NF—κB、TNF-α仪在腹部火器伤肠管穿透后肝损伤机制中的作用

目的：探讨核因子-καB、肿瘤坏死因子-α在腹部火器伤肠管穿透后肝损伤中的作用。方法：健康长白仔猪42头随机等分为对照组和伤后1h、2h、4h、8h、12h和24h组,实验组建立腹部火器伤肠管穿透模型后,用免疫组化图像分析法测定各组肝内NF-κB、TNF-α表达,同时测定肝细胞凋亡和血清中ALT变化情况,在光镜下观察各组肝脏组织学变化。结果：伤后各组肝内NF-κB表达、TNF-α表达、肝细胞凋亡指数和血清ALT水平明显高于对照组,NF-κB表达于伤后1h和8h出现2个高峰（P〈0、05）;TNF-α表达、肝细胞凋亡指数和血清ALT水平于伤后2h和12h出现2个高峰（P〈0．05）;且第2个高峰值均大于第1个高峰值（P〈0．05）。伤后1h,2h、4h组出现逐渐加重的肝细胞水肿、变性,伤后8h、12h、24h组出现逐渐加重的肝细胞点状坏死、灶状坏死和炎细胞浸润,对照组光镜下未见明显的损伤性变化。结论：腹部火器伤肠管穿透后,NF-κB可能在促进肝细胞凋亡的同时使TNF-α仪表达增多来共同介导肝损伤。     

奥美沙坦减轻高脂饮食诱导的非酒精性脂肪肝病的机制研究

目的探讨奥美沙坦对于高脂诱导的非酒精性脂肪肝病（NAFLD）的影响及可能机制。方法健康雄性8周龄C57BL／6小鼠24只随机分为高脂组（n=16）和正常饮食组（n=8）,高脂组小鼠高脂饮食（60％的脂肪）12w后再随机分为高脂饮食对照组（n=8）、高脂饮食治疗组（n=8）。高脂饮食治疗组小鼠给予0．75mg／kg／d的奥美沙坦灌胃8w,灌胃结束后处理小鼠,留取空腹血样本检测AST和ALT。肝组织冰冻切片行油红O染色观察脂肪变;石蜡切片行HE和F4／80免疫组化染色观察肝脏炎症变化;实时荧光定量PCR检测肝脏TNF-α和IL-6mRNA的表达水平;WesternBlot检测肝组织中IκB-α、p-IκBa、NF—κB信号通路的活化。结果奥美沙坦显著抑制了高脂诱导的NAFLD脂肪变性,并明显改善肝功能。实时荧光定量PCR结果表明奥美沙坦能显著降低肝脏组织中TNF-α和IL-6mRNA表达水平（P〈0．05）;Western Blot结果显示奥美沙坦显著抑制肝脏NF-κB信号通路活化。结论奥美沙坦显著抑制NAFLD小鼠肝脏炎性病变而保护肝功能,其机制与抑制NF-κB信号通路活化以及降低肝脏TNF-α和IL-6mRNA水平有关。     

NF-κB和TNF-α在暴发性肝衰竭肝组织中的表达及其意义

目的探讨NF-κB,TNF-α与暴发性肝衰竭发生、发展的关系及其意义。方法雄性Wistar大鼠腹腔注射D-GalN＋LPS制造暴发性肝衰竭模型,采用免疫组化方法动态观察肝组织中NF-κB p65蛋白和TNF-α表达情况。结果①动态观察了暴发性肝衰竭病理变化过程。②模型组NF-κB p65蛋白表达阳性细胞主要为肝细胞、枯否细胞。造模后4h、8h、12h时核阳性表达的细胞数逐渐增多,明显高于对照组。2h组主要是非实质细胞的胞质着色。而4h、8h、12h、24h组以肝细胞胞核着色为主。对照组不同时间点NF-κB p65蛋白表达无明显差异（P〉0．05）。模型组则随着肝细胞坏死程度的增加而增加（r=0．694,P〈0．01）。③随着肝细胞炎症坏死程度的增加,模型组肝细胞质TNF-α表达逐渐增加（r=0．896,P〈0．01）,以肝细胞表达为主。对照组肝细胞质TNF-α表达较弱（P〉0．05）。④肝组织中NF-κB活化与TNF-α表达呈密切正相关（r=0．852,P〈0．01）。结论NF-κB和TNF-α参与了暴发性肝衰竭的发生发展。NF-κB可能是暴发性肝衰竭肝细胞炎症坏死过程中的关键环节。     

