Prevention of ischemia-reperfusion-induced hepatic microcirculatory disruption by inhibiting stellate cell contraction using rock inhibitor

BACKGROUND: We demonstrated that hepatic stellate cells (HSCs) isolated from rat livers exposed to warm ischemia are significantly contractile when compared with HSCs from intact rat livers. This suggests that ischemia-reperfusion (IR)-induced impairment of sinusoidal microcirculation results, at least in part, from contraction of HSCs. METHODS: Rho-associated coiled-coil forming protein serine/threonine kinase (ROCK) is one of the key regulators of HSCs motility. Therefore we investigated whether Y-27632, a p160ROCK-specific inhibitor, has beneficial effects on warm IR injury in an in vivo rat partial liver IR model and a rat orthotopic liver transplantation model. RESULTS: After reperfusion following 90 min of warm ischemia, livers in untreated control rats had persistent congestion and impaired mitochondrial respiration, as demonstrated by increasing deoxy-hemoglobin and reduced cytochrome oxidase contents in the hepatic tissues using in vivo near-infrared spectroscopy. Serum levels of transaminase and endothelin (ET)-1 in these rats were markedly increased 1 hr after reperfusion. In contrast, when Y-27632 (3-30 mg/kg) was administered orally, hepatic tissue contents of deoxy-hemoglobin and cytochrome oxidase rapidly normalized. In such animals, the elevation of serum transaminase levels, but not that of ET-1 levels, was significantly suppressed. This is consistent with in vitro data demonstrating that Y-27632 causes HSCs to undergo relaxation even in the presence of ET-1. Moreover, in a rat orthotopic liver transplantation model, Y-27632 pretreatment dramatically improved the survival of recipients with liver grafts subjected to 45 min of warm ischemia. CONCLUSIONS: Y-27632 attenuates IR-induced hepatic microcirculation disruption by inhibiting contraction of HSCs.     

ROCK inhibitor Y-27632 prevents primary graft non-function caused by warm ischemia/reperfusion in rat liver transplantation

Hepatic stellate cells (HSCs) can easily be activated by ischemia/reperfusion, and this activation results in hepatic microcirculatory disturbance by cell contraction. ROCK is one of the key regulators of the motility of HSCs, and Y-27632 suppresses the activation of HSCs. We examined whether Y-27632 treatment prevents primary graft non-function caused by 45-min warm ischemia in orthotopic liver transplantation (OLT). Donor and recipient rats were administered Y-27632 (3-30 mg/kg). Y-27632 treatment at 30 mg/kg in both donor and recipient prevented congestion of the grafted livers, as demonstrated by analysis of hemoglobin (Hb) content in the grafted livers, using in-vivo near-infrared spectroscopy. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and hyaluronic acid at 4 h after OLT in the 30-mg/kg Y-27632-treated group were significantly lower than those in the control group. Specimens from the untreated control recipients showed sinusoidal congestion and massive fresh hepatocyte necrosis, whereas specimens from the Y-27632-treated recipients demonstrated minimal histological changes. Moreover, Y-27632 pre-treatment dramatically improved the survival of recipients. These results suggest that Y-27632 would be clinically useful for preventing liver failure associated with ischemia/reperfusion in liver transplantation.     

Liver cirrhosis in rats: regeneration and assessment of the role of phenobarbital

A common model for producing experimental liver cirrhosis is the administration of CCl4 to phenobarbital (PhB)-stimulated rats. However, concern may arise due to the complex actions of PhB upon liver metabolism. This study examined the role of PhB in the production of CCl4-induced liver cirrhosis in the rat. In addition, regenerative capacity of the liver after partial hepatectomy (PH) or portal branch ligation (PBL) was studied in cirrhotic rats, rats treated with CCl4 alone, and in PhB-treated controls. In rats given PhB throughout the CCl4-induction period, ascitic form of micronodular cirrhosis was found in 93% with only 3% mortality. In contrast, rats pretreated with PhB for only 2 weeks followed by CCl4 alone for 18 weeks did not develop liver cirrhosis. In most of the cirrhotic rats, PH induced hepatic regeneration associated with improved liver histology. PBL was less effective. Treatment with PhB alone for 10 weeks resulted in liver atrophy and reduced hepatic regenerative capacity. Impaired regeneration response was also found in rats treated with CCl4 alone. In conclusion, treatment with PhB throughout the CCl4-induction period seems necessary for the production of liver cirrhosis in rats. However, prolonged treatment with PhB alone results in liver atrophy and an impaired regenerative response. Therefore, though necessary for the cirrhotic model, PhB by itself has negative hepatotrophic influences which questions the thoroughness of the PhB/CCl4 experimental model.     

