Effects of Surfactant Retreatment in Vitro: A Method to Evaluate Changes in Cell Junctions and in Cell Viability

Abstract

Madin-Darby canine kidney (MDCK) cells form cell junctions in vitro, which can be damaged and restored following exposure to a mild cytotoxicant. Both tight junctional integrity and cell viability can be measured by using the fluorescein leakage assay and the Alamar Blue™ assay, respectively, without terminating the cell cultures. By combining these two assay endpoints, it is possible to examine the effects of a repeated cocamidopropylbetaine treatment on a confluent layer of MDCK cells. While the tight junctions could be restored after a single treatment with 2.5mg/ml or 10mg/ml cocamidopropylbetaine, after a second insult, recovery was noted for those treated with 2.5mg/ml, but not for those exposed to 10mg/ml. Following the second insult, the cells did not regain the control level of viability.