Cell Production and Migration in the Epithelial Layer of the Cornea

Abstract

Tritium-labeled thymidine is used in the study of cellular desoxyribonucleic acid (DNA) synthesis. Thymidine is incorporated into DNA during the premitotic coupling stage of a new cell and this process normally leads to cell division. Once the labeled thymidine is incorporated into the nucleus it is retained in a polymerized form which undergoes very slow turnover throughout the life of the nucleus. This radioactive label can be qualitatively located and semiquantitatively studied by means of high resolution autoradiographic stripping-film techniques. This method was used to study the proliferation and the subsequent history of the epithelial cells of the cornea of the eye. Earlier studies on the growth activity of the corneal epithelium have been summarized by Buschke, Friedenwald, and Fleischmann.¹ While earlier authors indicated that the growth activity of the epithelium was slow² unless the cornea was injured, the above authors¹ in studies on rats, found that