Changes in glycosaminoglycan composition of normal human placentas with maturation

Crude glycosaminoglycan preparations were isolated from acetone-powder of first-, second-, and third-trimester human placentas. Glycosaminoglycan composition was examined by electrophoresis and densitometric scanning before and after treatment with testicular hyaluronidase and chondroitinase ABC. Hexosamines were determined in electrophoretic fractions in order to identify the individual glycosaminoglycans. The results showed a decrease in glycosaminoglycans and an increase in protein contents in the preparations as the placenta matured. The main glycosaminoglycans in all placentas were dermatan sulfate, chondroitin sulfates, hyaluronic acid, and heparan sulfate. With aging of the placenta, the proportion of hyaluronic acid remained unchanged and that of chondroitin sulfate decreased, whereas the proportions of dermatan and heparan sulfates increased. Age-dependent changes in the glycosaminoglycan composition of the placenta appear to follow a pattern similar to that reported for other mammalian tissues.