还原型谷胱甘肽在离体肝脏保存中应用的实验研究

目的:研究UW液中加入还原型谷胱甘肽在离体肝脏保存中对肝细胞的保护作用。方法:封闭群雄性Wistar大鼠,采用原位灌注切取肝脏,分别用UW液、改良UW液(加入谷胱甘肽0.95g/L)0～4℃保存12h、24h、36h后行Krebs-Henseleit液离体灌注,记录肝脏胆汁分泌总量,并检测灌注流出液AST、LDH含量。结果:随着保存时限延长,灌洗液中AST、LDH值升高,胆汁分泌总量呈下降趋势。12h、24h,两组之间均无统计学差异(P>0.05)。保存36h,两组差异均无统计学意义(P<0.05)。离体灌注液生化指标显示改良UW液组长时间保存时肝脏细胞损伤程度较低。结论:在离体肝脏保存过程中,UW液中加入还原型谷胱甘肽对肝脏长期保存(36h)有保护作用,但24h内对肝脏保存效果影响不大,临床需在24小时内完成肝移植手术,故保存不需要添加还原型谷胱甘肽。     

谷氨酰胺对肝门阻断后肠道损伤的影响及其意义

目的：探讨谷氨酰胺（Gln）对肝门阻断后肠道损伤的影响及其意义.方法：将雄性Wistar大鼠,随机分为三组：假手术组（A组）、对照组（B组）和实验组（C组）.采用Pringle法进行肝门阻断,持续35min,在肝门阻断前C组大鼠腹腔注射Gln.分别于肝门阻断前及再灌注后2、4、24 h,每组各选取10只大鼠,测定肠道组织谷胱甘肽（GSH）、超氧化物歧化酶（SOD）、丙二醛（MDA）的水平,检测血清TNF-α水平以及门静脉血浆内毒素水平.结果：与A组相比,再灌注后B组肠组织中MDA水平增高（P＜0.05）,而GSH及SOD水平下降（P＜0.05）,TNF-α及内毒素水平明显增高（P＜0.05）.再灌注后2h及4h,C组肠道GSH水平均明显高于B组（P＜0.05）.与B组相比,再灌注后C组肠道组织SOD活性明显增高,而MDA水平明显降低（P＜0.05）;血清TNF-α及内毒素水平均明显降低（P＜0.05）.结论：肝门阻断可以造成肠道屏障的破坏;而Gln对肠道屏障具有保护作用,并将减少内毒素易位、炎性因子的释放.     

Glutathione‐S‐transferase‐oxidative stress relationship in the internal spermatic vein blood of infertile men with varicocele

This study aimed to assess glutathione‐S–transferase (GST) enzyme‐ oxidative stress (OS) relationship in the internal spermatic vein (ISV) of infertile men associated with varicocele (Vx). Ninety five infertile oligoasthenoteratozoospemic (OAT) men associated with Vx were subjected to history taking, clinical examination and semen analysis. During inguinal varicocelectomy, GST, malondialdehyde (MDA) and glutathione peroxidase (GPx) were estimated in the blood samples drawn from ISV and median cubital veins. The mean levels of GST, GPx were significantly decreased and the mean level of GPx was significantly increased in the ISV compared with the peripheral blood. The mean level of GST and GPx in the ISV was significantly decreased, and the mean level of MDA was significantly increased in Vx grade III compared with Vx grade II cases. There was nonsignificant difference in the mean level of GST in the ISV in unilateral Vx cases compared with bilateral Vx cases. There was significant positive correlation of GST with sperm count, sperm motility, GPx and significant negative correlation with sperm abnormal forms, MDA. It is concluded that ISV of infertile men associated with Vx has decreased levels of GST compared with peripheral venous circulation that is correlated with both OS and Vx grade.     

大鼠骶髂关节传入神经通路的实验研究

目的:通过逆行神经追踪法研究大鼠骶髂关节的传入神经通路。方法:30只雄性Sprague-Dawley大鼠随机分成非交感神经切除组(A组)和交感神经切除组(B组),每组15只,交感神经切除组切除左侧L1以下椎旁交感干。两组左侧骶髂关节注入30%的辣根过氧化物酶(HRP)20μl,72h后取出双侧的L1-S1背根神经节(DRG),TMB法染色后在光学显微镜下观察HRP阳性神经元细胞并计数。结果:两组左侧L1、L2背根神经节内HRP阳性神经元差异有显著性意义(P<0·05),B组HRP阳性神经元明显减少;左侧L3-S1背根神经节内HRP阳性神经元差异无显著性意义(P>0·05)。结论:L1-S1神经节含有支配同侧骶髂关节的传入神经元,同侧椎旁交感干可能是骶髂关节到L1-L2神经节重要的传入神经旁路,而不是到L3-L5神经节的传入旁路或重要的传入旁路。     

Neuroprotective effects of alpha-lipoic acid in experimental spinal cord injury in rats

Background:

Oxidative stress is a mediator of secondary injury to the spinal cord following trauma.