Successful treatment of CCl4-induced acute liver failure with portal vein arterialization in the rat

BACKGROUND: Optimization of the conditions for regeneration is a major goal in the management of patients with acute liver failure (ALF). Previous observations suggested that hyperoxygenation of the liver may improve its regenerative capacity. Thus, this study aimed to determine whether an additional supply of oxygenated blood achieved by portal vein arterialization (PVA) is protective in rat ALF caused by toxin administration or hepatectomy. METHODS: Sprague-Dawley rats were subjected or not to PVA after CCl(4) intoxication or extended hepatectomy. PVA was performed by interposing a stent between the left renal artery and splenic vein after left nephrectomy and splenectomy. Liver injury was evaluated by the serum ALT level and necrotic cell count. Hepatocyte regeneration was assessed by calculating the mitotic index and bromodeoxyuridine (BrdU) staining. The 10-day survival was assessed in separate experimental groups. RESULTS: The pO(2) in portal blood increased significantly following PVA. In the CCl(4)-induced ALF, serum ALT levels and necrosis were significantly reduced in arterialized than non-arterialized rats. PVA greatly promotes liver regeneration in both models. Finally, PVA significantly improved survival compared to controls (CCl(4): 100 versus 40%; 90% hepatectomy: 90 versus 30%). Interestingly, in the CCl(4)-induced ALF, survival was 100% even when the shunt was closed after 48 h. CONCLUSION: These data indicate that the additional supply of arterial oxygenated blood through PVA promotes a rapid regeneration leading to the resolution of toxic-induced massive liver necrosis and a faster restoration of liver mass after partial hepatectomy in rats. Thus, PVA may represent a novel tool for optimizing hepatocyte regeneration.     

Study on chronic renal injuries induced by carbon tetrachloride: selective inhibition of the nephrotoxicity by irradiation.

Carbon tetrachloride (CCl4) was intraperitoneally injected into Balb/c mice 4 times at biweekly intervals, and the morphological changes of the liver and kidney were examined during 12 weeks after the last injection. The renal injuries progressed in spite of cessation of CCl4 treatment; microcysts with tubular-cell degeneration were manifest on day 42 after the last injection of CCl4. At the end of the experiment, however, interstitial fibrosis with inflammatory cell infiltration was much more prominent. Glomerular changes with IgG deposits also developed following the tubulointerstitial changes. The CCl4 treatment induced liver damage as well, but it promptly subsided without formation of cirrhosis. The CCl4 nephrotoxicity was completely inhibited by whole body irradiation (200 rad) exposed at each injection of CCl4. In contrast, the hepatic damage was not changed by irradiation. These results seem to indicate etiologic independence of renal and hepatic events induced by CCl4 treatment. It is also suggested that chronic CCl4 nephrotoxicity is mediated, at least in part, by radiosensitive responses of the mice themselves.     

