosylmethionine in the liver of rats treated with CCl4 and ethanol for one month.

An experimental model of toxic liver injury in rats was employed to assay the effect of Nifedipine (a calcium antagonist blocker) and S-Adenosylmethionine (a precursor of glutathione). An important decrease in both perivenular fibrosis and cirrhosis was found. Furthermore, a significant decrease in lactic acid levels was found in the group of animals treated with pharmacologic therapy, although no correlation was seen between lactic acid levels and the different degrees of perivenular fibrosis. No significant variations in ALT and AST enzymes were observed between both groups, as opposed to a significant decrease in LDH enzyme in the Nifedipine+S-Adenosylmethionine group. The results indicate an improvement in the histologic picture of the liver in rats treated by means of pharmacological association, without any change in inflammatory infiltrate and with a slight decrease in necrosis, indicating an action mechanism via creeping fibrosis (instead of a hepatitis pathway).     

IGF1 gene transfer into skeletal muscle using recombinant adeno-associated virus in a rat model of liver cirrhosis

Systemic administration of recombinant IGF1 at low levels has been shown to improve hepatic function, nutritional status and testicular atrophy in rats with CCl4-induced cirrhosis. We have developed a recombinant adeno-associated (rAAV) viral vector containing the cDNA for rat IGF1 and confirmed the expression of IGF1 after intramuscular injection of this vector in a rat model of liver cirrhosis. Although weight of injected muscles was significantly increased in rats with mild cirrhosis, this was not the case in rats with advanced, de-compensated cirrhosis. Furthermore, we found no significant amelioration of liver damage in treated rats at any stage of liver cirrhosis. Our results suggest that IGF1 gene transfer into muscle results in a local effect, at least at the vector dose employed here.     

培菲康对肝硬化血浆内毒影响的研究

目的　探讨益生菌制剂培菲康治疗肝硬化内毒素血症的作用机制。方法　采用大鼠肝硬化模型,其中治疗组予以培菲康液每天灌胃治疗,共8周,检测治疗组及对照组血浆内毒指标;并选取70例肝硬化Child-Pugh分级为B级的患者,其中治疗组口服培菲康胶囊(每次2粒,每天3次) 3周,观察治疗前后血浆内毒素变化。结果　培菲康治疗组的肝硬化大鼠及患者血浆内毒素均明显低于对照组( P<0 .0 5 )。结论　培菲康能明显降低肝硬化患者血浆内毒素水平,可作为肝硬化患者的辅助用药     

Combined prednisone and levothyroxine improve treatment of severe thrombocytopenia in hepatitis B with compensatory cirrhosis accompanied by subclinical and overt hypothyroidism

The aim of the present study was to investigate the relationship between hypothyroidism and thrombocytopenia in hepatitis B-related compensatory liver cirrhosis and to determine whether treatment with levothyroxine and prednisone is superior in a multicenter, open-label, observational study in China. In total, 125 consecutive hepatitis B-related compensated liver cirrhosis patients with severe thrombocytopenia accompanied by hypothyroidism were included. The patients were divided into four groups according to treatment strategy: a control group (n=29), a prednisone group (n=25), a levothyroxine group (n=32) and a prednisone plus levothyroxine group (n=39). Severe thrombocytopenia was more prevalent in hepatitis B-associated compensatory liver cirrhosis patients with hypothyroidism than in euthyroid patients (29.6% vs. 14.7%, P<0.05). Combination treatment with prednisone and levothyroxine decreased the risk of bleeding and improved platelet recovery compared to control treatment and treatment with either prednisone or levothyroxine alone. The platelet count before therapy, serum thyroid stimulating hormone and combination treatment with prednisone and levothyroxine were associated with bleeding events. Therefore, the present study suggests that hypothyroidism is associated with severe thrombocytopenia in hepatitis B-associated compensatory liver cirrhosis. Treatment with prednisone plus levothyroxine may present a novel approach in these patients.     

