不同性别肝大部切除小鼠的肝再生

背景:各种病因所致的肝硬化及肝癌发病率存在明显的性别差异.肝受损或手术后肝脏均可通过其自身强大的再生能力进行代偿,但肝再生过程中不同性别肝细胞的再生状况是否存在差异尚不清楚.目的:比较肝大部切除后不同性别小鼠肝脏再生能力是否存在差别.方法:采用不同性别成年昆明小鼠行肝脏大部切除,称量手术切除的肝组织,并于术后1,3,5,7,10,14 d取再生肝组织,称量后常规制作组织切片备用,取材前2 h腹膜下注射5一溴脱氧尿核苷50 mg/kg.观察比较不同性别小鼠再生肝组织的结构变化、细胞形态,以及术后各时间点肝再生率、肝组织5一溴脱氧尿核苷的标记指数.结果与结论:苏木精一伊红染色切片镜下结果显示,肝脏大部切除后各时间点不同性别小鼠肝组织结构无明显差别.不同性别小鼠肝大部切除后各时间点肝再生率及5一溴脱氧尿核苷标记指数差异均无显著性意义(P>0.05).提示肝大部切除后不同性别小鼠肝的再生能力无明显差别.     

不同性别小鼠化学性肝损伤后的肝再生能力比较

背景:肝脏再生能力受多重因素的影响,而性别是否是再生修复过程的一个重要因素尚无定论。目的:比较不同性别小鼠化学性肝损伤后肝脏再生能力是否有差异。方法:采用四氯化碳小鼠皮下注射方法建立急性化学性肝损伤模型。120只昆明小鼠随机均分为糖原染色组和5-溴脱氧尿嘧啶核苷组,各组再按照性别均分为雌雄两组,于造模后第1,3,5,7,10天完整取下小鼠肝脏并称质量,取材前称量小鼠体质量。结果与结论:造模后第7天雌性鼠恢复原肝质量/体质量比,而雄性鼠则表现为下降趋势,不同性别小鼠肝质量/体质量比在各时间点差异无显著性意义(P>0.05);四氯化碳诱导的急性肝损伤主要部位为肝小叶周围的门管区及界板区,损伤部位肝细胞出现脂肪变,少数肝组织出现点状坏死;损伤后1,5,7d雌性小鼠糖原染色明显强于雄性组(P<0.05);肝损伤后3d雌性鼠肝脏5-溴脱氧尿嘧啶核苷标记指数高于雄性小鼠(P<0.05),而第1,5,7,10天则未见明显差异(P>0.05)。说明肝损伤后雌性鼠的再生修复比雄性鼠强,于第7天完成修复。不同性别的昆明小鼠对四氯化碳诱导的急性肝损伤后恢复期中肝脏再生能力具有差异性。     

大鼠肝部分切除后肝细胞再生及肝星状细胞α-平滑肌肌动蛋白表达变化与肝细胞生长因子的干预作用

背景:肝细胞的再生主要受细胞因子的整体控制,肝细胞生长因子在肝细胞的再生过程中发挥着重要的作用,但其对肝星状细胞再生替代的研究较少.目的:观察肝细胞生长因子对大鼠肝部分切除后肝细胞再生及肝星状细胞α-平滑肌肌动蛋白表达的影响.设计、时间及地点:随机对照动物实验,于2006-11/2007-05在河南省组织再生重点实验室完成.材料:选用健康SD雌性大鼠52只,体质量(200±20)g,用于制造肝切除动物模型.肝细胞生长因子由北京生物药业有限公司提供.方法:将52只大鼠按随机数字表法分为3组,假手术组(n=12)打开腹腔,重新关腹.术后第2天腹腔注射生理盐水1 mL/d;肝部分切除组(n=20)行肝部分切除,术后第2天腹腔注射生理盐水1 mL/d;肝细胞生长因子组(n=20)肝部分切除术后第2天腹腔注射肝细胞生长因子12mg/(kg·d),1次,d.主要观察指标:各组分别于术后第1,2周末采血行血清学检测;取肝组织行苏木精-伊红及α-平滑肌肌动蛋白免疫组化染色,并行电镜观察.结果:52只大鼠全部进入结果分析.①与假手术组相比,术后第1周肝部分切除组血清谷丙转氨酶、谷草转氨酶活性升高,总蛋白含量降低,肝再生指数降低(P＜0.05),肝细胞生长因子组上述指标明显改善(P＜0.05).②术后第1,2周各组肝组织α-平滑肌肌动蛋白表达灰度值相近.③术后第1周肝细胞生长因子组肝细胞内的粗面内质网、线粒体均明显增多.第2周后各组肝细胞超微结构无明显差异.结论:应用外源性肝细胞生长因子可以改善大鼠肝部分切除后的肝功能,促进肝细胞增殖,但在肝部分切除术后2周内对肝星状细胞无明显影响.     

