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1.
目的探讨吡那地尔超极化停搏对大鼠离体心脏缺血再灌注时心肌线粒体损伤的影响。方法健康雄性SD大鼠,成功建立Langendorff再灌注模型的80个心脏随机分为5组:对照组(C组)、去极化停搏组(D组)、吡那地尔超极化停搏组(H组)、线粒体ATP敏感性钾通道阻滞剂5-羟葵酸(5-HD)+去极化停搏组(5-HD+D组)和5-HD+吡那地尔超极化停搏组(5-HD+H组)。以K-H液平衡灌注20 min后(平衡末),C组阻断主动脉,不予停搏液灌注,使其自然停搏,D组用37℃ST.ThomasⅡ停搏液灌注,H组用37℃超极化停搏液灌注,5-HD+D组和5-HD+H组分别用含有100μmol/L 5-HD的37℃ST.ThomasⅡ停搏液或超极化停搏液20 ml/kg灌注,缺血40 min。分别于平衡末及再灌注30 min时取8个心脏,测定心肌线粒体呼吸功能指标[4态呼吸耗氧速率、3态呼吸耗氧速率、呼吸控制率(PCR)及磷氧比(P/O)]、线粒体酶(NADH氧化酶、琥珀酸氧化酶和细胞色素C氧化酶)活性及线粒体膜电位(MMP),电镜下观察线粒体的超微结构。结果与平衡末比较,各组再灌注30 min时心肌线粒体呼吸功能指标(3态呼吸耗氧速率、PCR及P/O)、线粒体酶活性及MMP降低(P〈0.05或0.01);与C组比较,再灌注30 min时其余各组上述指标均升高(P〈0.01);再灌注30 min时H组线粒体的功能及病理损伤最轻。结论吡那地尔超极化停搏能明显改善大鼠离体心脏缺血再灌注时心肌线粒体功能,减轻线粒体超微结构损伤,其机制与开放线粒体ATP敏感性钾通道有关。  相似文献   

2.
目的 探讨吡那地尔超极化停搏对大鼠离体心脏缺血再灌注时心肌细胞凋亡的影响.方法 健康SD大鼠108只,随机分为6组(n=18),建立Langendorff离体心脏灌注模型,对照组(C组)持续灌注37.C含氧K-H缓冲液120 min不停搏;37℃含氧的K-H缓冲液平衡灌注15 min后,去极化停搏组(D组)灌注37℃St.Thomas停搏液(含K+16 mmol/L)20 ml/kg,超极化停搏组(H组)灌注37℃吡那地尔(50 μmol/L,K+5 mmol/L)超极化停搏液20 ml/kg,线粒体ATP敏感性钾通道阻滞剂5-羟葵酸+超极化停搏组(5-HD+H组)和膜ATP敏感性钾通道阻滞剂 HMR-1098+超极化停搏组(HMR-1098+H组)灌注100 μmol/L 5-HD或HMR-1098,5 min后灌注吡那地尔超极化停搏液20 ml/kg;5-HD+HMR-1098+H组先灌注100 μmol/L5-HD和100 μmol/L HMR-1098混合液,5 min后灌注吡那地尔超极化停搏液20ml/kg.各停搏组心脏常温停搏(缺血)40 min,再用37℃含氧K.H缓冲液再灌注60 min.于缺血前、缺血40 min和再灌注60 min时取心肌组织,测定caspase-3、caspase-9活性,观察细胞凋亡情况.结果 缺血前各组间各指标差异无统计学意义(P>0.05).与C组比较,其余各组细胞凋亡指数(AI)、caspase-3、caspase-9活性增加;与D组比较,H组AI、caspase-3、caspase-9活性降低;与H组比较,加阻滞剂的3组AI、caspase-3、caspase-9活性增加;与5-HD+H组、HMR-1098+H组比较,5-HD+HMR-1098+H组 AI、caspase-3、caspase-9 活性增加(P<0.05).与缺血前比较,在缺血40 min、再灌注60 min时,各组AI、caspase-3、caspase-9 活性增加(P<0.05).结论 吡那地尔超极化停搏可明显抑制大鼠离体心脏缺血再灌注时心肌细胞凋亡,产生心肌保护效应,其机制可能与降低caspase-3、caspase-9活性有关.  相似文献   