Desmosine and isodesmosine contents and elastase activity in normal and cirrhotic rat liver.

The contents of desmosine and isodesmosine, the cross-linking amino acids of elastin, were increased 4-fold in rat liver with carbon tetrachloride-induced cirrhosis, which suggests that insoluble elastin accumulates in cirrhosis. Elastase activity in the cirrhotic liver, as determined with 3-carboxypropionyl-L-alanyl-L-alanyl-L-alanine p-nitroanilide, was 17% less than in the normal liver; no change was found when Congo Red-elastin was used as a substrate.     

Hyperthermic modification of cyclophosphamide metabolism in rat hepatic microsomes and liver slices

The ability of rat liver microsomes and liver slices to metabolize the antineoplastic compound cyclophosphamide was studied at 37° and at elevated temperatures comparable to those used for human systemic hyperthermic antineoplastic therapy. Temperatures above 40.5° and 41.8° inhibited cyclophospamide metabolism by microsomes and liver slices respectively. Therefore, cyclophosphamide may not be a suitable drug for combination with systemic hyperthermia in cancer therapy.     

Bone-marrow-derived cells cultured in serum-free medium reduce liver fibrosis and improve liver function in carbon-tetrachloride-treated cirrhotic mice

We have previously developed autologous bone marrow cell infusion (ABMi) therapy for liver cirrhosis patients. One problem associated with ABMi therapy is that general anesthesia is required to obtain 400 ml bone marrow fluid from liver cirrhosis patients. However, many patients with decompensated cirrhosis do not meet the criteria, because of decreased liver function or an increased bleeding tendency. To overcome these issues, our aim is to derive liver repair cells from small amounts of autologous bone marrow aspirates obtained under local anesthesia and to use these cells in liver cirrhosis patients. Here, we conducted, by using a mouse model, basic research aimed at achieving novel liver regeneration therapy. We cultured bone marrow cells aspirated from the femurs of C57 BL/6 Tg14 (act-EGFP) OsbY01 mice (green fluoresent protein [GFP]-transgenic mice). After 14 days of culture with serum-free medium (good manufacturing practice grade), the obtained spindle-shaped GFP-positive cells were injected (1×10⁴ cells) via the caudal vein into mice with carbon tetrachloride (CCl₄)-induced cirrhosis. Numerous cultured macrophages and some mesenchymal stem cells repopulated the cirrhotic liver. The results showed that serum albumin, liver fibrosis and liver function were significantly improved in the group treated with cultured bone marrow cells (P<0.01). Moreover, matrix metalloproteinase-9 expression was increased in the liver (P<0.01). Thus, infusion of bone-marrow-derived cultured cells improved liver function and liver fibrosis in mice with CCl₄-induced cirrhosis.     

Betaine homocysteine methyltransferase: gene cloning and expression analysis in rat liver cirrhosis

It has been known for over half a century that homocysteine levels are elevated in liver cirrhosis, but the basis for it is not fully understood. Using differential display, we identified betaine homocysteine methyltransferase (BHMT) as a gene down-regulated in rat liver cirrhosis and most likely involved in this dysregulation. A partial BHMT clone was isolated by screening of a cDNA library with the differential display fragment. The full-length gene was generated by primer extension of cDNA. Expression levels of BHMT in cirrhotic livers of bile duct ligated rats were compared to controls by Northern and Western blotting as well as by enzyme activity measurements. BHMT mRNA levels were reduced to 29+/-23% in established liver cirrhosis induced by bile duct ligation (BDL) as compared to controls. Enzyme assays in crude liver homogenates showed a similar reduction in BHMT activity in bile duct ligated rat livers. By Western blotting, BHMT could be detected in crude liver homogenates of control animals, but was reduced to below the limit of detection in cirrhotic livers. In conclusion, these findings establish a reduced BHMT enzyme activity in cirrhotic rat livers, which may explain the elevated plasma homocysteine levels in cirrhosis.     

