内吗啡肽对过氧化氢诱导的大鼠胰岛损伤的保护作用

目的 研究过氧化氢(H2O2)对胰岛的损伤及内吗啡肽(EMs)对这种损伤的保护作用.方法 成年雄性Wistar大鼠18只,体质量200～300 g,体外分离、纯化和培养Wistar大鼠胰岛,双硫腙(DyTZ)染色鉴定,锥虫蓝染色检测细胞活力,葡萄糖刺激实验检测胰岛生物活性.四唑蓝(MTT)分析不同浓度的H2O2对胰岛的...     

胰岛破坏大鼠模型的血糖变化

目的探讨胰岛破坏与血糖的关系。方法将46只雄性SD大鼠随机分为实验组36只和对照组10只,实验组按60 mg/kg一次性腹腔内注射链脲佐菌素,对照组注射等量的缓冲液;在注射后的第7、14、28、42、56、84天检测空腹血糖并行腹腔葡萄糖耐量试验（IPGTT）;在第84天同时检测血清胰岛素,并取胰腺制作树脂切片;光镜下定性观察胰岛形态,用体视学方法测量胰岛的大小及总体积等。结果实验组成模大鼠19只为高血糖组、未成模大鼠10只又分为血糖正常组和血糖部分正常组各5只。与对照组比较,高血糖组大鼠（14.9 mmol/L≤血糖≤27.8 mmol/L）的胰岛平均面积、单位面积胰腺内胰岛数量和胰岛总体积分别减少了64.3%、68.2%和91.3%（P均〈0.05）,血清胰岛素减少了92.6%;血糖部分正常组大鼠（3.6 mmol/L≤血糖≤27.8 mmol/L）的IPGTT均异常,第56、84天的血糖分别升高了247.2%和313.2%（P均〈0.05）,血清胰岛素、胰岛总体积分别减少了94.0%、86.4%（P均〈0.05）;血糖正常组大鼠（4.5 mmol/L≤血糖≤7.9 mmol/L）的血糖、血清胰岛素和胰岛总体积无明显变化,但部分IPGTT异常。结论血糖水平与胰岛破坏的程度有关。     

Protective effects of chronic melatonin treatment against renal injury in streptozotocin-induced diabetic rats

The aim of this study was to investigate the effects of melatonin as an antioxidant, on prevention and treatment of streptozotocin (STZ)-induced diabetic renal injury in rats. Male Wistar rats were divided into four groups: (1) untreated, (2) melatonin-treated, (3) untreated diabetic (UD), (4) melatonin-treated diabetic (MD). Experimental diabetes was induced by single dose (60 mg/kg, i.p.) STZ injection. For 3 days prior to administration of STZ, melatonin was injected (200 microg/kg/day, i.p.); these injections were continued until the end of the study (4 weeks). Malondialdehyde (MDA) levels as a marker of lipid peroxidation were significantly increased in the renal homogenates of UD animals and decreased after melatonin administration. The activity of the antioxidative enzyme glutathione peroxidase (GSH-Px) was significantly reduced in UD rats. Melatonin treatment reversed STZ-induced reduction of GSH-Px activity without having an effect on blood glucose. Upon histopathological examination, it was observed that the melatonin treatment prevented the renal morphological damage caused by diabetes. Upon immunohistochemical investigation, glomerular anti-laminin beta1 staining decreased in MD rats. Additionally, no tubular anti-IGF-1 staining was observed in melatonin-treated rats. In conclusion, chronically administered melatonin reduced renal injury in STZ-induced diabetic rats and thus it may provide a useful therapeutic option in humans to reduce oxidative stress and the associated renal injury in patients with diabetes mellitus.     

硫化氢对大鼠压力负荷性心力衰竭发展过程中氧化应激的影响

目的腹主动脉缩窄大鼠心力衰竭(心衰)模型通过腹腔给予硫化氢(H_2S)供体硫氢化钠(NaHS),观察压力负荷性心衰形成过程中H_2S对氧化应激状态的影响。方法 SD大鼠63只,随机分为对照组、心衰组、NaHS组,每组21只。各组均在第4、8、12周时,各取7只大鼠取血及心脏进行检测。结果心衰组4、8、12周血清H_2S含量、心肌H_2S合酶活性均较对照组明显降低,NaHS组4、8、12周血清H_2S含量较心衰组明显升高,心肌H_2S合酶活性较心衰组略有增高,但仍低于对照组。与对照组比较,心衰组4、8、12周血清MDA含量明显升高,超氧化物歧化酶(SOD)活性明显降低;与心衰组比较,NaHS组SOD活性上升,MDA含量下降,其中MDA含量在8、12周时下降明显,但仍明显高于对照组;SOD在12周时明显增高,但仍明显低于对照组。与心衰组比较,NaHS组4、8、12周血清氧化型低密度脂蛋白含量明显降低,但8、12周时仍明显高于对照组。结论外源性给予H_2S供体NaHS能改善压力负荷引起的心衰大鼠体内和心肌内的氧化应激状态,可能是H_2S心脏保护作用机制之一。     

