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1.
Liver tissue engineering using hepatocyte transplantation has been proposed as a therapeutic alternative to liver transplantation toward several liver diseases. We have previously reported that stable liver tissue with the potential for liver regeneration can be engineered at extrahepatic sites by transplanting mature hepatocytes into an extracellular matrix. The present study was aimed at assessing the liver tissue persistence after induced regeneration by hepatectomy and repeat regeneration potential induced by repeat hepatectomy. Mouse isolated hepatocytes mixed in EHS extracellular matrix gel were transplanted under both kidney capsules of isogenic mice. The hepatocyte survival persisted for over 25 weeks. In some of the mice, we confirmed that the grafted hepatocytes developed a thin layer of liver tissues under the kidney capsule, determined by specific characteristics of differentiated hepatocytes in cord structures between the capillaries. We then assessed the regenerative potential and persistence of the exogenous liver tissue. To induce liver regeneration, we performed a two-thirds hepatectomy at 70 days after hepatocyte transplantation. Three weeks after this procedure, the engineered liver tissues showed active regeneration, reaching serum marker protein levels of 261 +/- 42% of the prehepatectomy level. We found that the regenerated liver tissue was stably maintained for 100 days (length of the experiment). Repeat regeneration potential was established by performing a repeat hepatectomy (that had been two-thirds hepatectomized at day 70) 60 days after the initial hepatectomy. Again, the regenerated engineered liver tissues showed active regeneration as there was an approximately twofold increase in the serum marker protein levels. The present studies demonstrate that liver tissue, which was recognized as a part of the host naive liver in terms of the regeneration profile, could be engineered at a heterologous site that does not have access to the portal circulation.  相似文献   

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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.  相似文献   

3.
The concept of injury in liver regeneration after partial hepatectomy (PHx), and the reason hepatocytes that have not been directly injured regenerate, remain unclear. It is known that shear stress resulting from blood flow plays an important role in the mechanism of remodeling blood vessels, and portal pressure reflects shear stress. This study was conducted to determine whether acute portal hypertension (APH) can become a trigger of liver regeneration as shear stress following PHx in a rat model. Portal pressures became elevated immediately after 70% and 90% PHx, peaking on postoperative day (POD) 3, and thereafter decreasing in proportion to the diminution of liver regeneration. The portal pressures after 90% PHx were significantly higher than those after 70% PHx even on POD 7, while those of the portocaval (PC) shunt groups decreased following PC shunting both with and without 70% PHx. The liver/body weight (LW/BW) ratio also decreased in the PC shunt both with and even without 70% PHx. The gradient expressions of class I antigen on sinusoidal endothelial cells (SEC) were found only in the periportal area, which has the highest portal pressure in the healthy rat liver. However, after hepatectomy these expressions were detected from the periportal area to the central venous area. These results suggest that APH as shear stress following PHx may not only become a trigger of hepatocyte regeneration, but also of SEC regeneration, and that surplus APH induces liver dysfunction.  相似文献   

4.
Small residual liver volume after massive hepatectomy or partial liver transplantation is a major cause of subsequent liver dysfunction. We hypothesize that the abrupt regenerative response of small remnant liver is responsible for subsequent deleterious outcome. To slow down the regenerative speed, NS‐398 (ERK1/2 inhibitor) or PD98059 (selective MEK inhibitor) was administered after 70% or 90% partial hepatectomy (PH). The effects of regenerative speed on liver morphology, portal pressure and survival were assessed. In the 70% PH model, NS‐398 treatment suppressed the abrupt replicative response of hepatocytes during the early phase of regeneration, although liver volume on day 7 was not significantly different from that of the control group. Immunohistochemical analysis for CD31 (for sinusoids) and AGp110 (for bile canaliculi) revealed that lobular architectural disturbance was alleviated by NS‐398 treatment. In the 90% PH model, administration of NS‐398 or PD98059, but not hepatocyte growth factor, significantly enhanced survival. The abrupt regenerative response of small remnant liver is suggested to be responsible for intensive lobular derangement and subsequent liver dysfunction. The suppression of MEK/ERK signaling pathway during the early phase after hepatectomy makes the regenerative response linear, and improves the prognosis for animals bearing a small remnant liver.  相似文献   

