Liver regeneration and tumor growth in the rat after partial hepatectomy

Tumor growth of Yoshida sarcoma implanted in the remnant liver was studied in rats subjected to a hepatectomy. After 70 percent hepatectomy, the liver progressively regenerated and the total liver weight was reverted to by 10 days after the operation. Concomitantly with liver regeneration, tumor growth in the remnant liver was stimulated significantly, compared with that in the sham-operated liver. Incorporation of tritiated thymidine into tumor cells in the remnant liver was strikingly high and progressive, while that in the sham-operated liver was low and retained. Mitomycin C given to the hepatectomized rats was more effective against the tumor in the remnant liver than in the sham-operated liver. We conclude from this study that cancer cell proliferation in the remnant liver can be accelerated by the process of liver regeneration.     

Liver pathology and cell proliferation after calcineurin inhibitors and antiproliferative drugs following partial hepatectomy in rats

Immunosuppressants are the cornerstones of treatment after solid organ transplantation. This study investigated the pathology and cell proliferation following partial hepatectomy (PH) in rats undergoing immunosuppressive treatment. After 1 day, all rats were subjected to 70% PH. Groups A and B (n = 10) received calcineurin inhibitors subcutaneously: either FK506 or cyclosporine (CyA). Groups C and D (n = 10) received antiproliferative drugs: either mycophenolate mofetil (MMF) or sirolimus (SRL) by gavage. A control group (n = 5) received 1 mL of tap water daily. On postoperative day 2, all rats were sacrificed to obtain liver tissue for pathologic examination. Using immunohistochemistry we separately examined the hepatectomy surface and the liver parenchyma. In the parenchyma, the Ki-67 indices were higher in the CyA and FK506 groups and lower in the SRL and MMF groups compared with controls (P < .01). CyA had the highest and MMF the lowest values. On the hepatectomy surface, Ki-67 indices and TGF-alpha expressions were higher in the CyA group and lower in the SRL and MMF groups compared with the control group (P < .01). Slightly higher values in the FK506 group were not significantly different compared with the control group (P > .05). All groups other than FK506 showed prominent cholangiolar epithelial phenotypes compared with the control group. In the CyA and SRL groups, the number of cholangiolar cells was higher (P < .01), and in the MMF group lower than in the control group (P < .01). Among all groups, SRL had the highest values.     

肝切除术后肝再生对大鼠结肠癌肝转移灶生长的影响

目的 探讨肝再牛进程触发大鼠结肠痛肝转移残肝内隐性转移灶进展的发生机制.方法 采用肝包膜下种植建立结肠癌肝转移大鼠模型,随机分为假手术组、37%肝切除组和70%肝切除组;采用腹膜后注射建市结肠癌腹膜后转移模型,随机分为假手术组和70%肝切除组.手术后3周处死动物,测定肝内转移瘤量、再生肝重及腹膜后瘤结节重.在含有肝切除后24 h和14 d的门静脉血清培养基中进行结肠癌细胞Lovo体外培养,5.溴脱氧尿核苷(5-BrdU)DNA掺入法检测细胞增殖反应.结果 手术切除明显促进70%肝切除组肝内残留癌牛长(P<0.05),对37%肝切除组肝内残留癌和结肠癌腹膜后转移瘤牛长无促进作用(P>0.05);肝切后24 h门静脉血清组5-BrdU DNA掺人率从第72小时开始增加,至第120小时呈持续增加趋势(P<0.05);肝切后14 d门静脉血清对结肠癌细胞生长无明显刺激作用(P>0.05).结论 结肠癌肝转移切除术后可诱发肝内微小残留灶的进展,并不通过血液循环全身性释放,对肝外转移瘤并不发挥作用.肝切除范围与诱发肿瘤生长有关,只有肝切除达到一定程度时,才足以刺激肿瘤生长.     