银杏黄酮对非酒精性脂肪肝模型小鼠的作用及NF-κB在其机制中的相关性分析

本文观察银杏黄酮对非酒精性脂肪性肝(NAFLD)模型小鼠的作用,并分析NF-κB与小鼠肝脏脂肪变性及血清丙氨酸氨基转移酶(ALT)的相关性。170只昆明小鼠随机分为正常对照组、模型组、银杏黄酮高[300mg/(kg·d)]、中[150 mg/(kg·d)]、低[75 mg/(kg·d)]剂量组。采用高脂饲料构建非酒精性脂肪肝小鼠动物模型,分别于给药后4周、8周和12周末处死,观察肝脏病理变化,计算肝指数,检测血清总胆固醇(TC)、ALT、TNF-α以及肝组织NF-κB的表达。各剂量银杏黄酮组小鼠肝指数,血清TC、ALT和TNF-α水平,肝组织NF-κBp65的表达量比模型组显著降低,肝脏脂肪变性明显减轻(P0.05或P0.01);肝组织NF-κBp65相对表达量与肝脏脂肪变性程度及血清ALT含量呈正相关(r0、P0.01或P0.05)。实验结果表明:银杏黄酮可降低NAFLD小鼠血脂、减轻肝脏脂肪变性、改善肝功能指标及肝脏大体形态,且有一定的剂量和时间依赖性;NF-κB上游炎症通路可能是其作用的主要机制。     

基于HMGB1/TLR4/NF-κB信号通路探讨忍冬苷对脓毒症肝损伤大鼠的影响

摘要 目的：基于高迁移率族蛋白B1（HMGB1）/Toll样受体4（TLR4）/核因子κB（NF-κB）信号通路探讨忍冬苷对脓毒症肝损伤大鼠的影响。方法：60只雄性SD大鼠随机分为模型组、对照组、阳性对照组（地塞米松10 mg/kg）、忍冬苷低剂量（7.5 mg/kg）、忍冬苷中剂量（15 mg/kg）、忍冬苷高剂量（30 mg/kg）组,每组10只。采用盲肠结扎穿刺法建立大鼠脓毒症模型。实验结束后麻醉大鼠取血制备血清,检测血清中超氧化物歧化酶（SOD）活性和丙二醛（MDA）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、白介素-10（IL-10）含量;分离肝组织称重,计算肝脏指数,一部分用于HE染色观察肝组织病理变化,一部分用于制备组织匀浆检测组织中肝功能指标谷丙转氨酶（ALT）、天冬氨酸转氨酶（AST）活性及HMGB1、TLR4、NF-κB蛋白表达。结果：与对照组比较,模型组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著增加（P＜0.05）,SOD活性与IL-10含量显著下降（P＜0.05）;且肝组织出现明显病灶,肝细胞水肿变性,大量炎性细胞浸润。与模型组比较,阳性对照组与忍冬苷各剂量组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著降低（P＜0.05）,SOD活性与IL-10含量显著升高（P＜0.05）;忍冬苷低、中剂量组仍可见病灶和水肿,但病变减轻;地塞米松组与忍冬苷高剂量组肝细胞结构趋于正常,未发现病灶。与阳性对照组比较,忍冬苷低、中剂量组大鼠血清中MDA、TNF-α、IL-6含量、肝脏指数以及肝组织中AST、ALT活性、HMGB1、TLR4、NF-κB蛋白表达显著升高（P＜0.05）,SOD活性与IL-10含量显著降低（P＜0.05）;忍冬苷高剂量组上述指标无显著差异（P＞0.05）。结论：忍冬苷通过下调HMGB1/TLR4/NF-κB信号通路的表达,抑制氧化应激,减轻炎症反应,改善肝功能,发挥对脓毒症肝损伤的保护作用。     

