高压氧对急性脑创伤后皮层一氧化氮合酶mRNA表达的影响

Effect of hyperbaric oxygen on the expression of nitric oxide synthase mRNA in cortex after acute traumatic cerebral injury

目的:拟观察高压氧(HBO)治疗对急性创伤性颅脑损伤后皮层NOSmRNA表达的影响,探讨HBO治疗急性脑损伤的机理。方法:采用自由落体法打击模型制备SD大鼠急性脑创伤,伤后1 h、12 h采用0.25 MPaHBO治疗,伤后6 h、24 h取样皮层,应用半定量逆转录聚合酶链反应(RT-PCR)观察神经元型一氧化氮合酶(nNOS)、内皮型一氧化氮合酶(eNOS)和诱导型一氧化氮合酶(iNOS)mRNA表达量变化。结果:0.25MPaHBO治疗各时间组nNOS、eNOS和iNOSmRNA较急性颅脑损伤各时间组显著下降(P<0.01),且HBO治疗24 h组较6 h组下降更明显(P<0.05,P<0.01),0.25 MPa常氧高氮各时间组与急性颅脑损伤各时间组NOSmRNA表达量无统计学意义。结论:HBO治疗可以下调nNOSmRNA、iNOSmRNA和eNOSmRNA的表达量,可能为HBO治疗脑创伤的机理之一。

Objective： To investigate the effect of hyperbaric oxygen（HBO） treatment on the expression of nitric oxide synthase（NOS） mRNA in cortex after acute traumatic cerebral injury,and to study the mechanism of HBO on brain injury.Methods： Acute traumatic brain injury model was established with restreceived free fall injury method in SD rats.0.25 MPa HBO treatment was used 1 h or 12 h after brain injury and the cortex was isolated 6 h or 24 h after brain injury respectively.The expression of mRNA coding for nNOS,eNOS or iNOS were assayed using reverse transcription polymerase chain reaction（RT-PCR）.Results： The expression of nNOS,eNOS and iNOS mRNA were signi-ficantly decreased in 0.25 MPa HBO treatment groups than those in acute cerebral injury groups（P0.01）.The amount of nNOS,eNOS and iNOS mRNA was significantly lower in HBOT 24h group than those in HBOT 6 h group（P0.05,P0.01）.There was no significantly difference among nNOS,eNOS and iNOS mRNA in 0.25 MPa normoxic hyperbaric nitrogen groups and acute cerebral injury groups（P0.05）.Conclusion： HBO may exert significant effects on the expression of nNOS mRNA/ iNOS mRNA and pretect cortical neuronal from traumatic cerebral injury.