Human,rat and crocodile liver microsomal monooxygenase activities measured using diazepam and nifedipine: effects of CYP3A inhibitors and relationship to immunochemically detected CYP3A apoprotein

Nifedipine oxidase and diazepam C₃-hydroxylase were tested as activities for selectively measuring CYP3A enzymes using liver microsomes from male and female human organ donors, male and female Wistar rats and male and female estuarine crocodiles. The association between CYP3A enzymes and these monooxygenations was confirmed for the human samples. Male rat samples had lower specific contents of CYP3A apoprotein than the human samples but had equivalent (nifedipine) or higher (diazepam) monooxygenase specific activities. CYP3A apoprotein was undetectable in female rat samples which had very low activities towards both substrates. Enzyme inhibition studies showed that diazepam C₃-hydroxylase of male rat liver was attributable to CYP3A but corresponding results for female rats suggested a contribution from non-CYP3A enzyme. Western blotting with immunochemical detection using anti-CYP3A4 IgG suggested the presence of putative CYP3A apoprotein in male and female crocodile liver samples and inhibition studies with diazepam as substrate suggested the presence of CYP3A subfamily monooxygenase activity in these enzyme preparations. Results for nifedipine oxidase with male and female rat liver and male crocodile liver suggested major contributions to catalysis from non-CYP3A enzymes. Inhibition studies suggested that a higher proportion of nifedipine oxidase in female crocodile liver may be attributable to the putative CYP3A enzyme(s) than in male crocodile liver. These results show the need for care in the assessment of CYP3A activity of fractionated tissues when using these substrates in cross-species studies and where gender is a variable.     

A natural process of cirrhosis resolution and deceleration of liver regeneration after thioacetamide withdrawal in a rat model

Characteristics of thioacetamide (TAA)-induced liver cirrhosis in rat was observed for 120 days after TAA withdrawal as part of the radiobiological study of partial liver irradiation on TAA-induced cirrhotic rats. The natural process focused on cirrhosis and regeneration was recorded as a baseline condition for the interpretation of the outcome of the partial liver irradiation study. Cirrhosis in rats was successfully induced by drinking 0.03% TAA water orally for 29 weeks with a modeling rate of 96%. After establishment of the cirrhosis model, the rats were observed for 120 days upon TAA withdrawal to investigate the dynamic changes of cirrhosis and regeneration. The following characteristics were observed: (1) Histological changes; (2) Liver functions; (3) Cirrhosis: trichrome stain, quantification of hydroxyproline in hydrolysed liver tissue and TGF-β1; (4) Liver regeneration: liver index, hepatocyte mitotic index (MI), hepatocyte proliferation index (PI) by flow cytometry, PCNA labeling index (LI) by IHC and expression of PCNA mRNA; and (5) Growth factors: serum HGF, VEGF, TGF-α, and IL-6. After TAA withdrawal, gradual improvement in liver functions was noted with decreases of ALT, AST, and ALP, and increase of PA. The resolution of cirrhosis was evident by histological improvement with attenuation of collagen fiber and decrease of TGF-β1 IHC index, and also decrease of trichrome stain and hydroxyproline content. However, cirrhosis was still existed on 120 days after TAA withdrawal. Significant deceleration of liver regeneration was demonstrated with TAA withdrawal, evidenced by decrease of MI and PI, reduced expression of PCNA mRNA and PCNA LI. In conclusion, upon TAA withdrawal hepatic cirrhosis was continuously resolved, but persisted up to 120 days, and liver regeneration was significantly decelerated.     

