血栓性脑缺血树鼩海马灌流液与动脉血液气体和酸碱度变化的研究

目的：检测血栓性脑缺血后海马灌流液和血液中气体及酸碱度变化并探讨其相互关系。方法：建立光化学诱导树鼩血栓性脑缺血模型，进行海马微灌流收集灌流液，同时经颈动脉插管取血，通过IL-1306型血气分析仪检测pH，PCO2，PO2和HCO3ˉ的变化。结果：脑缺血组中动脉血和灌流液的PO2均低于对照组，动脉血PO2平均值比对照组下降1．81 kPa(P＜0．01)，灌流液PO2下降4．17 kPa(P＜0．01)；血PCO2平均值比对照组升高0．87 kPa(P＜0．01)，灌流液PCO2变化不明显(P＞0．05)；血HCO3ˉ下降4．44mmol／L(P＜0．01)，灌流液中则下降6．62mmol／L(P＜0．01)。结论：局灶性脑缺血后，动脉血及海马灌流液均处于低氧状态并伴有不同程度、类型的酸碱平衡失调，血及脑细胞间液酸碱度的测定对伴有海马损伤的缺血性脑病防治具有重要意义。

Changes of Acid- base, Oxygen and Carbon Dioxide Pressures of the Extracellular Fluid and Blood after Cerebral Ischemia

Objective:To detect the changes of gas and acid-base levels in the hippocampal extrace- llular fluid(ECF)and arterial blood after thrombotic cerebral ischemia and to explore relationships between each other.Methods:The animal models of photothrombotic focal cerebral ischemia were produced in tree shrews.Hippocampal ECF was collected by microperfusion and arterial blood was taken from carotid artery,and pH,PCO 2,PO 2 and HCO - 3were analyzed by blood gas analyzer.Results:PO 2 of both arterial blood and hippocampal ECF in the ischemic was lower than that of the control.The average of PO 2 in arterial blood was 1.81 kPa,lower than that in the control(P<0.01),and PO 2 in ECF was 4.17 kPa(P<0.01).The average of PCO 2 in arterial blood of the ischemic was 0.87 kPa,higher than that in the control(P<0.01)with no significant difference in the ECF(P>0.05).HCO - 3 in arterial blood was 4.44 mmol/L and that in ECF was 6.62 mmol/L(P<0.01,respectively).Conclusions:Hypoxia and kinds of acid-base disturbances existed after local cerebral ischemia in tree shrews with the changes of the acid-base in arterial blood and hippocampal ECF may appear to be important to brain diseases with hippocampus injury.