Expression of anti-apoptotic protein, Bcl-2, in liver regeneration after a partial hepatectomy

BACKGROUND: Although Bcl-2 is well known to have anti-apoptotic activities in vitro and in vivo, the role of Bcl-2 relating to liver regeneration remains controversial. The aim of this study was to document the effect of Bcl-2 expression on liver regeneration in rats undergoing a partial hepatectomy. MATERIAL AND METHODS: Adult male Wistar rats (n = 4/group) at 72 h before undergoing a 70% partial hepatectomy (PH) were administered 1 x 10(9) plaque-forming units of adenovirus vector encoding either human Bcl-2 (group 1) or LacZ (group 2) intravenously and were sacrificed at 0, 12 h, and at 1, 2, 3, 7, 14, and 21 days postoperatively. In group 3, normal saline was injected instead of adenovirus vector. Liver regeneration was monitored by measuring the restituted liver mass and proliferating cell nuclear antigen (PCNA) immunostaining. The incidence of apoptosis in the liver was analyzed by the immunohistochemical detection of single-stranded DNA at 14 and 21 days postoperatively. RESULTS: The restituted liver mass showed significantly higher values in group 1 (26.1 +/- 7.2%) than in group 2 (14.7 +/- 6.8%) and 3 (13.6 +/- 5.0%) at 1 day after PH (P < 0.05). The PCNA labeling index was significantly higher in group 1 (47.2 +/- 9.9%) than in groups 2 (19.0 +/- 7.8%) and 3 (19.2 +/- 15.2%) at 1 day after a partial hepatectomy (P < 0.05). The hepatocyte growth factor (HGF) mRNA expression was significantly lower in group 1 than in group 2 at 12 h after PH (P < 0.05). The number of single-stranded DNA-positive cells decreased significantly more in group 1 (5.67 +/- 1.53 positive cells/10 fields per tissue) than those in group 2 (18.33 +/- 7.57 positive cells/10 fields per tissue) at 14 days after PH. CONCLUSIONS: These results thus indicated that an overexpression of anti-apoptotic protein Bcl-2 does not necessarily have an anti-apoptotic effect on liver regeneration but appears to have a pro-proliferative effect in the early phase of liver regeneration.     

人血管内皮生长因子165对肝硬化大鼠肝部分切除术后余肝再生能力的影响

目的 观察外源性人血管内皮生长因子165( VEGF165)对肝硬化大鼠肝部分切除术后余肝再生及肝功能恢复的影响.方法 采用基因重组技术构建人VEGF165慢病毒表达载体,传统CCl4诱导法制备大鼠肝硬化模型;126只肝硬化大鼠行50％肝切除术后随机分为3组:A组(VEGF165组)、B组(空病毒组)、C组(对照组),分别于术前、术后12、24、72 h、7、14、28 d检测各组大鼠余肝组织VEGF165 mRNA与蛋白的表达、肝再生率、细胞核抗原(PCNA)阳性表达率及门静脉血液中丙氨酸转氨酶(ALT)与天冬氨酸转氨酶(AST)含量.结果 人VEGF165慢病毒表达载体成功构建且可使大鼠肝脏表达VEGF165 mRNA及蛋白;肝硬化大鼠模型制模成型率为96.18％;VEGF165组术后72 h至术后28 d肝再生率分别为(34.98±6.22)％、(62.19±1.81)％、(83.54±4.50)％、(92.23±4.41)％,术后24h至术后28 d PCNA阳性表达率分别为(18.05 ±0.92)％、(42.89±5.52)％、(35.56±3.86)％、(26.37±1.35)％、( 19.48±2.70)％均显著高于对照组(P＜0.01);术后72 h至术后28 d血清ALT含量分别为(258.14±12.94)、(215.67±22.12)、(175.92±8.78)、(133.26±13.92) U/L,血清AST含量分别为(553.34±14.10)、(481.37±14.74)、(425.95±5.04)、(388.29±15.99) U/L均较对照组明显下降(P＜0.01).结论 外源性人VEGF165可促进肝硬化大鼠肝部分切除术后余肝的再生及肝功能的恢复.     

