Electrical Potential Profile of the Isolated Frog Cornea

Abstract

With the use of glass microelectrodes the electrical potential profile was determined in the isolated cornea of the frog, Rana catesbiana. The results indicate that the stroma of the cornea is always negative (up to -32 mv.) with respect to both endothelial and epithelial bathing solutions. A model was developed that excluded the epithelium as the location of a previously described chloride pump and indicates that the negativity of the stroma is consistent with the location of the pump only in the endothelium of the cornea. It also indicates that the steadystate concentration of sodium chloride in the stroma is higher than in both Ringer's solutions. The role of this electromotive force in the control of corneal hydration is discussed. The relevance of the transport mechanism in the cornea for its normal degree of hydration and transparency is not as yet completely clear.