钙通道拮抗剂对大鼠胰岛细胞胰岛素分泌的影响

目的　研究钙通道拮抗剂对大鼠胰岛细胞分泌胰岛素的影响和机制。方法　用放免和荧光方法分别检测不同治疗血浓度的硝苯地平 (NIF)、维拉帕米 (VER)、地尔硫 (DIL)等药物对低糖和高糖刺激状态下胰岛细胞Ca2 含量和胰岛素分泌量的影响。结果　低糖状态组 :NIF、VER、DIL在 2 5、50、10 0 μg/L药物浓度下未对胰岛细胞内Ca2 含量和胰岛素分泌量产生影响 ,其结果与对照组相比差异无统计学意义 (P >0 0 5)。在高糖状态组 ,NIF、VER、DIL在 2 5μg/L药物浓度下不抑制胰岛素分泌 ,NIF在 50、10 0 μg/L浓度时 ,胰岛细胞内Ca2 浓度和胰岛素分泌量明显减少 ,与对照组相比差异有显著性 (P <0 0 5)并呈剂量相关 (P <0 0 1)。VER在 50 μg/L时胰岛素分泌有减少趋势 ,10 0 μg/L时明显减少 (P <0 0 5)。DIL在 10 0 μg/L时胰岛素分泌量减少与对照组相比差异具有显著性 (P <0 0 5)。结论　高浓度药理治疗量的NIF、VER、DIL具有抑制高糖作用下的胰岛细胞外钙内流和使胰岛素分泌减少的作用     

过表达HSP20的慢病毒载体对H2O2诱导的大鼠心肌细胞凋亡的影响

目的构建过表达大鼠热休克蛋白20(HSP20)基因慢病毒载体,探讨其对H2O2诱导的大鼠H9C2心肌细胞凋亡的影响。方法构建大鼠HSP20基因pHIV-HSP20过表达质粒慢病毒,与包装质粒psPAX2、pMD2G共转染293FT细胞,检测其转染效率;包装慢病毒并转染H9C2心肌细胞;72 h后观察其转染效率,RT-PCR法检测细胞HSP20 mRNA表达,CCK-8、Hochest33258染色法检测H2O2诱导后H9C2心肌细胞凋亡情况。结果成功构建了HSP20慢病毒过表达载体,经293FT细胞包装后,其对H9C2细胞72 h的转染效率为95%;与慢性病毒组比较,H9C2细胞转染72 h后HSP20 mRNA水平显著升高,细胞活力下降,心肌细胞凋亡率明显降低(P均<0.01)。结论过表达HSP20能显著抑制H2O2诱导的H9C2心肌细胞凋亡。     

Effects of C-peptide on isolated human pancreatic islet cells

BACKGROUND: Recent data have demonstrated that pro-insulin-derived C-peptide can affect the function of several different cell types. We hypothesized that C-peptide might have an influence on the function and survival of isolated human islets. METHODS: Islets were prepared by combining enzymatic digestion and density gradient centrifugation, and the effects of human C-peptide were evaluated acutely and after 24-h incubation. Insulin secretion, apoptosis, quantitative RT-PCR and western-blotting experiments were then performed. RESULTS: Glucose-stimulated insulin secretion was not affected by C-peptide and, accordingly, mRNA expression of glucose transporter 2 and glucokinase did not differ between islets pre-cultured or not with the hormone. However, apoptosis was significantly lower in islets exposed to C-peptide than in control islets. This was accompanied by a significant increase of mRNA and protein expression of Bcl2, an anti-apoptotic molecule, with no change in the expression of Bax, a pro-apoptotic molecule. CONCLUSION: These results show that in human islets pro-insulin C-peptide has no direct effects on insulin secretion, but it decreases islet cell apoptosis. A direct role of C-peptide on beta-cell mass regulation is therefore suggested.     

