体外构建皮肤基底膜的组织学特征

目的观察制备的组织工程皮肤基底膜的组织学特征。方法取门诊正常儿童包皮环切术之包皮，采用胰蛋白酶胶原酶顺序消化得到角质形成细胞（KC）和成纤维细胞（Fb）悬液。制备复方壳多糖组织工程皮肤，浸没培养3d后，继续行气液界面培养。将培养7、10、15d的复方壳多糖组织工程皮肤用中性甲醛溶液固定后石蜡包埋、切片，行HE及高碘酸-雪夫（PAS）染色，并用免疫组织化学染色法观察基底膜的重要成分：Ⅳ型胶原、Ⅶ型胶原及层黏连蛋白（LN）的存在情况。结果HE染色可见培养的组织工程皮肤表皮结构分化良好，大致可分为基底层、棘层和角质层，各层均有数量不等的扁平梭形细胞。PAS染色显示真皮表皮间有一均匀红染的条带。免疫组织化学染色结果显示，Ⅳ型胶原、Ⅶ型胶原及LN呈阳性表达。结论复方壳多糖组织工程皮肤基底膜构建良好。     

培养基钙浓度对复方壳多糖组织工程皮肤基底膜构建的形态学研究

目的寻找最适于组织工程皮肤生长及基底膜构建的体外培养基钙浓度。方法按照鲁元刚等建立的方法制备复方壳多糖组织工程皮肤，根据培养基钙浓度不同，分为1．00、1．45、1．65和1．95mmol／L四组。在37℃、5％CO2及90％以上湿度孵箱内浸没培养3d后，将培养物置于不锈钢筛网上进行气一液界面三维培养，每天换液1次。培养7、15d，行HE、PAS染色观察组织工程皮肤的组织学特性；并利用免疫组织化学染色对基底膜的主要成分——Ⅳ型胶原进行观察，评价基底膜构建情况。结果各组组织工程皮肤组织学观察类似正常皮肤，有分化良好的表皮和致密真皮，但1．95mmol／L组表皮分化较其他组更好；1．00、1．45及1．65mmol／L组角化层外侧常伴未角化的角质形成细胞，1．95mmol／L组表皮细胞角化完全，且与颗粒层细胞结合牢固。PAS染色显示各组真、表皮间有紫红色带状结构；免疫组织化学染色显示真皮与表皮间Ⅳ型胶原反应呈阳性，且1．95mmol／L组阳性反应强于1．00mmol／L组。结论钙浓度为1．95mmol／L的培养基最适合于复方壳多糖组织工程皮肤生长及基底膜构建。     

应用胶原凝胶构建组织工程化皮肤的研究

目的探讨以胶原凝胶为支架材料构建组织工程化皮肤的可行性。方法体外分离、培养人皮肤表皮细胞和成纤维细胞；利用自制的胶原蛋白制成胶原凝胶作为组织工程支架材料；在成功构建人工真皮的基础上种植表皮细胞，构建复合人工皮肤；采用HE染色与免疫组织化学的方法对复合人工皮肤进行组织学检测。结果HE染色可见，构建的复合人工皮肤具有表皮和真皮双层结构；免疫组织化学染色显示，Ⅳ型胶原、纤维连接蛋白和层粘连蛋白阳性，在形态结构上与正常皮肤相似。结论培养的人表皮细胞和成纤维细胞种植于胶原凝胶支架上，气一液界面培养可构建出具有类似正常皮肤结构的组织工程化皮肤。     

不同代次角质形成细胞构建组织工程皮肤的增殖分化能力比较

目的 比较三维条件下不同代次角质形成细胞构建的表皮形态及增殖分化情况.方法 采用不同代次角质形成细胞构建组织工程皮肤,通过苏木精-伊红(HE)和高碘酸-希夫(PAS)染色,观察各组组织工程皮肤的结构形态;并利用角蛋白CK1/CK10、CK5/CK14、细胞增殖核抗原Ki-67免疫组织化学染色,比较各组组织工程皮肤表皮的增殖分化能力.结果 不同代次角质形成细胞构建的组织工程皮肤都有明显的表皮真皮结构.1、2代较其他代次分层情况好,2代表皮层厚度明显高于其他代次(P＜0.05).加Ⅳ型胶原组的表皮真皮间黏附的紧密程度高于未加Ⅳ型胶原组,Ⅳ型胶原对表皮的厚度影响不大(P＞0.05).Ⅳ型胶原组PAS染色阴性,说明单独加Ⅳ型胶原不能形成基底膜结构.2代角质形成细胞Ki-67增殖系数接近正常皮肤,其余各代次角质形成细胞的增殖系数逐渐减少(P＜0.05).CK1/CK10、CK5/CK14在1、2代皮肤中阳性表达明显,其余代次对于两种角蛋白的表达并不明显.结论 3代以前角质形成细胞有更好的增殖分化能力,更适合作为组织工程皮肤的种子细胞.     

