ABSTRACT
The acidic mucopolysaccharides secreted into the extracellular space are thought to play many important functions amongst which are binding of water and electrolytes on the polyanionic glycosaminoglycans. Characteristically these components undergo continuous changes during growth and development of the fetuses. Relationships of the concentrations of glycosaminoglycans to the water and principal electrolytes at different periods of gestation were studied in human fetuses. It was found that during growth of the human fetuses there was a progressive decrease in water, thiocyanate space, total sodium content and glycosaminoglycans. However the decrease of glycosaminoglycans was greater than the rate of decrease of the other constituents. Hence mucopolysaccharides were thought to play more important roles than just binding of water and cations.