肝再生增强因子促进肝再生的细胞信号途径研究

目的探讨肝再生增强因子（ALR）促进肝部分切除（PH）后再生的机制。方法采用肝再生率评价ALR对PH后肝再生的作用；MTT检测ALR协同肝再生大鼠血清对肝细胞增殖和ALR对TGF-β1抑制肝细胞增殖的作用；免疫组化观察再生肝中ALR的表达；免疫细胞化学和Western blot检测经ALR刺激后肝细胞中ALR表达变化。结果ALR明显促进PH后的肝再生，可协同肝再生大鼠血清促进肝细胞增殖；ALR能拮抗TGF-β1对肝细胞增殖的抑制；ALR主要表达于正常肝细胞浆内；PH后2～3d肝细胞ALR减少甚至消失，第6天随着肝再生的完成，ALR含量又恢复正常；ALR刺激后肝细胞内源性ALR表达增高。结论ALR能以自主分泌方式从肝细胞中释放，与间质细胞产生的肝再生调控因子相互作用，如抑制TGF-β1生物活性，间接促进PH后的肝再生过程。     

两种肝再生模型肝切除术后肝再生指数和肝再生度的实验研究

【摘要】目的　探讨大鼠肝细胞增殖介导肝再生和卵圆细胞增殖介导肝再生两种不同大鼠肝再生模型肝切除术后肝再生指数和肝再生度变化的情况。方法　SD 大鼠随机分为2组: ①肝细胞增殖介导肝再生模型组(PH)②卵圆细胞增殖介导肝再生模型组(2AAF/PH) ,计算两组模型肝切除术后4、8、12、16、20天残肝肝再生度及肝再生指数。结果　两组肝再生度、肝再生指数均在第4天明显升高,12天左右达到高峰,超过再生总量的2/3以上,至20天基本达到原肝重。在4、8、12天同一时间点内,PH组肝再生度比2AAF/PH组高（P<0.05）,而到16天时,2AAF/PH组肝再生度则比PH组高（P<0.05）。在4、8天同一时间点内,PH组肝再生指数比2AAF/PH组高（P<0.05）。在12、16、20天同一时间点内,两组肝再生指数无显著性差异(P>0.05)。结论　肝再生度与肝再生指数是评价肝再生质量变化较直观和准确的指标,肝再生度在反映肝再生规律方面要比肝再生指数更准确。     

术后肝再生进程中肝细胞脂肪聚积相关性基因的筛查分析

目的观察肝部分切除术(PH)后肝再生过程中肝细胞一过性脂肪聚积相关性基因的表达谱。方法小鼠随机分为70%PH组(按术后时间分为0-72 h时相小组,每小组5只)和假手术组(分组同前)。不同时相点获取的肝组织分别实施油红O染色的肝细胞脂聚积分析和RNA制备。用cDNA微阵列法筛查并用实时RT-PCR确认PH组和假手术组各时相点(0～24 h)生脂基因的诱导表达情况。结果与假手术组和手术组0 h等时相点比较,PH后的12 h和24h时相点的油红O染色明显增强。经cDNA微阵列筛查并经实时RT-PCR独立确认的、仅在PH后6 h和或12 h时相点诱导表达的生脂基因有:Adipsin、AP2、S3-12和FSP27。结论术后肝再生过程中,肝细胞在聚积大量脂肪之前启动了一个与脂肪聚积相关的生脂基因表达程序。     

索拉非尼对肝癌术后早期肝再生的影响

目的研究索拉非尼对肝癌患者术后早期肝再生、肝功能及凝血功能的影响,以及癌旁肝组织的血管内皮生长因子受体2（VEGFR-2）、血管内皮生长因子受体3（VEGFR-3）、血小板衍生的生长因子受体β（PDGFR-β）和原癌基因丝苏氨酸蛋白激酶1（C-Raf-1）的表达水平与肝再生的关系。方法 30例经病理确诊为肝细胞癌的患者,手术切除后接受不同剂量索拉非尼治疗。应用CT测量术后肝脏体积变化,比较不同剂量的索拉非尼对术后1、3个月时肝再生率的影响。分析不同剂量下,服药前及服药后1个月、3个月时患者肝功能及凝血功能的变化。通过免疫组化检测癌旁肝组织中VEGFR-2、VEGFR-3、PDGFR-β和C-Raf-1的表达,分析表达水平与术后1、3个月时肝再生率的相关性。结果索拉非尼服药剂量400 mg/d组的患者术后1个月、3个月时肝再生率平均增加量高于800 mg/d组的患者（P〈0.05）。两组患者服药后3个月时血清AST、ALT明显比服药前升高,血清凝血酶原时间（PT）明显延长（P〈0.05）。术后1、3个月时肝再生率与VEGFR-2、PDGFR-β表达呈负相关（P〈0.05）,VEGFR-2表达对肝再生率的影响最大。结论索拉非尼对肝癌术后早期肝再生有抑制作用,剂量越大抑制效果越明显。VEGFR-2是索拉非尼抑制早期肝再生的主要影响因素。     