抑制性寡脱氧核苷酸对实验性肝损伤细胞因子的影响

探讨抑制性寡脱氧核苷酸（suppressive oligonucleotides,Sup ODN）对刀豆蛋白A（Con A））诱导的小鼠实验性肝损伤的保护作用．实验采用Balb／C小鼠40只,随机分4组．分别为生理盐水（NS）组、对照寡脱氧核苷酸（control oligonucleotides,Con ODN）组、环孢菌素A（cyclosporin A,CsA）组、Sup ODN组．Con A（20mg,kg）尾静脉注射Ba1b/C小鼠,2h时腹腔给药,给药8h时观察小鼠的血清丙氨酸氨基转移酶（ALT）活性、死亡率;检测血清TNF-α、IFN-γ、TIL-4水平;RT-PCR检测肝组织TNF-α、IFN-γ mRNA的表达;并观察肝组织的病理改变．发现Sup ODN组与NS组、Con ODN组相比,ALT活性明显降低（P〈0．01）;与NS组、Con ODN组和CsA组比较,IFN-γ明显降低（P〈0．01）,IL-4明显升高（P〈0．01）,TIFN-γ mRNA表达亦显著减少：而且Sup ODN可明显减轻肝脏炎性细胞浸润和肝细胞坏死（P〈0．05）．实验表明Sup ODN对Con A小鼠实验性肝损伤有明显保护作用．     

NF-κB、TNF-α在腹部火器伤肠管穿透后肝损伤机制中的作用

目的:探讨核因子-καB、肿瘤坏死因子-α在腹部火器伤肠管穿透后肝损伤中的作用.方法:健康长白仔猪42头随机等分为对照组和伤后1 h、2h、4h、8h、12h和24h组,实验组建立腹部火器伤肠管穿透模型后,用免疫组化图像分析法测定各组肝内NF-κB、TNF-α表达,同时测定肝细胞凋亡和血清中ALT变化情况,在光镜下观察各组肝脏组织学变化.结果:伤后各组肝内NF-κ B表达、TNF-α表达、肝细胞凋亡指数和血清ALT水平明显高于对照组,NF-κB表达于伤后1h和8h出现2个高峰(P＜0.05);TNF-α表达、肝细胞凋亡指数和血清ALT水平于伤后2h和12h出现2个高峰(P＜0.05);且第2个高峰值均大于第1个高峰值(P＜0.05.伤后1h、2h、4h组出现逐渐加重的肝细胞水肿、变性,伤后8h、12h、24h组出现逐渐加重的肝细胞点状坏死、灶状坏死和炎细胞浸润,对照组光镜下未见明显的损伤性变化.结论:腹部火器伤肠管穿透后,NF-κB可能在促进肝细胞凋亡的同时使TNF-α表达增多来共同介导肝损伤.     

牛磺酸对肢体缺血／再灌注后肝损伤大鼠TNF-α、NF-κB表达的影响

目的：探讨给予牛磺酸预处理对肢体缺血／再灌注（limb ischemia-reperfusion,H／R）后大鼠肝脏损伤及,INn、NF—KB表达的影响及意义。方法：采用Wistar大鼠建立LI/R损伤模型,随机分为4组（n=10）：对照（C）组,缺血／再灌注（I／R）组,牛磺酸（T）组和牛磺酸＋缺血／再灌注（TR）组。比色法测定动物血浆ALT、AST、MDA,肝组织MDA、MPO、DNA裂解率和钙含量,放免法检测血浆及肝组织TNF-α水平;HE染色观察肝脏组织形态改变;免疫组化法观察NF-κB蛋白表达。结果：与C组比较,I／R和TR组各损伤性指标、TNF-α水平均升高,NF-κB蛋白表达增高（P〈0．01）;但TR组上述各项指标较I／R组显著降低。结论：牛磺酸预处理可减轻大鼠LI／R所致肝脏损伤,降低TNF-α、NF-κB表达。     