Nuclear matrix protein expressions in hepatocytes of normal and cirrhotic rat livers under normal and regenerating conditions

We explored the feasibility of studying nuclear matrix protein (NMP) expressions of the hepatocytes in normal and cirrhotic rat livers with liver regeneration after partial hepatectomy. Sixteen Wistar healthy rats were studied with experimental liver regeneration and/or liver cirrhosis. Two-dimensional (2-D) gel electrophoresis was used to generate these NMP compositions from these rat liver samples. Several antibodies against cytokeratin, vimentin, actin, B23, HNF4alpha, and heat shock protein 70 were used for identification by Western blot. Totally, 41 strongly stained protein spots were characterized on the 2-D gels. Thirty-four protein spots were detected in all of these rat livers, of which, cytokeratin, vimentin, actin, HNF4alpha, and heat shock protein 70 were identified. B23 was detected in the regenerated livers. Three protein spots (s33, s34, and s35) were detectable only in NMP preparation extracted from the regenerating rat livers after hepatectomy. Another three protein spots (s36, s37, and s38) were detectable only in NMP preparation extracted from thioacetamide-induced cirrhotic rat livers. Under these conditions including experimental liver regeneration and/or liver cirrhosis, Over thirty higher abundance NMPs of hepatocytes were consistently expressed and considered as common and basic NMPs. Some of the NMPs are specific for liver regeneration and may play a critical role in cell proliferation and cell cycle, and some are specific for liver cirrhosis.     

Impact of zinc,selenium and lycopene on capsaicin induced mutagenicity and oxidative damage in mice

Capsaicin is employed as a condiment and colorant in the cosmetic and pharmaceutical industries. Metabolism of capsaicin produces reactive phenoxy radicals, which inflict damage to DNA. Micronutrients such as zinc and selenium facilitate the expression of tissue repair factors, and lycopene has natural antioxidant action. The current study investigated the possible protective role of zinc, selenium and lycopene singly and in combination in ameliorating capsaicin induced mutagenicity. Fifty four Swiss albino mice received the vehicle, zinc (10 mg/kg), selenium (2 mg/kg), lycopene (2 mg/kg) alone, capsaicin alone (2 mg/kg), and capsaicin along with zinc (10 mg/kg), selenium (2 mg/kg) and lycopene (2 mg/kg) in combination by the oral route for 32 days. Animals were killed 24 h after the last treatment, and micronuclei formation in bone marrow and peripheral blood were assessed. Antioxidant status in plasma, the total protein, nucleic acids, and DNA fragmentation was assessed in the liver homogenate. Capsaicin substantially damaged nuclear material and increased oxidative stress. Individual therapy with lycopene was most effective in reducing micronuclei formation, lipid peroxidation, and in augmenting ferric reducing ability of plasma. This was closely followed by zinc and selenium. Zinc protected against DNA fragmentation followed by lycopene and selenium. The combination therapy was effective over individual treatment against DNA fragmentation, micronuclei and malondialdehyde formation. The combination did not exert a substantial benefit over individual therapy in enhancing the total antioxidant ability of plasma. The risk of capsaicin induced mutagenicity was lowered with the combination by reducing the generation of free radicals and by enhancing tissue repair.     

益生菌对肝硬化血氨影响的实验及临床研究

目的采用动物实验及临床观察,探讨益生菌制剂培菲康治疗肝硬化高氨血症的作用机制。方法采用大鼠肝硬化模型,其中治疗组予以培菲康悬液每天灌胃治疗共8周,检测治疗组及对照组血浆内毒素指标;并选用70例肝硬化Child-Pugh分级为B级的患者,其中治疗组口服培菲康胶囊(每次2粒,每日3次)3周,观察治疗前后血浆内毒素变化。结果培菲康治疗组的肝硬化大鼠及患者血浆内毒素均明显低于对照组(P<0.05)。结论培菲康能明显降低肝硬化患者的血氨水平,可作为肝硬化患者的辅助用药。     

Spironolactone lowers portal hypertension by inhibiting liver fibrosis, ROCK-2 activity and activating NO/PKG pathway in the bile-duct-ligated rat

Objective

Aldosterone, one of the main peptides in renin angiotensin aldosterone system (RAAS), has been suggested to mediate liver fibrosis and portal hypertension. Spironolactone, an aldosterone antagonist, has beneficial effect on hyperdynamic circulation in clinical practice. However, the mechanisms remain unclear. The present study aimed to investigate the role of spionolactone on liver cirrhosis and portal hypertension.