小鼠肝脏大部分切除后改良再生模型的建立

目的:探讨小鼠肝脏大部分切除后再生模型的改良制作方法。方法:将8~10周龄雄性C57BL/6小鼠腹腔麻醉后,用带针6-0 proline缝线环绕肝左外叶、肝中叶共同肝蒂,距肝蒂0.2 cm穿肝右中叶表面固定,结扎肝蒂,于结扎线远侧0.2 cm处切除小鼠肝脏左外叶、肝中叶(左、右)。观察小鼠术后成活率以及术后3 d、7 d、14 d小鼠肝脏质量。结果:成功建立小鼠肝脏大部分切除模型,该模型切除小鼠肝左外叶、肝中叶(左、右),切除肝质量占肝总质量的66.7%,术后小鼠存活率100%。术后小鼠剩肝代偿性增生,术后第3天恢复至原肝总质量的58.2%,第7天恢复至原肝总质量的78.0%,术后第14天恢复至原肝总质量的93.2%。结论:本研究建立的改进型小鼠肝脏大部分切除后再生模型,具有简便、可操作性强、成功率高等优点。     

倒千里光碱对肝大部分切除小鼠肝脏损伤后再生修复的影响

背景:目前大多数应用倒千里光碱造成肝损伤模型都是以大鼠为实验对象,有研究报道倒千里光碱并不能抑制小鼠肝细胞增殖,也有报道倒千里光碱对小鼠的肝细胞具有增殖抑制作用.目的:观察单纯肝脏大部分切除及其联合应用倒千里光碱致小白鼠对肝损伤后再生修复的影响.方法:40只C57BL/6J小鼠随机数字表法分为2组,每组20只.倒千里光碱/肝脏部分切除组:腹腔注射倒千里光碱溶液70 mg/kg,注射2次,每次间隔2周,4周后肝脏2/3切除.肝脏部分切除组:腹腔注射生理盐水70 mg/kg,注射2次,每次间隔2周,4周后行肝脏2/3切除.观察术后14 d肝脏大体结构恢复情况;苏木精-伊红染色观察术后第3,7天肝细胞损伤情况;BrdU染色观察术后第3天成熟肝细胞增殖情况;CK19和C-kit免疫组织化学方法观察术后第3,7,14天肝脏卵圆细胞增生情况.结果与结论:肝脏部分切除组14 d肝大体结构基本恢复正常,而倒千里光碱/肝脏部分切除组肝脏大小没有明显的恢复.苏木精-伊红染色可见倒千里光碱/肝脏部分切除组明显的肝细胞变性改变;BrdU染色肝脏部分切除组术后第3天有明显肝细胞增殖,而倒千里光碱/肝脏部分切除组肝细胞增殖很少.CK19和C-kit免疫组织化学结果显示倒千里光碱/肝脏部分切除组术后第3天开始肝脏主要通过肝卵圆细胞增生并逐渐向肝细胞和小胆管分化,从汇管区开始向肝小叶内延伸以修复损伤.提示倒千里光碱可抑制小鼠肝脏损伤后肝细胞增殖再生.建立倒千里光碱/肝脏部分切除小鼠模型可诱导肝脏卵圆干细胞增生.     