Gadolinium pretreatment decreases survival and impairs liver regeneration after partial hepatectomy under ischemia/reperfusion in rats

BACKGROUND: Modulation of Kupffer cell functions by treatment with gadolinium chloride protects the liver against reperfusion injury. However, its effect on liver regeneration after hepatectomy under ischemia/reperfusion has not been studied. Using a common clinical ischemia/reperfusion technique, we examined the effect of gadolinium on liver regeneration after hepatectomy in rats. METHODS: After an initial 15-minute ischemia and 15-minute reperfusion, 70% hepatectomy was performed during the second 15-minute ischemia period in gadolinium-pretreated (gadolinium group) and saline solution--pretreated (control group) rats. The 24-hour survival rate, relative liver weight, DNA synthesis rate, and hepatic adenosine triphosphate level were examined immediately after hepatectomy and on postoperative days (PODs) 1, 2, 3, and 7. Serum levels of total bilirubin, glutamic pyruvic transaminase, and endotoxin were also measured. RESULTS: The 24-hour survival rate was significantly lower in the gadolinium group (67%) than in the control group (100%). On POD 1, the relative liver weight and DNA synthesis rate were significantly lower in the gadolinium group than in the control group. On POD 1, serum total bilirubin and endotoxin levels were significantly higher in the gadolinium group than in the control group. Immediately after hepatectomy, the hepatic adenosine triphosphate level was significantly lower in the gadolinium group than in the control group. CONCLUSIONS: Under ischemia/reperfusion, gadolinium pretreatment impairs liver regeneration and energy status after hepatectomy and decreases postoperative survival.     

Role of the Fas system in liver regeneration after a partial hepatectomy in rats.

Apoptosis is involved in the homeostatic control of organs. The aim of this study was to define the in vivo role of apoptosis-related proteins including the Fas system and Bcl-2 in liver regeneration following a partial hepatectomy (PH). We used 70% hepatectomized rats which were serially sacrificed from 12 h to 28 days. The expressions of Fas, Fas ligand, and Bcl-2 were examined by semiquantitative RT-PCR and immunohistochemistry. Liver regeneration, as examined by PCNA staining, peaked from 24 h to day 3, and declined from day 5. On the other hand, hepatocyte apoptosis, as examined by TUNEL staining, was seldom observed until 24 h, but increased from 1 week after PH. In the RT-PCR study, Fas showed an early decline by 24 h, followed by a later peak from days 3 to 5, and then a constant expression thereafter. Meanwhile, the Fas ligand was also low until day 3, but showed a remarkable increase from days 5 to 7, followed by a gradual decrease. On the other hand, Bcl-2 showed an early peak until 24 h, followed by a decline from day 5. In an immunohistochemical study, the time courses of these protein expressions were almost synchronous with their mRNAs in the RT-PCR study. We thus conclude that the coordinated interplay between these apoptosis-related proteins and hepatocyte apoptosis suggests the possible involvement of these proteins in the course of liver regeneration.     

异甘草酸镁对肝硬化大鼠肝部分切除术后肝功能及肝再生的影响

目的 研究异甘草酸镁对肝硬化大鼠部分肝切除术后肝功能和肝再生的影响.方法 45只肝硬化Wistar大鼠行2/3肝部分切除,并随机分为对照组(A组)、治疗组(B组)、术前3 d治疗组(C组).手术当天起,B组给予腹腔注射异甘草酸镁(60mg·kg-1·d-1),A组给予同等剂量生理盐水,C组在手术前3 d即给药(60 mg·kg-1·d-1).各组大鼠分别于术后1、2、7 d处死,检测肝功、血清肝细胞生长因子(HGF)及磷脂酶A2(PLA2)、5-溴脱氧尿苷(BrdU)标记指数、肝再生率.结果 A组在术后第1天,BrdU标记指数及HGF均低于C组(分别t=2.831,3.427,均P＜0.05),而PLA2高于B、C组(分别t=2.794,2.902,均P＜0.05);在术后第2天A组BrdU标记指数均低于B、C组(分别t=2.736,3.083,均P＜0.05),HGF水平与其他两组比较,差异均无统计学意义,PLA2仍高于B、C组(分别t=2.794,2.902,均P＜0.05);A组术后第1、2天ALT、AST、TP水平及肝再生率与B、C组比较,差异均无统计学意义;术后第7天A组AST高于其他两组(A组与B组比较t=4.508,P＜0.05;A组与C组比较t=2.967,P＜0.05),TP水平及肝再生率则均低于B、C组(TP:A组与B组比较t=2.838,P＜0.05;A组与C组比较t=2.743,P＜0.05);肝再生率:(A组与B组比较t=3.316,P＜0.05;A组与C组比较t=4.093,P＜0.05),而BrdU标记指数、HGF、PLA2三组间比较,差异均无统计学意义.B组术后第1天BrdU标记指数及HGF均低于C组(t=2.831,P＜0.05;t=2.836,P＜0.05).结论 异甘草酸镁可降低肝硬化大鼠部分肝切除术后转氨酶水平,改善肝脏功能,促进肝细胞增生.     