芒果苷对大鼠酒精性肝炎的保护作用研究

研究芒果苷(MFN)对大鼠酒精性肝炎(AH)的保护作用及其作用机制。将实验大鼠随机分为正常组、模型组、水飞蓟宾组(SYN,20 mg/kg)和MFN高、低剂量组(100、50 mg/kg),采用灌胃给予40%酒精(10 m L/kg)建立AH大鼠模型,同时给予药物治疗。4周后,检测血清中ALT、AST、TBIL、DBIL和IBIL的浓度,肝组织中TNF-α和IL-6的水平以及NF-κB mRNA的表达,并观察肝组织HE和油红O染色情况。结果表明,模型组大鼠血清中ALT、AST、TBIL、DBIL和IBIL的浓度明显升高(P0.01),肝组织中TNF-α和IL-6含量以及NF-κB mRNA表达水平亦明显升高(P0.01),同时肝脏出现大量空泡病变、肝细胞肿胀、脂肪变性、炎性细胞浸润等现象。MFN高、低剂量组对上述指标异常均有明显的改善作用(P0.01,P0.05),肝细胞病变程度明显减轻,并且具有剂量依赖性。因此,MFN具有良好的抗AH的作用,其作用机制可能与促进肝细胞修复,调节肝细胞炎症因子TNF-α、IL-6水平和NF-κB的mRNA表达有关。     

Cell Surface Expression of I-A Products Is Required for Contact Sensitivity Induction by Trinitrophenyl-Coupled Epidermal Cells

Trinitrophenyl (TNP)-coupled epidermal cells (EC) injected subcutaneously (s.c.) were more capable of inducing contact sensitivity (CS) to 2, 4, 6-trinitro-1-chlorobenzene (TNCB) than similarly substituted spleen cells (TNP-SC). Furthermore, the intravenous (i.v.) or intraperitoneal (i.p.) injection of TNP-EC also induced CS responses, whereas the i.v. or i.p. injection of TNP-SC failed to induce them. Treatment of mice with cyclophosphamide (Cy; 50 mg/kg) or anti I-J serum allowed animals injected with TNP-SC i.v. to develop significant CS responses, suggesting that Cy-sensitive and I-J positive regulatory cells were involved in the induction of unresponsiveness by the i.v. injection of TNP-SC. Mapping studies of the major histocompatibility gene complex (MHC) region demonstrated that identity at the I-A subregion alone between EC donor and recipient mice was sufficient for the induction of CS by TNP-EC given i.v. Blocking experiments using antisera in the absence of complement indicated that I-A subregion-encoded antigens on the surface of TNP-EC apparently are involved in the induction of CS, and are not simply phenotypic markers on the surface of accessory cells.     

In vivo delivery of interleukin-6 using vaccinia virus: effects on T lymphocytes in nude mice

We have constructed a recombinant vaccinia virus (VV) expressing the human interleukin-6 (IL-6) gene, VV(IL-6). After injection of VV(IL-6) i.v. into Balb/c mice, circulating IL-6 was detected during 3 days with the peak activity on day 4, indicating that VV injection is an effective method to deliver lymphokines in vivo. We have further examined the effects of IL-6 in vivo in immunodeficient mice. Nude mice were injected i.v. with VV(IL-6). Ten days after the injection, mice were sacrificed and spleen cells were obtained. Spleen cells from VV(IL-6) injected mice proliferated remarkably in response to IL-2, while spleen cells from mice injected with unrelated VV manifested no particular proliferation in response to lymphokines. When spleen cells were further cultured in vitro for 5 days in the presence of Concanavalin-A stimulated rat spleen cell supernatant (Con-A factor), CD4 or CD8 positive cells were detected in the VV (IL-6) injected group, while few positive cells were detected in the control groups. These results suggest that IL-6 stimulates nude mice spleen cells in vivo, to a stage where they are able to proliferate in response to IL-2, or to differentiate into CD4 or CD8 positive cells in presence of rat Con-A factor.     

The In-Vivo Use of Superparamagnetic Iron Oxide Nanoparticles to Detect Inflammation Elicits a Cytokine Response but Does Not Aggravate Experimental Arthritis