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Enhanced effect on rat hepatocyte regeneration through activation of the reticuloendothelial system (RES) was investigated. RES was activated using by OK-432 and the phagocytic activity (K-value) increased 2-fold over control rats 24 hours after intraperitoneal injection of OK-432. In OK-432 treated rats, the amount of cyclic AMP in the regenerating liver also increased 1.5-fold higher than in control rats 14 hours after hepatectomy. After 70% partial hepatectomy, liver DNA synthesis in OK-432 treated rats increased 2 to 5-fold higher than in control rats. There was a good correlation between the K-value before hepatectomy and DNA synthesis 24 hours after hepatectomy (r = 0.96). Therefore the RES is one of the most important regulatory factors in liver regeneration. Augmentation of RES before hepatectomy may prevent hepatic failure after resection in liver diseases.  相似文献   

8.
BackgroundExcessive portal pressure after massive hepatectomy can cause hepatic sinusoidal injury and have deleterious impacts on hepatic functional recovery, contributing to developing post-hepatectomy liver failure. This study aimed to assess the effects of splanchnic vasoactive agents on hepatic functional recovery and regeneration while clarifying the underlying mechanism, using a 70% hepatectomy porcine model.MethodsEighteen pigs undergoing 70% hepatectomy were involved in this study and divided into three groups: control (n=6), terlipressin (n=6), and octreotide (n=6). Terlipressin (0.5 mg) and octreotide (0.2 mg) were administered 3 times a day for each group with the first dose starting just before surgery until the 7th postoperative day, at which time the surviving pigs were sacrificed. During the period, portal pressure, liver weight, biochemical analysis, histological injury score, and molecular markers were evaluated and compared between groups.ResultsThe 7-day survival rates in the octreotide, terlipressin, and control groups were 100%, 83.3%, and 66.7%, respectively. The portal pressures decreased in both terlipressin and octreotide groups than the control group at 30 minutes, 1 hour and 6 hours after hepatectomy. The amount of regeneration measured by liver weight to body weight ratio at the time of sacrifice in the terlipressin group was smaller than that in the control group (117% vs. 129%, P=0.03). Serum aspartate aminotransferase (AST) and total bilirubin levels at 1 and 6 hours after hepatectomy and prothrombin time/international normalized ratio (PT/INR) at 6 hours after hepatectomy were significantly improved in the terlipressin and octreotide groups compared to the control group. Serum endothelin-1 (ET-1) was significantly lower in the terlipressin group than that in the control group 6 hours after hepatectomy (P<0.01). The histological injury score in the control group was significantly higher than that in the terlipressin group on the 7th postoperative day (P<0.01).ConclusionsSplanchnic vasoactive agents, such as terlipressin and octreotide, could effectively decrease portal pressure and attenuate liver injury after massive hepatectomy.  相似文献   

9.
目的 观察70%门静脉分支高位结扎后大鼠肝组织细胞凋亡及相关基因Bax,Bcl-2的表达,以探讨肝细胞凋亡的发生机制.方法 Wistar大鼠60只,随机分成假手术对照组(n=30)和门静脉结扎组(n=30).观察术后第12小时和第1,2,3,7,14天的肝脏大体结构和血浆转氨酶的变化.用细胞凋亡原位末端标记技术(TUNEL)对结扎侧肝细胞凋亡进行定量分析,光学显微镜下观察未结扎侧肝细胞的增殖情况,采用逆转录-多聚酶链反应(RT-PCR)检测肝脏组织中Bax和Bcl-2 mRNA的表达.结果 70%门静脉分支高位结扎后,结扎侧肝叶以细胞凋亡的方式呈进行性萎缩变小,对侧则以有丝分裂的方式成比例地代偿性增生.全肝的总质量维持恒定,肝脏功能基本保持正常.结扎侧肝组织中以Bax mRNA的升高为主,而未结扎侧肝组织中以Bcl-2 mRNA的升高为主.结论 近70%门静脉分支高位结扎后,结扎侧肝脏由于Bax mRNA表达升高引起肝细胞大量凋亡,未结扎侧由于Bcl-2 mRNA表达升高引起肝细胞增殖,在维持全肝的质量和功能中具有重要意义.  相似文献   