3.
目的 探讨超极化停搏对猫体外循环(CPB)时心肌细胞膜脂区域流动性的影响.方法 家猫75只,体重3~4 kg,随机分为3组(n=25),CPB组:CPB建立后不阻断上腔静脉、下腔静脉和主动脉,仅行CPB 150 min;去极化停搏组:主动脉阻断60 min,再灌注60 min,心脏停搏液使用高钾St Thomas液;超极化停搏组:心脏停搏液使用含吡那地尔的低钾St Thomas液,余处理与去极化停搏组相同.应用自旋标记-电子自旋共振技术测定CPB时心肌细胞膜脂区域流动性.结果 与CPB组比较,去极化停搏组主动脉阻断30 min后心肌细胞膜脂S和τc均升高,超极化停搏组主动脉阻断60 min后心肌细胞膜脂S和τc均升高(P<0.01);与去极化停搏组比较,超极化停搏组主动脉阻断30 min后心肌细胞膜脂S和τc均降低(P<0.01).结论 与去极化停搏相比,超极化停搏能够更好地维持家猫CPB时心肌细胞膜脂的区域流动性.  相似文献   

4.
超极化停搏与高钾停搏对心肌保护效果的比较   总被引:17,自引:4,他引:13  
目的 比较观察超极化停搏与高钾停搏的心肌保护效果,并评价低温对心脏超极化停搏的影响。方法 18条犬分为三组,每组6条。低温高钾组、常渐超极化组和低温超极化组,分别以4℃标准St.Thomas液(K^+16mmol/L)、含吡那地尔50μmmol/L的37℃St.Thomas液(K^+5mmol/L)和含吡那地尔50μmol/L的4℃St.Thomsa液(K^+5mmol/L)为心停搏液。结果 低温  相似文献   

5.
吡那地尔介导超极化心脏停搏液对心肌的保护作用   总被引:1,自引:1,他引:0  
目的:为了提高心脏停搏液的心肌保护作用,探讨含吡那地尔(pinacidil)超极化心脏停搏液对心肌的保护作用。方法:32只新西兰兔根据体外循环中使用不同的心脏停搏液分为对照组和实验组,对照组用St Thomas Ⅱ号心脏停搏液,实验组用含吡那地尔(50μmol/L)的心脏停搏液。两组又根据主动脉阻断后是否再灌注,分别分为两组(对照组A、对照组B、实验组A、实验组B),每组8只兔。对照组A和实验组A在主动脉阻断60分钟后结束实验;对照组B和实验组B于主动脉阻断60分钟、复滞30分钟结束实验。记录心脏电机械停搏时间,复跳时的心律失常情况,测定实验结束时各组心肌三磷酸腺苷(ATP)、总腺苷酸(TAN)、Ca^2 、丙二醛(MDA)含量,对照组B和实验组B血清心肌酶含量,并观察心肌超微结构变化。结果:4组心脏均迅速发生电机械停搏,对照组B、实验组B复跳时均发生心律失常3例,未发生严重心律失常;实验组A和实验组B的ATP、TAN分别高于对照组A和对照组B(P<0.01),而Ca^2 和MDA分别显著低于对照组A和对照组B(P<0.05),实验组B心肌酶的漏出量显著低于对照组B(P<0.01)。实验组B超微结构损伤轻,优于对照组B。结论:含吡那地尔的心脏停搏液对心肌保护的作用优于高K^ 心脏停搏液。  相似文献   

6.
钾通道开放剂心脏超极化停搏保护效果的研究   总被引:1,自引:0,他引:1  
Yu T  Liu X  Yu Z  Yang S  Ye Y  Yang X  Gao Z 《中华外科杂志》2000,38(12):931-934
目的 对比观察大量三磷酸腺苷(ATP)敏感性钾通道开放剂吡那地尔对常温/低温体外循环(CPB)心脏超极化停跳缺血心肌的保护作用。方法 18只犬随机分3组,每组6只,低温超极化组(LH):阻断升主动脉后,心脏灌注4℃含吡那地尔停跳液,CPB血温为26~28℃,开放前复温至37℃,全心缺血60min,恢复灌注30min;常温超极化组(WH):CPB血温35~37℃,心脏灌注37地70含吡那地尔(50μmol/L)停跳液,余同LH组;对照组(C);无吡那地尔的标准St、Thomas停跳液,余37℃含昆那地尔(50umol/L)停跳液,余同LH组;对照组(C):无吡那地尔的标准St.Thomas停跳液,余同LH组,对比观察吡那地尔心脏超极化停跳不同时相各项指标的变化。结果 (1)停复跳情况:LH组、C组灌注后心脏停跳较  相似文献   

