Passage of low-density lipoproteins through Bruch's membrane and choroid.
Passage of low-density lipoproteins through Bruch's membrane and choroid.
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DOI：
10.1016/j.exer.2011.10.016
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发表时间：
2011-12
影响因子：
3.4
通讯作者：
Johnson, Mark
中科院分区：
文献类型：
--
作者：
Cankova, Zdravka;Huang, Jiahn-Dar;Kruth, Howard S.;Johnson, Mark
血浆脂蛋白被认为是将胆固醇、维生素和类胡萝卜素运输到视网膜色素上皮(RPE)，供光感受器最终使用。然而，为了到达RPE，这些脂蛋白颗粒必须穿过Bruchs膜。测定Bruch膜(BRM)对低密度脂蛋白(LDL)的反射系数。取47只牛眼的Bruch膜和脉络膜。标本放置在Ussing小室中，用磷酸盐缓冲盐水(PBS)灌流(31例)或不加(16例)荧光低密度脂蛋白(DII-LDL)。测定了牛眼和牛眼组织的水力传导性。在DII-LDL灌流中，测量外排DII-LDL的荧光强度，并测定BRM/脉络膜制剂对DII-LDL的反射系数。进行了渗漏测试以确认组织的完整性。几个标本在灌流前后用扫描电子显微镜(SEM)检查组织完整性。渗漏试验证实BRM在灌流前后均完好无损。牛眼视网膜/脉络膜灌注的平均水力传导率为1.4 2±0.5 5×10−9m/S/帕(平均±标准差，n=11)。牛眼平均导水率为4.94±1.48×10−10m/S/帕(n=5)，随年龄增长，平均导水率下降近3倍。在PBS灌流过程中，流量保持不变，而在DII-LDLS灌流过程中，流量随时间而降低。我们的主要发现是在所有使用DII-LDLS的灌流液中收集的流出物中有荧光，表明低密度脂蛋白通过组织。小牛BRM/脉络膜制剂对DiI-LDL的平均反射系数为0.58±0.25(n=23)，牛眼组织的反射系数分布与之相似(0.51±0.33，n=8)。我们的数据表明，DiI-LDL被组织适度地阻碍和/或捕获。这可能解释了随着DII-LDL的持续灌流，渗透系数进行性下降的原因。
Plasma lipoproteins are thought to transport cholesterol, vitamins and carotenoids to the retinal pigment epithelium (RPE) for ultimate use by the photoreceptors. However, to reach the RPE, these lipoprotein particles must cross Bruch’s membrane. We examined the reflection coefficient of Bruch’s membrane (BrM) to low-density lipoprotein (LDL). Bruch’s membrane and choroid were removed from 47 bovine eyes. Specimens were placed in a Ussing chamber and perfused with phosphate-buffered saline (PBS) with (31 specimens) or without (16 specimens) fluorescent low-density lipoproteins (DiI-LDL). The hydraulic conductivity of the tissue was determined for both calf and cow eyes. In the perfusions with DiI-LDL, the fluorescence intensity emitted by DiI-LDL in the efflux was measured and the reflection coefficient of BrM/choroid preparations to DiI-LDL determined. Leakage tests were done to confirm tissue integrity. Several specimens were examined using scanning electron microscopy (SEM) to examine tissue integrity before and after perfusion. Leak testing confirmed that BrM was intact both before and after perfusion. The average hydraulic conductivity of BrM/choroid perfusion of calf eyes with PBS alone was 1.42 ± 0.55 ×10−9 m/s/Pa (mean ± SD, n = 11). The average hydraulic conductivity of the cow eyes was 4.94 ± 1.48 ×10−10 m/s/Pa (n = 5), nearly a 3-fold decrease with age. While the flow rate remained constant during the PBS perfusions, it decreased as a function of time during perfusion with DiI-LDLs. Our major finding was of fluorescence in the effluent collected in all perfusions with DiI-LDLs, demonstrating passage of LDL through the tissue. The average reflection coefficient of calf BrM/choroid preparations to DiI-LDL was 0.58 ± 0.25 (n = 23); a similar distribution of reflection coefficients was seen in tissue from cow eyes (0.51 ± 0.33, n = 8). Our data suggested that the DiI-LDL was modestly hindered and/or captured by the tissue. This might explain the progressive decrease of hydraulic conductivity with continued perfusion of DiI-LDL.
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影响因子：
4.4
作者：
Hillenkamp, J;Hussain, AA;Marshall, J
通讯作者：
Marshall, J
影响因子：
4.4
作者：
Huang, Jiahn-Dar;Curcio, Christine A.;Johnson, Mark
通讯作者：
Johnson, Mark
影响因子：
4.4
作者：
Gordiyenko, N;Campos, M;Rodriguez, IR
通讯作者：
Rodriguez, IR
DOI：
10.1073/pnas.72.6.2347
发表时间：
1975-01-01
影响因子：
11.1
作者：
FISHER, WR;HAMMOND, MG;WARMKE, GL
通讯作者：
WARMKE, GL
影响因子：
17.8
作者：
Curcio, Christine A.;Johnson, Mark;Huang, Jiahn-Dar;Rudolf, Martin
通讯作者：
Rudolf, Martin