骨髓单个核细胞经门静脉移植对大鼠肝纤维化的减轻作用

目的 对比研究骨髓单个核细胞经门静脉移植治疗大鼠肝硬化的疗效,为临床应用提供依据.方法 采用四氯化碳(CCl4)综合法制作Wisrar大鼠肝硬化模型,8周后经病理检查证实成模者共20只进入实验.随机分为治疗组和对照组,每组10只,两组大鼠分别经门静脉注入骨髓单个核细胞和等体积的肝素生理盐水.各组大鼠继续皮下注射CCl4(CCl4使用方法与前述造模方法相同),在原环境下继续饲养4周后处死.切取肝组织分别作HE及Masson染色.疗效评价指标包括:①一般情况;②肝脏羟脯氨酸和胶原纤维含量;③肝纤维化病理学分级.结果 (1)治疗组大鼠一般情况改善;对照组无明显改变.(2)治疗组与对照组中肝脏羟脯氨酸含量分别为(0.50±0.12)g、(0.59±0.34)g;胶原纤维含量百分数分别为(3.75±0.98)%、(5.02±0.44)%.两组之间各指标均有统计学差异(P<0.05).(3)治疗组肝纤维化病理分级也有下降,治疗前后差异明显(P<0.05),而对照组无明显变化.表明治疗组行骨髓单个核细胞移植后大鼠肝纤维化程度减轻.结论 骨髓单个核细胞肝内移植能改善大鼠肝纤维化程度,为临床肝硬化的治疗带来了新的手段.     

Impairment of activation of hepatocyte growth factor precursor into its mature form in rats with liver cirrhosis

BACKGROUND: Hepatocyte growth factor (HGF) has a crucial role in liver regeneration following injury. The conversion of an inactive precursor form of HGF (proHGF) into a biologically active form (mature HGF) is essential, as HGF is involved in the recovery of liver damage. Liver regeneration is markedly poor in patients with liver cirrhosis after resection. We hypothesized that impairment of liver regeneration in cirrhosis is in part because of the absence of activation of proHGF to mature HGF. Studies were performed to clarify the molecular form of HGF in the liver of rats with fibrosis/cirrhosis before and after liver resection. METHODS: Rat models of liver fibrosis/cirrhosis were induced by intraperitoneal administration of dimethylnitrosamine, followed by 45% partial hepatectomy or sham operation. HGF was purified from the liver and plasma on a SP-Sepharose column and was analyzed by Western blotting. RESULTS: Production of proHGF in the liver increased in the following order: rats with normal liver, rats with fibrosis, and rats with cirrhosis. However, the levels of proHGF were similar after liver resection in the liver of these groups. A small but significant level of mature HGF was detected before resection in the fibrosis group, but not in the normal and cirrhosis groups. Liver resection increased the levels of mature HGF in the normal and fibrosis groups, but marginally in the cirrhosis group. CONCLUSIONS: These results demonstrate that the conversion of proHGF into mature HGF is impaired after liver resection in liver cirrhosis, while proHGF production is similar in the livers of normal, fibrosis, and cirrhosis groups. Acceleration of the processing of the HGF molecule may contribute to the improvement of liver dysfunction in cirrhosis.     

Reduction of hepatic ischemia/reperfusion-induced injury by a specific ROCK/Rho kinase inhibitor Y-27632

BACKGROUND: The low-molecular-weight GTPase Rho is known to act as a molecular switch by activating several downstream effectors, one of which is Rho-associated coiled-coil forming protein kinase (ROCK). ROCK/Rho kinase mediates cytoskeleton-dependent cell functions, such as actomyosin-based smooth muscle contraction and integrin-mediated cell adhesion. A specific inhibitor of ROCK/Rho kinase, Y-27632, was recently developed. The present study examined whether Y-27632 could provide a beneficial effect on hepatic ischemia/reperfusion (I/R)-induced injury through the attenuation of microcirculatory disturbance. MATERIALS AND METHODS: In male Sprague-Dawley rats, normothermic partial ischemia was induced by clamping the hepatic pedicle to the left and median lobes for 90 min, followed by 2 h of reperfusion. In the treatment group, Y-27632 was intravenously administered prior to ischemic insult. Hepatic microcirculation was investigated by using intravital fluorescence microscopy. Liver enzyme release and histological changes of the liver tissue were also evaluated. RESULTS: Y-27632 significantly improved sinusoidal perfusion and reduced the number of leukocytes sticking in hepatic sinusoids and adhering in postsinusoidal venules. The postischemic narrowing of both sinusoids and postsinusoidal venules was also markedly suppressed. Consequently, liver enzyme release was reduced and postischemic histological damage was suppressed. CONCLUSIONS: A specific ROCK/Rho kinase inhibitor, Y-27632, was useful to alleviate hepatic I/R-induced injury through ameliorating postischemic microcirculation. The administration of Y-27632 may be a novel strategy for conquering hepatic I/R-induced injury.     

