人参二醇组皂苷对人前列腺癌DU145细胞增殖与凋亡的影响

目的 观察人参二醇组皂苷(panoxadiol saponin PDS)体外对DU145前列腺癌细胞增殖及凋亡的影响.方法 采用MTT比色法检测不同浓度PDS对DU145细胞增殖活力的影响.吖啶橙染色观察PDS诱导细胞凋亡情况;流式细胞仪分析细胞周期及凋亡,并计算细胞平均凋亡率;细胞免疫化学和Western blot技术观察细胞内激活的caspase3的表达.结果 经中(100mg/L)、高(200mg/L)剂量的PDS处理后,DU145细胞生长受到不同程度抑制,且呈现剂量依赖性;吖啶橙荧光染色可见经中、高剂量PDS处理后的细胞呈明显凋亡形态,并随药物剂量增加,凋亡细胞数增多;流式细胞术结果显示,PDS可明显提高细胞的凋亡率,呈剂量依赖关系;免疫细胞化学染色和Western blot结果,随着PDS剂量增加,细胞内激活的caspase3的表达上调.结论 PDS体外对DU145细胞增殖具有明显的抑制作用,其机制可能与诱导细胞凋亡有关.     

iNOS基因转染对雄激素非依赖性前列腺癌细胞DU145生长的影响

目的:观察诱导型一氧化氮合酶(iNOS)基因转染对雄激素非依赖性前列腺癌细胞DU145生物学行为的影响。方法:将iNOS基因转染到DU145细胞并筛选出阳性细胞进行扩增,并设空载体组和对照组。观察细胞的形态变化,MTT法绘制生长曲线;流式细胞术检测细胞凋亡率;了解NOS抑制剂对转染细胞的影响。结果:转染iNOS后,DU145细胞分泌的NO[(272.50±15.82)μmol/L]显著高于空载体组[(122.00±18.93)μmol/L]和对照组[(121.00±6.98)μmol/L](P<0.05)。流式细胞术检测结果提示转染iNOS组细胞凋亡率[(42.78±2.01)%]明显高于空载体组[(30.65±1.46)%]和对照组[(28.96±1.50)%](P<0.05)。MTT测定结果提示转染组细胞生长较空载体组和对照组减慢(P<0.05),NOS抑制剂可以加快其生长,但无显著性差异(P>0.05)。结论:iNOS基因转染可以使DU145细胞分泌较高浓度的NO,诱导细胞凋亡,抑制细胞生长,为晚期雄激素非依赖性前列腺癌的基因治疗提供一个有效的靶点。     

硼替佐米增强前列腺癌细胞对NK细胞介导细胞杀伤作用的敏感性

目的:探讨硼替佐米是否能够增强前列腺癌细胞对NK细胞介导杀伤作用的敏感性,以及是否在不同类型的人前列腺癌细胞系中有相似的作用。方法:以激素依赖性的前列腺癌细胞株LNCaP和激素非依赖性的前列腺癌细胞株DU145为模型,不同浓度(0、5、10、15、20、25nmol/L)硼替佐米处理细胞后,CCK-8法检测肿瘤细胞的增殖,Annexin V/PI法检测细胞凋亡率。结果:15、20、25nmol/L硼替佐米处理DU145细胞48、72h后,各处理组细胞的增殖率分别为(82.79±2.04)%、(73.59±2.95)%、(74.16±6.16)%和(71.24±5.30)%、(51.20±2.91)%、(38.02±2.67)%,同样处理LNCaP细胞后,各处理组细胞的增殖率分别为(77.04±7.74)%、(42.61±6.62)%、(23.85±6.04)%和(36.45±7.02)%、(14.94±5.76)%、(11.65±5.87)%。与对照组相比,硼替佐米强烈抑制两种细胞系的增殖(P0.05)。15、20、25nmol/L硼替佐米处理DU145细胞24h后,DU145细胞的凋亡率分别为(14.41±1.32)%、(16.13±1.55)%、(14.48±1.42)%,而在LNCaP细胞,20、25nmol/L硼替佐米处理24h后,凋亡率为(12.77±1.28)%和(14.84±1.65)%,与对照组相比有统计学差异(P0.05),DU145细胞对硼替佐米诱导的凋亡作用较LNCaP细胞更加敏感。但是,在短期分析中硼替佐米不能致敏两种细胞系对NK细胞介导的杀伤作用。在长效分析中,用硼替佐米处理肿瘤细胞后,20nmol/L硼替佐米+NK组诱导的DU145细胞和LNCaP细胞凋亡率分别为(41.83±5.06)%和(30.31±3.62)%,较单独应用硼替佐米或者NK细胞更高(P0.05)。结论:硼替佐米能够应用于致敏前列腺癌细胞对NK细胞介导的杀伤作用的敏感性,提高当前前列腺癌的治疗水平。而且此治疗策略对雄激素非依赖性的前列腺癌患者更有效。     