小鼠胚胎背主动脉发育过程中内皮和平滑肌标志物表达时相及其变化

目的:观察小鼠胚胎发育过程中背主动脉胎肝激酶1、α-平滑肌肌动蛋白的表达时相,初步探讨背主动脉内皮和平滑肌细胞的形成及其可能起源。方法:实验于2006-01/2007-01在解放军沈阳军区总医院全军心血管病研究所心内科完成。①实验材料:昆明种小白鼠50只,体质量20～22g,其中雌鼠30只。②实验方法:将雌鼠分别放入公鼠笼内过夜、交配,从怀孕第8.5天开始获取胚胎,在雌鼠怀孕第8.5～18.5天,每一时间点取10个小鼠胚胎。③实验评估:对胎鼠组织切片分别行苏木精-伊红染色,观察背主动脉形态学变化;免疫组织化学染色法观察内皮细胞标志物胎肝激酶1、CD31、Ⅷ因子相关抗原,α-平滑肌肌动蛋白表达变化及其相互关系。结果:①胚胎8.5～9.5d胎鼠背主动脉由单层细胞构成,呈胎肝激酶1、CD31阳性,α-平滑肌肌动蛋白、Ⅷ因子相关抗原阴性。②胚胎10.5d胎鼠背主动脉仍为单层细胞,但胎肝激酶1、CD31、Ⅷ因子相关抗原、α-平滑肌肌动蛋白均呈阳性。③胚胎11.5d背主动脉管壁发育为多层,内层细胞呈胎肝激酶1阳性、α-平滑肌肌动蛋白阴性,外层细胞呈胎肝激酶1阴性而α-平滑肌肌动蛋白阳性,血管与周围间充质无明显分界,背主动脉管壁周围可见散在α-平滑肌肌动蛋白阳性细胞。④11.5d之后,背主动脉管壁平滑肌细胞数量增多且由不规则型转变为纺锤型,内层内皮细胞继续呈胎肝激酶1阳性、α-平滑肌肌动蛋白阴性,外层平滑肌细胞胎肝激酶1阴性、α-平滑肌肌动蛋白阳性,血管与周围间充质分界清楚,背主动脉血管周围无散在α-平滑肌肌动蛋白阳性细胞。结论:胚胎背主动脉的平滑肌细胞可能最早起源于胎肝激酶1、CD31阳性细胞,后期可能来源于周围间充质细胞的募集分化。     

肾素-血管紧张素系统的阻断对小鼠肝脏再生及肝功能的影响

目的探讨应用卡托普利阻断肾素-血管紧张素系统(RAS)后对肝切除术小鼠肝脏再生及肝功能的影响。方法制备肝部分切除术后小鼠模型,实验组予以卡托普利腹腔内注射,分别于术后第1、3、5、7、9天测定肝脏再生情况及肝功能变化,并应用免疫组化方法检测肝组织中IL-6的表达,与对照组比较,应用统计学方法分析RAS阻断对其肝脏再生及肝功能的影响。结果术后第3天开始,RAS阻断可明显增加肝脏体重比(t=7.006,P=0.000),而至第7天,卡托普利反而可以降低肝脏体重比;术后第3天开始,应用卡托普利阻断RAS能够明显降低谷丙转氨酶(ALT)及谷草转氨酶(AST)及胆红素(BIL)的水平,而白蛋白实验组却明显高于对照组(P=0.013),然而血清碱性磷酸酶(ALP)的水平却没有变化,而自第7天开始,ALP表现为降低趋势,而ALT及AST未再出现显著差异。而IL-6在小鼠肝组织中表达,实验组明显低于对照组,二者具有统计学差异(χ2=7.500,P=0.006)。结论 RAS阻断可促进肝切除早期小鼠肝脏再生,并促进肝部分切除术后小鼠早期肝功能的恢复。     

