酸性鞘磷脂酶/神经酰胺在模拟失重大鼠颈总动脉功能调控中的作用  

Modulation effects of acid sphingomyelinase/ceramide on the common carotid arteries of simulated weightless rats

作　　者：程耀萍 谢小萍[1] 薛莉[1] 王忠超[2] 刘焕[2] 张海军[1] 常耀明[1] 暴军香[2] 

机构地区：[1]第四军医大学航空航天卫生与卫生勤务学教研室,西安710032 [2]第四军医大学航空航天生理学教研室,西安710032

出　　处：《中华航空航天医学杂志》2015年第1期1-7,79,80,共9页Chinese Journal of Aerospace Medicine

基　　金：国家自然科学基金（81401550,31071045,81171871）

摘　　要：目的 观察模拟失重大鼠颈总动脉酸性鞘磷脂酶（acid sphingomyelinase,ASM）/神经酰胺（ceramide,Cer）改变,并探讨其在血管功能调控中的作用. 方法 雄性Sprague-Dawley大鼠36只,按体重配对原则随机分为对照组和悬吊组,每组18只.悬吊组采用4周尾部悬吊模拟失重影响,应用免疫蛋白印迹技术和免疫组织化学方法检测ASM及Cer的含量和分布,通过血管环张力描记技术检测颈总动脉血管环收缩和舒张功能,采用二氢乙啶荧光探针检测血管环超氧阴离子（superoxide anion,O2-·）水平. 结果 与对照组相比,4周尾部悬吊组大鼠颈总动脉ASM及Cer含量均显著降低（t=3.626～9.922,P＜0.01或＜0.05）,对KCl和苯肾上腺素的收缩反应及对乙酰胆碱和硝普钠的舒张反应均无明显改变.C6-神经酰胺孵育后,对照组大鼠颈总动脉Cer水平、收缩和舒张反应性以及O2-·水平均无显著变化,而悬吊组大鼠颈总动脉Cer水平显著增加,对KCl和苯肾上腺素的收缩反应性及O2-·水平显著增高（t=3.015～7.088,P＜0.05）,对乙酰胆碱和硝普钠的舒张反应则无影响. 结论 模拟失重使大鼠颈总动脉ASM/Cer水平下降,可降低颈总动脉O2-·水平并下调其收缩功能.Objective To investigate the alteration of acid sphingomyelinase （ASM）/ ceramide （Cer） and its role in vasoconstriction of the common carotid arteries （CA） of simulated weightless rats.Methods Thirty-six male Sprague-Dawley rats that matched for weight were randomly assigned to suspended group （n=18） and control group （n=18）.Suspended group was in simulated weightless by tail suspension for 4 wk.Western blot and immunohistochemistry were conducted to examine the content and distribution of ASM and Cer.Isometric force recording system was used to detect the vasoconstriction and vasodilation functions.Dihydroethidium fluorescent probe was used to evaluate the level of superoxide anion （O2-·） in arteries.Results Four-week suspension made the ASM protein and Cer level in the CA of suspended group significantly decreased as compared with that of control group （t=3.626-9.922,P〈0.01 or 〈0.05）,while vasoconstriction response to KCl and phenylephrine or vasodilation response to acetylcholine and sodium nitroprusside did not change much in two groups.Incubation with C6-ceramide （C6-Cer） did not significantly change the Cer level,vasoconstriction,vasodilation and O2-· level of CA in control group but increased Cer level,vasoconstriction response to KC1 and O2-· level in suspended group （t=3.015-7.088,P〈0.05）.The suspension influenced less on vasodilation response to acetylcholine and sodium nitroprusside.Conclusions Simulated weightlessness makes the drop on ASM/Cer level and the O2-· level in CA as well as its vasoconstriction adaptation.

关 键 词：失重模拟 颈总动脉 磷脂酶类 神经酰胺类 氧化性应激 

分 类 号：R85[医药卫生—航空、航天与航海医学]