应用胶原凝胶构建组织工程化皮肤的研究

目的探讨以胶原凝胶为支架材料构建组织工程化皮肤的可行性。方法体外分离、培养人皮肤表皮细胞和成纤维细胞;利用自制的胶原蛋白制成胶原凝胶作为组织工程支架材料;在成功构建人工真皮的基础上种植表皮细胞,构建复合人工皮肤;采用HE染色与免疫组织化学的方法对复合人工皮肤进行组织学检测。结果HE染色可见,构建的复合人工皮肤具有表皮和真皮双层结构;免疫组织化学染色显示,Ⅳ型胶原、纤维连接蛋白和层粘连蛋白阳性,在形态结构上与正常皮肤相似。结论培养的人表皮细胞和成纤维细胞种植于胶原凝胶支架上,气-液界面培养可构建出具有类似正常皮肤结构的组织工程化皮肤。     

组织工程口腔黏膜固有层修复皮肤缺损的初步研究

目的探讨两种组织工程口腔黏膜固有层移植修复皮肤缺损的效果.方法分别以胶原凝胶和壳多糖-胶原凝胶为网架与体外培养的Wistar大鼠口腔黏膜成纤维细胞构建胶原凝胶口腔黏膜固有层(fibroblast-populated collagen lattice,FPCL)、壳多糖-胶原凝胶口腔黏膜固有层(fibroblast -populated chitosan collagen lattice,FPCCL),用BrdU标记其中的成纤维细胞后,移植修复同种异体大鼠背部全层皮肤圆形缺损.将36只21～25周龄Wistar大鼠分为FPCL组、FPCCL组及创口仅覆盖纱布的对照组,每组12只.术后行大体观察创面愈合情况;4、7、14和21 d 3组创面直径测量;组织学及免疫组织化学染色观察其组织修复情况.结果术后大鼠创面均无感染,创面结痂在14及17 d自然脱落,创面逐渐愈合,被新生表皮覆盖,术后21 d新生皮肤光滑,颜色与正常皮肤接近,无体毛.术后各时间点3组创面直径均逐渐变小,差异有统计学意义(P＜0.01),14 d以后,创口大小较稳定.术后7 d,FPCL组受植创面比FPCCL组受植创面和对照组创面小(P＜0.01).组织学观察:术后7 d,3组创面未完全表皮化;14、21 d,FPCL组、FPCCL组受植区完全表皮化,有钉突,对照组无明显钉突,表皮已分层,基底细胞层完整,最表面有角化物;真皮中新生胶原纤维细,含毛细血管.免疫组织化学染色显示,FPCL组、FPCCL组术后各时间点阳性成纤维细胞出现在肉芽组织的细胞密集处和新生真皮中,与新生肉芽组织共同参与了皮肤缺损的修复重建,未出现免疫排斥现象.结论口腔黏膜成纤维细胞作为修复皮肤缺损的种子细胞是可行和有效的,壳多糖胶原凝胶在限制受植区创面收缩变小方面优于单纯胶原凝胶.FPCL和FPCCL两组新生皮肤的质量优于对照组,两种组织工程口腔黏膜固有层作为皮肤缺损区永久性真皮替代物是可行和有效的.     

