Developmental study of human fetal placental fibronectin: Alterations in carbohydrates of tissue fibronectin during gestation
Human term placental tissue fibronectin contains about twice the carbohydrate content of human adult plasma fibronectin or fetal plasma fibronectin. The chief difference is the presence of substantial amounts of large N-linked polylactosamine chains on the placental fibronectin. The large carbohydrate on placental tissue fibronectin weakens the binding of fibronectin to denatured collagen. To examine whether a developmental change takes place in the placental fibronectin during gestation, fibronectin was isolated from placentas of different developmental stages beginning with the first trimester and ending with term. Polylactosamine carbohydrate, as well as total quantity of carbohydrate, increased steadily during gestation, reaching a maximum at term of more than 9% carbohydrate. Weakened binding of fibronectin to collagen occurred near the end of gestation concomitant with an increase in the quantity of larger polylactosamine glycopeptides. Relationships among these developmental changes, the impending birth, and the end of the function of the placenta remain to be investigated. © 1987.