Changes in the glycosaminoglycans distribution pattern in the human uterine cervix during pregnancy and labor.

ABSTRACT

PIP: This study attempted to quantitate the presence of glycosaminoglycans in the uterine cervix during pregnancy and labor. Distribution patterns, within the cervical samples, of the glycosaminoglycans were determined by proteolytic digestion and subsequent chromatographic separation. Cervical samples studied were from 42 women of reproductive age. During pregnancy, the keratan sulfate content increased significantly; the chondroitin concentration remained unchanged; and the contents of the chondroitin sulfates and dermatan sulfate decreased. During labor, a considerable rise of chondroitin was noted, whereas the concentrations of keratan sulfate, chondroitin 4- and 6-sulfates, and dermatan sulfate did not change. Hyaluronate content of a postpartum cervix was significantly higher than in nonpregnant women. The total glycosaminoglycans content (related to dry weight of the cervix) was not larger during pregnancy as compared with samples of nonpregnant women. During labor, however, there was an increase from 8.57 mcmol/gm of dry weight. The hydroxyproline content dropped during pregnancy and labor. The ratio of total glucosaminoglycans content to that of hydroxyproline changed in favor of the glycosaminoglycans during pregnancy, and it became more pronounced during labor. Distribution patterns of serial transverse cervical sections showed an increasing content of hyaluronate from the external os upward to the lower uterine segment. The other glucosaminoglycans did not show any definite trend. Both the changes in the solubility of collagen as well as glycosaminoglycans distribution patterns were related to cervical dilatation.