本文選題：視網(wǎng)膜血管 + 穿孔膜片鉗�。� 參考：《復(fù)旦大學(xué)》2011年博士論文

【摘要】：第一部分：大鼠視網(wǎng)膜血管的電緊張傳導(dǎo) 研究目的在于探討視網(wǎng)膜血管各級血管之間相互的電緊張聯(lián)系,進(jìn)一步了解視網(wǎng)膜血管收縮舒張的自主調(diào)節(jié)機(jī)制。選用成年L-ng-Evans大鼠,新鮮分離視網(wǎng)膜血管,臺盼藍(lán)染色觀察其細(xì)胞活性,玻璃電極封接血管壁層細(xì)胞,穿孔膜片鉗單記錄觀察各級血管電流-電壓(Ⅰ-Ⅴ)關(guān)系,并利用穿孔膜片鉗雙記錄觀察各級血管電緊張傳導(dǎo),探討其電緊張傳導(dǎo)模式。 結(jié)果顯示：新鮮分離的視網(wǎng)膜血管可穩(wěn)定獲得,按血管管腔大小、壁層細(xì)胞密度和形態(tài),可將獲得的視網(wǎng)膜血管分為第二級小動脈、第三級小動脈及毛細(xì)血管三級。各級血管的細(xì)胞的成活率為90%以上,顯微鏡下清晰可辨各級血管壁層細(xì)胞,適于膜片鉗記錄其離子變化；視網(wǎng)膜各級血管壁層細(xì)胞單一電生理記錄顯示,各級血管的靜息電位為-38±1mV(n=27),-42±1mV(n=29)和-45±1 mV(n=10),經(jīng)單因素方差分析無明顯統(tǒng)計學(xué)差異(P=0.27)。當(dāng)細(xì)胞膜電壓為-50mV時,各級血管的輸入電阻分別為：175±19 MΩ(n=27),151±9 MΩ(n=29)和127±15 MΩ(n=10),單因素方差分析無明顯統(tǒng)計學(xué)差異(P=0.58)。于壁層細(xì)胞行膜片鉗雙記錄,結(jié)果發(fā)現(xiàn),電緊張傳導(dǎo)沿毛細(xì)血管水平軸向最為高效,其電緊張傳導(dǎo)比為0.56±0.15(n=27),每100μm的衰減僅為2±2%(n=27)；在第三級小動脈,其電緊張傳導(dǎo)比為0.27±0.09(n=22),每100μm的衰減僅為6±8%(n=22)；在第二級小動脈,電緊張傳導(dǎo)比為0.25±0.19(n=10),每100μm的衰減為6±8%(n=10)。三組間的衰減率沒有統(tǒng)計學(xué)差異。 研究發(fā)現(xiàn),視網(wǎng)膜血管的電緊張傳導(dǎo)主要通路為壁層細(xì)胞—內(nèi)皮細(xì)胞—壁層細(xì)胞,各級血管內(nèi)部的水平軸向傳導(dǎo)高效,尤以毛細(xì)血管傳導(dǎo)效率最高,傳導(dǎo)的衰減主要發(fā)生于壁層細(xì)胞和內(nèi)皮細(xì)胞之間,以及跨各級血管的水平軸向傳導(dǎo)之間。 第二部分：血管緊張素Ⅱ?qū)Υ笫笠暰W(wǎng)膜血管電緊張傳導(dǎo)的影響 目的在于研究血管活性因子——血管緊張素Ⅱ?qū)σ暰W(wǎng)膜血管自主調(diào)控的影響。選用成年Long-Evans大鼠,新鮮分離視網(wǎng)膜血管,免疫組織化學(xué)顯示血管緊張素Ⅱ1型受體在血管上的表達(dá),利用穿孔膜片鉗單記錄觀察500nM血管緊張素Ⅱ?qū)σ暰W(wǎng)膜各級血管電生理的影響,利用鈣離子顯像觀察500nM血管緊張素Ⅱ在視網(wǎng)膜各級血管壁層細(xì)胞引起的細(xì)胞內(nèi)鈣離子的變化,并利用穿孔膜片鉗雙記錄觀察其對視網(wǎng)膜血管電緊張傳導(dǎo)的影響。 結(jié)果顯示：視網(wǎng)膜各級血管均表達(dá)血管緊張素Ⅱ1型受體,形態(tài)學(xué)分布未見明顯差異。500nM血管緊張素Ⅱ引起壁層細(xì)胞非選擇性陽離子通道開放,電流產(chǎn)生主要部位為毛細(xì)血管,從-108mV至-38mV,產(chǎn)生的內(nèi)向電流明顯大于生理對照；從+12mV至+22mV,外向電流亦明顯大于對照(n=8,P0.0001)。然而,在第三級小動脈和第二級小動脈,500nM血管緊張素Ⅱ引起的電流變化明顯小于毛細(xì)血管的電流變化,與生理對照相比亦無統(tǒng)計學(xué)差異。500nM血管緊張素Ⅱ引起壁層細(xì)胞內(nèi)鈣離子升高的主要部位亦是毛細(xì)血管,其周細(xì)胞鈣離子濃度改變最大值達(dá)325±20 nM(n=81),明顯高于第三級小動脈肌細(xì)胞鈣離子濃度變化(55±3 nM,n=149,P0.0001)和第二級小動脈平滑肌細(xì)胞鈣離子濃度變化(10±2 nM,n=130,P0.0001)。500nM血管緊張素Ⅱ明顯抑制視網(wǎng)膜各級血管水平軸向電緊張傳導(dǎo)(每100μm衰減率～50%),但是對壁層細(xì)胞-內(nèi)皮細(xì)胞之間的傳導(dǎo)無明顯作用。 研究發(fā)現(xiàn)：在視網(wǎng)膜血管,雖然血管緊張素Ⅱ1型受體分布于視網(wǎng)膜各級血管,其介導(dǎo)的非選擇性陽離子通道的開放和鈣離子增加主要部位卻是毛細(xì)血管。然而,血管緊張素Ⅱ可使各級血管水平軸向電緊張傳導(dǎo)的效率明顯降低,且這種作用并不依賴于細(xì)胞內(nèi)鈣離子明顯變化。視網(wǎng)膜血管的電緊張傳導(dǎo)是動態(tài)接受局部血管活性因子調(diào)節(jié)的。
[Abstract]:Part I : Electric tension conduction in rat retinal vessels


