基础与临床研究 >文章正文
基础与临床研究 >文章正文
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苏殿三 王祥瑞 郑拥军 赵延华 张挺杰 (上海第二医科大学仁济医院麻醉科, 上海 200127) Changes of hemodilution on MDA,LDHand ATPase of rat hippocampus after deep hypothermia circulation arrest SU Dian2 san,WANG Xiang2 rui,ZHENG yong2 jun,ZHAO Yan2 hua,ZHANG Ting2 jie (Department of Anesthesiology,Renji Hospital,Shanghai Second Medical University,Shanghai 200127,China) Abstract Objective:To observe the effects of various degrees of hemodilution on the malondialdehyde(MDA)lactate dehydrogenase(LDH)and adenosine triphosphate enzyme(ATPase)of hippocampus after deep hypothermia circulation arrest(DHCA)of rat. Methods:The rat DHCA models were established and divided into four groups:Hct 10% group,Hct 20% group,Hct 30% group and sham operation group. After success of the model,hippocampuses were dissected to measure the changes of MDA,LDH and ATP enzyme with the colorimetric method. ResultsComparing with the groups of Hct 10% and Hct 20%,the concentration of MDA in hippocampus of group Hct 30% was the lowest one,but higher than the sham operation group;the enzymatic activities of LDH and ATP of the group Hct 30% were the highest but still lower than those of the sham operation group. Conclusion Keeping higher Hct during DHCA does have the neuroprotective effect. Key words:deep hypothermia circulation arrest;hemodilution;haematocrit;malondialdehyde;lactate dehydrogenase;adenosine triphosphate enzyme |
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深低温停循环(deep hypothermia circulation arrest,DHCA)时进行血液稀释的最初目的是为了减少异体血的大量输注,后来发现血液稀释可以对抗由于低温造成的血液流变学改变,如血液粘度增加和红细胞的脆性增加等不利影响,因此广泛应用于DHCA手术以减少脑损伤。但是,过度的血液稀释可以导致携氧量下降,加之低温造成的氧解离曲线左移,有可能造成脑缺血缺氧损害的危险。因此血液稀释程度不当是DHCA后脑损害的重要因素之一。本实验拟从大鼠海马生化指标的改变来研究DHCA期间最佳的血液稀释程度,为临床上进行适当的血液稀释提供实验基础。 材料与方法 动物与分组 成年健康雄性SD大鼠24只,体重400~450g(中国科学院上海动物中心提供),随机分成四组:血细胞压积(haematocrit,Hct)10%组、Hct20%组、Hct30%组和假手术对照组,每组各6只。 主要仪器 血泵:兰格蠕动泵BT00-100M/YZ1515为滚柱式蠕动移液泵,泵头转速1.6~100r/min,配套硅胶管内径4mm;微型膜式氧合器(上海复旦大学生物材料有限公司提供):为中空纤维膜式氧合器(氧合面积为0.1m2)与血液变温器一体设计,中央走血式,预充量为8mL,氧合器内中空纤维为聚丙烯材料,共900根,长15cm,变温器内为中空纤维,共70根,长13cm,变温面积0.03m2,主要成份是聚乙烯。变温器连接变温水箱,水温可调范围10~42℃;RSP1002型大鼠呼吸机:购自KentScientific公司;血气分析仪:NOVA Biomedical Staprofile M。 体外循环的建立和监测 体外循环(cardiopul2 monary bypass,CPB)回路由20号压力注射管连接储血器(10mL注射器)、血泵和氧合器组成。储血器位于心脏平面以下15cm。血泵将储血器内的血液泵入氧合变温器,然后经过股动脉插管泵入大鼠的血管系统。预充液总量为20mL(氧合器和储血器各8mL,其余管道4mL)。Hct30%组的预充液为全血10mL、乳酸林格氏液4mL、20%甘露醇1mL、肝素1mL(100IU)、6%贺斯(HES)4mL;Hct20%组预充液为乳酸林格氏液10mL、20%甘露醇1mL、肝素1mL(100IU)、6%贺斯8mL;Hct10%组预充液成分与20%组相同,但是在转机开始前抽血10mL,并同时补充乳酸林格氏液和贺斯(1∶1)混合液10mL。连续测量动物直肠温度、心电图(ECG)、心率(HR)、平均动脉压(MAP),血气分析仪测定颈内静脉血和股动脉血氧分压(PaO2)、pH值、Hct、颈静脉血氧饱和度(Sj2vO2)和血乳酸(Lac)。 模型制作 1.麻醉和气管插管:术前30min,肌肉注射阿托品0.03mg/kg。腹腔注射混合麻醉药2.4mL/kg(芬太尼0.005%,氯胺酮5%,氟哌利多0.25%)诱导。插管后麻醉仍以该复合液维持,应用透光法明视下行气管插管,机械通气,呼吸频率60次/min。 |
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> 2.CPB操作:双侧股动脉穿刺,穿刺成功后注射肝素150IU全身肝素化,一侧连续测动脉压,并按时监测动脉血气,另一侧供CPB动脉灌注。分离右侧颈内静脉,并插管以监测颈内静脉血气。分离右侧颈静脉,以末端带有很多侧孔的14G静脉留置针穿 样品制备与检测 从液氮中取出脑组织,解冻后分离海马,称重,加入9倍体积的生理盐水,超声匀浆后分装在4个eppendorf管中。考马斯亮兰试剂盒检测蛋白含量;TBA法检测MDA含量;比色法测定LDH和Na+-K+ATP酶的活性。以上试剂均购自南京建成生物工程研究所,严格按照试剂说明书提供的方法操作。 统计分析 数据用 结 果
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