富氢液联合浅低温对大鼠脑缺血再灌注损伤的影响

Effects of hydrogen-rich saline combined with mild hypothermia on cerebral ischemia-reperfusion injury in rats

目的 观察富氢液联合浅低温对大鼠脑缺血再灌注损伤的影响.方法 雄性SD大鼠50只,周龄9～10周,体重250～300 g,随机分为5组（n=10）：假手术组（S组）、脑缺血再灌注组（IR组）、富氢液组（H组）、浅低温组（M组）、富氢液＋浅低温组（HM组）.IR组、H组、M组和HM组采用结扎双侧颈总动脉的方法制备大鼠脑缺血再灌注模型,缺血15 min,再灌注6 h.H组和HM组于再灌注即刻腹腔注射富氢液5 ml/kg,其余3组腹腔注射等容量生理盐水.同时S组、IR组和M组维持直肠温37～38 ℃;M组和HM组于15 min内将直肠温降至32～34 ℃,并维持6 h.再灌注6 h时处死大鼠,取一侧海马组织,分别行尼氏染色和HE染色,光镜下观察病理学结果;取另一侧海马组织,采用Western blot法测定CA1区HO-1表达、MDA和TNF-α的含量.结果 H组、M组和HM组病理学损伤较IR组减轻,其中HM组减轻最明显.与S组比较,IR组、H组、M组和HM组海马HO-1表达上调,MDA和TNF-α的含量增加（P＜0.05）;与IR组比较,H组、M组和HM组海马HO-1表达上调,MDA和TNF-α的含量降低（P＜0.05）;与H组和M组比较,HM组海马HO-1表达上调,MDA和TNF-α的含量降低（P＜0.05）;H组和M组上述指标差异无统计学意义（P＞0.05）.结论 富氢液联合浅低温可减轻大鼠脑缺血再灌注损伤,可能与上调海马HO-1的表达,降低MDA和TNF-α的含量有关.

Objective To investigate the effect of hydrogen-rich saline combined with mild hypothermia on cerebral ischemia-reperfusion （IR） injury in rats. Methods Fifty male SD rats, aged 9-10 weeks, weiging 250-300 g, were randomly divided into 5 groups （n= 10 each）： sham operation group （group S）, group IR, hygrogen-rich saline group （group H）, mild hypothermia group （group M） and hydrogen-rich saline ＋ mild hypothermia group （group HM）. In group IR, H, M and HM cerebral IR was induced by 15 min ligation of bilateral carotid artery followed by 6 h reperfusion. In group H and HM intraperitoneal hydrogen-rich saline 5 ml/kg was injected immediately after reperfusion, while the equal volume of normal saline was injected instead of hydrogen-rich saline in the other three groups. At the same time, the rectal temperature was maintained at 37-38 ℃ in group S,IR and M, while it was reduced to 32-34 ℃ by physical method within 15 min, lasting for 6 h, in group M and HM. The animals were sacrificed after 6 h of reperfusion, and then the hippocampus was removed for microscopic examination. The expression of HO-1 and content of MDA and TNF-α were determined by Western blot. Results The cerebral IR injury was attenuated in group H, M and HM compared with group IR, with the slightest injury in group HM. The expression of HO-1 and content of MDA and TNF-α were significantly higher in group IR, H, M and HM than in group S. The expression of HO-1 was significantly higher, while the content of MDA and TNF-α were lower in group H, M and HM than in group IR, and in group HM than in group H and M. There was no significant difference in the expression of HO-1 and content of MDA and TNF-α between group H and M. Conclusion Hydrogen-rich saline combined with mild hypothermia can attenuate cerebral I/R injury in rats via up-regulating the expression of HO-1 and decreasing the content of MDA and TNF-α in hippocampus.