Rabbit corneal endothelial fluxes of sodium, bicarbonate, inulin, and dextran have been measured in ambient solutions containing either 0.5 mM adenosine alone (A), 0.3 mM glutathione alone (G), both adenosine and glutathione, or neither adenosine nor glutathione. Addition of A alone to a solution lacking both additives caused a decrease in both Jstro endo and Jstro str sodium fluxes coupled with an increase in Jstro endo Addition of G alone caused no effect, whereas addition of A and G together caused a decrease in both Jstro endo and Jstro str sodium fluxes and a large increase in Jstro endo net. Addition of A or G caused an increase in Jstro endo bicarbonate flux, but no change in Jstro str flux. Addition of A and G caused an increase in both Jstro endo and Jstro str bicarbonate flux and a decrease in Jstro endo net. None of the solution variations caused an alteration in either inulin or dextran permeability. Since both A and G influence Jstro endo net bicarbonate and sodium transport, this may provide an explanation of the beneficial effects of these compounds on the endothelium to both enhance and prolong corneal thickness and hydration regulation.