SUGAR TRANSPORT ACROSS CORNEAL ENDOTHELIUM

A system for mounting the rabbit's cornea and perfusing both its surfaces is described. The chambers in contact with the surfaces have to be small and well-mixed in order to follow the rapid exchanges of solutes that may occur. The efflux of radioactive sugars and other substances a cross the endothelium was examined by loading the corneal tissue with the material and then following its concentration in the perfusate. The flux of glucose and methylglucose out across the layer is faster than would be expected on the basis of their size, suggesting that their exchange is facilitated. This is confirmed, in the case of glucose, by its high concentration in the corneal water in spite of its consumption by the tissue. However, the expected effect of the glucose consumption could not be detected in a comparison of its efflux curves with those for methylglucose. © 1969 Academic Press Inc. (London) Limited.