PPARa激动剂非诺贝特诱导前列腺癌DU145细胞氧化损伤和凋亡的作用

目的探讨过氧化物酶体增殖因子激活受体α激动剂非诺贝特诱导雄激素非依赖性前列腺癌DU145细胞氧化损伤和凋亡的作用及可能机制。方法用0、50、100μmol/L浓度的非诺贝特作用于DU145细胞,24h后利用荧光显微镜和流式细胞仪检测各组细胞中活性氧、超氧化物阴离子、一氧化氮含量和细胞凋亡率的变化。Westernblot检测细胞内凋亡相关蛋白BCL-2和BAX的表达变化。结果不同浓度非诺贝特作用细胞后细胞凋亡率显著上调,活性氧、超氧化物阴离子和一氧化氮含量较对照组明显上升并呈剂量依赖性(P<0.05)。50μmol/L非诺贝特作用后,DU145细胞内BCL-2表达明显下调,BAX表达升高。结论非诺贝特能诱导前列腺癌细胞DU145氧化损伤和细胞凋亡,其机制可能与氧化应激增强及抗凋亡蛋白表达下降有关。     

全反式维甲酸诱导前列腺癌DU145细胞凋亡中caspase-3及其细胞骨架蛋白F-actin的变化

目的探讨全反式维甲酸(ATRA)诱导雄激素非依赖型前列腺癌细胞系DU145凋亡过程中半胱氨酰天冬氨酸特异性蛋白酶(caspase)3及其细胞骨架蛋白F-actin的变化。方法应用吖碇橙(AO)染色,荧光显微镜观察细胞凋亡形态,流式细胞术(FACScan)测定ATRA对DU145细胞凋亡峰的形成,应用Westernblot测定ATRA在DU145细胞凋亡过程中caspase-3表达的变化,免疫荧光染色观察F-actin纤丝的形态。结果荧光显微镜观察细胞凋亡数目增多,48h时凋亡细胞比例为85.0%,流式细胞术检测可观察到凋亡峰,Westernblot检测显示裂解的caspase-3表达增多,免疫荧光染色可见F-actin的正常结构被破坏。结论ATRA诱导DU145细胞凋亡可能通过caspase-3介导,并导致细胞骨架蛋白破坏。     