Steroid administration before partial hepatectomy with temporary inflow occlusion does not influence cyclin D1 and Ki-67 related liver regeneration

Background and aims If temporary inflow occlusion is required during liver resection, the postoperative course might be complicated by ischaemia–reperfusion injury. Steroids protect against ischaemia–reperfusion injury; however, due to its anti-proliferative character concerns exist on its use on liver regeneration after resection. We investigated the effects of methylprednisolone on hepatocyte proliferation after partial hepatectomy with temporary inflow occlusion.Patients and methods Prior to surgery, one group of Wistar rats received methylprednisolone, while a second group served as non-treated controls. Ischaemia–reperfusion injury was indicated by AST, ALT, and GLDH at 6 h after surgery. Immunohistochemistry tools were used to determine the mitotic index and Ki-67 expression, while cyclin D1 expression characterized the proliferative activity on days 1, 4, 7, and 10.Results The post-ischaemic liver enzyme release had significantly decreased in the methylprednisolone group, while expression of cyclin D1, percentage of Ki-67-positive cells, and mitotic cell index were comparable in both groups. Similar results were found for bilirubin and albumin and for weight of proliferating liver.Conclusion Although steroid administration significantly reduced ischaemia–reperfusion-associated tissue injury, it has no apparent effects on hepatic regeneration. Thus, steroids could be recommended if a temporary liver ischaemia is required during surgery, in order to reduce complications caused by severe ischaemia-related organ dysfunction.     

肝脏类器官构建及其对小鼠部分肝切除术后肝再生的作用#br#

目的 观察肝脏类器官对小鼠部分肝切除术后肝再生的作用。方法 体外构建肝脏类器官,通过形态学、PCR和免疫荧光对类器官进行初步鉴定。C57BL/6小鼠随机等分为对照组和治疗组,每组18只。对照组进行肝左叶、中叶切除术+肝包膜注射200 μL PBS;治疗组进行肝左叶、中叶切除术+肝包膜移植200 μL类器官悬液。建模成功后分别于术后第1、4、7天收集标本。通过血清生化检测、免疫组化和Western blotting评估肝脏类器官对小鼠肝部分切除术后肝再生的作用。结果 类器官体外培养3 d,从直径20 μm的囊性结构扩增到约125 μm的细胞团（P＜0.05）,直径扩增近6 倍。肝脏干细胞标志基因EPCAM、SOX9和CK19明显上调（P＜0.05）,传代前后基因保持稳定。免疫荧光显示CK8、Desmin、AFP和PCNA呈阳性。HE显示术后第4天,治疗组肝细胞形态大小基本恢复正常,形态较清晰,无炎症细胞浸润,无脂肪或气球样变。对照组小鼠肝细胞核仁染色加深,仍有炎性细胞浸润,部分区域存在肝细胞坏死区。免疫组化Ki67和Western blotting对增殖水平进行检测,结果显示治疗组增殖能力是对照组的3 倍。肝功能检测发现治疗组在术后第4天ALT、AST、TBIL和DBIL明显下降,ALB合成增加（P＜0.05）。结论 具有肝脏干细胞属性和增殖能力的肝脏类器官,能通过保护肝细胞、改善部分肝切除术后小鼠肝功能,发挥促进肝再生作用。     

Intraabdominal bacterial infections significantly alter regeneration and function of the liver in a rat model of major hepatectomy

