浅低温联合七氟烷对大鼠海马脑片氧糖缺失损伤细胞外氨基酸含量的影响

目的:在离体海马脑片缺氧无糖(OGD)损伤模型上用反向高效液相色谱(HPLC)技术探讨氨基酸递质在浅低温联合七氟烷脑保护中的作用。方法:制备并孵育好雄性SD大鼠的海马脑片OGD损伤模型,随机分为4组(每组n=8):氧糖缺失组(OGD组)、七氟烷组(Sev组)、浅低温组(MH组)、浅低温加七氟烷组(MH+Sev组)。各组在不同处理后检测OGD损伤开始之前、结束即时、复氧30 min和60 min时细胞外液天门冬氨酸(aspartic acid,Asp)、谷氨酸(glutamic acid,Glu)、牛磺酸(taurine,Tau)、甘氨酸(glycine,Gly)和γ-氨基丁酸(γ-aminobutyric acid,GABA)的浓度。结果:与OGD组相比,其余3组在OGD结束后各个时间点Glu、Asp和Gly浓度降低,Tau和γ-GABA浓度增加,MH+Sev组较其余3组在OGD结束后各个时间点中Asp和Glu的浓度显著降低(P<0.01,P<0.05),Tau和γ-GABA浓度显著增加(P<0.01),Gly浓度也有所降低。结论:浅低温(32℃)联合4%七氟烷后抗海马脑片OGD损伤作用得到加强,其作用机制可能与减轻细胞外液兴奋性氨基酸的聚积及机体建立抑制性保护机制有关。

Influence of a Combination of Mild Hypothermia and Sevoflurane on Oxygen-Glucose Deprivation Injury inRat Hippocampal Slices

To explore the role of amino acids in the extracellular fluid of rat＇s hippocampus slices in the protective effects of combination of mild hypothermia and sevoflurane on oxygen-glucose deprivation injury through HPLC. Methods： Hippocampal slices were randomly divided into 4 groups（n = 8 each） ： Group Ⅰ OGD; Group Ⅱ sevoflurane （Sev） ; Group Ⅲ mild hypothermia（MH） and Group IV MH ＋ Sev oflurane. Slices were randomly exposed to experiment condition for 14 min before OGD and for another 14 rain during OGD. The concentration of amino acid aspartic acid （Asp）, glutamic acid （Glu）, glycine （Gly）, taurine （Tau）, γ-aminobutyric acid （GABA） before OGD, at the end of OGD and 30 min, 60 min of reoxygen- ation were detected. Results： Compared with the OGD group , the concentration of Asp,Glu and Gly decreased, but Tau and GABA increased in other groups at the end of OGD and 30 rain, 60rain of reoxygenation. In the group of MH ＋ Sev, the levels of Asp and Glu decreased but the levels of Tau and GABA increased; compared with the other groups. Conclusions： The pro- tective effect of combination of mild hypothermia and sevoflurane on OGD injury in rat hippocampal slices is associated with the decrease in the level of extracellular excitatory amino acid.