Systemic infusion of FLK1(+) mesenchymal stem cells ameliorate carbon tetrachloride-induced liver fibrosis in mice

BACKGROUND: Fibrosis is the common end stage of most liver diseases, for which, unfortunately, there is no effective treatment available currently. It has been shown that mesenchymal stem cells (MSCs) from bone marrow (BM) could engraft in the lung after bleomycin exposure and ameliorate its fibrotic effects. This study was designed to evaluate the effect of Flk1 MSCs from murine BM (termed here Flk1 mMSCs) on fibrosis formation induced by carbon tetrachloride (CCl4). METHODS: A CCl(4)-induced hepatic fibrosis model was used. Flk1 mMSCs were systemically infused immediately or 1 week after mice were challenged with CCl(4). Control mice received only saline infusion. Fibrosis index and donor-cell engraftment were assessed 2 or 5 weeks after CCl(4) challenge. RESULTS: We found that Flk1 mMSCs transplantation immediately, but not 1 week after exposure to CCl(4), significantly reduced CCl(4)-induced liver damage and collagen deposition. In addition, levels of hepatic hydroxyproline and serum fibrosis markers in mice receiving immediate Flk1 mMSCs transplantation after CCl(4) challenge were significantly lower compared with those of control mice. More importantly, histologic examination suggested that hepatic damage recovery was much better in these immediately Flk1 mMSCs-treated mice. Immunofluorescence, polymerase chain reaction, and fluorescence in situ hybridization analysis revealed that donor cells engrafted into host liver, had epithelium-like morphology, and expressed albumin, although at low frequency. CONCLUSION: These results suggest that Flk1 mMSCs might initiate endogenous hepatic tissue regeneration, engraft into host liver in response to CCl(4) injury, and ameliorate its fibrogenic effects.     

Cryopreserved fetal liver cell transplants support the chronic failing liver in rats with CCl4-induced cirrhosis

Hepatocyte transplantation is a promising method for supporting hepatic function in a broad spectrum of liver diseases. The aim of this work was to test the efficacy of human fetal liver cells to support the chronic failing liver in an experimental model of carbon tetrachloride (CCl4)-induced cirrhosis in rats. Liver cirrhosis was induced by intraperitoneal administration of CCl4 at a dose of 0.2 ml (50% v/v solution)/100 g body weight, twice a week for 3 months in rats. Ten days after stopping CCl4 administration (experimental day 0), rats received intrasplenic injection of cryopreserved fetal liver cells (FLC, 1 x 10(7) cells in 0.3 ml medium). As a cirrhotic control group, CCl4-induced cirrhotic rats were used with intrasplenic injection of an equal volume of medium alone. Animals were sacrificed on experimental day 15. Human fetal liver cell transplantation almost completely prevented the death of cirrhotic animals during the 2 weeks after treatment, while high ongoing mortality was seen in the cirrhotic control group. Cell transplantation into the spleen normalized total bilirubin and TBARSs levels and increased albumin levels in blood serum, as well as restoring mitochondrial function and liver detoxification function (assessed by cytochrome P450 contents and activity) compared with the activities seen in the cirrhosis control group. In parallel with this restoration of biochemical and functional liver indices, morphological patterns of liver recovery or regeneration after liver cell transplantation were demonstrated in day 15 samples by light microscopy. These were absent in the group that had received only medium alone.     

