Lentropin: a factor in vitreous humor which promotes lens fiber cell differentiation.

Abstract

An activity was identified in chicken vitreous humor which stimulates embryonic chicken lens epithelial cells to elongate and specialize for lens crystallin synthesis. The activity is heat-labile and is destroyed by treatment with trypsin or agents that reduce disulfides. Gel filtration and ultrafiltration analyses indicate that it has a MW of .apprxeq. 60,000. Its properties differ from those of an activity present in serum which can promote lens fiber cell formation in vitro. This material, called lentropin, apparently is responsible for stimulating lens fiber cell formation in vivo and plays an important role in determining the shape and polarity of the lens.