AXL表达在前列腺癌细胞多西他赛耐药中的作用研究

目的:观察AXL表达在前列腺癌PC-3和DU145细胞多西他赛化疗耐药中的作用及可能机制。方法:应用Western印迹测定多西他赛刺激PC-3和DU145后AXL蛋白表达,通过多西他赛浓度递增间断刺激PC-3和DU145细胞,建立耐药细胞PC-3-DR和DU145-DR,应用Western印迹测定PC-3和DU145细胞耐药前后AXL,AXL磷酸化蛋白激酶(p-AXL)及配体蛋白生长阻滞特异性因子-6(Gas6)蛋白表达。用脂质体Lipofectamine 2000将经过筛选证实有效的AXL-shRNA序列和阴性NCshRNA序列转染PC-3和DU145细胞,应用CCK8和流式细胞仪检测转染前后加入多西他赛后的细胞增殖和凋亡情况。应用MTT和流式细胞仪检测加入AXL抑制剂MP470和多西他赛单独及联合应用的细胞增殖率、凋亡率和细胞周期分布。Western印迹检测AXL抑制剂R428,多西他赛单独或联合处理耐药细胞后ABCB1的表达情况。结果:多西他赛刺激PC-3和DU145细胞后,AXL表达上升(P0.05);与PC-3和DU145细胞相比,PC-3-DR和DU145-DR中AXL,p-AXL蛋白表达明显上升,Gas6蛋白表达明显下降(P均0.05)。AXL转染PC-3和DU145后的细胞经多西他赛处理48 h,细胞增殖率分别为(51.03±3.16)%和(57.39±2.37)%,明显高于未转染细胞(36.41±4.28)%和(45.5±3.93)%(P0.05),转染后细胞凋亡率分别为(42.37±3.43)%和(39.54±2.39)%,明显低于未转染细胞(65.48±3.16)%和(54.98±2.84)%(P0.05)。MP470可明显抑制细胞增殖和促进耐药细胞凋亡,MP470与多西他赛联合应用后的耐药细胞增殖抑制率和凋亡率明显高于单独应用,联合应用后G2/M期细胞百分数亦明显高于单独应用(P均0.05)。R428可明显降低耐药细胞的ABCB1表达,与多西他赛联用后,ABCB1的蛋白表达水平明显低于单独用药组(P均0.05)。结论:AXL表达上调可促进前列腺癌PC-3和DU145细胞耐药,AXL抑制可增加细胞对多西他赛的敏感性,这一作用可能与G2/M期细胞凋亡率升高和ABCB1表达降低有关。     

ABL-N诱导前列腺癌细胞凋亡及其机制

目的 探讨旋覆花内酯(ABL)-N诱导前列腺癌细胞凋亡的作用及其机制.方法 0～40μmol/L ABL-N分别处理前列腺痛细胞后,利用噻唑蓝(MTF)检测对细胞增长的抑制作用;流式细胞学、TUNEL染色等方法检测其诱导凋亡的作用,并检测Capase活性,Western blot测定bax、bel-2水平变化.结果 ABL-N明显抑制前列腺癌细胞PC3、LNCaP及DU145的生长,并呈剂量依赖性.40 μmol/L ABL-N作用24 h后,(73.34±4.41)%的PrEC细胞存活,而3种前列腺癌细胞分别为(11.92±2.31)%、(12.55±1.94)%、(13.28±2.26)%.膜联蛋白/碘化丙锭(Annexin V/PI)及TUNEL染色表明ABL-N呈剂量依赖性诱导PC3凋亡.ABL-N可激活Caspase活性,尤其Caspase-3,20μmol/L ABL-N作用24 h后其活性是对照组的4.23倍;bax/bcl-2比率随浓度增加明显增高.结论 ABL-N可通过Caspase途径及bax/bcl-2蛋白途径,诱导PC3等前列腺癌细胞凋亡,抑制前列腺癌细胞增殖.

Abstract：

Objective To explore the ABL-N-induced apoptosis of human prostate cancer cells and the mechansim. Methods After administration of 0-40 μmol/L ABL-N for 24 h, the effects of ABL-N on the induction of apoptosis in human prostate cancer cells PC3 were measured by methyl thiazol tetrazolium ( MTT) colorimetry, Annexin V/propidium iodide staining and TUNEL staining. The levels of bax and bcl-2 were tested by Western blotting. Caspase activity was assayed. Results ABL-N treatment to PC3,LNCaP, and DU145 cells resulted in a dose-dependent inhibition of cell growth without any substantial effect on normal human prostate epithelial PrEc cells. About (73. 34 ±4. 41)% of PrEC cells were viable following a 24-h exposure to 40 μmol/L ABL-N, whereas only (11. 92 ± 2. 31) % of PC3, (12. 55 ±1. 94) % of LNcap, and (13. 28 ± 2. 26) % of DU145 cells survived under similar conditions of ABL-N treatment. ABL-N treatment resulted in a dose-dependent induction of apoptosis of PC3 cells. Furthermore,ABL-N induced the activation of Caspases, especially Caspase 3. The Caspase-3 activity of PC3 cells treated with ABL-N (20 μmol/L) (0. 95) was significantly increased by about 4. 2-fold of the untreated cells (0. 24) at 24 h. The ratio of bax/bcl-2 was also increased significantly. Conclusion ABL-N induces apoptosis though the activation of Caspase 3 and pro- and anti-apoptotic Bcl-2 family proteins in prostate cancer cells.     

