异丙酚对哮喘豚鼠离体气管平滑肌张力的作用

目的 探讨异丙酚对哮喘豚鼠离体气管平滑肌张力的作用及其作用机制。方法 48只健康豚鼠随机分为哮喘组(n=28)和正常组(n=20),卵蛋白致敏法建立哮喘豚鼠模型,每只豚鼠制备5-7个气管平滑肌环,依据悬挂平滑肌环的营养液中处理因素不同将气管平滑肌环随机分为control亚组、10％Intralipid亚组、10、30、100、300μmol/L Propofol亚组,通过与气管环相连的力-位移换能器记录其张力变化,采用悬挂平滑肌环的营养液中无Ca2+的方法测定异丙酚对Ryanodine受体介导的细胞内Ca2+释放的影响。结果 (1)100μmol/L异丙酚显著舒张哮喘豚鼠静息气管平滑肌。四种浓度异丙酚对乙酰胆碱所致气管平滑肌收缩呈剂量依赖的舒张作用。(2)四种浓度异丙酚预适应可剂量依赖性抑制乙酰胆碱所致气管平滑肌收缩。哮喘组30μmol/L异丙酚预适应使乙酰胆碱所致的气管平滑肌依内钙性收缩由(37.7±2.8)％降为(27.7±1.9)％,依外钙性收缩由(62.3±4.5)％降为(51.5±3.5)％,与control亚组比较差异有显著性(P<0.01)。(3)四种浓度异丙酚抑制乙酰胆碱所致气管平滑肌依内钙性收缩作用,与无Ryanodine作用组比较,差异无显著性(P>0.05)。结论临床相关浓度异丙酚预适应显著抑制乙酰胆碱收缩哮喘豚鼠离体气管平滑肌的作用,其作用机制与Rvanodine受体介导     

粉防己碱舒张离体新西兰白兔阴茎海绵体平滑肌的机制研究

目的观察粉防己碱(tetrandrine,Tet)对阴茎海绵体平滑肌胞内钙释放和胞外钙内流的影响,初步探讨其舒张作用的机制。方法采用离体阴茎海绵体平滑肌肌条张力记录法,观察Tet对去氧肾上腺素(phenylephrine,PE)和氯化钾(KCI)诱导收缩的肌条的影响；采用无Ca~(2 )-复Ca~(2 )实验法,观察Tet对PE诱导的依赖细胞内钙和细胞外钙的肌条收缩反应的影响。结果Tet对PE或kcl诱导的肌条收缩均具有浓度依赖性的抑制作用。100μmol/L Tet可抑制20μmol/L PE引起的依赖细胞内钙和细胞外钙的肌条收缩(P＜0．05)；结论Tet可通过阻滞电压依赖性钙通道、受体依赖性钙通道和抑制细胞内钙库释放,从而介导其对海绵体平滑肌的舒张作用。     

不同靶浓度异丙酚对犬单肺通气时肺内分流的影响

单肺通气(OLV)时发生的缺氧性肺动脉收缩反应(HPV)是机体对缺氧所产生的一种保护性自动调节机制,使非通气侧肺小动脉收缩,肺血管阻力增加,血流向通气侧肺转移,从而改善失调的通气/血流比,减少肺内分流,维持正常的PaO2[1].异丙酚可抑制大鼠离体肺动脉环缺氧性收缩反应,且呈浓度依赖性[2],而不同浓度异丙酚对在体HPV的影响有待进一步探讨.本研究拟通过比较不同靶浓度异丙酚对犬单肺通气时肺内分流的影响,探讨其对HPV的影响,为临床研究提供依据.     

