Fasano W J, Manning L A, Green J W
The DuPont Company, Haskell Laboratory for Health and Environmental Sciences, PO Box 50 Elkton Road, Newark, DE 19714, USA.
Toxicol In Vitro. 2002 Dec;16(6):731-40. doi: 10.1016/s0887-2333(02)00084-x.
An approach is presented that allows for rapid selection of robust rat and human epidermal membranes for use on in vitro dermal regulatory studies. Tritiated water (THO) permeability was correlated with electrical resistance (ER) and the results used to propose ER values to judge membrane integrity. Rat and human epidermal membranes were prepared and mounted onto in vitro glass static diffusion cells (0.64 cm(2)) maintained at 32 degrees C. THO permeability coefficients (Kp) were determined and compared with ER measurements. Electrical resistance was also determined for various in vitro cell exposure areas from 0.64 cm(2) to 2.54 cm(2). Our results show that rat epidermal membrane THO Kp values exhibited a lognormal distribution with a median value of 2.76 x 10(-3) cm/h. Human epidermal membrane THO Kp values were best described by a Weibull distribution with a median value of 1.13 x 10(-3) cm/h. The corresponding median electrical resistance measurements were 5.59 kOmega for rat and 23 kOmega for human epidermal membranes. Based on the widely used and accepted single point THO Kp thresholds of </=2.5 x 10(-3) cm/h (rat) and </=1.5 x 10(-3) cm/h (human), the corresponding ER values of >/=5.87 kOmega and >/=17.1 kOmega were calculated and proposed as acceptable benchmarks for pre-qualifying membranes. In our research exploring the relationship between ER and exposure area we report that an inverse relationship exists between ER and in vitro cell exposure area; as cell area increased, ER decreased. The use of electrical resistance provides a rapid and reliable method for evaluating the integrity of rat and human epidermal membranes for in vitro dermal kinetic testing.
本文提出了一种方法，可快速筛选出用于体外皮肤调节研究的健壮大鼠和人表皮膜。将氚标记水（THO）渗透率与电阻（ER）相关联，并将结果用于提出判断膜完整性的ER值。制备大鼠和人表皮膜，并将其安装在保持在32℃的体外玻璃静态扩散池（0.64 cm²）上。测定THO渗透系数（Kp）并与ER测量值进行比较。还测定了从0.64 cm²到2.54 cm²的各种体外细胞暴露面积的电阻。我们的结果表明，大鼠表皮膜THO Kp值呈对数正态分布，中值为2.76×10⁻³ cm/h。人表皮膜THO Kp值最好用威布尔分布描述，中值为1.13×10⁻³ cm/h。大鼠和人表皮膜相应的中值电阻测量值分别为5.59 kΩ和23 kΩ。基于广泛使用和认可的单点THO Kp阈值≤2.5×10⁻³ cm/h（大鼠）和≤1.5×10⁻³ cm/h（人），计算出相应的ER值≥5.87 kΩ和≥17.1 kΩ，并将其作为膜预合格的可接受基准。在我们探索ER与暴露面积之间关系的研究中，我们报告ER与体外细胞暴露面积之间存在反比关系；随着细胞面积增加，ER降低。使用电阻为评估用于体外皮肤动力学测试的大鼠和人表皮膜的完整性提供了一种快速可靠的方法。