7.
吡那地尔超极化停搏液心肌保护的效果   总被引:1,自引:0,他引:1  
我们利用犬体外循环工作模型,以心肌损伤标志物心肌肌钙蛋白 I(troponin I,TnI)净释放为指标,结合围术期血液动力学变化,旨在对比研究体外循环中吡那地尔超极化停搏液与传统高钾停搏液对犬缺血心肌的保护效果。  相似文献   

8.
超极化停搏对体外循环中心肌细胞膜微粘度变化的影响   总被引:3,自引:1,他引:2  
目的比较超极化停搏和去极化停搏对体外循环(CPB)中心肌细胞膜流动性变化的影响,评价超极化停搏液的心肌保护作用. 方法根据随机数字表法将72只家猫均分为3组,每组24只.对照组:不阻断上、下腔静脉和主动脉,仅行并行循环180分钟;去极化停搏组:阻断主动脉60分钟,再灌注90分钟,心脏停搏液使用St.Thomas液(K 16mmol/L);超极化停搏组:心脏停搏液使用含吡那地尔的St.Thomas液(K 5mmol/L),其余处理与去极化停搏组相同.应用荧光偏振法测定心肌细胞膜的微粘度(η),以η的倒数表示心肌细胞膜流动性. 结果去极化停搏组主动脉阻断期间心肌细胞膜η值明显上升,且于再灌注期间进一步升高;超极化停搏组主动脉阻断期间亦呈升高趋势,但各时间点η值均明显低于去极化停搏组(P<0.01). 结论超极化停搏比去极化停搏能更有效地维持CPB中缺血-再灌注心肌细胞膜的流动性,从而起到更好的心肌保护作用.  相似文献   

9.
目的 探讨ATP敏感性钾通道开放剂(KCOs)吡那地尔(Pinacidil)药物预处理对常温及低温犬体外循环(CPB)晶体高钾停搏液间断灌注心肌的保护效果。方法 18条犬随机分为三组,每组6条,分别建立犬的常温及低温CPB全心缺血Pinacidil预处理模型。对照组(A组):低温CPB,主动脉根部灌注4℃St.Thomas停搏液(K~+16mmol/L)10ml/kg,阻断30min复灌一次(1/2首量);B组:常温CPB,主动脉根部灌注37℃含氧Pinacidil液(0.083mg/kg);C组:低温CPB,主动脉根部灌注液同B组。三组心脏均接受60min缺血和30min再灌注。阻断主动脉前,开放后15min、30min测血液动力学改变;并循环5min,阻断循环30min、60min及开放循环20min于左心室取心肌组织,测定心肌腺苷酸含量。结果 再灌注期间C组的血液动力学指标明显好于A、B组(P<0.01),而B组又较A组好(P<0.01)。缺血及再灌注期间C组心肌的ATP含量也明显高于A、B组(P<0.01),B组又高于A组(P<0.01)。结论 Pinacidil预处理时对CPB下缺血心肌具有良好的保护效果,低温的效果优于常温。  相似文献   

10.
目的探讨吡那地尔超极化停搏对大鼠离体心脏蛋白激酶C(PKC)ε及热休克蛋白70 (HSP70)的影响。方法成年雄性SD大鼠,成功建立Langendorff离体再灌注模型的32个心脏,随机分为4组(n=8):自然停搏组(A组)、St.Thomas组(B组)、吡那地尔超极化组(C组)和白屈菜赤碱组(D组)。A组、B组和C组K-H液平衡灌注15min后,A组停止灌注,B组灌注St.Thomas停搏液,C组灌注超极化停搏液;D组K-H液平衡灌注10min后,白屈菜赤碱液灌注5min,再灌注超极化停搏液。记录各组平衡灌注15min和再灌注20min时冠脉流量(CF)、心率(HR)、左室发展压(LVDP)、左室收缩峰压(LVSP)和左室压力瞬时最大变化率(dp/dtmax);再灌注30min时测定心肌膜性PKCε和HSP70的表达。结果与K-H液平衡灌注15min时相比,再灌注20min时A组、B组和D组CF、HR、LVSP、LVDP及dp/dtmax降低(P〈0.05);与C组相比,其余各组再灌注20min时CF、HR、LVSP、LVDP及dp/dtmax降低,膜性PKCε和HSP70的表达下调(P〈0.05)。结论吡那地尔超极化停搏通过上调膜性PKCε和HSP70表达,促进大鼠心肌缺血再灌注时心功能恢复。  相似文献   

11.
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 (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.  相似文献   

12.
Don Dame 《Artificial organs》1996,20(5):613-617
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

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Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.  相似文献   

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