Angiotensin II and the endocrine pancreas: effects on islet blood flow and insulin secretion in rats

Summary An intrinsic angiotensin system has been described in the pancreas, with angiotensin II specific receptors being present on both exocrine, endocrine and vascular cells. The aim of the present study was to evaluate the effects of angiotensin II on insulin secretion and blood flow regulation in the pancreas. Blood flows were determined with a microsphere technique. Infusion of angiotensin II induced a dose-dependent reduction in both whole pancreatic and islet blood flow, which was most pronounced in the former. Administration of enalaprilate, an inhibitor of angiotensin-converting enzyme, and saralasin, a non-selective angiotensin II receptor antagonist, preferentially increased islet blood flow. The effects of angiotensin II on insulin release were examined by measuring insulin concentrations in the effluents from isolated perfused pancreata. In these preparations, enalaprilate affected neither basal nor glucose-stimulated insulin release, whereas angiotensin II delayed the first phase of insulin release in response to glucose. The effect of angiotensin II was probably due to initial marked vasoconstriction. The retardation of insulin release could be avoided by adding angiotensin II to the perfusion medium 20 min before glucose administration, i. e. so that the vasoconstriction had disappeared when glucose-stimulation began. The present study suggests that the angiotensin-system is important in regulation of islet blood flow and points to a pivotal role of islet blood perfusion for an adequate insulin release. [Diabetologia (1998) 41: 127–133] Received: 7 April 1997 and in revised form: 27 August 1997     

胎儿胰腺组织中巢蛋白阳性细胞的分离和体外增殖以及诱导分化

目的 研究从胎儿胰腺组织中分离巢蛋白(Nestin)阳性细胞以及该细胞的体外扩增与向胰岛内分泌细胞分化的能力。方法 采用胶原酶消化法，从胎儿胰腺组织中分离获得胰岛样细胞簇(islet-like cell clusters，ICCs)，ICCs经手工挑拣后接种，待形成单层上皮样细胞后，进行传代培养和诱导分化。利用逆转录-聚合酶链反应(RT-PCR)、免疫荧光染色及放射免疫分析(RIA)等方法，检测该细胞中分子标志物的表达，并对其向胰岛内分泌细胞分化的能力进行鉴定。结果 (1)上述单层上皮样细胞具有很强的增殖能力，可至少连续传16代；(2)RT-PCR、免疫荧光染色分析显示，该细胞可表达干细胞的标志分子巢蛋白和ABCG2；(3)RT-PCR分析显示，在多种细胞因子和无血清的条件下，巢蛋白阳性细胞经诱导后可出现胰岛素、胰升糖素和胰十二指肠同源盒基因-1(PDX-1)mRNA的表达，而巢蛋白和Neurogenin3(Ngn3)mRNA表达消失。RIA分析也可检测到诱导后的细胞内有胰岛素产生。结论 从胎儿胰腺中分离得到的巢蛋白阳性细胞具有胰腺前体细胞的特性，在体外具有很强的增殖能力，并可诱导分化为胰岛内分泌细胞。该细胞有望为胰岛移植提供一种新的细胞来源。     

夹竹桃麻素对兔心房电重构时氧化应激损伤保护作用的研究

目的研究还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶抑制剂夹竹桃麻素(APO)对兔心房电重构引起氧化应激损伤的保护作用。方法选择18只新西兰白兔,随机分为对照组、心房快速起搏(RAP)组和APO+RAP组,每组6只。术前3 d,APO+RAP组给予APO 30 mg/(kg·d)灌胃,对照组和RAP组术前生理盐水等体积灌胃。对照组术中未给予RAP,RAP组和APO+RAP组术中以最快能维持心房1:1起搏频率(500～600/min)给予快速刺激3 h。在完成电生理检查后,立即取出心脏并分离左、右心房和肺静脉,分别检测各组织超氧化物歧化酶(SOD)活性、乳酸脱氢酶(LDH)活性和钙含量。结果与对照组比较,RAP组左、右心房、肺静脉SOD活性明显降低(P<0.05),LDH活性和钙含量明显升高(P<0.05),APO+RAP组左、右心房、肺静脉SOD活性、LDH活性和钙含量比较,差异无统计学意义(P>0.05)。与RAP组比较,APO+RAP组左、右心房、肺静脉SOD活性明显升高,左、右心房LDH活性明显降低(P<0.05)。对照组肺静脉钙含量明显高于左、右心房(P<0.05)。结论心房颤动能够引起氧化应激损伤,APO能部分预防氧化应激损伤发生。     