Changes in hepatic venous oxygen saturation related to the extent of regeneration after partial hepatectomy in rats

BACKGROUND: Changes in hepatic oxygen metabolism in relation to the extent of liver regeneration are expected after partial hepatectomy. There are few reports, however, about hepatic oxygen metabolism during liver regeneration. In this study, we evaluated changes in hepatic oxygen metabolism related to the regeneration rate, and the relationship between hepatic venous oxygen saturation (Shvo2) and liver regeneration after partial hepatectomy. METHODS: The work was done using 50% hepatectomized rats with continuous infusion of octreotide for inhibition of liver regeneration or with saline as control. The hepatic hemodynamics, oxygen metabolism, and Shvo2 levels as well as the regenerating liver status were evaluated for 3 days after hepatectomy. RESULTS: Administration of octreotide resulted in a significant reduction of the regenerating liver weight on days 1 and 3 after hepatectomy compared with the control group. Significantly decreased DNA synthesis and proliferating cell nuclear antigen labeling index were also found on day 1. Meanwhile, hepatic oxygen consumption (HVO2) and oxygen extraction ratio were significantly decreased in the octreotide-treated group on day 1. In contrast, the Shvo2 levels in the octreotide-treated group were significantly higher than those in the control group, and were inversely correlated with the HVO2. CONCLUSION: The remnant liver demands an increased amount of oxygen in relation to the extent of regeneration, and changes in the Shvo2 are inversely correlated with the HVo2. Therefore, monitoring the Shvo2 could be useful for estimating liver regeneration after partial hepatectomy.     

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.     

Expression of MRP2 and MRP3 during liver regeneration after 90% partial hepatectomy in rats

BACKGROUND: Small-for-size grafts often cause persistent conjugated hyperbilirubinemia in the recipient after adult-to-adult living donor liver transplantation, but the cause has not yet been clarified. In physiologic status, bilirubin is excreted from hepatocytes to the bile canaliculus by means of multidrug resistance protein (MRP) 2 and, in particular circumstances, by means of MRP3 to the sinusoidal space. The aim of this study was to research whether there is any change in bilirubin excretion pattern during liver regeneration with reference to expression of MRP2 and MRP3. METHODS: Sprague-Dawley rats underwent sham operation (n=37), 70% hepatectomy (n=38), or 90% hepatectomy (n=37). The degree of liver regeneration, total and direct bilirubin, protein synthesis, and interleukin (IL)-6 were serially assessed. Expression of MRP2 and MRP3 were semiquantified by Western blotting. RESULTS: The proliferating cell nuclear antigen labeling index indicated rapid liver regeneration after 70% and 90% hepatectomy. Serum levels of total and direct bilirubin increased significantly (P<0.05), and conjugated hyperbilirubinemia was proved only in the 90% hepatectomy group. Coagulation factor VII dipped but increased as early as 12 to 24 hr postoperatively in both hepatectomy groups. Plasma IL-6 levels were significantly increased in the 90% hepatectomy group (P<0.05). Expression of MRP2 was decreased and MRP3 was expressed at 36 and 72 hr postoperatively in the 90% hepatectomy group, whereas no change was observed in MRP expression in the 70% hepatectomy group. CONCLUSIONS: During liver regeneration after critical hepatectomy such as 90% hepatectomy, decrease of MRP2 and expression of MRP3 may play an important role in postoperative hyperbilirubinemia.     