Rho-Associated Kinase Inhibitor Reduces Tumor Recurrence After Liver Transplantation in a Rat Hepatoma Model

Tumor recurrence after liver transplantation still remains a significant problem in patients with hepatocellular carcinoma. The small GTPase Rho/Rho-associated kinase (ROCK) pathway is involved in the motility and invasiveness of cancer cells. We investigated whether tacrolimus activated the Rho/ROCK signal pathway to promote the invasiveness of rat hepatocellular carcinoma cells. We also investigated whether the ROCK inhibitor Y-27632 suppressed tumor recurrence after experimental liver transplantation in a rat hepatocellular carcinoma model. Orthotopic liver transplantation was performed in hepatocellular carcinoma cell line McA-RH7777-bearing rats. Tacrolimus was administered to liver transplant rats and these rats were divided into two groups: the Y-27632-treated (10 mg/kg, for 28 days) group and the Y-27632-untreated group. Tacrolimus enhanced the cancer cell migration and stimulated phosphorylation of the myosin light chain (MLC), a downstream effector of Rho/ROCK signaling. Y-27632 suppressed the cancer cell migration and tacrolimus-induced MLC phosphorylation. Suppression of tumor recurrence after liver transplantation and significant prolongation of survival were observed in the Y-27632-treated rats in comparison with theY-27632-untreated rats. Tacrolimus stimulates the Rho/ROCK signal pathway to enhance the invasiveness of hepatocellular carcinoma, and the ROCK inhibitor Y-27632 can be used as a new antimetastatic agent for the prevention of tumor recurrence after liver transplantation.     

Y-27632 prevents tubulointerstitial fibrosis in mouse kidneys with unilateral ureteral obstruction

BACKGROUND: The small GTPase Rho is involved in cell-to-substratum adhesion and cell contraction. These actions of Rho mediated by downstream Rho effectors such as Rho-associated coiled-coil forming protein kinase (ROCK) may be partly responsible for the progression of renal interstitial fibrosis. METHODS: The anti-fibrosis effects of Y-27632, a specific ROCK inhibitor, were studied both in vivo (unilateral ureteral obstruction; UUO) and in vitro. To investigate the therapeutic efficacy of Y-27632 in UUO kidneys, smooth muscle alpha actin (SMalphaA) expression, macrophage infiltration and fibrosis in the obstructed kidneys were studied. SMalphaA, transforming growth factor beta (TGF-beta), alpha1 (I) collagen, osteopontin, macrophage chemoattractant peptide-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) gene expression were examined by Northern blotting. To elucidate the mechanism linking the Rho-ROCK pathway with renal fibrosis, the effects of Y-27632 on in vitro cell proliferation and cell migration were studied. RESULTS: In vivo analysis showed that Y-27632 suppressed SMalphaA expression, macrophage infiltration and interstitial fibrosis, and that Y-27632 suppressed SMalphaA, TGF-beta and alpha1 (I) collagen mRNA expression. In vitro analysis showed that Y-27632 did not suppress proliferation of renal fibroblasts but suppressed migration of macrophages. CONCLUSIONS: The Rho-ROCK system may play an important role in the development of tissue fibrosis, and the Rho-ROCK signaling pathway may be a new therapeutic target for preventing interstitial fibrosis in progressive renal disease.     

A novel inhibitor of Rho-associated protein kinase,Y-27632, ameliorates hepatic ischemia and reperfusion injury in rats

BACKGROUND: A Rho-ROCK signal system induces vascular contraction and neutrophil migration, both of which are characteristic features found with ischemia and reperfusion injury of the liver. We tested our hypothesis that a novel ROCK I inhibitor, Y-27632, attenuates hepatic ischemia and reperfusion injury. METHODS: Rats underwent 70% partial hepatic ischemia for 120 minutes and subsequent reperfusion. Y-27632 of 10mg/kg was given orally 1 hour before ischemia, while distilled water was given to the control animals. One week animal survival, systemic hemodynamics, hepatic tissue blood flow, liver function tests, plasma endothelin-1, serum hyaluronic acid levels, myeloperoxidase activity and malondialdehyde level in liver tissue, membrane attack complex-1 and intracellular adhesion molecule-1 staining, and histological architecture were analyzed. RESULTS: Y-27632 prolonged 1-week animal survival from 25% of untreated animals to 75% accompanied with significant amelioration of hepatic tissue blood flow, liver function tests and histological architecture without any adverse effects on systemic hemodynamics. In addition, plasma endothelin-1 and serum hyaluronic acid levels decreased markedly compared to the control, concomitant with remarkable suppression of membrane attack complex-1 stain positive neutrophils infiltration, myeloperoxidase activity and malondialdehyde level. CONCLUSION: Present study suggests that activation of a Rho-ROCK signal system is associated with ischemia and reperfusion injury of the liver, and that Y-27632 may be an attractive agent for application in major liver resection using temporary inflow occlusion and hepatic preservation.     

