CAJ | 학술논문

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.
목적 관찰모의실중대서경총동맥산성초린지매(acid sphingomyelinase,ASM)/신경선알(ceramide,Cer)개변,병탐토기재혈관공능조공중적작용. 방법 웅성Sprague-Dawley대서36지,안체중배대원칙수궤분위대조조화현조조,매조18지.현조조채용4주미부현조모의실중영향,응용면역단백인적기술화면역조직화학방법검측ASM급Cer적함량화분포,통과혈관배장력묘기기술검측경총동맥혈관배수축화서장공능,채용이경을정형광탐침검측혈관배초양음리자(superoxide anion,O2-·)수평. 결과 여대조조상비,4주미부현조조대서경총동맥ASM급Cer함량균현저강저(t=3.626～9.922,P＜0.01혹＜0.05),대KCl화분신상선소적수축반응급대을선담감화초보납적서장반응균무명현개변.C6-신경선알부육후,대조조대서경총동맥Cer수평、수축화서장반응성이급O2-·수평균무현저변화,이현조조대서경총동맥Cer수평현저증가,대KCl화분신상선소적수축반응성급O2-·수평현저증고(t=3.015～7.088,P＜0.05),대을선담감화초보납적서장반응칙무영향. 결론 모의실중사대서경총동맥ASM/Cer수평하강,가강저경총동맥O2-·수평병하조기수축공능.
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.