异种肝前体细胞移植治疗急性肝损伤大鼠

背景：成体肝前体细胞可在受体肝脏内定植并分化为肝细胞。不过,异种肝前体细胞移植能否促进急性肝损伤的恢复,脾脏微环境能否促进移植物的存活和向肝细胞分化,尚没有研究。目的：评价异种肝前体细胞移植治疗急性肝损伤的作用;监测移植肝前体细胞在大鼠脾脏实质内的定植及向肝细胞的分化。方法：体外培养雄性小鼠来源的肝前体细胞系肝上皮样前体细胞。通过CCl4腹腔注射联合2/3肝切除构建急性肝损伤大鼠模型,进行肝上皮样前体细胞脾脏移植。在肝切除后1,5,14和21 d,苏木精-伊红染色观察肝脏病理改变,全自动生化分析仪监测血清转氨酶变化,PCR反应检测脾脏组织Y染色体特异性序列Sry,脾脏CK-19和Alb免疫组织化学追踪移植肝上皮样前体细胞的植入和肝细胞分化。结果与结论：肝上皮样前体细胞可在体外长期培养,保持增殖能力和双向分化潜能。肝上皮样前体细胞脾脏移植后,肝损伤大鼠肝细胞肿胀明显减轻,丙氨酸转氨酶和天门冬氨酸转氨酶下降更明显。移植后1,5,14和21 d,脾脏DNA中均能检测到Sry序列。在整个实验期间CK-19阳性细胞在大鼠脾脏实质内始终存在。Alb阳性细胞在移植后5 d在脾脏实质中出现,随后阳性细胞数逐渐增多。实验表明,移植肝前体细胞能在大鼠脾脏实质中植入,并分化为肝细胞,能有效促进CCl4腹腔注射联合2/3肝切除诱导的大鼠急性肝损伤的修复过程。     

部分肝切除大鼠不同时期肝再生组织中转化生长因子β1的表达

背景:肝部分切除的安全性高低依赖于余肝的再生能力,了解肝硬化情况下肝部分切除后的肝再生情况,对肝硬化患者的治疗及预后具有重要意义.目的:探讨转化生长因子β1在肝硬化大鼠肝部分切除后肝组织中的表达和意义.方法:正常组大鼠不施加任何干预因素,模型组大鼠建立肝硬化模型,实验组大鼠建立肝硬化模型后行肝部分切除,复制肝再生模型.运用免疫组织化学方法和Western blotting技术,检测各组肝部分切除后12,24,72h肝组织中转化生长因子β1的表达.结果与结论:与模型组比较,实验组术后12,24 h肝组织转化生长因子β1的表达无明显差异(P0.05),术后72 h肝组织中转化牛长因子β1的表达显著增强(P<0.01).提示硬化肿部分切除后早期转化生长因子β1表达无明显增加,主要从中晚期可能通过与其他细胞因子的相互作用,继而开始发挥调节肝再生的功能.     

肝再生过程中肝窦内皮细胞膜蛋白质组学研究的可行性探讨

学术背景:肝再生是关系到肝移植、肝切除的重要病理生理过程,部分肝切除术后肝再生过程涉及血管新生的证据已经得到证实。目的:回顾肝再生的研究背景,综合分析开展肝再生过程中肝窦内皮细胞膜蛋白质组学研究的可行性。检索策略:由熊力、李选文联机检索CHKD(www.chkd.cnki.net)和PubMed(http://www.ncbi.nlm.nih.gov/entrez/)数据库1994-01/2007-07有关肝再生过程中肝窦内皮细胞膜蛋白质组学方面的文献,关键词(中文或其他语言)为"肝再生;肝窦内皮细胞;亚细胞蛋白质组;膜蛋白;肝移植"。获得相关中英文文献64篇,初筛后排除研究目与课题无关及内容重复的研究,保留39篇文献进一步分析。未发表的文献存档备用。文献评价:①文献来源情况:随机对照试验15篇,循证医学系统综述5篇,汇总分析14篇,经验交流5篇。②评价人:熊力。资料综合:有关肝再生的信号通路研究较多,目前认为存在两条通路,但蛋白质层面的机制尚待研究。肝窦内皮细胞是具有重要功能的非实质细胞,然而有关肝窦内皮细胞在肝再生中作用的研究较少,也未见关于肝再生过程中肝窦内皮细胞膜蛋白质组学的研究报道。结论:目前有关肝再生过程中肝窦内皮细胞膜蛋白质组学的研究报道极少。作者首次提出肝窦内皮细胞可能是肝再生瓶颈的假想,认为开展肝窦内皮细胞膜蛋白质组学的相关研究对于肝切除、肝移植具有重要意义。     

Hepatic regeneration and metabolism after partial hepatectomy in normal rats: effects of insulin therapy