Combination gene therapy of HGF and truncated type II TGF-beta receptor for rat liver cirrhosis after partial hepatectomy

BACKGROUND: In a cirrhotic liver, the regenerative ability and specific functions are impaired; a hepatic resection increases the possibility of postoperative liver failure. Hepatocyte growth factor (HGF) stimulates liver regeneration, accelerates restoration of hepatic function, and improves fibrosis. A truncated type II transforming growth factor-beta receptor (TbetaTR), which specifically inhibits TGF-beta signaling as a dominant-negative receptor, appears to prevent the progression of liver fibrosis. We demonstrated the therapeutic efficacy of adenovirus-mediated HGF and TbetaTR gene transduction after partial hepatectomy for liver cirrhosis. METHODS: Rats were treated with dimethylnitrosamine for 3 weeks, and they all had severe cirrhosis. After partial hepatectomy (10%), we injected adenovirus expressing bacterial beta-galactosidase (AdLacZ), adenovirus expressing a truncated type II TGF-beta receptor (AdTbetaTR), adenovirus expressing hepatocyte growth factor (AdHGF), or AdTbetaTR + AdHGF into the portal vein, which was followed by an additional 2-week dimethylnitrosamine treatment. RESULTS: On histologic examination, fibrotic tissue had decreased in the livers of the AdTbetaTR + AdHGF-treated rats compared with rats that were treated by AdLacZ, AdTbetaTR alone, and AdHGF alone. Liver function, which included serum levels of alanine aminotransferase, improved significantly in AdTbetaTR + AdHGF-treated rats compared with all other groups. The number of hepatocytes that were positive for proliferating-cell nuclear antigen was greater (P < .05) in AdHGF alone and AdTbetaTR + AdHGF-treated rat livers than in AdLacZ- and AdTbetaTR-treated rats. All AdTbetaTR + AdHGF-treated rats survived >60 days, and AdTbetaTR + AdHGF treatment markedly improved the survival rate after a partial hepatectomy. CONCLUSION: Our results suggest that the combination of HGF and TbetaTR gene therapy may increase the possibility of hepatectomy in a cirrhotic liver by improving fibrosis, hepatic function, and hepatocyte regeneration.     

Administration of rhHGF-activator via portal vein stimulates the regeneration of cirrhotic liver after partial hepatectomy in rats

BACKGROUND/AIMS: Cirrhotic liver has less ability to regenerate than normal liver, but it can produce the precursor of hepatocyte growth factor (proHGF) similarly to normal liver after resection. Studies were performed to examine whether the exogenous administration of recombinant human (rh) HGF-activator converts proHGF to biologically active (mature) HGF, inducing an enhancement of liver regeneration in cirrhosis. MATERIALS AND METHODS: Rats with liver cirrhosis were treated by 45% partial hepatectomy, and rhHGF-activator or vehicle was injected via the portal vein 24 h after resection. Liver injury and its regeneration, the conversion of proHGF to mature HGF, and the activation of its signal through HGF receptor (c-Met) were analyzed. RESULTS: rhHGF-activator improved the recovery of liver function after resection in cirrhotic liver as compared with the control group. rhHGF-activator also enhanced the proliferating cell nuclear antigen labeling index and liver regeneration rate. rhHGF-activator converted the proHGF to mature HGF, showing the maximal effect at 10 min after injection, which was followed by tyrosine phosphorylation of insulin receptor substrate (IRS)-1, and the association of IRS-1 with c-Met and phosphatidylinositol 3-kinase. CONCLUSIONS: Results demonstrate that the administration of rhHGF-activator stimulates the recovery of liver function and regeneration after resection in cirrhotic liver through the activation of proHGF and its intracellular signal. It may be potentially useful treatment for patients with liver cirrhosis.     