山莨菪碱对离体大鼠腹主动脉舒缩张力的作用及其机制

目的 观察山莨菪碱对离体大鼠腹主动脉舒缩张力的作用,探讨其作用机制.方法 采用Wistar大鼠离体腹主动脉环(长4～5 mm的血管)灌流技术,观察山莨菪碱累积浓度(每5 min加入山莨菪碱,使营养液中山莨菪碱浓度分别达3×10-6,10-5,3×10-5,10-4,3×10-4 mol/L)对单剂量苯肾上腺素(PE)(10-5 mol/L)预处理的血管舒张作用的影响,及不同浓度山莨菪碱(10-6,10-5,10-4 mol/L)预孵对累积浓度PE(每5 min加入PE,使营养液中PE浓度分别达10-8,3×10-8,10-7,3×10-7,10-6,3×10-6 mol/L)收缩血管作用的影响,分别运用一氧化氮合酶抑制剂左旋硝基精氨酸甲酯(L-NAME)(100 μmol/L)(对照组加入等容积的蒸馏水)和KATP通道阻断剂格列苯脲(Gly)(100 μmol/L)(两对照组分别加入等容积的蒸馏水及溶剂二甲基亚砜DMSO)处理血管环,观察对山莨菪碱舒张血管的抑制作用.结果 山莨菪碱累积浓度对单剂量PE预收缩内皮完整及去内皮血管环均有舒张作用,最大舒张分别为(78.6±6.9)%和(65.76±11.39)%.程度相似,差异无统计学意义(P＞0.05).不同浓度山莨菪碱预孵对累积浓度PE收缩血管环作用呈浓度依赖性抑制,浓度越大,抑制作用越明显.用阻断剂L-NAME及Gly处理后,L-NAME可阻断山莨菪碱的舒张血管(内皮完整)作用(P＜0.05),而Gly对去内皮血管具阻断作用,但只在2 min时与对照组差异有统计学意义(P＜0.05).结论 山莨菪碱具有内皮及平滑肌依赖性舒张血管作用,即通过内皮上一氧化氮-环鸟苷酸(NO-cGMP)及平滑肌上α受体发挥作用.山莨菪碱抑制血管收缩主要通过ATP依赖性K+通道发挥作用.     

静脉麻醉药对去甲肾上腺素累积剂量致兔肺动脉环收缩量-效关系的影响

目的:通过硫喷妥钠、异丙酚、氯胺酮对去甲肾上腺素(NE)收缩肺动脉量-效关系的影响,了解三种药物对肺血管平滑肌的直接作用,以及内皮细胞完整性对其作用的影响。方法:制备兔离体肺动脉环,应用DC-001型离体器官测定仪,观察三种药物(1mM)对NE累积剂量量-效曲线的影响。结果:与NE对照组比较,完整内皮时,硫喷妥钠可加强肺动脉环对低浓度NE(10~(-10)M)的收缩反应,高剂量NE(10~(-3)、10~(-4)M)时收缩幅度低于对照组(P<0.05);异丙酚、氯胺酮均使NE累积剂量量-效曲线呈非平行性右移,表现为非竞争性抑制。去内皮时,硫喷妥钠组高剂量NE时收缩幅度与完整内皮时比较有所降低(P<0.05);异丙酚、氯胺酮组高剂量NE时收缩幅度与完整内皮时比较明显增加(P<0.05)。结论:硫喷妥钠增强了NE对肺动脉的收缩作用;异丙酚和氯胺酮均可抑制NE的肺动脉收缩作用,且异丙酚的作用呈内皮依赖性。     

静脉麻醉药对去甲肾上腺素预收缩兔肺动脉环的作用

本研究采用兔离体肺动脉环作为实验标本 ,观察了静脉麻醉药硫喷妥钠(ＳＴＰ)、氯胺酮 (ＫＥＴ)、异丙酚 (ＰＲＯ)对张力正常及去甲肾上腺素 (ＮＥ)预收缩肺动脉环的作用 ,以及肺动脉内皮完整性对药物作用的影响材料与方法一、离体肺动脉环的制备、张力测定和去内皮试验[1] 。二、药物对张力正常肺动脉环的直接作用　将ＰＲＯ以累积剂量 0 0 3ｍｍｏｌ/Ｌ、0 1ｍｍｏｌ/Ｌ、 0 3ｍｍｏｌ/Ｌ、 1 0ｍｍｏｌ/Ｌ、3 0ｍｍｏｌ/Ｌ分别加入浴槽 ,每剂量作用5ｍｉｎ ,观察每种药物对肺动脉环的直接作用。三、药物对去甲肾上腺素 (ＮＥ)预收缩肺…     

内源性一氧化碳对离体犬阴茎海绵体平滑肌的作用

目的:探讨内源性一氧化碳(CO)对离体犬阴茎海绵体平滑肌作用的影响。方法:利用水浴条件下阴茎海绵体肌条的张力测定技术,用CO合成的关键酶血红素氧合酶(HO)的诱导剂———氯高铁血红素诱导海绵体平滑肌生成内源性CO,观察CO对去氧肾上腺素(PE)诱导收缩的阴茎海绵体肌条作用的影响。结果:氯高铁血红素对10μmol/L PE诱导的肌条收缩具有浓度依赖性的松弛作用,10~100μmol/L氯高铁血红素对平滑肌肌条的松弛效应与空白对照相比明显升高(P<0.01)。用锌原卟啉-Ⅸ(ZnPP-Ⅸ)或亚甲蓝孵育处理后的肌条,氯高铁血红素的舒张作用明显减弱(P<0.01)。结论:内源性CO具有浓度依赖性松弛阴茎海绵体平滑肌的作用,其机制可能是通过CO环磷酸鸟苷途径作用所致。     

