DISTRIBUTION OF EPIDERMAL GROWTH-FACTOR RECEPTORS IN RABBIT LENS EPITHELIAL-CELLS

Purpose. This study examined the growth-promoting effect of epidermal growth factor (EGF) on rabbit lens epithelial cells and the distribution of EGF receptors in these cells. Methods. Rabbit lens epithelial cells were cultured in TC-199 medium containing 0.5% fetal bovine serum and EGF for 1 to 5 days, and the growth-promoting effects of EGF were calculated with absorbance of methylene blue staining method. EGF receptors in the cells were analyzed by Scatchard plots using I-125-EGF in serum-free culture. Results. EGF, which enhanced the cell growth in a dose-dependent manner, was stimulatory at 0.1-100 ng/ml and maximal (328.2%) with 10 ng/ml on day 5. The cells had two different affinity receptors. The number and the dissociation constant of the low affinity receptors were 5.81 X 10(4)/cell and 1.488 nM, respectively, and those of the high affinity receptors were 1.53 X 10(4)/cell and 0.159 nM, respectively. Conclusion. EGF may contribute to the development of living lenses.