An enzyme (β‐D‐N‐acetylglucosaminidase) released from the decidua to maternal plasma prior to the onset of labor

Abstract

Changes in the activity of beta-N-acetylglucosaminidase (E.C. 3.2.1.30; NAG), a lysosomal marker enzyme, in the maternal plasma and utero-placental tissues during late pregnancy and parturition were examined in order to determine if lysosomal enzymes participate in the cervical ripening. NAG activity in the plasma gradually increased as gestation advanced, to reach a maximum 3-4 days before the spontaneous onset of labor, and remaining at this level until the second stage. The activity measured in decidua and amnion obtained from the women who had undergone routine repeat cesarean section after labor onset was lower than in those before the onset. Since the decidua was much heavier than the amnion, it was concluded that NAG was released to the maternal circulation mainly from the decidua and only partly from the amnion. Our data revealed that lysosomal enzyme release occurs prior to the onset of labor, and that NAG may play a role primarily in the ripening of the cervix rather than in the onset of labor, by hydrolysing GAGs in the uterine cervix.

Reference Intervals of Renal Function Set Established for Healthy Pregnant Women

“…NAG was released to the maternal circulation mainly from the decidua and only partly from the amnion. Lysosomal enzyme release occurs prior to the onset of labor, it may play a role primarily in the ripening of the cervix [27]Previous studies have shown that NGAL participated in a variety of biochemical processes involving embryonic development and cell differentiation, this may be the reason why there were signi cant differences between pregnant women and non-pregnant women. there was no variation of serum NGAL values through the whole pregnancy and is consistent with the study by D'Anna R, [20] During the late pregnancy, the sensitivity of osmoceptor to antidiuretic hormone dropped This change may be mediated by increased β-human chorionic gonadotropin, a pattern also seen to a lesser degree in menstruating women during the luteal cycle[28]and then led to retention of sodium and water and further caused GFR rose ,which increased with the raised blood volume and renal blood ow (RBF); so the excretion of urea nitrogen and creatinine would increase and then the level of urea nitrogen and creatinine in serum would decrease, it's accordance with ndings in this report that a signi cant decrease in BUN, Cr.…”

Activity of Placental β‐N‐Acetyl‐Glucosaminidase in Cows with and without Retained Fetal Membranes

“…The presence of Nagase in uterine fluid may be important for implantation and may play a role as an initiator of its adhesive phase (Boving 1963). The experiments describing Nagase activity during human parturition revealed that the enzyme may be involved in cervical ripening (Takenaka et al 1991). The enzyme may also alter glycosaminoglycan metabolism, change cell permeability or affect cell‐cell interactions and show luteal involvement (Hansen et al 1984).…”