INCREASED INTRACELLULAR PRESSURE ACCOMPANYING ACTIVE TRANSPORT IN CORNEAL ENDOTHELIUM

WHEN a cornea is exposed to low temperatures it swells; if it is subsequently warmed, it can expel its excess fluid and revert to physiological thickness. The phenomenon is called temperature reversal and has been used to show that active transport of fluid out of the cornea is controlled by the endothelium, lining the posterior surface of the cornea. Temperature reversal occurs in vivo1,2 or in vitro if a suitable fluid such as KEI3 bathes the endothelium. Metabolizing cells of the corneal endothelium also generate to a positive intracellular pressure which causes convex bowing of the unattached posterior cell membrane4. We report here direct observations on the posterior cell membranes of the endothelium during temperature reversal using a recently described specular microscope5. © 1969 Nature Publishing Group.