BackgroundSuperparamagnetic Iron Oxide Nanoparticles (SPION) are used in diagnostic imaging of a variety of different diseases. For such in-vivo application, an additional coating with a polymer, for example polyvinyl alcohol (PVA), is needed to stabilize the SPION and prevent aggregation. As the particles are foreign to the body, reaction against the SPION could occur. In this study we investigated the effects that SPION may have on experimental arthritis after intra-articular (i.a.) or intravenous (i.v.) injection.MethodsPVA-coated SPION were injected either i.a. (6 or 24 μg iron) or i.v. (100 μg or 1 mg iron) into naïve Toll-like receptor-4 deficient (TLR4-/-) or wild-type C57Bl/6 mice, or C57Bl/6 mice with antigen-induced arthritis. As control, some mice were injected with PVA or PBS. MR imaging was performed at 1 and 7 days after injection. Mice were sacrificed 2 hours and 1, 2, 7, 10 and 14 days after injection of the SPION, and RNA from synovium and liver was isolated for pro-inflammatory gene expression analysis. Serum cytokine measurements and whole knee joint histology were also performed.ResultsInjection of a high dose of SPION or PVA into naïve knee joints resulted in an immediate upregulation of pro-inflammatory gene expression in the synovium. A similar gene expression profile was observed after SPION or PVA injection into knee joints of TLR4-/- mice, indicating that this effect is not due to LPS contamination. Histological analysis of the knee joints also revealed synovial inflammation after SPION injection. Two hours after i.v. injection of SPION or PVA into naïve mice, an upregulation of pro-inflammatory gene expression was detected in the liver. Administration of SPION or PVA into arthritic mice via i.a. injection did not result in an upregulation in gene expression and also no additional effects were observed on histology. MR imaging and histology showed long-term retention of SPION in the inflamed joint. However, 14 days after the injections no long-term effects were evident for gene expression, histology or serum cytokine concentrations.ConclusionsInjection of SPION, either locally or systemically, gives an acute inflammatory response. In the long term, up to 14 days after the injection, while the SPION reside in the joint, no further activating effects of SPION were observed. Hence, we conclude that SPION do not aggravate arthritis and can therefore be used safely to detect joint inflammation by MR imaging.     

Generation of tumor-specific cytotoxic T lymphocytesin vivo by combined treatment with inactivated tumor cells and recombinant interleukin-2

In order to search for a new therapy that would maximize the effect of interleukin-2 (IL-2) in evoking antitumor immunity in vivo, the therapeutic effect of a combination of mitomycin-C(MMC)-treated tumor cells and recombinant IL-2 was examined for its induction of antitumor activity against established melanoma metastasis. In C57BL/6 mice intravenously (i. v.) injected with B16 melanoma cells on day 0, the combined treatment with an intraperitoneal (i. p.) injection of MMC-treated melanoma cells on day 6 and 2500 U rIL-2 (twice daily) on days 7 and 8 markedly reduced the number of pulmonary metastases. This antitumor activity was more effective than that in untreated controls and mice that were injected with MMC-treated melanoma cells alone or rIL-2 alone. When the i. p. injection of MMC-treated tumor cells was replaced by other syngeneic tumor cells, antitumor activity against metastatic melanoma was not induced. The antitumor activity induced by this treatment increased in parallel with an increase in the dose of rIL-2 injected. In contrast, an i. p. injection of soluble tumor-specific antigens alone could induce only a marginal level of antitumor activity, and this activity was not augmented by subsequent i. p. injections of rIL-2. In vivo treatment with anti-CD8 monoclonal antibody (mAb), but not with anti-CD4 mAb or anti-asialo-GM1 antibody, abrogated the antitumor activity induced by this combined therapy. This suggests that the antitumor effect was dependent on CD8⁺ T cells. Lung-infiltrating lymphocytes from mice that had been i. v. injected with melanoma cells 11 days before and were treated with this combined therapy, showed melanoma-specific cytolytic activity. This combined therapy also showed significant antitumor activity against subcutaneously inoculated melanoma cells. These results demonstrate that the combined therapy of an i. p. injection of MMC-treated tumor cells and subsequent and consecutive i. p. administration of rIL-2 increases antitumor activity against established metastatic melanoma by generating tumor-specific CD8⁺ CTL in vivo.     

Experimental autoimmune encephalomyelitis (EAE) induced by antigen pulsed dendritic cells in the C57BL/6 mouse: influence of injection route.