Objective:

To investigate the putative neuroprotective effect of α-lipoic acid (LA), a powerful antioxidant, in a rat model of spinal cord injury (SCI).

Methods:

Wistar albino rats were divided as control, vehicle-treated SCI, and LA-treated SCI groups. To induce SCI, a standard weight-drop method that induced a moderately severe injury (100 g/cm force) at T10 was used. Injured animals were given either 50 mg/kg LA or saline at 30 minutes postinjury by intraperitoneal injection. At 7 days postinjury, neurologic examination was performed, and rats were decapitated. Spinal cord samples were taken for histologic examination or determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and DNA fragmentation. Formation of reactive oxygen species in spinal cord tissue samples was monitored by using a chemiluminescence (CL) technique.

Results:

SCI caused a significant decrease in spinal cord GSH content, which was accompanied with significant increases in luminol CL and MDA levels, MPO activity, and DNA damage. Furthermore, LA treatment reversed all these biochemical parameters as well as SCI-induced histopathologic alterations. Conversely, impairment of the neurologic function caused by SCI remained unchanged.

Conclusion:

The present study suggests that LA reduces SCI-induced oxidative stress and exerts neuroprotection by inhibiting lipid peroxidation, glutathione depletion, and DNA fragmentation.     

生精冲剂对精索静脉曲张大鼠睾丸生精功能保护作用的研究

目的探讨生精冲剂对精索静脉曲张睾丸损伤的保护作用。方法观察生精冲剂对实验性精索静脉曲张大鼠睾丸组织结构、超微结构的影响。测定各组实验大鼠睾丸超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、乙酰胆碱脂酶(ACE)活性和脂质过氧化物(LPO)、一氧化氮(NO)含量。结果治疗组鼠睾丸组织结构与超微结构的损害程度明显低于模型组,SOD、CAT、ACE活性测定值明显高于模型组,LPO、NO含量明显低于模型组(P<0.01)。结论生精冲剂对精索静脉曲张造成的睾丸损害有保护作用,其提高精子质量和生育率的机制可能与抗脂质过氧化和增强抗氧化酶活性有关。     

The effects of N-acetylcysteine on antioxidant enzyme activities in experimental testicular torsion

Testicular torsion is a serious problem in male children and, if not treated at the right time, can lead to subfertility and infertility. The main reason for testicular damage is ischemia-reperfusion injury. A number of chemical substances have been used to protect testes against ischemia-reperfusion injury in experimental animals. The possible protective effect of N-acetylcysteine on testicular tissue after testicular detorsion was examined in the current study. Twenty-four rats were divided into four groups: sham operation, torsion, detorsion, and NAC + detorsion groups (n = 6 for each group). Excluding sham operation group, the rats were subjected to unilateral torsion (720-degree rotation in clockwise direction). After torsion (5 h) and detorsion (2 h), unilateral orchidectomy was performed. Malondialdehyde levels and superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities were determined in testicular tissue. Administration of N-acetylcysteine caused a decrease in malondialdehyde levels and an increase in glutathione peroxidase levels compared to detorsion group. The results suggest that N-acetylcysteine may be a potential protective agent for preventing the negative biochemical changes related to oxidative stress in testicular injury caused by testis torsion.     