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OBJECTIVE: The aim of this study was to assess the influence of severe steatosis with inflammation on hepatocellular recovery after 70% hepatectomy in a rat model of diet-induced steatosis. BACKGROUND: Patients with steatosis have an increased risk of inflammatory complications after liver resection. This might be attributable to Kupffer cell-mediated inflammation in steatotic livers causing progressive injury. METHODS: Male Wistar rats were fed a standard methionine- and choline-deficient diet for 1 or 5 weeks. A 70% partial hepatectomy (PH) was performed, after which rats were killed at 24, 48, or 72 hours. The extent of steatosis and inflammation was determined by assessment of hepatic triglycerides, cytokine content, and histopathology. Outcome parameters were: liver regeneration (MIB-5 proliferation rate, mitotic index, and regenerating liver mass), hepatocellular injury (plasma aminotransferases, lipid peroxidation, histopathology, and apoptosis), Kupffer cell-mediated proinflammatory response (TNF-alpha, IL-1beta, IL-6, IL-10 in plasma and liver) and antioxidant content (total glutathione). RESULTS: Methionine- and choline-deficient diet induced uncomplicated steatosis after 1 week (<30% hepatocytes affected without inflammation) and severe steatosis after 5 weeks (>60% hepatocytes affected, including prominent inflammation) as confirmed by histopathology. After PH, liver regeneration was impaired at all time points in the severe steatosis group as compared with the mild and control groups (P < 0.05). Hepatocellular injury was significantly increased in the severe steatosis group at all time points (P < 0.05). Kupffer cell-mediated inflammatory responses were aggravated in the severe steatosis group along with decreased antioxidant content (P < 0.05). Necrosis was the main type of cell death in severe steatotic livers compared with mainly apoptotic cell death in mild steatotic and normal livers. CONCLUSION: Steatosis with prominent inflammation impaired liver regeneration probably because of increased hepatocellular lipid peroxidation and damage in concert with Kupffer cell-mediated proinflammatory responses. These results suggest an increased risk of performing extensive liver resection in the presence of severe steatosis.  相似文献   

12.
The competition between the native and the grafted liver in heterotopic auxiliary liver transplantation (HALT) with portal vein arterialization (PVA) was investigated in a rat model. The experimental groups were: HALT with flow-regulated PVA and 70% resection of a native liver and graft (n = 32; group I) versus 70% liver resection (n = 32; group II). After HALT, the weight of the native liver increased until the sixth postoperative week (431% +/- 55% of the intraoperative weight), whereas, the graft weight was only 76% +/- 31% of the intraoperative weight at this time. In group II, liver weight increased continuously to 529% +/- 30% of the intraoperative weight after 6 weeks. On postoperative day 2, there was significantly increased proliferative hepatocellular activity in all groups. This was highest in the resected livers of group II, followed by the native livers of group I, and the grafts of group I (301 +/- 126 vs 262 +/- 97 vs 216 +/- 31 Ki-67-positive hepatocytes/10 visual fields). However, the differences between the groups were not significant. With regard to hepatocellular apoptosis, the livers were similar among all groups and at all time points, M30-positive hepatocyte counts were 相似文献   

13.
BACKGROUND: Liver regeneration after partial hepatectomy is regulated by several factors that activate or inhibit hepatocyte proliferation. A short period of ischemia-reperfusion (IR), called ischemic preconditioning (IPC), protects the liver against subsequent sustained ischemic insults. The present study investigated the effects of IPC on liver regeneration after partial hepatectomy under IR in rats. MATERIALS AND METHODS: Male Wistar rats were subjected to 45 min of total hepatic ischemia, and 70% hepatectomy was performed just before reperfusion. Animals were pre-treated with either IPC (10/15 min) (IPC + PHx group) or not (ischemia + PHx). The survival rate, serum transaminases, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-6 levels, hepatocyte proliferation and histological change of the remnant liver were measured in both groups and compared with non-ischemic controls subjected to 70% hepatectomy alone (PHx group). RESULTS: The survival rate was significantly better in the IPC + PHx group than in the ischemia + PHx group. Furthermore, IPC reduced liver injury determined by liver histology and serum transaminases. There was an early rise in serum TNF-alpha and IL-6 levels in the ischemia + PHx group. Compared with non-ischemic controls, IPC significantly decreased TNF-alpha, but not IL-6 during the late (24 and 48 h) phases of reperfusion. Rats subjected to 70% hepatectomy and 45 min of hepatic ischemia showed significantly reduced hepatocyte proliferation (mitotic index, proliferating cell nuclear antigen, and relative liver weight) when compared with animals subjected to hepatectomy alone. However, hepatocyte proliferation was markedly increased in rats pretreatment with IPC when compared with ischemic controls. CONCLUSION: These results suggest that ischemic pre-conditioning ameliorates the hepatic injury associated with ischemia-reperfusion and has a stimulatory effect on liver cell regeneration that may make it valuable as a hepatoprotective modality. Il-6 appears to be key mediator in promoting regeneration after combined ischemia and hepatic resection.  相似文献   

