R-(+)-verapamil, S-(-)-verapamil, and racemic verapamil inhibit human retinal pigment epithelial cell contraction

Purpose: To evaluate the effects of R-(+)-verapamil, S-(-)-verapamil, and the racemate on in vitro contraction of human retinal pigment epithelial cells. Methods: RPE cells from human donor eyes were enzymatically dissociated and cultured on collagen gels. Transdifferentiated RPE cells (seventh and eighth passage) were used for experiments. The contraction assays were treated with different concentrations (10-1000 mu M) of R-(+)-verapamil, S-(-)-verapamil, and racemic verapamil. Results: Verapamil inhibited the gel contraction of human RPE cells. R-(+)-verapamil, S-(-)-verapamil, and racemic verapamil acted equally in a dose-dependent manner from 10-1000 mu M. Conclusion: The results indicate the effectiveness of verapamil to inhibit the contraction of RPE cells. R-(+)-verapamil is recommended because it is associated with fewer systemic and local side effects.