Effect of minoxidil on rabbit lens epithelial cell behavior in vitro and in situ.

Abstract

Lens epithelial cell (LEC) proliferation and the associated production of extracellular matrix (ECM) are responsible for capsular opacification after cataract-IOL surgery. Minoxidil is an inhibitor of lysyl hydroxylase, an enzyme involved in procollagen hydroxylation. To evaluate the potential efficacy of minoxidil in inhibiting postoperative capsular opacification, we examined the effects of minoxidil on LEC behavior in cell and organ cultures. We examined minoxidil effects on collagen production, migration and proliferation of cultured rabbit LECs as well as its ultrastructural effects, and also its effects on the cell population in organ-cultured capsular bag. No cytotoxicity was identified by MTT assay at the concentrations up to 3.0 mM of minoxidil, whereas it decreased the collagen production in LECs. Minoxidil also inhibited migration and proliferation of cells. Ultrastructural observation revealed the presence of dilated endoplasmic reticulum in LECs treated with minoxidil, indicating the accumulation of protein, probably underhydroxylated collagen precursors. The capsules cultured with minoxidil appeared less opaque than control specimens. On histological examination the numbers of cells on equatorial capsules were found to be significantly lower in minoxidil culture than in control culture. No lens cells were detected on the central posterior capsule of minoxidil culture, whereas they were seen in control. Minoxidil inhibited LEC migration and proliferation in vitro, as well as collagen secretion. Collagen secretion may be essential for LEC migration and proliferation. Minoxidil also attenuated repopulation of LECs on the inner surface of organ-cultured capsules. Minoxidil may be a potential inhibitor of postoperative capsular opacification.