The permeability of the corneal epithelium and endothelium to water

doi:10.1016/S0014-4835(67)80049-6

Experimental Eye Research

Volume 6, Issue 1, January 1967, Pages 10-32

https://doi.org/10.1016/S0014-4835(67)80049-6 Get rights and content

The anterior chamber of the enucleated rabbit eye was perfused with tissue culture medium (TC 199); the temperature of the medium (35°C), the intraocular pressure (20 mmHg), and the rate of perfusion (0·33 cc/min) were controlled. The corneal surface of the living rabbit was bathed with 0·9% sodium chloride solution after the aqueous humor had been replaced with silicone oil. These procedures did not affect the normal corneal thickness for a period of 4 hr.

Various degrees of hypertonicity were produced in the perfusing solutions by the addition of various solutes, i.e. sodium chloride, urea, glucose, sucrose, raflinose, and albumin. When a cornea came into contact with a hypertonic solution, its thickness rapidly decreased, reaching a new steady state in 10–15 min. When TC 199 or 0·9% sodium chloride solution was then applied, the thickness rapidly increased to the original level. An analysis of the time sequence of the changes in corneal thickness, from the viewpoint of the thermodynamics of irreversible processes, yielded values for the hydraulic conductivity of the corneal epithelium and endothelium and for their reflection coefficients with the different solutes used.

The hydraulic conductivity of the epithelium and endothelium, respectively, was approximately 1·0 × 10⁻⁴ mm/min msOm l⁻¹ and 2·3 × 10⁻⁴ mm/min mOsm l⁻¹. The reflection coefficient of the epithelium was 1 with all solutes used; that of the endothelium was 0·6 with urea and sodium chloride and 1 with solutes of larger molecular weights than glucose.

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^*: This investigation was supported in part by a PHS research grant (B-02220) from the National Institute of Neurological Diseases and Blindness, U.S. Public Health Service, and in part by the Massachusetts Lions Eye Research Fund, Inc. Part of this paper was the subject of a preliminary report at the meeting of the Biophysical Society, 22–25 February 1966, Boston, Mass., U.S.A.

^†: The author conducted this investigation during the tenure of a Fight for Sight Post-Doctoral Fellowship of the National Council to Combat Blindness, Inc., New York, N.Y. Present address: Department of Ophthalmology, College of Physicians and Surgeons, Columbia University, New York, N.Y., U.S.A.

^‡: The author conducted this investigation during the tenure of a Fight for Sight Post-Doctoral Fellowship of the National Council to Combat Blindness, Inc., New York, N.Y. Present address: Department of Ophthalmology, University of Lund, Swoden.

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The permeability of the corneal epithelium and endothelium to water*

Am. J. Ophthalmol.

Am. J. Ophthalmol.

Am. J. Ophthalmol.

Exptl Eye Res.

Exptl Eye Res.

Exptl Eye Res.

Exptl Eye Res.

Biochim. Biophys. Acta

Exptl Eye Res.

Exptl Eye Res.

Exptl Eye Res.

Am. J. Ophthalmol.

Am. J. Ophthalmol.

Doc. Ophthalmol.

Invest. Ophthalmol.

Conduction of Heat in Solids

Arch. Ophthalmol. (Chicago)

Arch. Ophthalmol. (Chicago)

Biochem. J.

J. Physiol. (London)

Intern. Rev. Cytol.