The effect of insulin therapy on liver regeneration has been studied in normal fed rats 12, 24 and 48 h after partial hepatectomy. Dry weight of regenerating liver increased between 12 and 48 h after partial hepatectomy and was unaffected by insulin therapy. [6-3H] Thymidine uptake peaked at 24-h (24.7 +/- 2.4% of total liver cells) and insulin treatment had no additional effect. At 12-h after partial hepatectomy, hepatic [ATP] was decreased 15%, while [ADP] and [AMP] were increased 47% and 83% respectively compared with sham-operated animals. Partial hepatectomy also caused an increase in hepatic [triglyceride], a decrease in hepatic [glycogen] and an increase in the levels of glucose and several glycolytic intermediates. The hepatic redox ratios, [lactate]:[pyruvate] and [3-hydroxybutyrate]:[acetoacetate], were elevated. Insulin therapy had only minor effects on hepatic adenine nucleotide levels, intermediary metabolite concentrations or intrahepatic redox ratios after partial hepatectomy. These findings suggest a decreased hepatic intracellular energy state in regenerating liver; insulin therapy in normal rats does not influence this metabolic change nor the regenerative response.     

Pleomorphism of hepatic regeneration

The pleomorphism of hepatic regeneration was studied in acute liver injury and partial hepatectomy of rats. Increases in 3H-thymidine incorporation into the liver DNA fraction and in liver ornithine decarboxylase (ODC) activity were observed similarly in acute liver injury and following a two-thirds partial hepatectomy in normal rats. However, the increase in serum AFP levels was significant only in carbon tetrachloride (CCl4)-treated rats, and the portal-peripheral vein difference in plasma glucagon concentrations was great only in rats that underwent a partial hepatectomy. The weight of the remaining liver increased rapidly following a 67% hepatectomy in normal rats, but not in cirrhotic rats, of which three of five died within 6 days. Increases in liver prostaglandin E levels, 14C-orotate incorporation into the liver RNA fraction and hepatic ODC activity were observed up to 10 h following a partial hepatectomy of normal liver but not after similar removal of cirrhotic liver. Three kinds of hepatic regeneration, i.e., normal and pathologic regeneration following surgical removal of either normal or injured liver and repair of liver damage following chemically induced liver deficiency, were proposed from the observations.     

肝细胞生长因子对慢性肝损伤时肝部分切除术后肝再生和肝功能的影响

目的研究肝细胞生长因子对慢性肝损伤时肝部分切除术后肝再生和肝功能的影响。方法对慢性肝损伤模型SD大鼠行30%肝部分切除术,术后10d,经腹腔注射肝细胞生长因子,同时建立正常对照组。观察不同剂量肝细胞生长因子对肝再生,肝功能和肝储备功能的影响。结果实验组与对照组相比,AST,ALT,总胆固醇、动脉血酮体比具有显著的统计学意义(P<0.01)。结论应用外源性肝细胞生长因子可明显改善肝功能和肝储备功能,促进肝细胞再生。     

Effect of carbon tetrachloride on extrarenal erythropoietin production in rats.

Liver regeneration after partial hepatectomy is associated with an increase in extrarenal Ep production; however, this surgical procedure is time-consuming and difficult to standardize. Carbon tetrachloride (CCl4) ingestion in rats is an easy and reproducible way to induce liver damage and regeneration. We therefore studied the effects of CCl4 on extrarenal Ep production in rats. Just as is the case following partial hepatectomy, extrarenal Ep production in response to hypoxia was reduced immediately after ingestion of CCl4. Thereafter it rose to supranormal levels which peaked 3 to 4 days after CCl4 ingestion (at this time Ep titers of nephrectomized, CCl4-fed rats rose to greater than 1.0 U/ml of plasma after exposure to 0.42 atmosphere for 7 hr). Extrarenal Ep production then declined, but was still supranormal 7 days after CCl4. Carbon tetrachloride did not significantly affect extrarenal Ep production in rats nephrectomized 18 hr prior to initiation of hypoxia even if they received injections of renin prior to being made hypoxic, nor did it affect Ep production in response to hypoxia in nonnephrectomized rats under the conditions used in this study.     