Methods

Liver cirrhosis was induced by bile duct ligation (BDL). Spironolactone was administered orally (20 mg/kg/d) after bile duct ligation was performed. Liver fibrosis was assessed by histology, Masson''s trichrome staining, and the measurement of hydroxyproline and type I collagen content. The activation of HSC was determined by analysis of alpha smooth muscle actin (α-SMA) expression. Protein expressions and protein phosphorylation were determined by immunohistochemical staining and Western blot analysis, Messenger RNA levels by quantitative real time polymerase chain reaction (Q-PCR). Portal pressure and intrahepatic resistance were examined in vivo.

Results

Treatment with spironolactone significantly lowered portal pressure. This was associated with attenuation of liver fibrosis, intrahepatic resistance and inhibition of HSC activation. In BDL rat liver, spironolactone suppressed up-regulation of proinflammatory cytokines (TNFα and IL-6). Additionally, spironolactone significantly decreased ROCK-2 activity without affecting expression of RhoA and Ras. Moreover, spironolactone markedly increased the levels of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS and the activity of NO effector- protein kinase G (PKG) in the liver.

Conclusion

Spironolactone lowers portal hypertension by improvement of liver fibrosis and inhibition of intrahepatic vasoconstriction via down-regulating ROCK-2 activity and activating NO/PKG pathway. Thus, early spironolactone therapy might be the optional therapy in cirrhosis and portal hypertension.     

Hepatocyte growth factor in ascites from patients with cirrhosis.

Hepatocyte growth factor (HGF) stimulating DNA synthesis of adult rat hepatocytes in primary culture was found in the ascites and plasma from patients with liver cirrhosis, but not in those from patients without cirrhosis. HGF was purified about 400-fold in 10% yield from cirrhotic ascites by ultrafiltration, cation-exchange chromatography on a S-Sepharose column, and affinity chromatography on a heparin-Sepharose CL-6B column. The partially purified factor was a heat- and acid-labile cationic protein with a molecular weight of 100,000-150,000. Its effect was half-maximal at 3.8 micrograms/ml, and was additive with those of insulin and epidermal growth factor. HGF in ascites from patients with cirrhosis had the same properties as HGF purified and characterized from rat platelets. These findings suggest that HGF is secreted into the ascites from the plasma or liver of patients with cirrhosis and may increase in the plasma with the development of hepatic impairment and act in repair of the damaged liver of patients with chronic liver disease.     

Effects of IGF-I treatment on osteopenia in rats with advanced liver cirrhosis

IGF-I is an anabolic hormone which has been reported to increase bone formation in several conditions of undernutrition. Advanced liver cirrhosis is associated with osteopenia and also with low serum levels of IGF-I. Previous results showed that low doses of IGF-I increase osteoblastic activity and decrease bone reabsorption in early liver cirrhosis. The aim of this study was to evaluate whether IGF-I-treatment also induces beneficial effect on osteopenia associated with advanced cirrhosis. Rats with ascitic cirrhosis were divided into two groups: group CI (n=10) which received saline and group CI+IGF (n=10) which were treated with IGF-I (2 microg/100 g bw x day, sc, during 21 days). Healthy controls which received saline were studied in parallel (CO n=10). On the 22nd day, the animals were sacrificed, and bone parameters were analyzed in femur. Posterior-anterior diameter was similar in all groups. No significant differences were observed in bone content of calcium, total proteins, collagen and hydroxyapatite in cirrhotic rats as compared with controls. However, CI rats showed significant reductions in total bone density (-13.5%, p<0.001) assessed by densitometry and radiological study. In CI+IGF rat bone density (assessed by densitometry) improved significantly as compared with CI animals. In summary, osteopenia characterized by loss of bone mass and preserved bone composition was found in rats with advanced cirrhosis induced by CCl4 and phenobarbital in drinking water. This bone disorder is partially restored by treatment with low doses of IGF-I during only three weeks. Thus, IGF-I could be considered as a possible therapy for osteopenia associated with advanced liver cirrhosis.     