多烯磷脂酰胆碱联合谷胱甘肽治疗妊娠期肝内胆汁淤积症患者的效果及对围产结局的影响

目的探讨多烯磷脂酰胆碱联合谷胱甘肽治疗妊娠期肝内胆汁淤积症(ICP)患者的效果及对围产结局的影响。方法选取2015年1月～2018年12月ICP患者124例,随机分为两组。两组均予以卧床休息、间断吸氧、高渗葡萄糖、维生素C及能量合剂等治疗。对照组在此基础上予以多烯磷脂酰胆碱针15 mL静脉滴注,1次/d;观察组在对照组基础上再加谷胱甘肽针2.4 g静脉滴注,1次/d。两组均连用2周。观察两组治疗后临床症状及血清生化指标改善情况,并比较其围产结局。结果治疗2周后,两组瘙痒评分均较治疗前显著下降(P0.01或P0.05),且观察组下降幅度较对照组更明显(P0.05);观察组黄疸和瘙痒消失时间明显少于或短于对照组(P0.05)。治疗2周后,两组血清ALT、TBA和AST水平均较治疗前明显下降(P0.01或P0.05),且观察组下降幅度较对照组更明显(P0.05)。同时观察组宫内窘迫、早产和新生儿窒息发生率明显低于对照组,分娩出血量明显少于对照组,新生儿体重明显大于对照组(P0.05)。结论多烯磷脂酰胆碱联合谷胱甘肽治疗ICP患者不仅能明显改善其临床症状,降低肝酶指标与胆汁酸水平,而且能降低发生不良围产结局,有利于母婴安全。     

Beta-catenin is temporally regulated during normal liver development

BACKGROUND & AIMS: beta-Catenin, a key component of the Wnt pathway, plays an important role in unregulated liver growth in liver tumors, in regulated growth during liver regeneration, and in ex vivo embryonic liver cultures. METHODS: We used developing livers from several stages of gestational development to examine beta-catenin expression, protein-protein interactions, localization, and regulation in prenatal and postnatal livers. RESULTS: Microarray, Northern, and protein analyses showed peak expression of beta-catenin during early liver development at Embryonic day 10 (E10)-E12, followed by a decrease and a complete loss of normal beta-catenin (97-kilodalton species) after E16 through the remaining prenatal period. At the early stages, beta-catenin localized to the cytoplasm and nuclei of resident cells in addition to its normal membranous localization, which was seen at all later stages and in adult liver. Decreases in beta-catenin levels at E14 onward coincided with its decreased gene expression and increased degradation, as seen by an increase in serine 45/threonine 41-phosphorylated beta-catenin and its other negative regulators, such as axin, adenomatous polyposis coli gene product (APC), and glycogen synthase kinase-3 beta. Finally, we showed an intact association of E-cadherin and beta-catenin despite the loss of beta-catenin at E16-E18, owing to the presence of membrane-associated smaller-molecular-weight beta-catenin species. CONCLUSIONS: We also identified a stage-specific expression and regulation of beta-catenin during liver development that might be crucial for physiological liver development. Nuclear and cytoplasmic beta-catenin corresponded to cell proliferation in liver development. Finally, a smaller-molecular-weight species of beta-catenin might be maintaining normal interactions at the membrane.     

The fate of electron opaque tracers (horseradish peroxidase and lanthanum chloride) during valproic acid-induced choleresis

ABSTRACT— Horseradish peroxidase (HRP) and lanthanum chloride (LaCl₃) are useful tools for, respectively, the study of vesicular transport through the hepatocyte and the study of the permeability of junctional complexes. These tracers have been used to detect the changes associated with the choleresis independent of bile acids induced by valproic acid (VPA) in rats. The animals were given a single dose of VPA (600 mg/kg, ip). HRP (100 mg/kg) or 5 mM LaCl₃ were given intraportally after 1 h, when bile flow had increased twofold. The excretion of HRP in bile was measured colorimetrically up to 2 h after HRP. Ultrastructural morphometry was conducted on liver of intact rats taken from 1 to 40 min after HRP. The volume density (VD) of HRP-containing vesicles and of HRP-containing multivesicular bodies (MVB) was counted. In VPA-treated rats, HRP appeared in bile with a peak showing at 5 min against 20 min in controls, but the total amount of HRP excreted was less than in controls. The intrahepatocytic vesicular transport of HRP was also modified, showing a peak at 3 min in VPA-treated rats compared to 10 min in controls, together with a decreased VD of pericanalicular vesicles. This was accompanied by an increase of HRP-containing MVB, already evident at 5 min. VPA-induced changes in HRP transport through the hepatocytes appeared twofold: 1) during VPA-induced stimulation of bile flow, there was an early and short-lived increase of transcellular transport and biliary elimination of HRP: 2) a diversion of HRP towards the indirect, lysosomal pathway apparently occurred, in agreement with previous findings concerning the formation of numerous cytolysomes induced by VPA (Hepatology 1984: 4 : 1159–1166). The decreased amount of HRP excreted in bile could be accounted for by a diversion of HRP towards the degradation pathway. The pattern of distribution of LaCl₃ was similar in VPA-treated animals and in controls, suggesting that gross structural alterations of the junctional complexes are unlikely to occur during VPA-induced choleresis.