Foetal 'flat' bile acids reappear during human liver regeneration after surgery

Background  Changes in bile acid (BA) pool, such as the reappearance of typically foetal-type molecular species with a 'flat' structure at the steroid ring, occur during hepatocarcinogenesis, both in humans and rodents. Moreover flat-BAs also appear during rat liver regeneration. These changes can be detected in urine. The aim of the present study was to investigate whether flat-BAs also reappear during human liver regeneration, and whether this change correlates with the magnitude of liver resection.
Materials and methods  Patients undergoing partial hepatectomy were divided in two groups: major hepatectomy group (> 50% of hepatic tissue resection, n  = 17) and minor hepatectomy group (< 50%, n  = 13). BAs were extracted from serum and urine (collected over 24 h) and analysed by gas chromatography-mass spectrometry. Samples were obtained before surgery (day 0) and on the third and seventh days after hepatectomy.
Results  In serum, total BAs significantly increased on day seven after hepatectomy, but only a moderate increase in flat-BA concentrations was observed. By contrast, urinary excretion of total as well as flat-BAs significantly increased at day three and day seven after hepatectomy. Moreover, the amount of flat-BAs excreted in urine during the first week after partial hepatectomy correlated with the magnitude of the resection.
Conclusions  Urinary BA output increases and flat-BAs reappear in urine during human liver regeneration. These results suggest that determination of BAs in urine may be an interesting parameter obtained by non-invasive techniques whose actual clinical value during human liver regeneration warrants further evaluation.     

L-谷氨酰胺与肝脏大部分切除后的再生

背景：L-谷氨酰胺作为DNA和谷胱甘肽等合成的氮前体,在肝组织再生,肝细胞增殖的过程中扮演着极其重要的角色。目的：观察经饮食由来补充L-谷氨酰胺对大鼠肝脏大部切除后肝再生能力的影响。方法：Wistar大鼠随机分组3组,L-谷氨酰胺组和L-丙氨酸组大鼠肝切除前分别灌服10%L-谷氨酰胺或10%L-丙氨酸,肝切除后继续加入饮用水中饮用,对照组肝切除前后均使用饮用水。结果与结论：大鼠肝切除后72hL-谷氨酰胺组肝再生率明显高于对照组及L-丙氨酸组（P〈0.05）。肝切除后24h和72hL-谷氨酰胺组肝细胞增殖均明显高于对照组和L-丙氨酸组（P〈0.01;P〈0.05）。肝切除后24h和72h总RNA水平在两种氨基酸与对照组之间差异无显著性意义。肝切除后72h基因组DNA的含量L-谷氨酰胺组显著高于对照组和L-丙氨酸组（P〈0.05）。提示肝损伤围手术期投用高浓度L-谷氨酰胺对大鼠肝再生有促进作用,而投用L-丙氨酸则没有此作用。     

Synthesis and degradation of ribosomal RNA in regenerating liver

A simple double-isotope method is described which permits precise determination of both synthetic and degradative rates of liver cell constituents during the course of regeneration after partial hepatectomy. By employing animals which have previously received both tritiated thymidine and an appropriate 14C-labeled precursor it is possible to obtain precise turnover data in individual animals by comparing the concentration and the total isotope content of the 14C-labeled component in the initially excised and regenerating portions of liver. The presence of a 3H marker in the liver DNA makes it possible in addition to calculate the exact size of the initial liver remnant and hence to interpret the observed 14C turnover data in terms of specific rates of synthesis and degradation. As an illustration of its usefulness this method has been employed to study changes in cell proliferation rate after partial hepatectomy, and to determine the day-to-day rates of synthesis and degradation of ribosomal RNA, the major component of rat liver RNA. It is shown that during the first 24 h after a 70% hepatectomy ribosomal RNA synthesis undergoes a nearly fourfold stimulation to a rate of approximately 53% per unit mass per day. This accelerated rate of synthesis is sustained for an additional 2 days and is accompanied by exponential DNA synthesis until the hepatic remnant has more than tripled its initial DNA and ribosomal RNA content to attain values identical to those in the initial intact liver; the rates of DNA and RNA synthesis then fall abruptly. In striking contrast to the marked fluctuations in its rate of synthesis, ribosomal RNA continues to be degraded throughout the course of regeneration at a constant rate of 12% per day, a rate virtually identical to that observed in normal liver. The approach described here permits the accurate determination of turnover rates over intervals considerably shorter than even one half-life, and should be applicable to the study of the specific rates of synthesis and degradation of other cell components as well.