Dendritic cells (DCs) are the most potent antigen-presenting cells (APC) of the immune system, and are critically involved in initiation of immune responses in autoimmune diseases. They can modulate the nature of immune responses to stimulatory or tolerogenic fashion. Previous studies have demonstrated that the administration route of DCs is an important variable in eliciting anti-tumor immunity. In this study we used experimental autoimmune encephalomyelitis (EAE) as an animal model of multiple sclerosis to compare different protocols of DC delivery in autoimmunity or tolerance induction. Dendritic cells were generated from bone marrow cells of C57BL/6 mice by culturing in the presence of GM-CSF and IL-4 for 7 days, followed by 2 days culture with TNF-alpha. The obtained DCs were pulsed in vitro with myelin oligodendrocyte glycoprotein (MOG) peptide and injected (5 x 10(5) cells/mouse) via the intravenous (i.v.), intraperitoneal (i.p.) or subcutaneous (s.c.) route into female C57BL/6 mice. In some instances pertussis toxin was also injected zero and 48 hours after DC injection. After follow up of the mice pretreated in this way for 4 weeks, in the i.v. group in which no clinical signs of EAE occurred, the mice were immunized with MOG peptide for EAE induction via the common method and the results were compared with mice that were not pre-immunized. Only after three s.c. DC injections with pertussis toxin, the mice showed mild clinical signs of EAE, whereas mice given i.v. or i.p. injections with or without pertussis toxin failed to develop EAE after 4 weeks. Induction of EAE via the common method after three injections of TNF-alpha treated DCs, in i.v. injected groups showed no protection from EAE. It seems that several factors influence the tolerance versus immunity induction by DCs. Our results showed that the administration route of DCs is one of the pivotal factors in DC-based induction of autoimmune diseases.     

Migration of iron-labeled KHYG-1 natural killer cells to subcutaneous tumors in nude mice, as detected by magnetic resonance imaging

Background aimsA novel cell line of cytotoxic natural killer (NK) cells, KHYG-1, was examined in vivo for immunotherapy against prostate cancer. The feasibility of using magnetic resonance imaging (MRI) tracking to monitor the fate of injected NK cells following intravenous (i.v.), intraperitoneal (i.p.) and subcutaneous (s.c.) administration was assessed.MethodsPC-3M human prostate cancer cells were injected s.c. into the flank of nude mice (day 0). KHYG-1 NK cells were labeled with an iron oxide contrast agent and injected s.c., i.v. or i.p. on day 8. Mice were imaged by MRI on days 7, 9 and 12. Tumor sections were examined with fluorescence microscopy and immunohistologic staining for NK cells.ResultsNK cells were detected in the tumors by histology after all three administration routes. NK cells and fluorescence from the iron label were co-localized. Signal loss was seen in the areas around the tumors and between the tumor lobes in the s.c. group.ConclusionsWe are the first to label this cell line of NK cells with an iron oxide contrast agent. Accumulation of NK cells was visualized by MRI after s.c. injection but not after i.v. and i.p. injection.     

Effects of thymoquinone on liver miRNAs and oxidative stress in Ehrlich acid mouse solid tumor model

We investigated the effects of thymoquinone (TQ) on the expression of liver microRNAs (miRNAs), liver histopathology and oxidative stress in Ehrlich acid solid tumor model induced mice. We used 24 male BALB/c mice divided randomly into three groups. Control (C) group mice were injected intraperitoneally (i.p.) with 0.5 ml saline for four weeks. Tumor (T) group mice were injected i.p. with 0.5 ml saline for four weeks, then Ehrlich acid tumor cells were injected subcutaneously into the neck to induce solid tumor formation. TQ (T + Tq) group mice injected i.p. with 10 mg/kg TQ for four weeks, then Ehrlich acid tumor cells were injected subcutaneously into the neck of the mice in this group to induce solid tumor formation. At the end of the study, liver from all groups were removed for histopathological and miRNAs analysis, and oxidative stress measurement. We found that the expression of miR-206b-3p was up-regulated and the oxidative stress and necrosis increased in the liver tissue of mice with Ehrlich acid solid tumor. TQ application decreased the oxidative stress, prevented necrosis, increased regeneration and down-regulated the expression of miR-206b-3p in the liver tissue.     

Central injection of nicotine increases hepatic and splenic interleukin 6 (IL-6) mRNA expression and plasma IL-6 levels in mice: involvement of the peripheral sympathetic nervous system.