Background No systematic investigations of interactions of postoperative infections and liver regeneration after resection are available. Materials and methods Male Sprague–Dawley rats underwent sham operation, 70% partial hepatectomy (PH), cecal ligation and puncture (CLP), or synchronous PH + CLP and were killed at regular intervals. Liver regeneration and function were measured by the mitotic index, Bromo-deoxy-uridine labeling, and Ki-67 as well as bilirubin, albumin, and indocyanine green plasma disappearance rate. The inflammatory response was evaluated by determination of IL-1β and myeloperoxidase (MPO) activity. Bacterial concentrations in different organs were quantified. Results Simultaneous CLP + PH resulted in a significantly delayed regeneration kinetic, which was most pronounced at 24 h. This was preceded by hyperinflammation with increased liberation of pro-inflammatory cytokines in the PH + CLP group at 6 h. After 48 h, the pro-inflammatory response declined, and regeneration proceeded also in the PH + CLP group. Liver function was found impaired in both groups; however, it was significantly worse in the PH + CLP group. Especially after 48 h, when regeneration peaked in this group, liver function significantly declined. At 96 h, only minor differences were seen, but the persistently elevated proliferative activity indicated the delay of regeneration after PH + CLP. Conclusion The present analysis shows that infectious conditions delay liver regeneration. Our data suggest a cross-linkage of both conditions via the functional liver capacity. A direct role of microorganisms seems unlikely; however, the inhibitory effect of the pro-inflammatory cytokines may be involved. Best abstracts — Surgical Forum 2007.     

Mechanism of postoperative liver failure after excessive hepatectomy investigated using a cDNA microarray

Background/Purpose: Excessive hepatectomy often causes fatal liver failure. We have reported that this is mainly mediated by apoptosis, characterized pathologically by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) assay-positive hepatocytes and a ladder pattern in DNA fragmentation assays. Methods: To investigate the mechanism, we used cDNA microarray analysis to compare clearly differentiated rat partial hepatectomy (PHx) models (90%PHx, and 95%PHx). All 90%PHx rats survived, but the 95%PHx animals died of hepatic failure within 96 h. Remnant liver was obtained at four time points (1, 3, 12, and 24 h after PHx). After RNA extraction, two samples were labeled with different fluorescent dyes and hybridized to the Institute of Physical and Chemical Research (RIKEN) set of 18 816 full-length enriched mouse cDNA arrays. Scanning for fluorescent dye signals was performed, and the mRNA expression ratio of the two models was examined. Results: Genes of the p21 cyclin-dependent kinase (CDK) inhibitor, Fas, interleukin (IL)-18, and many caspases were upregulated at 1 h after PHx in the 95%PHx group. On the other hand, genes of Bcl-2, heat shock proteins, and glutathione-S-transferase were downregulated. Conclusions: We concluded that fatal hepatic failure after excessive hepatectomy was characterized by increased apoptosis and diminished liver regeneration. Received: July 25, 2001 / Accepted: November 16, 2001     

The role of polyamines in liver regeneration after hepatectomy with ischemic injury

A total of 175 rats were divided into: (1) a sham operation group, in which the liver was slightly mobilized after laparotomy; (2) a control group in which 68% of the liver was resected without the blockade of blood flow; (3) an ischemia + hepatectomy group, in which the vessels entering the right and caudate lobes were clamped for 30 min, and the nonischemic lobes were resected; (4) a DFMO + ischemia + hepatectomy group, in which the same procedure as for the ischemia + hepatectomy group was performed, but the animals received α-difluoromethylornithine (DFMO); (5) a DFMO + Put + ischemia + hepatectomy group, in which the animals underwent the same procedure, but were given putrescine (Put) in addition to DFMO. There were 6 to 7 rats in each of the five groups. The putrescine level and ornithine decarboxylase (ODC) activity were significantly higher in the ischemia + hepatectomy group than in the control group, but were markedly decreased in the DFMO + ischemia + hepatectomy group. However, the lipid peroxide level was significantly higher in the DFMO + ischemia + hepatectomy group than in the ischemia + hepatectomy group. The incorporation of [³H]thymidine in the DFMO + ischemia + hepatectomy group was significantly lower than that in the control group. The increase in the lipid peroxide level and the decrease in [³H]thymidine found in the DFMO + ischemia + hepatectomy group tended to be reversed by the administration of putrescine. These results suggest that putrescine suppressed the production of lipid peroxides and promoted DNA synthesis in regenerating the liver after ischemia-reperfusion injury.     