14.
目的 探索在正常及高胆红素血症情况下,大鼠70%肝切除联合肝固有动脉切除对肝功能、肝细胞能量代谢以及肝再生和细胞凋亡的影响.方法 雄性成年SD大鼠133只,将其中40只分为2组,每组20只,均行胆总管-十二指肠插管桥接,同时行70%肝切除或70%肝切除联合肝固有动脉切除.另87只行胆总管结扎制备梗阻性黄疸模型.5 d后手术分为70%联合肝切除胆肠再通内引流组,及70%肝切除联合肝固有动脉切除、胆肠再通内引流2组.动态观察术后24 h、72 h、7 d肝功能和肝细胞能量代谢、肝组织HGF和bcl-2 mRNA含量及其蛋白表达、肝细胞增殖指数和凋亡指数的变化,并统计各组死亡率.另取6只作为假手术组,测定术后0 h肝功能和肝细胞能量指标.结果 正常大鼠能够耐受70%肝切除联合肝动脉切除,术后肝细胞能量代谢和肝功能迅速恢复正常,肝再生良好.高胆红素血症时,大鼠术后肝再生受抑制,细胞凋亡增多.较之70%肝切除组,70%肝切除联合肝固有动脉切除组对肝细胞能量代谢的影响更为显著,术后肝功能恶化,肝组织HGF和Bcl-2 mRNA含量显著减少,肝再生明显受抑制,细胞凋亡增多,死亡率显著增高(P<0.05).结论 正常大鼠70%肝切除联合肝动脉切除术后肝再生不受影响,高胆红素血症时,70%肝切除联合肝动脉切除的大鼠死亡率高,因此术前引流减黄应是必要的措施.  相似文献   

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目的 探讨90%门静脉分支结扎后大鼠门静脉压力变化与肝再生的关系.方法 45只雄性SD大鼠行90%门静脉分支结扎术,其中5只进行假手术作为对照.观察不同时相点门静脉压力和非结扎侧肝脏质量变化,光学显微镜下观察非结扎侧肝细胞的形态学变化,免疫组织化学方法检测未结扎侧肝细胞的增殖细胞核抗原(PCNA),TUNEL法检测未结扎侧肝细胞的凋亡情况,并进行定最分析.采用Pearson相关分析和t检验分析数据.结果 95%(38/40)的大鼠存活.结扎侧肝叶进行性萎缩,非结扎侧肝叶占全肝质量的比例随时问推移而增加,12 h内增加较缓慢,仅为10.75%;而1~5 d则增加速度明显加快,达到27.57%;7~28 d达到平台期,缓慢增加到32.37%.术前门静脉压力为(9.1±1.8)cm H_2O(1 cm H_2O=0.098 kPa);结扎后立即升高,12 h达到高峰(15.8±2.7)cm H_2O,与术前比较差异有统计学意义(t=6.847,P<0.05);1~28 d由(13.6±2.3)cm H_2O逐渐下降为(9.3±2.0)cm H_2O.术前大鼠PCNA阳性细胞计数为7%±3%,术后12 h至3 d由14%±5%上升至21%±6%,第5天达到高峰为26%±7%,与术前比较差异有统计学意义(t=9.129,P<0.05),随后逐渐恢复正常.TUNEL法检测结果显示,术前大鼠肝脏和术后各时相点大鼠未结扎侧肝脏仅见极少量凋亡细胞.大鼠门静脉压力与非结扎侧肝叶肝细胞PCNA的表达在术后1、3、5 d呈正相关(r=0.913,0.896,0.908,P<0.05),在术后14 d时相点呈负相关(r=-0.926,P<0.05).结论 大鼠90%门静脉分支结扎术后,引起未结扎侧肝细胞的活跃再生,再生后的肝脏可恢复原来的质量;肝再生以肝细胞增殖加速为主,而非肝细胞凋亡减少;门静脉压力变化在肝再生过程中可能发挥重要作用.  相似文献   

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BACKGROUND: Hepatocyte transplantation could be an alternative to whole liver transplantation for the treatment of metabolic liver diseases. However, the results of clinical investigations suggest that the number of engrafted hepatocytes was insufficient to correct metabolic disorders. This may partly result from a lack of proliferation of transplanted hepatocytes. In rodents, portal ligation enhances hepatocyte engraftment after transplantation. We investigated the effects of partial portal ligation and embolization on engraftment and proliferation of transplanted hepatocytes in primates. METHODS: Hepatocyte autotransplantation was performed in Macaca monkeys. The left lateral lobe was resected for hepatocyte isolation. The first group of monkeys underwent surgical ligation of the left and right anterior portal branches; in the second group, the same portal territories were obstructed by embolization with biological glue. To evaluate the proportion of cell engraftment hepatocytes were Hoechst-labeled and transplanted via the portal vein. Cell proliferation was measured by BrdU incorporation. RESULTS: Hepatocyte proliferation was induced by both procedures but it was significantly higher after partial portal embolization (23.5% and 11.2% of dividing hepatocytes on days 3 and 7) than after ligation (3% and 0.8%). Hepatocytes engrafted more efficiently after embolization than after ligation. They proliferated and participated to liver regeneration representing 10% of the liver mass on day seven and their number remained constant on day 15. CONCLUSIONS: These data suggest that partial portal embolization of the recipient liver improves engraftment of transplanted hepatocytes in a primate preclinical model providing a new strategy for hepatocyte transplantation.  相似文献   