Anticholinesterase drugs stimulate smooth muscle contraction of the rat trachea through the Rho-kinase pathway

We performed this study to determine the effects of Rho-kinase inhibitors, Y-27632 and fasudil, on the anticholinesterase (anti-ChE)-induced contractile and phosphatidylinositol responses of the rat trachea. In vitro measurements of isometric tension and [3H] inositol monophosphate (IP1) that was formed were conducted by using rat tracheal rings or slices. Neostigmine- and pyridostigmine-induced contractions were almost completely inhibited by Y-27632 and fasudil at 30 microM each, whereas acetylcholine-induced contraction was inhibited incompletely, i.e., by 56% by Y-27632 and by 51% by fasudil, at 100 microM for each, respectively. The inhibitory effects of fasudil on neostigmine- and acetylcholine-induced contractions were completely reversed by calyculin-A, a myosin phosphatase inhibitor. Neostigmine-induced IP1 accumulation was attenuated by fasudil at 100 microM. The results suggest that anti-ChEs cause airway smooth muscle contraction, in part, through activation of the Rho-kinase pathway.     

Thioacetamide- and carbon tetrachloride-induced liver cirrhosis

Two methods of inducing liver cirrhosis in the rat were studied. Intragastric administration of CCl4 for 16 weeks according to Proctor and Chatamra was compared to the administration of thioacetamide in the drinking water (0.3 g/l) for the same period. CCl4 administration induced micronodular cirrhosis in 6/8 animals with a 27% mortality. Thioacetamide induced cirrhosis in 6/8 animals without mortality. The histologic pictures differed somewhat in that the CCl4 group exhibited more necrosis and cellular swelling while the thioacetamide group had more nuclear atypias and proliferation. Biochemically both groups had elevated plasma levels of aspartate aminotransferase. The lysosomal enzyme beta-hexosaminidase (beta-NAG) showed a transient increase in the thioacetamide animals, while beta-glucuronidase decreased. CCl4-induced cirrhosis led to an increase in beta-NAG. Plasma zinc decreased in both groups as well as liver zinc content in the CCl4 group, while there was a continuous elevation of liver zinc in the thioacetamide group. We conclude that oral administration of thioacetamide is a simple and reliable method of inducing experimental liver cirrhosis. The differences in histological appearances and some biochemical parameters may be caused by the different mechanisms of action of thioacetamide and CCl4.     

姜黄素抑制大鼠肝纤维化的研究

目的：探讨姜黄素抑制肝纤维化的效应及其分子机制。方法：培养大鼠肝星状细胞(HSC)并以刀豆蛋白(ConA)激活,再用不同剂量姜黄素处理;建立大鼠四氯化碳(CCl4)肝纤维化模型,以不同剂量姜黄素处理各模型动物,检测其血清透明质酸(HA)、层粘连蛋白(LN)、Ⅲ型前胶原(PCⅢ)和Ⅵ型胶原(Ⅵ.C)水平,检测肝组织纤维化程度和肝组织及HSC基质金属蛋白酶-2(MMP-2)的表达。结果：CCl4成功诱导肝纤维化大鼠模型。与模型组比较,姜黄素治疗后能降低血清肝纤维化各项指标(HA,LN,PCⅢ及Ⅵ.C)的表达（P<0.05）,肝组织纤维化评分明显降低（P<0.05）。姜黄素处理后,纤维化大鼠肝组织MMP-2呈剂量依赖性减少（P<0.05）,活化肝星状细胞MMP-2的表达呈剂量依赖性减少（P<0.05）。结论：姜黄素可通过减少MMP-2表达抑制大鼠肝纤维化。     

Risk of major liver resection in patients with underlying chronic liver disease: a reappraisal

