Gong H, Johnson M, Ye W, Kamm R D, Freddo T F
Department of Ophthalmology, Boston University School of Medicine, MA 02118, USA.
Exp Eye Res. 1997 Dec;65(6):747-56. doi: 10.1006/exer.1997.0382.
In our previous studies, we noted a non-uniform distribution of protein tracer preferentially entering the anterior stromal lamellae of the cornea from the limbus. Given other differences reported previously between the anterior and posterior lamellae of the cornea, and the number of corneal disorders in which abnormalities are preferentially confined to either the anterior or posterior lamellae, we were prompted to examine the distribution of albumin in normal human and bovine cornea. The distribution of albumin in bovine and human cornea was studied immunohistochemically. Total soluble protein and albumin in the anterior 1/3 and posterior 2/3 of the central, middle and peripheral cornea of bovine eyes was measured biochemically. To aid in interpreting the findings, a theoretical model was developed based upon the combined effects of diffusive and convective transport. Using immunohistochemical methods, in both bovine and human eyes, intense staining of albumin was found in the anterior 1/3 of the corneal stroma. There was a gradual reduction in staining intensity from the limbus to the central cornea in the anterior corneal stroma. Less staining was found in the posterior 2/3 of corneal stroma. Additionally, a greater concentration of soluble protein and albumin was found in the anterior stroma than in the posterior stroma of the bovine eyes by biochemical analyses. The theoretical model demonstrated that this distribution of protein required a difference in excluded volume fraction between the anterior and posterior stroma and was consistent with a convective flux originating at the limbus and passing through the corneal stroma. The soluble proteins of the bovine and human cornea are preferentially concentrated in the anterior cornea and near the limbus. This distribution is likely due to differences in excluded volume fraction between the anterior and posterior stroma and a small convective flux passing through the cornea.
在我们之前的研究中，我们注意到蛋白质示踪剂从角膜缘优先进入角膜前基质板层时分布不均匀。鉴于先前报道的角膜前后板层之间的其他差异，以及许多角膜疾病的异常情况优先局限于前板层或后板层，我们因此着手研究白蛋白在正常人和牛角膜中的分布。通过免疫组织化学方法研究了白蛋白在牛和人角膜中的分布。通过生化方法测量了牛眼中央、中间和周边角膜前1/3和后2/3中的总可溶性蛋白和白蛋白。为了帮助解释研究结果，基于扩散和对流运输的综合作用建立了一个理论模型。使用免疫组织化学方法，在牛和人眼中，均发现角膜基质前1/3有强烈的白蛋白染色。在前角膜基质中，从角膜缘到中央角膜，染色强度逐渐降低。在角膜基质后2/3中染色较少。此外，通过生化分析发现，牛眼前基质中的可溶性蛋白和白蛋白浓度高于后基质。理论模型表明，这种蛋白质分布需要前后基质之间的排阻体积分数存在差异，并且与起源于角膜缘并穿过角膜基质的对流通量一致。牛和人角膜中的可溶性蛋白优先集中在前角膜和角膜缘附近。这种分布可能是由于前后基质之间排阻体积分数的差异以及穿过角膜的小对流通量所致。