Long-term effectiveness of high-dosed ornithine-aspartate on urea synthesis rate and portal hypertension in human liver cirrhosis

Summary The effectiveness of ammonia reducing amino acids on hyperammonemia and hepatic encephalopathy is well known in patients suffering from liver cirrhosis. Data concerning long-term therapy on hepatic function and urea synthesis rate (UNSR) are still lacking. According to Vilstrup/Poulsen it is a good standard for functioning liver mass. Therefore, 25 patients with histologically proven liver cirrhosis and distinct portal hypertension were treated daily with 9 gr. ornithinasparte over 13 years (8–20 years). Shunt operations, esophageal varicosis sclerosis, or portal pressure reducing medication were not applied. Rigorous alcohol abstinence and 60 gr protein/day were prescribed. During the investigation, 3 laparoscopies and 4 liver biopsies were performed, on the average, on each individual. Significant improvements of clinical and biochemical results (Child-Pugh-Index; Composite Clinical and Laboratory Index) were obtained during the long-term therapy with ornithine-aspartate. Esophageal varicosis II–III was either reduced to 0-I or totally eliminated. Also significant was an increased urea synthesis rate and a decreased hyperammonemia.A plausible explanation for the long-term therapy effectiveness with ornithine-aspartate is the possible recovery of the functioning mass without hepatic size increase. Also important is the rigorous alcohol abstinence. It leads to a significant reduction of portal hypertension in patients suffering from alcohol induced liver cirrhosis (Reynolds, own observations).Additional favorable factors are intensive muscle training and absence of gastrointestinal bleeds.     

The source of ascitic fluid in experimental cirrhosis in the rat.

In order to disclose the source of ascitic fluid in liver cirrhosis, normal and cirrhotic rats were injected with fluorescein into the paracecal vein. The green fluorescence was then evaluated on the surface of the liver, the intestine and the peritoneum. Among healthy rats and in those with anascitic cirrhosis a very slight fluorescence was detected on the liver capsule whereas among rats with ascitic cirrhosis a distinct fluorescence was shown on the liver surface, the small intestine and the peritoneum. Therefore, the peritoneum is a source of ascitic fluid in cirrhosis of the rat.     

Expression and distribution of the prolactin receptor in normal rat liver and in experimental liver cirrhosis.

Recent results have suggested a role for prolactin (PRL) as a regeneration factor in the liver. In order to investigate the involvement of prolactin in the pathogenesis of liver cirrhosis, we studied the expression of the prolactin receptor (PRLR) and PRL during the development of cirrhosis in an animal model. 30 male rats were exposed to CCl4 by inhalation. Phenobarbitone was added to the drinking water to accelerate the formation of toxic metabolites by enzyme induction. Two control groups of 30 animals each were treated with phenobarbitone only or received no treatment. 10 animals of each group were sacrificed 35, 55, and 70 days after initiation of treatment. Liver tissue was subjected to histological examination, which demonstrated fibrosis of different grades and cirrhosis in the CCl4-treated rats. Expression of PRLR mRNA was investigated by mRNA extraction, RT-PCR and computer-supported densitometric evaluation. Compared to control liver, PRLR mRNA was expressed at a higher level in fibrotic and cirrhotic liver specimens. In normal tissue, immunohistochemical staining showed a high concentration of PRLR around the central vein and in the epithelium of the bile ducts. This pattern of distribution was lost in fibrosis and cirrhosis. An accumulation of PRLR was demonstrated within the damaged cells. Neither PRL nor PRL mRNA was detectable in normal, fibrotic, or cirrhotic liver. We conclude that PRLR is distributed in normal rat liver in a typical pattern which is lost with increasing fibrosis. PRL is not produced by rat liver, indicating that PRL does not act through autocrine or paracrine mechanisms.