OBJECTIVE: To explore the relation of patient age, status of liver parenchyma, presence of markers of active hepatitis, and blood loss to subsequent death and complications in patients undergoing a similar major hepatectomy for the same disease using a standardized technique. SUMMARY BACKGROUND DATA: Major liver resection carries a high risk of postoperative liver failure in patients with chronic liver disease. However, this underlying liver disease may comprise a wide range of pathologic changes that have, in the past, not been well defined. METHODS: The nontumorous liver of 55 patients undergoing a right hepatectomy for hepatocellular carcinoma was classified according to a semiquantitative grading of fibrosis. The authors analyzed the influence of this pathologic feature and of other preoperative variables on the risk of postoperative death and complications. RESULTS: Serum bilirubin and prothrombin time increased on postoperative day 1, and their speed of recovery was influenced by the severity of fibrosis. Incidence of death from liver failure was 32% in patients with grade 4 fibrosis (cirrhosis) and 0% in patients with grade 0 to 3 fibrosis. The preoperative serum aspartate transaminase (ASAT) level ranged from 68 to 207 IU/l in patients with cirrhosis who died, compared with 20 to 62 in patients with cirrhosis who survived. CONCLUSION: A major liver resection such as a right hepatectomy may be safely performed in patients with underlying liver disease, provided no additional risk factors are present. Patients with a preoperative increase in ASAT should undergo a liver biopsy to rule out the presence of grade 4 fibrosis, which should contraindicate this resection.     

脾切除对肝纤维化大鼠肝脏PDGF-B表达及血清PDGF-BB水平的影响

目的 研究脾切除对肝纤维化大鼠肝脏PDGF-B表达和血清PDGF-BB水平的影响,探讨脾切除在肝纤维化治疗中的作用.方法 大鼠皮下注射CCl4,建立65只肝纤维化大鼠模型.于建模开始、肝纤维化期以及肝硬化期三组切除大鼠睥脏,并设立同期假手术组作为对照组.第一、二组及其对照组于建模后第10周,第三组及其对照组于建模后12周分别取大鼠肝脏和血液标本.用免疫组化SABC法测定肝脏PIGF-B的表达.HE染色检测肝纤维化,用双抗体夹心ELISA法测定血清PIGF-BB水平.结果 各切脾组PDGF-B阳性细胞A值(光密度值)明显低于其对照组;各切脾组血清PDGF-BB含量明显低于其对照组.根据HE染色,建模开始时切脾再行肝纤维化诱导,肝纤维化进程缓慢;建模第5周切脾后,肝脏病理状态比对照组明显缓解;肝硬化期切脾后,肝脏炎性改变和纤维化程度有一定减轻.结论 早期脾脏切除对实验性肝纤维化有一定延缓作用.脾切除后PDGF水平的下降可能是造成该延缓的机制之一.

Abstract：

Objective To explore the effects of splenectomy on hepatic fibrosis and on the expression of PDGF-B in the liver and PDGF-BB in the serum of rats with hepatic fibrosis. Methods By hypodermic injection CCl4, we established 65 rat models with hepatic fibrosis, splenectomies were performed in the three groups at different phases: before hypodermic injection CCl4 (A group), five weeks after hypodermic injection CCl4 (B group), and ten weeks hypodermic injection CCl4 (C group). The control groups were established at the same time, with samples of the livers and serum of the rats taken in different phases. The expressions of PDGF in the liver were detected by immunohistochemistry technique and the degree of hepatic fibrosis was detected by HE staining. The serum levels of PDGF-BB were analyzed by ELISA technique. Results Absorbance values of PDGF-B in the experimental group were significantly lower than the control groups (P＜0. 05). Serum levels of PDGF-BB of the rats after splenectomy were significantly lower than those in the control groups (P＜0.05). HE and Masson's staining showed that the progression of Hepatic fibrosis was slow in the A group. Hepatic pathologic state was significantly relieved in the B group and the inflammation and fibrosis was relieved in the C group. Conclusion Earlier period splenectomy could delay the proceeding of experimental hepatic fibrosis. After splenectomy the decline in the level of PDGF may be one of the mechanisms causing the delay.