Activities of some glycosaminoglycan- degrading enzymes in Wharton's jelly and their alteration in EPH-gestosis (Pre-eclampsia).

Oedema, proteinuria, hypertension (EPH)-gestosis (pre-eclampsia) is associated with a premature replacement of hyaluronic acid by sulphated glycosaminoglycans (GAGs), both in the umbilical cord arteries and in Wharton's jelly. It may be concluded from our previous report that such a phenomenon may be the result of reduction in degradation of these compounds. In order to support such a conclusion the activities of GAG-degrading enzymes in normal umbilical cord arteries and those taken from newborns delivered by mothers with EPH-gestosis were compared. It was found that EPH-gestosis results in a significant reduction in the activities of neutral endoglycosidases degrading most of the sulphated GAGs (except keratan sulphate). In the case of acidic endoglycosidases, no characteristic alterations have been found. Only the activity of heparan sulphate-degrading endoglycosidase significantly decreased. In contrast to the above-mentioned endoglycosidases, the activities of arylsulphatase B and 6-sulphatase distinctly increased. The decrease in the activities of endoglycosidases are thought to be responsible for EPH-gestosis-associated accumulation of sulphated GAGs in extracellular matrix of Wharton's jelly. This leads to the suspicion that EPH-gestosis-induced changes in the GAGs composition may alter the fibrillogenesis conditions in Wharton's jelly. The sulphated GAGs accumulated in Wharton's jelly may interact with some growth factors which modify the myofibroblasts' proliferation, gene expression, protein biosynthesis and other processes. A significance of EPH-gestosis-induced alteration in Wharton's jelly is discussed.