异丙酚对内毒素性休克大鼠血管反应性的影响

目的评价异丙酚对内毒素性休克大鼠血管反应性的影响。方法40只雄性SD大鼠随机分为4组(n=10),对照组;休克组:静脉注射内毒素(LPS)15 mg·kg-1;异丙酚组:静脉注射LPS 后1 h,静脉注射异丙酚10 mg·kg-1后10 mg·kg-1·h-1持续静脉泵注4 h;5-甲氧色胺组:静脉注射LPS 后1 h,腹腔注射5-甲氧色胺10 mg·kg-1。注射LPS后6 h,各组大鼠依次静脉注射去氧肾上腺素(PE) 0.5、1、2、2.5 μg·kg-1,记录注药后平均动脉压(MAP)的增幅百分比。注射LPS后6 h,经心内穿刺取血, 测定血浆丙二醛(MDA)及一氧化氮浓度(NO2-/NO3-)。所有在体实验结束后取大鼠胸主动脉环做离体张力实验,建立去氧肾上腺素的剂量-张力反应曲线,并计算相应主动脉环最大收缩张力(Emax)、半数有效浓度(EC50)。结果休克组、异丙酚组、5-甲氧色胺组MAP增幅百分比均低于对照组(P< 0.05),异丙酚、5-甲氧色胺组MAP增幅百分比均高于休克组(P<0.05)。异丙酚组、5-甲氧色胺组血浆MDA及NO2-/NO3-浓度均低于休克组(P<0.05)。在离体实验中,休克大鼠主动脉环对PE反应的Emax及EC50与均低于对照组(P<0.05),但是异丙酚组和5-甲氧色胺组主动脉环对PE的反应均升高(P<0.05)。异丙酚组和5-甲氧色胺组主动脉收缩力均高于休克组,并且主动脉环对PE的Emax增高,EC50降低(P<0.05)。结论异丙酚可能通过减少氧自由基,抑制NO的合成,从而改善内毒素性休克大鼠的血管低反应性。     

Tamoxifen对真皮成纤维细胞种植胶原网格的抑制效应

目的 探索Tamoxifen用于治疗皮肤瘢痕挛缩的可能性。方法 将人真皮成纤维细胞种植于Ⅰ型胶原构成的胶原网格内培养，加入1－50μmol/L的Tamoxifen，测定网格收缩率；采用MTT染色法原位观察网格内的细胞形态及活力变化。结果 Tamoxifen对胶原网格收缩具有抑制效应，其浓度低于5μmol/L时对网格收缩无影响，高于30μmol/L时网格收缩被不可逆性完全抑制，处于10－20μmol/L时对网格收缩作用呈现剂量及时间依赖性抑制。MTT染色后观察显示网格收缩变化与处于三维培养的细胞突起伸展状态相关；Tamoxifen并不直接导致网格内的细胞死亡，而是通过抑制细胞功能发挥作用。结论 Tamoxifen可对真皮成纤维细胞体外模拟的瘢痕挛缩产生抑制效应，提示对活体瘢痕挛缩具有潜在的抑制作用。     

丙泊酚对肺动脉高压大鼠肺动脉的作用及机制

目的观察丙泊酚对肺动脉高压大鼠（pulmonary hypertensive rat,PHR）离体肺动脉环的影响,探讨其机制与ATP敏感性钾通道的关系。方法建立PHR模型。分为丙泊酚组和空白对照组。丙泊酚组：PHR离体肺动脉环以去甲肾上腺素（NE）10μmol／L预收缩血管达最大收缩幅度后,加入丙泊酚10、30、100μmol／L,记录张力变化。空白对照组：加入NE10μmol／L收缩稳定后不给任何药物。给100μmol／L丙泊酚前10min给予格列苯脲5μmol／L,观察肺动脉环张力的变化。结果各浓度丙泊酚组均有舒张PHR肺动脉环的作用,与空白对照组对应时点比较,差异有统计学意义（P〈0．01）。各浓度组之间比较差异有统计学意义（P〈0．01）,浓度越高舒张作用越强。格列苯脲可部分拈抗丙泊酚扩张PHR肺动脉环的作用（P〈0．01）。结论本研究表明丙泊酚对PHR肺动脉有舒张作用,该舒张作用与ATP敏感性钾通道有关。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.