Liver regeneration after atypical hepatectomy in the rat. A comparison of CO2 laser with scalpel and electrical diathermy

Rats were subjected to partial hepatic lobectomy with removal of about two thirds of the liver either by scalpel, by CO2 laser, or by electrical diathermy. Macroscopic examinations of livers at various days after surgery indicated that CO2 laser surgery results in minor tissue damage, reduced complications from inflammation and infections, and faster healing compared to electrical diathermy, but it is less satisfactory than the scalpel with respect to all these parameters. Rat liver regeneration was followed at the molecular level by measuring the changes of protein biosynthesis activity in the liver, as monitored by modifications of ribosome organization. Activation of the protein biosynthesis process started 1 day after surgery when hepatectomy was performed by scalpel, while 2 days were required when CO2 laser or electrical diathermy were used instead.     

肝切除联合肝动脉切除对梗阻性黄疸大鼠肝细胞再生和凋亡的影响

目的 探索在梗阻性黄疸时,不同范围肝切除联合肝动脉切除对肝细胞再生和凋亡的影响.方法 155只雄性SD大鼠行胆总管结扎制备梗阻性黄疽模型,5 d后二次手术分为:胆肠再通内引流组;肝切除(42%、70%)联合胆肠再通内引流组;肝切除(42%,70%)联合肝固有动脉切除、胆肠再通内引流组.动态观察二次手术后24 h、72 h、7 d肝组织HGF、bcl-2 mRNA含量及蛋白表达、肝细胞增殖和凋亡指数的变化,并统计各组死亡率.结果 高胆红素血症、行胆肠冉通内引流的同时,大鼠肝切除或肝切除联合肝动脉切除后,肝再生均受抑制,凋亡增多;较之肝切除组和42%肝切除联合肝固有动脉切除组.70%肝切除联合肝固有动脉切除组术后肝组织HGF、bcl-2 mRNA含量显著减少,肝细胞再生明显受抑而凋亡显著增多,死亡率显著增高(P<0.05).结论 高胆红素血症时,肝切除量是影响大鼠肝切除联合肝动脉切除实施安全性的重要因素,42%肝切除联合肝固有动脉切除、胆肠再通内引流,对肝细胞再生和凋亡影响较小,安全町行;70%肝切除联合肝动脉切除、胆肠再通内引流后肝细胞再生显著受抑制,凋亡增多,死亡率高,应避免实施.     

细胞外信号调节激酶和蛋白激酶B在去势大鼠阴茎海绵体的表达

目的:研究细胞外信号调节激酶(Erk1/2)和蛋白激酶B(PKB/Akt)在去势大鼠阴茎海绵体中的表达及活性,探讨其在去势大鼠勃起功能障碍(ED)发生中的作用机制。方法:20只8周龄雄性SD大鼠随机分成假手术组(A组)和去势组(B组),术后4周检测两组大鼠血清睾酮(T)水平,免疫组化及RT-PCR检测磷酸化Erk1/2和磷酸化PKB/Akt活性蛋白(累积光密度/面积,IA/Area)及Erk1/2、Akt mRNA(内参为GAPDH)在大鼠阴茎海绵体中的表达。结果:术后4周B组血清T水平[(1.339±0.642)nmol/L]较A组[(10.090±3.026)nmol/L]显著降低(P<0.05),Erk1/2和PKB/Akt在两组大鼠阴茎海绵体中均有表达,Erk1、Erk2的mRNA和磷酸化Erk1/2蛋白的相对表达量在B组(0.840±0.062、0.876±0.141、0.142±0.020)较A组(0.479±0.090、0.599±0.100、0.119±0.029)显著升高(P均<0.05);PKB/Akt mRNA和磷酸化PKB/Akt蛋白的相对表达量在B组(0.974±0.040、0.164±0.036)与A组(0.942±0.054、0.162±0.025)差异无显著性(P>0.05)。结论:Erk1/2及PKB/Akt在去势组及假手术组大鼠阴茎中均有表达。去势大鼠阴茎海绵体磷酸化Erk1/2表达增强与ED发生有关。     