Increased intraabdominal pressure impairs liver regeneration after partial hepatectomy in rats

BACKGROUND: There are many experimental studies showing that increased intraabdominal pressure (IAP) reduces liver blood flow, leading to ischemia and portal venous congestion. But, there is no study evaluating the effect of increased IAP on liver regeneration. It is well known that acute liver ischemia and portal venous congestion impair liver regeneration. We, therefore, aimed to determine the effect of increased IAP on liver regeneration in this study. METHODS: Sprague-Dawley rats underwent partial hepatectomy with or without IAP of 12-14 mm Hg for 24 h or sham operation. Rats were randomly divided into six groups: two sham-operated groups, two hepatectomy groups, and two hepatectomy with increased IAP groups. Mitotic index, proliferating cell nuclear antigen (PCNA)-labeling index, and liver regeneration rate as liver regeneration parameters were studied on day 1 or on day 4 after operation. Additionally, serum aspartate transaminase (AST) level and histopathological changes in intestinal mucosa were studied. RESULTS: Hepatectomy with/without increased IAP groups had significantly higher serum AST levels than the sham-operated group on day 1. Serum AST level was found to be significantly higher in the hepatectomy with increased IAP group than in the other groups on day 4. Intestinal mucosal injury was found in the hepatectomy with increased IAP groups on days 1 and 4. Mitotic index and PCNA-labeling index were markedly higher in all hepatectomy with/without increased IAP groups than in the sham-operated groups. However, together with liver regeneration rate, both indices were significantly less in the hepatectomy with increased IAP groups than in the hepatectomy groups both on day 1 and on day 4. CONCLUSION: Maintenance of IAP between 12 and 14 mm Hg for 24 h impaired liver regeneration after partial hepatectomy in rats.     

乙酰肝素酶siRNA对部分肝切除大鼠术后肝再生的抑制作用

目的探讨乙酰肝素酶(HPSE)siRNA对部分肝切除大鼠术后肝再生的抑制作用。方法设计合成HPSE siRNA,以vivo-jetPEI-Gal为载体转染70%肝切除大鼠,以逆转录-聚合酶链反应(RT-PCR)检测转染后HPSE mRNA表达,以Western blot检测AFP、ALB、CK-18和CK-19蛋白表达,以原位末端标记法(Tunel)检测肝细胞凋亡,以免疫组化检测肝组织增殖细胞核抗原(PCNA)表达,并测定肝再生率。结果与各对照组相比,siRNA干扰组HPSE mRNA表达明显降低,AFP、ALB、CK-18和CK-19蛋白表达明显降低,肝细胞凋亡指数明显增高,增殖指数明显降低,肝再生率明显降低,差别显著(P0.05)。结论 siRNA沉默HPSE表达后,部分肝切除大鼠术后肝再生受到明显抑制,提示HPSE对肝再生具有调控作用。     

Impact of hepatic vein deprivation on liver regeneration and function after major hepatectomy

Background and aims In extended liver resections, the preservation of vascular and biliary structures of the entire remnant liver is of paramount importance. The impact of venous outflow impairment and its consequences for liver regeneration and function are still a matter of debate. Materials and methods Rats (n = 75) were subjected to a 90% partial hepatectomy (PH), to a 70% liver resection with narrowing of the hepatic outflow of an additional 20% parenchyma (70%+ PH) or to an anatomic 70% PH. Postoperatively hepatocyte proliferation (Ki-67), liver function and survival were assessed. Gene expression analysis for markers of regeneration was determined by in-house complementary (DNA) arrays and quantitative real-time polymerase chain reaction (RT-PCR). Results Ninety percent PH led to a greater regenerative response as shown Ki-67 compared to animals with a 70%+PH (p < 0.05). However, liver function was equally impaired in both groups. Rats with 70% PH showed a greater proliferation index with less hepatic injury and better liver function. While mortality was 0% in the group of 70% PH, rats with 90% PH and 70+PH had a reduced survival of 75% (p < 0.05) Conclusion Venous outflow obstruction leads to an impairment of liver regeneration and liver function. In cases with critically small liver remnants, restoration of an adequate venous outflow may be mandatory.     

大鼠肝切除术后肝损伤程度与肝再生状态的动态对比研究

目的：探讨肝切除术后肝损伤程度与肝再生状态的关系。方法：Wistar大鼠随机分为三组：（1）假手术组；（2）正常大鼠肝切除组；（3）肝硬化大鼠肝切除组，建立大鼠肝切除模型，观察围手术期血清和肝组织匀浆液中丙氨酸转氨酶（ALT）和天冬氨酸转氨酶（AST）水平、肝重／体重、肝再生率，以及应用免疫组化方法（SABC法）检测肝组织中增殖细胞核抗原（PCNA）的表达。结果：与正常大鼠相比，肝切除后肝硬化大鼠血清ALT和AST水平升高显著，持续时间较长（P＜0．05）；PCNA在肝切除后肝组织的表达显著延迟（P＜0．05），血清ALT和AST水平与肝再生率呈显著负相关（P＜0．05）。结论：肝损伤程度和肝再生状态呈负相关，肝损伤的程度影响肝再生状态，肝切除后检测血清ALT、AST水平的变化可以间接的了解肝再生情况。     

