目的 探讨维生素C对脓毒症大鼠脑损伤的改善作用.方法 将SPF级雄性SD大鼠按随机数字表法分为对照组、假手术组、脓毒症组、脓毒症治疗组.脓毒症组通过阑尾结扎穿孔术建立脓毒症模型.脓毒症治疗组在造模后3h通过尾静脉注射维生素C,其余组大鼠予等量9 g/L盐水.分别在相应时间点进行神经反射评估后断头取脑.提取脑组织蛋白,按照检测试剂盒说明书测定活性氧(ROS)、超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)、诱导型一氧化氮合成酶(iNOS)和过氧化氢酶(CAT).采用苏木精-伊红(HE)染色观察脑组织病理学变化.结果 脓毒症组(7d生存率为30%)较对照组(7d生存率为100%)及假手术组(7d生存率为100%)生存率明显下降,脓毒症治疗组(7d生存率为45%)较脓毒症组生存率明显升高,差异均有统计学意义(均P <0.05).神经反射评分在脓毒症组6h开始下降,24h达到最低(6.00±0.53),脓毒症治疗组较脓毒症组评分明显升高(7.62±0.52),72 h开始逐渐恢复(8.63±0.52),与脓毒症组比较,差异有统计学意义(P<0.05).ROS、SOD、MDA、NO、iNOS在脓毒症组和脓毒症治疗组24h均达高峰,72 h已经下降,脓毒症治疗组较脓毒症组均有显著下降,差异有统计学意义(P<0.05);CAT的变化与之相反.SOD/CAT在脓毒症组24h最高,脓毒症治疗组则有明显改善,SOD/CAT与MDA呈强正相关(r=0.968,P<0.05);HE染色可见脓毒症组脑组织结构明显破坏,脓毒症治疗组较脓毒症组有明显改善.结论 在SD大鼠脓毒症模型中,静脉给予维生素C可明显改善生存率及脑病症状,其机制可能与减少氧化应激有关.
Objective To preliminarily investigate the role of Vitamin C in cecal ligation and puncture-induced septic brain injury.Methods Male specific pathogen free (SPF) Sprague-Dawley male rats were randomly assigned into control group,sham operation group,sepsis group and sepsis therapy group.The rats in sepsis group were prepared by cecal ligation and puncture.The rats in sepsis therapy group were injected sodium ascorbate through the tail vein 3 h after the cecal ligation and punature procedure.The animals in other groups were subjected only to subcutaneous bolus injection of 9 g/L saline only.Animals were evaluated by neurologic reflex scores before sacrifice and brain tissues were quickly removed at the indicated time points.Reactive oxygen species (ROS),superoxide dismutase (SOD),malondialdehyde (MDA),nitric oxide (NO),inducible nitric oxide synthase (iNOS) and catalase (CAT) were determined by using enzyme assay kits.Hematoxylin-eosin (HE) staining was used to observe morphological changes in brain tissues.Results The survival rate of the sepsis group (30% at 7th day) was significantly lower than that of the control group (100% at 7th day)and sham operation group(100% at 7th day).The survival rate of the sepsis therapy group (45% at 7th day)was significantly higher than that of the sepsis group(P < O.05).The neurological reflex assessment began to decrease at 6 h in sepsis group and reached the lowest at 24 h (6.00 ± 0.53).The sepsis therapy group (7.62 ± 0.52) was significantly higher (P < 0.05) than the sepsis group and began to recover at 72 h (8.63 ±0.52).ROS,SOD,MDA,NO and iNOS in the sepsis group and the sepsis therapy group reached a peak at 24 h,which decreased at 72 h.The value in sepsis therapy group was significantly decreased than that in the sepsis group,and the difference was statistically significant(P <0.05).CAT changed in the opposition.The SOD/CAT in sepsis group was the highest 24 h after the operation,while the ratio in sepsis therapy group was significantly improved.SOD/CAT and MDA were positively correlated(r =0.968,P < 0.05).HE staining showed significant damage to the brain tissue structure in the sepsis group,however some improvement was observed in the sepsis therapy group.Conclusion Vitamin C can significantly improve the survival rate and encephalopathy prognosis in the cecal ligation and puncture SD rat models.The mechanism may be related to the reduction of oxidative stress.