Paper - WANFANG MED ONLINE

You Position: Home > Paper

In-vivo and ex-vivo studies on region-specific remodeling of large elastic arteries due to simulated weightlessness and its prevention by gravity-based countermeasure

( views:104, downloads:0 )

Author:: No author available

Journal Title:: Acta Physiologica Sinica

Issue:: 1

DOI:: No doi available

Key Word:: 微重力;航天飞行后心血管失调;间断性人工重力;血管重塑;局部肾素-血管紧张素系统;血管灌流培养

Abstract：为阐明失重致大动脉区域特异性重塑的特点和重力性对抗措施的机理,我们进行了整体与血管培养实验研究.整体实验:以大鼠尾部悬吊法模拟失重4周(SUS组),以1 h/d恢复站立体位模拟间断性人工重力(S+D组),并设同步对照组(CON).观察模拟失重对大鼠大动脉血管(颈总动脉和腹主动脉)的重塑影响及对抗措施的效果；用免疫组织化学、蛋白免疫印迹分析、原位杂交及实时PCR等方法检测血管组织血管紧张素原(angiotensinogen,Ao)和血管紧张素Ⅱ 1型受体(angiotensin Ⅱ type 1 receptor,AT1R)的蛋白与基因表达变化,以揭示血管局部肾素-血管紧张素系统(local renin-angiotensin system,L-RAS)是否参与调节.结果显示:与CON组相比,SUS组颈总动脉与腹主动脉近管腔的平滑肌层分别发生肥厚与萎缩变化；Ao与AT1R表达分别上调和下调.但在S+D组,上述适应性变化可被完全防止.血管培养实验:本文建立了可以控制流量、压力的血管培养系统,并得到下述结果.在高压(150 mmHg)下培养颈总动脉3d,可引起平滑肌层c-纤维粘连蛋白表达增强,且以靠近管腔的肌层最为显著；培养液Ang Ⅱ的生成量也增多;但如在3d灌流期间,每天有4或1h使灌流压降至0或80mmHg,则上述改变即可被完全防止.以上结果支持我们的假说:跨壁压分布变化是失重引起动脉区域性重塑的始动原因;但每日只要短时间使其恢复常态,血管重塑及L-RAS的变化即可被完全防止.

Reference

[1]孟庆军,李剑,张文红,等.抗血管紧张素原多克隆抗血清的制备及鉴定[J].2003,(1).
[2]张立藩.人工重力的生物医学问题：以往工作回顾与面临的挑战[J].2001,(1).
[3]Mao QW,Ma J,Zhang LF,etc.Peripheral effector mechanism hypothesis of postflight cardiovascular dysfunction.[J].2001,72(6).
[4]Tanaka K..Regional difference of blood flow in anesthetized rats during reduced gravity induced by parabolic flight[J].2005.
[5]C J, Chuong,Y C, Fung.On residual stresses in arteries.[J].1986,108(2).
[6]Vernikos J,Russomano T,Tripp LD,etc.The Bellagio Report: Cardiovascular risks of spaceflight: implications for the future of space travel.[J].2005,76(9).
[7]Huang WQ,Huang J,Gao F,etc.Regional specificity of adaptation change in large elastic arteries of simulated microgravity rats[J].2009,96(2).
[8]T, Shimizu.Development of the aortic baroreflex system under conditions of microgravity.[J].1999,6(1).
[9]Lehoux S,Tedgui A.Signal transduction of mechanical stresses in the vascular wall.[J].1998,32(2).
[10]Campbell D J,Habener J F.Angiotensinogen gene is expressed and differentially regulated in multiple tissues of the rat.[J].1986.
[11]Nathalie Bardy,Regine Merval,Joelle Benessiano,etc.Pressure and Angiotensin II Synergistically Induce Aortic Fibronectin Expression in Organ Culture Model of Rabbit AortaEvidence for a Pressure-Induced Tissue Renin-Angiotensin System[J].1996,79(1).
[12]J, Wiener,A V, Loud,F, Giacomelli,etc.Morphometric analysis of hypertension-induced hypertrophy of rat thoracic aorta.[J].1977,88.
[13]Hai-Chao HanDavid N. Ku.Contractile Responses in Arteries Subjected to Hypertensive Pressure in Seven-Day Organ Culture[J].2001,29(6).
[14]Lehoux S,Tedgui A.Cellular mechanics and gene expression in blood vessels.[J].2003,36(5).
[15]Convertino VA.Status of cardiovascular issues related to space flight: Implications for future research directions.[J].2009,169(Suppl.1).
[16]Zhang LF,Bao JX,Ma J.Angiotensinogen and AT1R expression in cerebral and femoral arteries during hindlimb unloading in rats.[J].2007,78(9).
[17]Fujiki N,Matsuda T,Gotoh TM,etc.Acute hemodynamic responses in the head during microgravity induced by free drop in anesthetized rats.[J].2004,286(6).
[18]A R, Kotovskaia.[The problem of artificial gravity: the present status and possible approaches].[J].1900,42(6).
[19]Lin L J,Gao F,Bai Y G.Contrasting effects of simulated microgravity with and without daily-G_x gravitation on structure and function of cerebral and mesenteric small arteries in rats[J].2009,107(6).
[20]V A, Convertino.Exercise as a countermeasure for physiological adaptation to prolonged spaceflight.[J].1996,28.
[21]Tytell JD,Wang N,Ingber DE.Mechanotransduction at a distance: mechanically coupling the extracellular matrix with the nucleus.[J].2009,10(1).
[22]Kozaburo Hayashi,Takeo Matsumoto.Stress and strain distribution in hypertensive and normotensive rat aorta considering residual strain[J].1996,118(1).
[23]Berk BC.Vascular smooth muscle growth: autocrine growth mechanisms.[J].2001,81(3).
[24]L N, Zhang,L F, Zhang,J, Ma.Simulated microgravity enhances vasoconstrictor responsiveness of rat basilar artery.[J].2001,90.