硝基酪氨酸在糖尿病大鼠胰岛中的表达及普罗布考的干预作用

目的观察硝基酪氨酸（NT）在糖尿病大鼠胰岛中的表达,以及普罗布考的干预对其表达和对胰岛β细胞的影响。方法大鼠高脂高糖饲料喂养4周后,腹腔注射链脲佐菌素30mg／kg复制2型糖尿病大鼠模型,普罗布考组（PB组）每天同时灌胃普罗布考500mg／kg,10周后测定空腹血糖（FPG）、空腹胰岛素（Fins）、总胆固醇（TC）、甘油三酯（TG）、丙二醛（MDA）、超氧化物歧化酶（SOD）,计算胰岛素敏感指数（ISI）,用免疫组化的方法观察NT在胰岛中的表达。结果糖尿病组（DM组）及PB组大鼠的FPG、TG、TC及MDA水平较正常对照组（NC组）明显增加（P〈0．01）,NT的平均光密度也明显高于NC组（P〈0．01）,但PB组上述指标的测定显著低于DM组（P〈0．01）;DM组和PB组大鼠的SOD水平、ISI明显低于NC组（P〈0．01）,PB组这些指标的测定显著高于DM组（P〈0．01）;NC组和PB组的Fins比较差异没有统计学意义,但都明显高于DM组（P〈0．01）。结论NT在胰岛的表达增强,普罗布考作为抗氧化剂,对于STZ引起的或糖尿病引起的氧化应激,均在一定程度上减轻其损伤,保护了胰岛功能。     

Melatonin reduces apoptosis and necrosis induced by ischemia/reperfusion injury of the pancreas

The pancreas is highly susceptible to the oxidative stress induced by ischemia/reperfusion (IR) injury leading to the generation of acute pancreatitis. Melatonin has been shown to be useful in the prevention of the damage by ischemia-reperfusion in liver, brain, myocardium, gut and kidney. The aim of the study was to evaluate the cytoprotective properties of melatonin against injury induced by IR in pancreas. The obstruction of gastro-duodenal and inferior splenic arteries induced pancreatic IR in male Wistar rats. Melatonin was intraperitoneally administered before or/and after IR injury. The animals were killed at 24 and 48 hr after reperfusion and there were evaluated parameters of oxidative stress (lipoperoxides, superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione), glandular endocrine and exocrine function (lipase, amylase, insulin) and cell injury (apoptosis and necrosis). The IR induced a marked enhancement of oxidative stress and impaired pancreatic function. The histological analysis showed that IR induced acute pancreatitis with the accumulation of inflammatory infiltrate, disruption of tissue structure, cell necrosis and hemorrhage. Melatonin administration before or after pancreatic IR prevented all tissue markers of oxidative stress, biochemical and histological signs of apoptosis and necrosis, and restored glandular function. No histological signs of pancreatitis were observed 48 hr after reperfusion in 80% of the animals treated with melatonin, with only a mild edematous pancreatitis being observed in the remaining rats. Preventive or therapeutic administration of melatonin protected against the induction of oxidative stress and tissue injury, and restored cell function in experimental pancreatic IR in rats.     

Protective effects of trimetazidine against vascular endothelial cell injury induced by oxidation

Objective To explore the protective effects of trimetazidine on vascular endothelial cells injury induced by hydrogen peroxide (H2O2) and its pharmacological mechanisms of anti-oxidation. Methods Human umbilical vein endothelial cells (HUVECs) were injured by H2O2. Next, the cells were treated with three different concentrations of trimetazidine (1μmol/L,10μmol/L,100μmol/L, respectively). The viability of cells was detected by methyl thiazoeyl tetrazolium (MTT) assay. In addition, malondialdehyde (MDA) contents, superoxide dismutase (SOD) and secretion of NO were measured. Results Trimetazidine could enhance the viability of the injured HUVECs induced by oxidation, decrease the level of MDA, enhance the SOD activity, and increase the secretion of nitrogen monoxide. These effects were in a certain dose-dependent manner and the difference was significant among the three concentrations (P<0.05). Conclusions Our results suggest that trimetazidine may protect lipid peroxidation and prevent oxidation-induced cellular dysfunction of HUVECs.     

