FUNCTIONAL AND MORPHOLOGICAL-DIFFERENTIATION OF NONPIGMENTED CILIARY BODY EPITHELIAL-CELLS GROWN ON COLLAGEN RAFTS

We have examined the effect of alteration in cell shape on promoting d ifferentiated morphology and physiology in cultured nonpigmented epith elial cells from the ciliary body. We have grown pure populations of n onpigmented cells on collagen gels released from the culture dish to c reate collagen rafts. Shortly after the gels were detached, the cells shrank in diameter and increased in height while they contracted the g el. Concurrently, the actin cytoskeleton reorganized to the cell corte x as found in vivo. After this differentiated morphology developed, la rge changes in intracellular Ca2+ could be elicited by simultaneous ac tivation of acetylcholine and epinephrine or acetylcholine and somatos tatin receptors as seen in intact tissue. Explant cultures of isolated nonpigmented cell layers maintained their actin distribution and also showed synergistic Ca2+ increases. Spread cells, grown on rigid subst rates, had a disorganized cytoskeleton and rarely showed synergism. Th ese data suggest that the mechanism underlying synergistic Ca2+ respon ses in the ciliary body is functional in nonpigmented cells grown on c ollagen rafts. In addition, this pathway appears to be sensitive to th e disposition of the cell's cytoarchitecture.