重组人生长激素对肝硬化大鼠肝部分切除术后生长激素/胰岛素样生长因子-1轴的影响

目的探讨rhGH对肝硬化大鼠肝部分切除术后GH/IGF-1轴的影响。方法6只正常大鼠作为正常对照组,24只肝硬化大鼠随机分为术前组6只,肝部分切除术后1d组6只,肝部分切除后行PN5d组6只,肝部分切除术后行rhGH+PN5d组6只。测大鼠肝功能、血糖及血清GH、IGF-1、IGFBP-3水平,用RT-PCR法检测肝ALBmRNA、IGF-1mRNA、IGFBP-3mRNA的表达。肝组织行Ki67免疫组化染色。结果与PN组比较,rhGH+PN组血清ALP显著下降(P<0·05),血清ALB显著升高(P<0·05),血糖显著升高(P<0·05),血清GH、IGF-1、IGFBP-3水平显著升高(P<0·05),肝ALBmRNA、IGF-1mRNA表达水平显著升高(P<0·05),肝Ki67指数也显著升高(P<0·05)。且血清GH水平与血糖呈正相关(P<0·05),血清IGF-1、IGFBP-3水平与血清AST、ALT、ALP呈负相关(P<0·05),与血清ALB量正相关(P<0·05)。结论rhGH可以改善肝硬化大鼠肝部分切除术后GH/IGF-1轴,血清IGF-1、IGFBP-3水平有助于判断营养支持的效果。     

FR167653 improves survival and pulmonary injury after partial hepatectomy under ischemia/reperfusion in rats.

BACKGROUND: FR167653 is a potent suppressant of production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, which play an important role in hepatic and pulmonary injury due to ischemia/reperfusion of the liver and in liver regeneration after hepatectomy. We examined the effects of FR167653 on hepatectomy under ischemia/reperfusion in rats. METHODS: After initial 15-min ischemia and 5-min reperfusion, 70% hepatectomy was performed during the second 15-min ischemia period in FR167653-treated (FR group) and saline-treated (saline group) rats. The survival rate, relative liver weight, TNF-alpha, IL-1 beta, DNA synthesis rate of the remnant liver, and histological change and adhesion molecule (ICAM-1) of the lung were examined. Serum glutamic pyruvic transaminase and hepatic malondialdehyde were also measured. RESULTS: Expressions of TNF-alpha and IL-1 beta in the remnant liver were significantly inhibited in the FR group compared to the saline group. The survival was significantly better and pulmonary damage was less in the FR group after hepatectomy under ischemia/reperfusion. ICAM-1 expression of the lung was not altered after hepatectomy and was not significantly different between the two groups. Liver regeneration and injury were not significantly different between the two groups. CONCLUSION: FR167653 does not affect liver injury and regeneration after hepatectomy under ischemia/reperfusion, while it ameliorates pulmonary injury and improves the survival.     

HGF和SAM对慢性肝损伤大鼠肝部分切除术后肝细胞的影响

目的:比较肝细胞生长因子（HGF）和S-腺有蛋氨酸（SAM）对大鼠慢性肝损伤时肝部分切除术后肝再生和肝功能的影响,为临床应用提供依据。方法:以四氯化碳和乙醇联合诱导大鼠慢性肝损伤模型,成模后大鼠行30%肝部分切除术,然后随机分为肝硬化对照组,HGF组,SAM组,HGF+SAM组。手术当天起,肝硬化组肌内注生理盐水2 mL/d,HGF组予腹腔注射肝细胞生长因子0.65 mg/（100g·d）,SAM组予肌内注SAM20 mg/（kg·d）,HGF+SAM组同时按上述方法和剂量注射2种药物。各组大鼠分别于术后15d被处死,取血检测AST,ALT,ALB和TB; 同时在光镜及电镜下观察肝组织的病理改变及超微结构变化。结果:HGF组,SAM组,HGF+SAM组术后15 d AST,ALT,TB明显低于肝硬化组(P＜0.05),ALB水平明显高于肝硬化组(P＜0.05); 而HGF组,SAM组,HGF+SAM组3组之间无统计学差异。结论:肝硬化的大鼠肝脏行部分肝切除术后,肝功能及肝储备功能均有一定程度的受损,肝脏再生亦有障碍。HGF和SAM都可促进术后肝细胞再生。     

