Possible regulatory mechanisms of the cornea. I. Epithelial-stromal interaction in vitro

D. BenEzra and T. Tanishima

Electron microscopic studies of pure epithelial and stromal cultures and of combined cultures demonstrated that keratocytes activity was inhibited by the presence of epithelial cells in culture. The degradation of collagen and the formation of clear zones around the keratocytes within the explants of pure stroma is interpreted as an indication for the production of a collagenolytic substance by the active keratocytes. The collagenolytic activity of the keratocytes was not observed within the stroma of combined cultures and was probably inhibited by the activity of epithelial cells in these cultures. Furthermore, using a microculture method for the assessment of the metabolic activity of corneal cells in vitro, supernatants of epithelial cell cultures were shown to have a marked inhibitory effect on the capacity of keratocytes to synthesize DNA. No effect of stromal cell supernatant on epithelial cell activity could be detected by the same methods. It is suggested that this "one way" influence as observed in vitro might, in certain conditions, play a role as a regulatory mechanism in vivo.