牛眼冲洗过程中房水流畅度增加的机制。

The mechanism of increasing outflow facility during washout in the bovine eye.

作者信息

Overby Darryl, Gong Haiyan, Qiu Guanting, Freddo Thomas F, Johnson Mark

机构信息

Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, USA.

出版信息

Invest Ophthalmol Vis Sci. 2002 Nov;43(11):3455-64.

PMID:12407156

Abstract

PURPOSE

To investigate the relationship between outflow facility and separation between the inner wall of the aqueous plexus and the juxtacanalicular connective tissue (JCT) during washout in the bovine eye.

METHODS

Facility was recorded during 3 hours of anterior chamber perfusion at 15 mm Hg in eight pairs of bovine eyes. One eye of each pair was then lowered to 0 mm Hg for 1 hour, whereas the fellow eye was kept at 15 mm Hg. After a brief perfusion at 15 mm Hg, both eyes were perfusion fixed and processed for electron microscopy. Micrographs of the inner wall were analyzed for separation from the JCT. To study the role of cellular adhesion between the inner wall and JCT, 12 additional pairs were perfused with integrin-binding peptide (RGD: Arg-Gly-Asp) or sham control peptide (RGE: Arg-Gly-Glu) at 2 micro M to 2 mM, before IOP was reduced.

RESULTS

During the first 3 hours, facility increased in both eyes because of "washout." However, after 1 hour of 0 mm Hg, facility decreased by 13% (P < 0.006), whereas facility increased by 20% (P < 0.001) in the fellow eyes maintained at 15 mm Hg. Two types of separation were observed between the inner wall and JCT: cell-matrix separation between the endothelial cell and basal lamina and matrix-matrix separation between the basal lamina and JCT. A significant positive correlation (P = 0.042) was found between the degree of matrix-matrix separation and the change in outflow facility after 1 hour of 0 mm Hg. Compared with RGE control, RGD had no apparent effect on outflow facility (P > 0.35) or on the change in outflow facility after 1 hour at 0 mm Hg (P > 0.15).

CONCLUSIONS

The increase in outflow facility that occurs during washout in the bovine eye is reversible and correlates with the degree of separation between the basal lamina of the inner wall endothelium and the JCT. Therefore, adhesions tethering the inner wall to the JCT may be important ultrastructural features involved in the regulation of aqueous humor outflow resistance.

摘要

目的

研究牛眼冲洗过程中房水流出率与房水丛内壁和近小管结缔组织（JCT）之间分离的关系。

方法

对八对牛眼在15 mmHg下进行3小时前房灌注，记录流出率。然后每对眼睛中的一只眼压降至0 mmHg持续1小时，而另一只眼睛保持在15 mmHg。在15 mmHg短暂灌注后，两只眼睛均进行灌注固定并处理用于电子显微镜检查。分析内壁的显微照片以观察与JCT的分离情况。为研究内壁与JCT之间细胞黏附的作用，在降低眼压之前，另外12对眼睛用2 μM至2 mM的整合素结合肽（RGD：精氨酸 - 甘氨酸 - 天冬氨酸）或假对照肽（RGE：精氨酸 - 甘氨酸 - 谷氨酸）进行灌注。

结果

在最初3小时内，由于“冲洗”两只眼睛的流出率均增加。然而，在0 mmHg 1小时后，流出率下降了13%（P < 0.006），而保持在15 mmHg的另一只眼睛流出率增加了20%（P < 0.001）。在内壁与JCT之间观察到两种类型的分离：内皮细胞与基膜之间的细胞 - 基质分离以及基膜与JCT之间的基质 - 基质分离。在0 mmHg 1小时后，基质 - 基质分离程度与流出率变化之间存在显著正相关（P = 0.042）。与RGE对照相比，RGD对流出率（P > 0.35）或在0 mmHg 1小时后的流出率变化（P > 0.15）无明显影响。