Local osmotic coupling to the active trans-endothelial bicarbonate flux in the rabbit cornea.

The present experiments investigate HCO3-, Cl- and fluid fluxes across partially destromalised corneas. Although there is no net flux of Cl-, there is a net flux of HCO-3 across the endothelium from stromal side to aqueous side which is accompanied by a flux of water in the same direction. Bulk phase osmosis cannot account for the initiation of the flux of fluid. Local osmotic coupling between ions and water is postulated to occur in the preparation. The exudate is hypertonic to the bathing Ringer solution.