Variations in peroxisomal catalase of neonatal rat hepatocyte subpopulations

Alcohol consumption during pregnancy is teratogenic and induces severe alterations in hepatocytes. In the hepatocyte peroxisomal system, ethanol is converted in the presence of H₂O₂ to acetaldehyde and water. Therefore, peroxisomal catalase also acts as an antioxidant defence mechanism by removing H₂O₂ and preventing the formation of hydroxyl radicals in the cell. Alterations in peroxisomal catalase after pre- and pre+postnatal alcohol exposure were investigated in the rat. The effect of pre- and postnatal exposure to ethanol on hepatocyte subpopulations was analysed in isolated hepatocytes originating from periportal, intermediate and perivenous zones. Analysis of catalase revealed that the total activity and content of this enzyme were higher in 12-day-old cells than in cells from newborns and that this increment was more pronounced in treated cells. In controls, the amount of peroxisomal catalase increased mainly in periportal cells, whereas alcohol exposure induced a significant increase in the catalase of perivenous hepatocytes. We conclude that pre- and postnatal alcohol exposure mainly affects the perivenous hepatocyte peroxisomes and that the increase in peroxisomal catalase could constitute a defence mechanism against free radical generation induced by alcohol exposure during the perinatal period.     

Hepatocyte isolation from pig livers after warm ischaemic injury

Abstract Hepatocyte cultures have been used extensively for a wide variety of physiological, pharmacological and experimental studies. The warm ischaemic period before isolation is kept to a minimum to achieve a high yield of cells isolated and a good viability for culture. We have recently introduced a new concept of liver resuscitation after warm ischaemia that is based on a 3-h reperfusion period with an improved perfusate and simultaneous dialysis. In this study, we applied the new technique for hepatocyte isolation from livers subjected to 80 min of complete ischaemia at 37 °C. Cell yield was improved by a resuscitating perfusion from 58% to 73% and viability from 39% to 76%.     

闭合型双循环生物人工肝支持系统治疗犬急性肝功能衰竭实验研究

目的探讨和评价闭合型双循环生物人工肝支持系统(CBC-BALSS)在治疗犬急性肝功能衰竭模型过程中的稳定性、安全性和有效性。方法建立犬急性肝功能衰竭模型(门腔分流联合胆总管离断),采用CBC-BALSS进行支持治疗。20只模型犬分为两组CBC-BALSS治疗组(n=11);无肝细胞CBC-BALSS对照组(n=9)。治疗时限6h。检测实验犬血氨、生化全套、凝血因子(FactorⅦ)、支/芳氨基酸(BCAA/AAA)、单乙基甘氨酸二甲苯胺(monoethylglycinexylidide,MEGX)和细胞循环路生化全套、肝细胞密度和数量。结果CBC-BALSS细胞回路细胞悬液总体积200ml,肝细胞的总数1×1010个、密度5×107/ml、活率98%左右。治疗中16只犬的生命体征平稳,在治疗30min内均出现一过性低血压;2只转流开始15min出现过敏反应;1只转流中因上消化道出血死亡;1只因穿刺部位出血死亡。模型治疗前血氨、ALT、TBil/DBil、白蛋白、FactorⅦ和BCAA/AAA分别达150mmol/L、400U/L、80/55mmol/L、35g/L、20%和1.6;CBC-BALSS治疗6h后,血氨、TBil/DBil下降均显著低于对照组;ALT存在下降趋势且在第6小时差异有统计学意义;白蛋白、FactorⅦ和BCAA/AAA在所有时段、组间差异均无统计学意义。在治疗1h和2h,MEGX差异有统计学意义,治疗组MEGX比对照组提前2h达最高点。治疗15~30min后,双循环路压力至115mmHg趋于平稳,且在±5mmHg波动。在治疗过程中,治疗组细胞循环路ALT显著性升高;组间细胞循环路TBil/DBil变化差异无统计学意义,而两组在各时间点均显著性升高;白蛋白变化无统计学意义。结论CBC-BALSS治疗犬急性肝功能衰竭过程中,安全、有效、稳定且代谢支持作用明显。     

High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel

Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 10⁷ cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit.     

7例肝细胞体内移植患者临床护理需求的探讨

目的观察肝细胞体内移植术的有效性与安全性,探讨相应的护理需求。方法从自愿捐献者的肝脏内分离纯化肝细胞,制成悬液,经股动脉插管行脾动脉灌注移植,观察治疗后肝衰竭患者的肝功能恢复率、恢复时间、治疗不良反应及患者心态变化,针对不良反应及患者心理给予完善护理,建立肝细胞体内移植术护理规范。结果7例肝衰竭患者治疗后,4例临床治愈,有效率为57.1%,胆红素、凝血酶原活动度改善50%以上的发生时间约在术后4周。术后患者不同程度出现恶心、呕吐(57.1%),少量腹水(57.1%),肝性脑病(42.9%),发热(42.9%),穿刺点皮下血肿(28.6%),肺部真菌感染(14.3%)。术后71.4%的患者有焦虑情绪。经过相应的临床及心理护理,症状均有不同程度的改善。结论肝细胞体内移植可延长终末期肝病患者生存期,但病情明显改善所需时间约4周,防治肝性脑病、预防穿刺点皮下血肿及运用心理护理消除患者焦虑情绪是重要的护理需求。     

Dietary restriction: effects of short-term fasting on protein uptake and cell death/proliferation in the rat liver