Accumulating evidence suggests that plasma levels of interleukin 6 (IL-6), a major cytokine stimulating the synthesis of acute-phase proteins, are intimately regulated by the central nervous system. Nicotine, one of the major drugs abused by humans, has been shown to affect immunological functions. In the present study, effects of intracerebroventricular (i.c.v.) injection of nicotine on plasma IL-6 levels were investigated in mice. Nicotine administered i.c.v. dose-dependently increased plasma IL-6 levels; the lowest effective dose was 0.3 ng/mouse and the maximal effect was attained with the dose of 105 ng/mouse. The nicotine (105 ng/mouse, i.c.v.)-induced plasma IL-6 levels peaked at 3 h and approached basal levels 6 h after injection. Mecamylamine, a nicotinic receptor antagonist, blocked nicotine-induced plasma IL-6 levels. Depletion of peripheral norepinephrine with 6-hydroxydopamine [100 mg/kg, intraperitoneal (i. p.)] inhibited the nicotine-induced plasma IL-6 levels by 57%, whereas central norepinephrine depletion with 6-hydroxydopamine (50 microgram/mouse, i.c.v.) had no effect. Pretreatment with prazosin (alpha1-adrenergic antagonist; 1 mg/kg, i.p.), yohimbine (alpha2-adrenergic antagonist; 1 mg/kg, i.p.), and ICI-118,551 (beta2-adrenergic antagonist; 2 mg/kg, i.p.), but not with betaxolol (beta1-adrenergic antagonist; 2 mg/kg, i.p.), inhibited nicotine-induced plasma IL-6 levels. Among the peripheral organs, including the pituitary, adrenals, heart, lung, liver, spleen, and lymph nodes, nicotine (105 ng/mouse, i.c.v.) increased IL-6 mRNA expression only in the liver and spleen, which was inhibited by peripheral norepinephrine depletion. These results suggest that stimulation of central nicotinic receptors induces plasma IL-6 levels and IL-6 mRNA expression in the liver and spleen via the peripheral sympathetic nervous system, alpha1-, alpha2-, and beta2-adrenoreceptors being involved.     

Immunoscintigraphy using different methods of applying a 99mTc labeled monoclonal anti-CEA-antibody in the staging of patients with liver metastases before partial hepatectomy

It was the aim of this study to determine the value of portal-venous (p.v.), intra-arterial (i.a.) or intravenous (i.v.) IS in the detection of liver metastases. Immediately after angiography and i.a. CT (20 patients) or p.v. CT (6 patients), 0.7–1.2 GBq of the ^99mTc labeled anti-CEA MoAb were injected via the i.a. catheter, and in 10 patients i.v. Planar scanning was performed. Using IS in the detection of liver metastases a total sensitivity of 61% was established. However, IS was still found to be the decisive method of excluding extrahepatic tumor deposits.     

Endothelin-induced sudden death and the possible involvement of platelet activating factor (PAF)

Endothelin (5 nmol/kg, i.v.) caused a transient hypotension followed by a lasting hypertension in rats. However, an abrupt fall in the blood pressure was observed in most rats 6 to 30 min after the injection of endothelin and sudden death followed with lethality noted over 60 min. An abnormal electrocardiogram (ECG) (ventricular arrhythmias) was observed in rats injected with endothelin. Endothelin (i.v.) also caused sudden death in mice. Pretreatment (5 or 60 min) with specific PAF antagonists, CV-6209 (0.1-3 mg/kg, i.v.) and WEB 2086 (30 mg/kg, p.o.), and a calcium channel blocker, diltiazem (60 mg/kg, p.o.) prevented death and attenuated the ECG changes induced by endothelin, but CV-6209 did not prevent the blood pressure changes induced by endothelin. CV-6209 (0.5-3 mg/kg, i.v.), WEB 2086, diltiazem and dexamethasone (5 mg/kg, i.v.) protected mice against the death induced by endothelin. On the other hand, aspirin (cyclooxygenase inhibitor, 100 mg/kg, p.o.) did not protect mice from the death. Thus, endothelin is a highly toxic peptide with cardiotoxic effects, and PAF may be involved in the pathogenesis of the sudden death.