Preoperative internal biliary drainage is superior to external biliary drainage in liver regeneration and function after hepatectomy in obstructive jaundiced rats

OBJECTIVE: To examine the differences in regeneration rates and functions of the liver at the time of and after hepatectomy in obstructive jaundiced rats with preoperative external and internal biliary drainage. SUMMARY BACKGROUND DATA: The significance of biliary drainage before surgery is controversial in patients with obstructive jaundice. METHODS: After biliary obstruction for 7 days, rats were randomly divided into three groups: obstructive jaundice and hepatectomy (OJ-Hx), external biliary drainage and hepatectomy (ED-Hx), and internal biliary drainage and hepatectomy (ID-Hx). The OJ-Hx group underwent hepatectomy without biliary drainage; the other two groups underwent hepatectomy after biliary drainage for 7 days. At the time of hepatectomy, all rats were provided with internal biliary drainage. On days 0, 1, 2, 3, and 7 after hepatectomy, the DNA synthesis rate and the concentrations of adenine nucleotides and malondialdehyde in the liver were determined as markers of the hepatic regeneration rate, energy status, and lipoperoxide concentration, respectively. Portal endotoxin concentrations were measured and serum hyaluronic acid concentrations were determined as an indicator of hepatic endothelial function. RESULTS: The relative liver weight was significantly higher in the ID-Hx group than in the OJ-Hx group on days 1, 3, and 7 after hepatectomy and than in the ED-Hx group on days 1 and 2. The rate of hepatic DNA synthesis was significantly higher in the ID-Hx group than in the OJ-Hx and ED-Hx groups on day 1. The rate was similar in the ED-Hx and ID-Hx groups on day 2 but was significantly higher than in the OJ-Hx group. The hepatic malondialdehyde concentration was significantly higher on day 1 in the ED-Hx group than in the other two groups. It was lowest in the ID-Hx group throughout the study. Both biliary drainage procedures lowered the portal endotoxin concentration and serum hyaluronic acid concentration at the time of hepatectomy. The serum hyaluronic acid concentration was lowest in the ID Hx group. Hepatic adenine triphosphate concentrations and energy charge levels were similar among the three groups. CONCLUSION: Although both external and internal biliary drainage before hepatectomy improved serum liver function tests, portal endotoxin concentration, and serum hyaluronic acid concentration at the time of surgery, preoperative internal biliary drainage was superior to external drainage, as evidenced by the better liver regeneration and function after hepatectomy.     

Beneficial effects of prostaglandin E(1) incorporated in lipid microspheres on liver injury and regeneration after 90% partial hepatectomy in rats

The aim of this study was to assess how the administration of prostaglandin E(1) incorporated in lipid microspheres (Lipo PGE(1)) affects liver injury and regeneration after massive hepatectomy in rats. Two hundred and eight male Wistar rats underwent 90% partial hepatectomy. Lipo PGE(1) of 1, 10 or 30 microg/kg were administered intraperitoneally at 6 h prior to and 0 and 6 h after hepatectomy. Postoperative increases in serum GOT, total bilirubin, IL-6 and plasma endotoxin levels were significantly suppressed by Lipo PGE(1). The depressed phagocytic index and arterial ketone body ratio and hepatic DNA synthesis after 90% partial hepatectomy were significantly enhanced by Lipo PGE(1), which resulted in the improvement of survival. Lipo PGE(1) might bring about a protective effect on liver injury and an enhancement of liver regeneration after massive hepatectomy.