自体BMSCs复合胶原膜修复猪全层皮肤缺损

目的 探讨自体BMSCs与胶原膜复合构建组织工程皮肤修复小型香猪全层皮肤缺损,为组织工程皮肤的临床应用提供实验依据.方法 取4只贵州小型香猪骨髓各20 mL培养BMSCs,传至第3代.取新鲜牛肌腱通过化学交联的方法制备成直径为5 cm的圆形Ⅰ型胶原膜.将密度为2×107个/mL第3代BMSCs用DAPI标记后种植到Ⅰ型胶原膜上孵育24 h,制备组织工程皮肤.在猪背部正中线两侧分别由前向后切取5个直径5 cm、深达筋膜的圆形全层皮肤缺损创面,随机分为两组(n=10).对照组行单纯Ⅰ型胶原膜修复,实验组行组织工程皮肤修复.于术后3、8周,观察创面愈合情况,并取材行HE染色及透射电镜观察,并于术后3周对实验组行荧光显微镜及糖原染色观察.结果 动物均存活至实验完成.术后3周对照组创面约40%皮肤发黑、结痂、坏死,8周时仍见坏死组织且瘢痕挛缩明显;术后3周实验组创面皮肤成活,无明显瘢痕形成,8周创面愈合良好;两组创面愈合率差异有统计学意义(P<0.01).组织学观察:术后3周对照组可见肉芽组织增生,无表皮层覆盖:实验组具有良好的表皮和真皮结构,糖原染色可见基底膜呈完整连续深红染色.术后8周两组均形成正常皮肤样结构.透射电镜观察:术后3周对照组真皮层有大量中性粒细胞和成纤维细胞,未见表皮超微结构;实验组可见大量表皮细胞并以桥粒相连,表皮基底细胞与基膜以半桥粒连接:真皮层可见大量成纤维细胞,以及细胞外大量胶原微纤维沉积,可见内皮细胞形成的毛细血管.术后3周实验组荧光显微镜观察,带有DAPI标记的BMSCs定位于重建的表皮和真皮组织中,表皮主要定位于基底膜附近,真皮层可见大量荧光标记的BMSCs.结论 以自体BMSCs为种子细胞与胶原膜复合构建组织工程皮肤,可有效修复猪全层皮肤缺损,有望成为一种较理想的组织工程皮肤.     

体外培养表皮干细胞构建组织工程皮肤的研究

目的探讨应用表皮干细胞构建组织工程皮肤修复皮肤缺损的可行性。方法运用黏附实验将人表皮干细胞分选出来后大量培养，将成纤维细胞和表皮干细胞转移到真皮底物上构建组织工程皮肤，并将之移植于裸鼠皮肤缺损模型，于术后第1、2、4周处死动物，收集标本，进行组织学、透射电镜及免疫组织化学检查。结果组织工程皮肤移植后4周具备完整的表皮层和真皮层，表皮层中具备基底层、棘层、颗粒层和角质层。表皮细胞间还可以看到有桥粒、半桥粒、角质透明颗粒和粗张力微丝柬。表、真皮层间有连续的、完整的基底膜。真皮网架破坏明显，大量的成纤维细胞增殖活跃，胶原纤维排列整齐，有丰富的毛细血管。结论本研究所构建的组织工程皮肤组织学形态和超微结构上已接近于正常的皮肤，从而为临床修复皮肤缺损的研究打下了坚实的理论和实践基础。     

以活性复合真皮基质为载体构建组织工程皮肤的研究

目的 构建含活性真皮基质的组织工程皮肤. 方法将人成纤维细胞(Fb)与Ⅰ型牛胶原混合接种于猪脱细胞真皮基质(PADM)的表面,构建活性真皮替代物.其上接种人表皮细胞进行气-液面培养,获得组织工程皮肤,进行组织学观察. 结果 Fb在胶原内结构完整,与PADM形成复合真皮基质.所构建的组织工程皮肤表皮层结构与人正常皮肤相似,具备基底层、棘层、颗粒层和角质层,细胞之间有桥粒连接,细胞分化良好. 结论 Fb-胶原-PADM真皮替代物可作为较好的构建组织工程皮肤的真皮支架.     

利用聚羟基乙酸构建组织工程皮肤的实验研究

目的 以聚羟基乙酸(PGA)为培养支架，用组织工程方法在体外构建双层、有活性皮肤。方法应用酶消化法分别获取人成纤维细胞(FB)和表皮角质形成细胞(KC)，体外扩增培养。接种HF与PGA上1周后，在复合物表面接种KC，共培养1周将复合物置于气-液界面继续培养。于不同时间段取材。行组织学、超微结构及免疫组织化学检测。结果接种表皮角质形成细胞在“FB-PGA”复合物表面1周后可见2～3层连续的HK在复合物上生长良好；4周时PGA已部分降解，表皮分层分化较完善，抗involucrin染色阳性，透射电镜观察可见表皮细胞分层分化良好。细胞的相邻面有桥粒连接。结论 采用组织工程技术可以在体外构建双层、有活性的人工皮肤；组织工程皮肤具有和正常皮肤相似的组织学特征及生化成分。     

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 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.     

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.     

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.     

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.     

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.