环巴胺对DU145细胞增殖和细胞周期的影响

目的:研究Hedgehog信号通路阻断剂(环巴胺)对DU145细胞增殖的抑制作用。方法:不同浓度(1、10、50、100μmol/L)环巴胺干预DU145细胞,分别在24、48、72h后采用噻唑蓝比色法检测其对细胞增殖的抑制作用;流式细胞术检测环巴胺对细胞周期的影响;RT-PCR检测50μmol/L环巴胺作用48h后实验组和对照组细胞周期蛋白E(cyclinE)mRNA表达水平的差异。结果:环巴胺对DU145细胞的抑制作用呈时效和量效依赖关系,当浓度>10μmol/L作用24h后会显著抑制细胞增殖,10、50、100μmol/L浓度组对细胞的抑制率分别为7.42%、12.70%和59.15%,与空白对照组相比,差异有统计学意义(P<0.05)。流式细胞术检测发现,当环巴胺浓度达10μmol/L以上,干预48h后G1期细胞比例明显升高。对照组、10、50μmol/L浓度组的G1期细胞百分比分别为:(52.17±2.21)%、(60.13±2.75)%和(74.30±3.52)%,差异有统计学意义(P<0.01);凋亡峰也随环巴胺浓度增加而逐渐增高。50μmol/L环巴胺作用48h后DU145细胞cyclinEmRNA表达显著降低,与空白对照组相比降低61.90%(P<0.01)。结论:环巴胺可以抑制DU145细胞的增殖能力,其机制可能与下调DU145细胞cyc-linEmRNA表达水平,从而将DU145细胞阻滞于G1期有关。环巴胺亦可以诱导DU145细胞凋亡。     

Sorafenib对前列腺癌DU145细胞的抑制作用的研究

目的 观察索拉非尼(Sorafenib)对雄激素非依赖性前列腺癌DU145细胞的抑制作用.方法 用不同浓度Sorafenib处理前列腺癌DU145细胞24、48和72 h后,MTT法检测Sorafenib对DU145细胞的抑制作用,流式细胞仪检测细胞凋亡变化,Western blot检测不同浓度Sorafenib处理72 h后DU145细胞内ERK和Bcl-2的表达.结果 Sorafenib能显著抑制DU145细胞的体外生长,呈时间与剂量依赖性.DU145细胞凋亡率随着Sorafenib剂量的增加而增大,具有良好的量效关系(P<0.01);Sorafenib处理DU145细胞72 h后,ERK和Bcl-2蛋白的表达明显下调(P<0.01).结论 Sorafenib抑制DU145细胞增殖、诱导细胞凋亡,可显著抑制雄激素非依赖性前列腺癌细胞的体外生长.     

鱼藤素诱导人前列腺癌细胞凋亡及其机制研究

目的 观察鱼藤素对于激素抵抗型前列腺癌(HRPC)细胞PC3和DU145增殖、细胞周期和凋亡的影响并探讨其机制.方法 设阴性对照组(有细胞但不加药),空白对照组(无细胞仅有培养液),阳性对照组(渥曼青霉素100 nmoL/L),及鱼藤素分别10、100、1 ìmol/L共6组.CCK-8法进行细胞毒性实验,检测细胞生长抑制率.流式细胞术检测细胞周期和凋亡,Westem-blot检测Akt、MAPK及其磷酸化蛋白表达,探讨药物作用机制.结果 10 nmol/L～1 ìmol/L鱼藤素对PC3细胞均有生长抑制作用,呈现明显的时间、浓度依赖性,对DU145细胞则无此作用.鱼藤素使PC3细胞出现G2/M期阻滞现象并引起浓度依赖性的凋亡,而未改变DU145细胞的周期分布也不能诱导其凋亡.鱼藤素能够阻断P13K/AKT通路而对MAPK通路无影响.结论 鱼藤素通过阻断PI3K/AKT通路实现抑制PC3细胞增殖、诱导凋亡的作用.两株细胞间实验结果 的差异是因为其PI3K/AKT通路活化状态的差异造成的.     