Expression of the gene for a membrane-bound fatty acid receptor in the pancreas and islet cell tumours in humans: evidence for GPR40 expression in pancreatic beta cells and implications for insulin secretion

Aims/hypothesis G protein-coupled receptor 40 (GPR40) is abundantly expressed in pancreatic beta cells in rodents, where it facilitates glucose-induced insulin secretion in response to mid- to long-chain fatty acids in vitro. However, GPR40 gene expression in humans has not been fully investigated, and little is known about the physiological and pathophysiological roles of GPR40 in humans. The aim of this study, therefore, was to examine GPR40 expression and its clinical implications in humans.Methods: GPR40 mRNA expression in the human pancreas, pancreatic islets and islet cell tumours was analysed using TaqMan PCR.Results: GPR40 mRNA was detected in all human pancreases collected intraoperatively. It was enriched approximately 20-fold in isolated islets freshly prepared from the pancreases of the same individuals. The estimated mRNA copy number for the GPR40 gene in pancreatic islets was comparable to those for genes encoding sulfonylurea receptor 1, glucagon-like peptide 1 receptor and somatostatin receptors, all of which are known to be expressed abundantly in the human pancreatic islet. A large amount of GPR40 mRNA was detected in insulinoma tissues, whereas mRNA expression was undetectable in glucagonoma or gastrinoma. The GPR40 mRNA level in the pancreas correlated with the insulinogenic index, which reflects beta cell function (r=0.82, p=0.044), but not with glucose levels during the OGTT, the insulin area under the OGTT curve or the index for the homeostasis model assessment of insulin resistance (HOMA-IR).Conclusions/interpretation The present study provides evidence for GPR40 gene expression in pancreatic beta cells and implicates GPR40 in insulin secretion in humans.     

丝胶对2型糖尿病大鼠胰岛细胞凋亡的保护作用

目的观察丝胶对2型糖尿病大鼠胰岛细胞凋亡的保护作用。方法雄性SD大鼠36随机分为3组:正常对照组、糖尿病模型组和丝胶治疗组。链脲佐菌素(STZ,25 mg/kg,连续3 d)腹腔注射建立2型糖尿病大鼠模型;待模型成功建立后,丝胶治疗组大鼠给予丝胶灌胃(2.4 g.kg-1.d-1)35 d。免疫组织化学染色观察胰岛β细胞Bcl-2和Bax蛋白的表达。结果与正常对照组大鼠相比,模型组大鼠胰岛β细胞Bax蛋白的表达明显升高(P<0.01),Bcl-2蛋白的表达明显降低(P<0.01);与模型大鼠相比,丝胶治疗组大鼠胰岛β细胞Bax蛋白的表达明显降低(P<0.01),Bcl-2蛋白的表达明显升高(P<0.01)。结论丝胶可通过上调胰岛β细胞Bcl-2蛋白的表达、下调胰岛β细胞Bax蛋白的表达,抑制2型糖尿病大鼠胰岛细胞凋亡,对糖尿病时胰岛细胞损伤具有一定的保护作用。     

Cytoprotective effects of melatonin against necrosis and apoptosis induced by ischemia/reperfusion injury in rat liver

Abstract:  Melatonin protects against organ ischemia; this effect has mainly been attributed to the antioxidant properties of the indoleamine. This study examined the cytoprotective properties of melatonin against injury to the liver caused by ischemia/reperfusion (I/R). Rats were subjected to 60 min of ischemia followed by 5 hr of reperfusion. Melatonin (10 mg/kg) or the vehicle was administered intraperitoneally 15 min before ischemia and immediately before reperfusion. The serum aminotransferase activity and lipid peroxidation levels were increased markedly by hepatic I/R, which were suppressed significantly by melatonin. In contrast, the glutathione content, which is an index of the cellular redox state, and mitochondrial glutamate dehydrogenase activity, which is a maker of the mitochondrial membrane integrity, were lower in the I/R rats. These decreases were attenuated by melatonin. The rate of mitochondrial swelling, which reflects the extent of the mitochondrial permeability transition, was higher after 5 hr of reperfusion but was attenuated by melatonin. Melatonin limited the release of cytochrome c into the cytosol and the activation of caspase-3 observed in the I/R rats. The melatonin-treated rats showed markedly fewer apoptotic (TUNEL positive) cells and DNA fragmentation than did the I/R rats. These results suggest that melatonin ameliorates I/R-induced hepatocytes damage by inhibiting the level of oxidative stress and the apoptotic pathway. Consequently, melatonin may provide a new pharmacological intervention strategy for hepatic I/R injuries.     

