Effects of Glucose Transport Inhibitors on Corneal Swelling Rate and Endothelial Ion Fluxes

AbstractBased on the observation that several glucose transport inhibitors were found to reduce osmotically generated fluid flows across the rabbit corneal en-dothelium, these inhibitors have been examined for their influence on corneal swelling and ion fluxes across the endothelium. Using specular microscopy, phloretin (2 mM), cytochalasin B (20 µg/ml), and ethylidene-D-glucose (200 mM) were found to cause corneal swelling, whereas phlorid-zin (2 mM) and dihydrocytochalasin B (20 µg/ml) did not cause a swelling rate significantly different from controls. Each of the inhibitors caused changes in the unidirectional fluxes of sodium or bicarbonate, or both ions. None of the changes appeared to be related to the changes in corneal thickness. Cytochalasin B and dihydrocytochalasin B, for example, had no effect on net bicarbonate flux, yet both agents increased net sodium flux. Cytochalasin B, but not dihydrocytochalasin B, caused corneal swelling. Phloridzin decreased both net ion fluxes to zero, but had no e...