Reduction of Plasma Fibrinogen, Immunoglobulin G, and Immunoglobulin M Concentrations by Immunoadsorption Therapy with Tryptophan and Phenylalanine Adsorbents

Abstract Immunoadsorption (1A) therapy with tryptophan (TR-350) or phenylalanine (PH-350) adsorbents has been used to reduce the concentration of serum antibodies in human lymphocyte antigen (HLA)-immunized patients. Other forms of plasma purification have been reported to reduce the level of fibrinogen, which affects the blood properties. In this study we investigated the effects of IA therapy using both adsorbents on plasma fibrinogen and immunoglobulins G and M in 13 patients (8 patients were treated with TR-350, and 5 patients were treated with PH-350). During each session 1 plasma volume (2.8 ± 0.4 L of plasma) was processed through the immunocolumn and then returned to the patient together with the blood cells. Compared with the pretreatment values, the plasma fibrinogen, IgG, and IgM concentrations were significantly reduced after IA therapy (p < 0.01 for TR-350; p < 0.04 for PH-350). There was a positive correlation between the degree of reduction of plasma proteins and the number of IA treatments given. A nonpara-metric test (Wilcoxon's signed-rank test or the Mann-Whitney test) was used for statistical analysis. We conclude from our study that IA therapy effectively lowers the plasma levels of fibrinogen, IgG, and IgM and thus can be considered a valuable alternative to other blood purification methods.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

The multiply injured child

Blunt trauma is the principal cause of childhood death in many developed countries. This review outlines the differences between adults and children with respect to resuscitation and treatment of orthopaedic injuries in a child with polytrauma. Recent advances in techniques of fracture stabilization are reported.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.     

Intravenous endotoxin does not increase tissue extravasation of albumin in rats

Background : It is unclear whether activation of the inducible nitric oxide synthase (iNOS) increases or decreases the extravasation of plasma.
Methods : Chloralose anaesthetised male Wistar rats received E. coli lipopolysacharide (LPS), 3 mg kg^-1 i.v., or the corresponding volume of saline, 3 or 5 h before the end of the experiment. Mean arterial pressure (MAP) and heart rate (HR) were recorded. Tissue clearance of radio-labelled albumin, during the last 2 h of each experiment, was determined by a double-isotope method. In separate animals, the serum concentration of nitrite and nitrate was determined, 5 h after LPS or the solvent.
Main Results : LPS initially decreased MAP and lastingly increased HR. In the 3-h LPS animals (n=8), tissue plasma clearance was lower in the heart and calf muscle and increased only in diaphragm, compared to corresponding control animals (n=8). In the 5-h LPS rats, clearance was lowered (n=8) in the entire gastrointestinal tract and in testes, compared to controls (n=8). The serum nitrite/nitrate concentration was higher in animals given LPS (n=6) than in controls (n=6).
Conclusion : After LPS, tissue clearance of albumin was not increased in any major tissue, in spite of increased serum levels of NO end products. Apparently, after activation of iNOS, the augmented release of NO is not necessarily associated with increased albumin extravasation.     

Adrenaline markedly improves thoracic epidural analgesia produced by a low-dose infusion of bupivacaine, fentanyl and adrenaline after major surgery: A randomised, double-blind, cross-over study with and without adrenaline

Background: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. Methods: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml · h^?1 of bupivacaine 1 mg · ml^?1, fentanyl 2 μg · ml^?1, and adrenaline 2 μg · ml^?1 were included. On the 1^st and 2^nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. Results: The number of hypaesthetic dermatomal segments decreased (P <0.001) and pain intensity at rest and when coughing increased (P <0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15–20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng · ml^?1 (P <0.01), and there was more sedation during the period without adrenaline. Conclusions: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.