摘要：
目的 探讨外源性硫化氢(hydrogen sulfide,H2 S)对血管性痴呆(vascular dementia,VaD)大鼠海马组织H2 S浓度和胱硫醚 β-合酶(cystathionineβ-synthase,CBS)表达的影响.方法 采用改良四血管法制作大鼠VaD模型,应用随机数字表法分为假手术组、模型组、小剂量和大剂量NaHS组,再按照模型制作后时间进一步分为1 d、7 d和30 d亚组.小剂量和大剂量NaHS组分别模型制作后每日腹腔注射NaHS 30μmol/kg和100μmol/kg,假手术组和VaD模型组每日腹腔注射等体积生理盐水.应用Morris水迷宫实验评价大鼠学习记忆能力,应用实时免疫荧光聚合酶链反应检测海马组织CBS mRNA表达,应用蛋白质印迹法检测海马组织CBS蛋白表达.结果 Morris水迷宫实验显示,模型组、小剂量和大剂量NaHS组逃避潜伏期均较假手术组显著延长(P均<0.05),穿越平台次数均较模型组显著减少(P均<0.05),小剂量和大剂量NaHS组逃避潜伏期均较模型组显著缩短(P均<0.05).模型组、小剂量和大剂量NaHS组海马H2 S含量均较假手术组显著降低,但小剂量和大剂量NaHS组显著高于模型组(P均<0.05).模型组、小剂量和大剂量NaHS组海马CBS mRNA和蛋白表达均显著低于假手术组(P均<0.05),且小剂量和大剂量NaHS组与模型组无显著差异.结论 外源性H2 S能改善VaD大鼠学习记忆能力,可能与增高海马组织H2 S含量有关,但对CBS表达无影响.%Objective To investigate the effect of exogenous hydrogen sulfide (H 2 S) on H2 S concentration and cystathionine β-synthase (CBS) expression in hippocampus in a rat model of vascular dementia (VaD). Methods A rat model of VaD was induced by using the modified four -vessel occlusion. The rats were divided into sham operation, model, low -dose and high-dose NaHS groups using the random number table method. They were further redivided into one day, seven -day, and 30-day subgroups according to the time after modeling. After modeling respectively, NaHS 30 μmol/kg and 100 μmol/kg were injected intraperitoneally every day in the low -dose and high-dose NaHS groups. The normal saline was injected intraperitoneally every day in the sham operation group and the VaD model group. Morris water maze test was used to evaluate the learning and memory ability of the rats. The expression of CBS in hippocampus was detected by real-time fluorescent polymerase chain reaction. Western Blotting was used to detect expression of CBS protein in hippocampus. Results Morris water maze test showed that the escape latencies of the model group, low -dose and high-dose NaHS groups were prolonged significantly compared with the sham operation group (P <0.05); the times of crossing the platform were decreased significantly compared with the model group (P <0.05); and the escape latencies were shortened significantly in the low -dose and high-dose NaHS groups compared with the model group ( P <0.05). The H2 S content in hippocampus was decreased significantly in the model group, low -dose and high-dose NaHS groups compared with the sham operation group, but the low -dose and high-dose NaHS group was significantly higher than that in the model group (all P <0.05). The expression of CBS mRNA and protein in the model, low -dose and high-dose NaHS groups was significantly lower than that of the sham operation group (all P < 0.05), and there was no significant difference between the low -dose and high-dose NaHS groups and the model group. Conclusions Exogenous H2 S may improve the learning and memory ability of the VaD rats. It may be associated with the increased H2 S content in hippocampus. However, it has no effect on CBS expression.
