Epidermal Growth Factor Stimulates Fluid Transport in Corneal Endothelium

Abstract

Abstract: : Purpose:Corneal thickness and hydration depends crucially on a balance between water leak and transport across corneal endothelium (CE). Since epidermal growth factor (EGF) stimulates fluid transport in rabbit SV40-immortalized lacrimal gland layers, we tested the effect of EGF on CE fluid transport Methods: We used deepithelialized in vitro rabbit corneal preparations. CE fluid transport activity was assessed by corneal thickness measurements with a specular microscope. Results: Discution Following thickness stabilization, EGF (20 ng/ml) application caused normal rabbit corneas (350 µm thick) to shrink after 30 min by 25 ± 0.7 µm. After 30 min exposure to hypertonic (10%) or hypotonic (-10%) conditions, application of EGF still produces shrinkage (11 ± 0.7 and 5.5 ± 0.7 µm), suggesting that the EGF effect is not on the passive leak. Experiments were done with a physiological concentration of EGF, suggesting an effect through EGF receptors in CE. Conclusions:Cytokines may play an important role in eye tissues hydration by effecting epithelial water transport activity

Keywords: pump/barrier function • cornea: endothelium • cytokines/chemokines