17.
Kinetics of hepatocellular regeneration after 30% and 70% hepatectomy and the effect of hepatotrophic factors on the normal liver and regenerating livers after hepatectomy were investigated by flow-cytometric analysis using adult male rats. The results were as follows: The DNA histogram of hepatocytes in the normal group had two peaks in G0G1 and G2M components; G0G1 29% S 13%, G2M 58%. In the 30% hepatectomized group, the peak of G2M slightly increased, and remarkable change was not noticed during 4 weeks. In the 70% hepatectomized group, the percentage of hepatocytes in G0G1 and G2M were markedly changed during 2 days after hepatectomy. The peak of G0G1 moved to S after 24 hours, to G2M after 36 hours and returned to G0G1 after 48 hours. Afterwards the G0G1 gradually decreased while the G2M increased and they finally reached a single peak of G2M at the 7th day. Supernatant of the intestinal homogenate after hepatectomy and EGF initiated the cell kinetics in normal and regenerating rat livers. Changes on cell kinetics was not observed after insulin and glucagon administration.  相似文献   

18.
We found that measurements of portal blood flow by continuous thermodilution were highly reproducible even after hepatectomy. Our subjects numbered 59 in all: In these patients having diseases of the liver and biliary tract, we studied portal hemodynamics during percutaneous transhepatic portography. Of these, 37 underwent hepatectomy. We chose 19 subjects from this group, and measured again both portal venous flow and portal venous pressure many times, continuing for 14 more days. In all 19 patients checked after hepatectomy, portal hemodynamics became hypodynamic, and this change was greater when the amount of liver resected was large. In 18 of these patients, hemodynamics started to improve after the 7th postoperative day. Changes in hemodynamics were not significantly different in patients with or without cirrhosis. In one patient who died of hepatic failure, the portal hypodynamic state did not improve. With this exception, in patients with major resections, portal venous flow per liver volume had increased after surgery and continued to increase. This was not true for patients with minor resections. Portal hemodynamics are important in the functioning and regeneration of the remaining liver, and it is necessary to understand and medically correct portal hemodynamics before and after hepatectomy.  相似文献   

19.
GOAL: The aim of this study was to assess liver regeneration after partial portal ligation. METHODS: 70% partial portal occlusion was obtained by ligation of the left portal vein branch. Total liver weight ratio were measured 96 hours after partial portal occlusion and in sham operated animals. The kinetics of hepatocytes division was evaluated by measuring the incorporation of 5-bromo-21-deoxyuridine into replicating cells at various time points by immunohistochemistry. RESULTS: Partial portal occlusion did not alter the total liver weight 96 hours after surgery. It resulted in atrophy of the ligated lobes and hypertrophy of the lobes with preserved portal flow. Hypertrophy was associated to an increase of the percentage of replicating hepatocytes. The replication rate was maximum at 28 hours with a peak at 12.5% and was prolonged beyond the 48th hour. CONCLUSIONS: Partial portal occlusion results in major and prolonged regeneration process in the liver lobes with preserved portal flow.  相似文献   

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门静脉动脉化对大鼠肝脏再生的影响   总被引:3,自引:0,他引:3  
目的探讨门静脉动脉化重建肝血流后对肝脏再生的影响。方法建立门静脉动脉化重建肝脏血流加半肝切除(43%)的大鼠实验模型,分别在术后3 d和10 d取出肝脏烘干称重、光镜下计数进入有丝分裂期的肝细胞和分离肝细胞进行流式细胞仪分析,以观察肝脏再生的情况。结果实验组术后3 d和10 d测定的肝脏干重分别为(67.56±3.70)%(、78.76±5.68)%,与对照组(71.66±3.24)%(、82.38±4.86)%相比无显著性差异(P>0.05);进入有丝分裂期的肝细胞计数(708.4±68.21、239.6±24.50)与对照组(724.8±69.99、216.2±23.81)相比无显著性差异(P>0.05);流式细胞仪测得的进入G2和M期的肝细胞的DNA含量[(25.72±4.78)%、(15.60±2.52)%]与对照组[(28.78±3.37)%、(13.34±2.88)%]相比无显著性差异(P>0.05)。结论行门静脉动脉化重建肝血流不影响肝脏的再生。  相似文献   

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