Reactive oxygen species derived from NADPH oxidase system is not essential for liver regeneration after partial hepatectomy

BACKGROUND: There is suggestive evidence that reactive oxygen species may play a role in the initiation of liver regeneration via a kupffer cell-mediated mechanism involving TNFa and NF-kappa B. In mammalian cells, a major source of reactive oxygen species derives from the membrane-bound NADPH oxidase system (no protein de novo synthesis is required) and it is known that the low levels of oxidants produced through NADPH oxidase play a role in liver cell proliferation because of peroxisome proliferators. METHODS: We used knockout mice lacking Cybb: subunit of NADPH oxidase to determine whether signaling at the start of liver regeneration after partial hepatectomy (PH) involves reactive oxygen species produced through NADPH oxidase and to analyze in more detail the abnormalities caused by lack of its component, which is required for the initiation of liver regeneration. RESULTS: Lack of Cybb had little effect on NF-kappa B and STAT3 binding, and no effect in TNFa and interleukin-6 production after PH. Cybb KO mice had normal liver structure and similar levels of hepatocyte DNA replication as those of wild type mice. CONCLUSIONS: We conclude that NADPH oxidase is not necessary for liver regeneration after PH. It is likely that there is a potential pathway not including NADPH oxidase to activate NF-kappa B and STAT3 binding for the initiation of liver regeneration after PH.     

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.     

Possible inhibitory mechanism of liver regeneration through non-parenchymal cells after combined hepatectomy and pancreatectomy

BACKGROUND: Recently, simultaneous hepatectomy (Hx) and pancreaticoduodenectomy have been performed in the treatment of biliary tract cancer. Postoperative hepatic failure is a common and potentially fatal complication. The aim of this study was to examine the reduced rate of liver regeneration after 70% Hx alone or in combination with 70% pancreatectomy (HPx). MATERIALS AND METHODS: Male Sprague-Dawley rats underwent Hx or combined Hx and Px. The ratio of liver-body weight, labeling index of hepatocytes in vivo, and DNA synthesis of hepatocytes and/or Kupffer cells in primary culture were analyzed. RESULTS: The ratio of liver-body weight in HPx rats was found to be significantly lower than that in Hx rats from 12 hours to 72 hours after surgery. There was no difference in blood glucose or ALT levels between the two groups. An inhibitory effect on DNA synthesis was observed in cocultured hepatocytes and Kupffer cells when portal plasma obtained one hour after surgery was added. We further observed that conditioned medium of Kupffer cells stimulated by portal plasma obtained one hour after HPx inhibited DNA synthesis by hepatocytes. This effect was abolished after incubation at 56 degrees C for 30 min. CONCLUSIONS: These results clearly indicate the existence of a growth inhibitory factor in portal serum after HPx. This heat-labile growth inhibitory factor was released from Kupffer cells stimulated by portal plasma after HPx and appears to act on hepatocytes in a paracrine manner.     

大块肝切除后急性肝损伤治疗的研究

将６０只大鼠随机分为２组，一组腹腔内注射肝细胞生长因子（ＨＧＦ）和１，６二磷酸果糖（ＦＤＰ），另一组代之以生理盐水做为对照，分别于术后３、７、１４天检测血清酶学变化、胃泌素含量和体外肝细胞培养蛋白质合成及ＤＮＡ合成。结果发现：治疗组大鼠术后３天ＡＬＴ较对照组迅速降低（Ｐ＜０．０１）；血浆脯肽酶（ＰＬＤ）在术后７天、１４天低于对照组（Ｐ＜０．０５）；血清胃泌素测定在术后３天、７天治疗组高于对照组（Ｐ＜０．０１）；肝细胞体外原代培养￣３Ｈ－亮氨酸掺入法显示治疗组术后３天蛋白质合成明显高于对照组（Ｐ＜０．０１）；￣３Ｈ－ＴｄＲ掺入肝细胞ＤＮＡ合成，治疗组术后各期均非常显著高于对照组（Ｐ＜０．０１）。结果证实大鼠大块肝切除后应用ＨＧＦ和ＦＤＰ，对急性肝损伤有重要的治疗作用。     

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.