胎鼠胰腺干细胞体外对胰岛的保护作用观察

目的观察胎鼠胰腺干细胞体外对胰岛功能的保护作用。方法将孕16d的sD大鼠胎鼠胰腺干细胞分离、纯化、培养传代,免疫细胞化学法及流式细胞术鉴定;分离纯化sD大鼠胰岛,双硫腙鉴定后分为A组和B组,分别行单纯胰岛培养及胰岛与胰腺干细胞联合培养14d,期间观察胰岛形态变化、检测胰岛存活率及细胞凋亡率,ELISA法检测胰岛素分泌量、计算刺激指数。取两组培养7d后悬浮生长的胰岛移植入糖尿病大鼠左肾包膜下,术后每天尾静脉采血以快速血糖测试仪检测血糖。结果胎鼠胰腺干细胞培养传代3代后免疫细胞化学可见巢蛋白（Nestin）阳性细胞,流式细胞术测定其含量占74．1％;培养第7、14天时B组胰岛存活率显著高于A组（P均〈0．01）,培养第7天时B组胰岛细胞凋亡率显著低于A组（P〈0．05）;培养第7、14天时B组高糖刺激后胰岛素分泌量及刺激指数均显著高于A组（P均〈0．01）;B组移植后大鼠血糖第5天降至正常。结论胎鼠胰腺干细胞与胰岛联合培养可明显延长胰岛体外存活时间并使其保持良好的活性。     

Cardioprotective effects of melatonin against myocardial injuries induced by chronic intermittent hypoxia in rats

Obstructive sleep apnea (OSA) associated with chronic intermittent hypoxia (CIH) increases the morbidity and mortality of ischemic heart disease in patients. Yet, there is a paucity of preventive measures targeting the pathogenesis of CIH‐induced myocardial injury. We examined the cardioprotective effect of melatonin against the inflammation, fibrosis and the deteriorated sarcoplasmic reticulum (SR) Ca²⁺ homeostasis, and ischemia/reperfusion (I/R)‐induced injury exacerbated by CIH. Adult male Sprague Dawley rats that had received a daily injection of melatonin (10 mg/kg) or vehicle were exposed to CIH treatment mimicking a severe OSA condition for 4 wk. Systolic pressure, heart weights, and malondialdehyde were significantly increased in hypoxic rats but not in the melatonin‐treated group, when compared with the normoxic control. Levels of the expression of inflammatory cytokines (TNF‐α, IL‐6, and COX‐2) and fibrotic markers (PC1 and TGF‐β) were significantly elevated in the hypoxic group but were normalized by melatonin. Additionally, infarct size of isolated hearts with regional I/R was substantial in the hypoxic group treated with vehicle but not in the melatonin‐treated group. Moreover, melatonin treatment mitigated the SR‐Ca²⁺ homeostasis in the cardiomyocyte during I/R with (i) Ca²⁺ overloading, (ii) decreased SR‐Ca²⁺ content, (iii) lowered expression and activity of Ca²⁺‐handling proteins (SERCA2a and NCX1),and (iv) decreased expressions of CAMKII and phosphorylated eNOS^ser1177. Furthermore, melatonin ameliorated the level of expression of antioxidant enzymes (CAT and MnSOD) and NADPH oxidase (p22 and NOX2). Results support a prophylactic usage of melatonin in OSA patients, which protects against CIH‐induced myocardial inflammation and fibrosis with impaired SR‐Ca²⁺ handling and exacerbated I/R injury.     

The protective role of Hepatopoietin Cn on liver injury induced by carbon tetrachloride in rats*

Background: Hepatopoietin Cn (HPPCn) is a member of the leucine‐rich acidic nuclear protein family (LANP), and studies of partially hepatectomized (PH) mice show that levels of HPPCn mRNA increase following liver injury. Furthermore, the recombinant human protein (rhHPPCn) was shown to stimulate hepatic DNA synthesis and activate signaling pathways involved in hepatocyte proliferation in vitro and in vivo. Aim: The aim of the study was to evaluate the protective effect of rhHPPCn on liver injury and fibrosis induced by carbon tetrachloride (CCl4) injection. Methods: Wistar rats weighing 200 g were given a single and repeated intraperitoneal injections of CCl4. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity in rat serum were measured using biochemical assay. Hepatic hydroxyproline (Hyp) level was determined in the hydrolysates of liver samples. Immunostaining and Masson's trichrome staining were conducted to evaluate hepatocyte proliferation and fibrosis. Results: The results showed that exogenous rhHPPCn could alleviate hepatocyte necrosis and protect the liver from the development of fibrotic lesions by proliferation stimulation. Additionally, HPPCn could reduce ALT/AST levels in rat serum following single and repeated CCl4 injection. Conclusion: It was suggested that HPPCn could protect hepatocytes from injury induced by CCl4 as a proliferation stimulator.