Dietary restriction (DR) is known to prolong life in laboratory animals. Intermittent (alternate-day) fasting or short-term repeated fasting has also been reported to increase the life span of animals. In the present study, we investigated the changes or induction of abnormalities of protein metabolism in rats during fasting, and measured asialoglycoprotein uptake and cell death/proliferation in the liver of rats receiving fasting and refeeding. In the results, liver weight decreased significantly after 48 h of fasting and increased during the refeeding period, returning to the pre-fasting level by 12 h of refeeding. Cell death, determined by single stranded DNA (ssDNA) staining method, increased during the fasting period, and returned to the pre-fasting level during the refeeding period. Cell proliferation, determined using antibodies (Ab) against proliferating cell nuclear antigen, decreased during the fasting period, and increased during the refeeding period. Changes in cell death and cell proliferation were inversely related. However, there was no significant difference in asialoglycoprotein uptake by the whole liver between the ad libitum (AL)-fed rats and 48 h fasted rats. Thus, neither the changes in liver weight nor cell death/proliferation affected asialoglycoprotein uptake on a living body. These results suggest that episodes of 48 h fasting do not induce protein metabolism abnormalities in the liver.     

Localization of Hepatocyte Growth Factor and Its Receptor met in Endocrine Cells and Related Tumors of the Gut and Pancreas: An Immunohistochemical Study

Hepatocyte growth factor (HGF), a stimulator of angiogenesis and cell migration, regulates the growth of a wide variety of cells by binding to its high-affinity receptor met and is involved in the growth and aggressiveness of several tumors. In this study we investigated the expression of HGF and met in normal endocrine cells and related neoplasms of the gut and pancreas to verify their possible role in tumor pathogenesis, growth, and aggressiveness. Normal tissues and 60 different endocrine tumors were immunostained using specific antibodies directed against HGF, met, and various hormones. HGF immunoreactivity (IR) was found in antroduodenal G cells, rectal enterochromaffin (EC) cells, and pancreatic A and B cells, whereas met IR was detected in antral EC and G cells, and in pancreatic B cells; 46 of 60 tumors examined were positive for HGF, and they were mainly represented by ECL-, EC-, and L-cell neoplasms. met IR was identified in 50/60 tumors of various phenotypes. HGF and met coexpression was found in 42/60 cases, most of which were represented by EC-cell tumors. HGF/met coexpression was significantly more frequent in ileolonic EC-cell tumors, which in the majority of cases were malignant, than in appendiceal EC-cell tumors, which were all benign. Our results demonstrated, for the first time, that HGF and met are specifically distributed in normal gut and pancreatic endocrine cells and, in addition, suggest that HGF and met may be implicated as autocrine/paracrine factors regulating the growth of gastroenteropancreatic endocrine tumors, mainly of ileocolonic EC-cell carcinoids.     

Effect of hepatocyte growth factor on sperm motility

PROBLEM: Hepatocyte growth factor (HGF) exists abundantly in seminal plasma and its receptor, c-met, is expressed on spermatozoa. Considering its motogenic activity, we speculated that HGF might affect the movement ability of spermatozoa. METHODS: Recombinant HGF was added to washed spermatozoa and their movements were analyzed using a computer-assisted sperm analyzer. The concentration of HGF in the seminal plasma of infertile patients (n = 83) was measured by ELISA, and the data were compared with their hormonal profile and semen parameters. RESULTS: The HGF physiological concentration (1 ng/mL) maintained the motility of sperm after a long incubation, though the difference was not statistically significant. Recombinant HGF did not affect the linearity or frequency of movement, which suggested that it does not evoke the hyperactivation of spermatozoa. The concentration of HGF in seminal plasma did not correlate with any clinical parameter of the patients. CONCLUSIONS: These findings contradict the theory that HGF controls the movement of sperm. The main role of this axis in the male reproductive system might be maturation in the epididymis.     

Effect of rectal administration of rebamipide on dextran sulfate sodium-induced colitis: Role of hepatocyte growth factor

Objective and design: Since rebamipide is effective for the treatment of ulcerative colitis (UC), we examined the involvement of hepatocyte growth factor (HGF) in the action of rebamipide. Materials: Fifty-five and forty female Balb/c mice, respectively, were used in Exp. 1 and 2. Treatment: 50 mg/kg/day rebamipide (Exp. 1) and 1 × 10⁷ pfu pAxCAHGF (the CAG promoter-driving HGF gene in adenovirus vector) (Exp. 2) were intrarectally introduced after induction of colitis by 4 % dextran sulfate sodium (DSS). Methods: Therapeutic effects were assessed by cell proliferation and apoptosis. Results: Rebamipide caused proliferation of epithelial cells at 10 days after treatment, and decreased apoptosis at 10, 14 and 21 days, compared with controls. Expression of HGF was greatly increased in rebamipide-treated mice. pAxCAHGF caused cell proliferation and apoptosis, which showed the same pattern as with rebamipide treatment. Conclusions: Rectal administration of rebamipide is effective for DSS-induced colitis in association with induction of HGF. Received 17 June 2006; returned for revision 23 August 2006; returned for final revision 29 October 2006; accepted by I. Ahnfelt-R?nne 14 December 2006     

肌动蛋白是大鼠肝细胞核基质的组分之一

目的：证实肌动蛋白存在于大鼠肝细胞核基质中。方法：应用SDS－PAGE法分析大鼠肝细胞核基质的组分,以肌动蛋白多克隆抗体进行Westem Blot免疫印迹检测。结果：核基质蛋白SDS－PAGE图谱中可见相当于肌动蛋白的43KD条带,Westem Blot分析证实核基质中存在肌动 蛋白条带。结论：肌动蛋白是大鼠肝细胞核基质的组分之一。