Department of Hospital Pharmacy, Nagasaki University Hospital, Nagasaki 852-8501, Japan.
Biol Pharm Bull. 2010;33(1):107-10. doi: 10.1248/bpb.33.107.
We developed a new electrophysiological method mimicking tear flow to evaluate the epithelial tight junction of rabbit cornea quantitatively. We investigated the effect of tear flow on the corneal damage induced by ophthalmic preservatives using this method. An Ussing chamber system with Ag/AgCl electrodes was used in the electrophysiological experiment. The excised rabbit cornea was mounted in the Ussing chamber and the precorneal solution in the chamber was perfused with a peristaltic pump at the rate of human tear flow. Corneal transepithelial electrical resistance (TEER) was monitored as corneal barrier ability. In the electrophysiological method mimicking tear flow, we observed stable TEER, which rapidly decreased with benzalkonium chloride (BAC), an eye drop preservative. Using this system, we first found that 0.004% BAC decreased corneal TEER reversibly. A high concentration of BAC showed strong irreversible damage to the tight junction. The influence of BAC on corneal TEER was not only concentration-dependent but also tear flow rate-dependent. The electrophysiological method mimicking tear flow was useful to evaluate the corneal barrier quantitatively. Using this method, we clarified that the tear flow was important to protect the corneal damage induced by preservatives.
我们开发了一种新的模拟泪液流动的电生理方法，用于定量评估兔眼角膜上皮紧密连接。我们使用这种方法研究了泪液流动对眼用防腐剂引起的角膜损伤的影响。在电生理实验中使用带有 Ag/AgCl 电极的 Ussing 室系统。将离体兔角膜安装在 Ussing 室中，并用蠕动泵以人泪液流动的速度向室中的预角膜溶液中灌注。监测角膜上皮跨膜电阻 (TEER) 作为角膜屏障能力。在模拟泪液流动的电生理方法中，我们观察到稳定的 TEER，其随着苯扎氯铵 (BAC) 的快速下降，一种滴眼防腐剂。使用该系统，我们首先发现 0.004% BAC 可逆地降低了角膜 TEER。高浓度的 BAC 对紧密连接显示出强烈的不可逆损伤。BAC 对角膜 TEER 的影响不仅取决于浓度，还取决于泪液流速。模拟泪液流动的电生理方法可用于定量评估角膜屏障。使用这种方法，我们阐明了泪液流动对于保护防腐剂引起的角膜损伤很重要。
