Ubels J L, Ditlev J A, Clousing D P, Casterton P L
Department of Biology, Calvin College, 3201 Burton St., SE, Grand Rapids, MI 49546, USA.
Toxicol In Vitro. 2004 Dec;18(6):853-7. doi: 10.1016/j.tiv.2004.04.005.
The bovine cornea opacity and permeability assay (BCOP) is a proposed alternative to the Draize rabbit test for potential eye irritants. In the standard BCOP, bovine corneas are mounted in a holder on a flat surface between two identical chambers. The flat configuration of the standard holder does not conform to the normal curved shape of the bovine cornea and it comes into direct contact with the cornea tissue. Mounting corneas in this holder causes extensive damage to both epithelial and endothelial corneal cell layers. Our laboratory has designed a new holder that allows the cornea to maintain its natural curvature and does not damage the cornea. Previous tests, using both the new and standard holders, and comparing corneal opacity, hydration and endothelial morphology, have shown that the new holder is a significant improvement over the standard holder. The present study extends the comparisons of the new and standard holders to measurement of corneal fluorescein permeability. The permeability (ng/cm(2)/min) of intact corneas, corneas with no epithelium, and corneas treated with 1% NaOH, isopropanol, acetone, 30% trichloroacetic acid or 30% sodium dodecysulfate for either 1 or 10 min was determined by measuring fluorescence of samples taken from the endothelial chamber after 90 min epithelial exposure to 0.04% sodium fluorescein. In all trials, the redesigned holders yielded not only lower permeability measurements but also decreased measurement variability. The data provide further evidence that the new holder is an improvement over the standard holder and should be incorporated into a new protocol for the BCOP.
牛角膜混浊和通透性试验（BCOP）是一种针对潜在眼刺激物提出的替代Draize兔眼试验的方法。在标准的BCOP中，牛角膜被安装在一个平面上两个相同腔室之间的固定器中。标准固定器的平面结构不符合牛角膜的正常弯曲形状，且会与角膜组织直接接触。将角膜安装在这种固定器中会对角膜上皮和内皮细胞层造成广泛损伤。我们实验室设计了一种新的固定器，它能使角膜保持其自然曲率且不会损伤角膜。此前使用新固定器和标准固定器进行的试验，通过比较角膜混浊、水合作用和内皮形态，结果表明新固定器相较于标准固定器有显著改进。本研究将新固定器和标准固定器的比较扩展到角膜荧光素通透性的测量。通过测量上皮暴露于0.04%荧光素钠90分钟后从内皮腔室采集的样本的荧光，来测定完整角膜、无上皮角膜以及用1%氢氧化钠、异丙醇、丙酮、30%三氯乙酸或30%十二烷基硫酸钠处理1分钟或10分钟后的角膜的通透性（纳克/平方厘米/分钟）。在所有试验中，重新设计的固定器不仅产生了更低的通透性测量值，而且测量变异性也降低了。这些数据进一步证明新固定器比标准固定器有所改进，应纳入BCOP的新方案中。