The purpose of this study was to investigate the relationship between retinal vessels at all levels and to further understand the mechanism of self - regulation of retinal vessel contraction .


The results showed that the newly isolated retinal vessels were stable and can be divided into secondary arterioles , tertiary arterioles and capillary vessels according to the size of the vessel lumen and the density and morphology of the wall cells . The survival rate of the cells at all levels was above 90 % .
When the cell membrane voltage was -50mV , the input resistance of all levels of blood vessels was 175 鹵 19 M惟 ( n = 27 ) , 151 鹵 9 M惟 ( n = 29 ) and 127 鹵 15 M惟 ( n = 10 ) .
At the third arterioles , the electrical stress - conduction ratio was 0.27 鹵 0.09 ( n = 22 ) , and the attenuation per 100 渭m was only 6 鹵 8 % ( n = 22 ) ;
In the second - stage arterioles , the electrical stress - conduction ratio was 0.25 鹵 0.19 ( n = 10 ) , and the attenuation per 100 渭m was 6 鹵 8 % ( n = 10 ) . There was no statistical difference among the three groups .


It was found that the main pathways of electrical stress conduction in retinal vessels were wall - layer cells - endothelial cell - wall - layer cells , and the horizontal axial conduction inside the vessels at all levels was highly effective , especially with the highest efficiency of capillary conduction , the attenuation of conduction mainly occurred between the wall - layer cells and endothelial cells , and the horizontal axial conduction across all levels of blood vessels .


The second part : the effect of angiotensin 鈪，

本文編號：1971966