Potassium ion fluxes in corneal epithelial cells exposed to UVB.

The goal of this study was to investigate the efflux of K(+) from human corneal limbal epithelial cells (HCLE) exposed to ambient levels of UVB, which is known to cause apoptosis, and to examine the effect of K(+) channel blockers on loss of potassium induced by UVB. HCLE cells were exposed to 100-200 mJ/cm(2) UVB, followed by incubation in culture media with 5.5-100 mM K(+), BDS-1, Ba(2+) or ouabain.

Inhibition of UV-B induced apoptosis in corneal epithelial cells by potassium channel modulators.

The goal of this study was to determine whether prevention of K(+) loss can protect human corneal-limbal epithelial (HCLE) cells from UV-B induced apoptosis. Immunostaining for activated caspase-3 of HCLE cells exposed to 150-200 mJ/cm(2) UV-B demonstrated induction of apoptosis 6 h after exposure. The number of apoptotic cells was decreased by incubation in medium with 25 or 100 mM K(+).