Hyaluronidase for cervical priming and induction of labour

Cervical histomorphology of successfully detorted uterine torsion affected buffaloes subjected to intracervical hyaluronidase or PgE1 treatment

Twenty-four buffaloes presented between 36-72 h of occurrence of uterine torsion were successfully detorted and equally divided to intracervical hyaluronidase enzyme or prostaglandin E1 (PgE1) treatment or control group for investigating the treatment effectiveness for complete cervical dilatation. Intracervical treatment was administered immediately after detorsion, and cervical biopsy was collected immediately before instituting treatment and at time of cervical dilatation or at 18 h post detorsion in case of non-dilated cervix. The doppler indices of middle uterine artery were evaluated at an hour before detorsion and 0.5 h after detorsion. In control group, none of the buffaloes exhibited cervical dilatation, whereas, 87.5% buffaloes of hyaluronidase group and 62.5% of PgE1 group exhibited cervical dilatation. Following intracervical treatment, lamina propria showed loosely arranged collagen fibres along with hemorrhages, polymorphonuclear (PMN) cells and intercollagen space filled by homogenous/ watery substance in case of dilated cervix. In non-dilated cervix, the collagen fibres were tightly arranged with lesser number of PMN cells and negligible haemorrhages at 18 h after treatment. The doppler indices of the middle uterine artery revealed improvement (P<0.05) in blood supply towards cervix and uterus in buffaloes exhibiting complete cervical dilatation. In conclusion, intracervical hyaluronidase treatment in immediate post-detorsion period in uterine torsion affected buffaloes can be an effective strategy to ensure complete cervical dilatation and per-vaginal fetal delivery.

Parturition and recruitment of macrophages in cervix of mice lacking the prostaglandin F receptor

Parturition does not occur in transgenic mice lacking the prostaglandin F receptor (Ptgfr(-/-)) because luteolysis is forestalled and progesterone production persists. Ovariectomy of pregnant Ptgfr(-/-) mice leads to a decline in circulating progesterone and delivery of live pups. The objective of the present study was to test the hypothesis that immigration of macrophages and increased innervation of the cervix of Ptgfr(-/-) mice was associated with ripening and parturition. The cervix of pregnant Ptgfr(-/-) mice was studied on Days 15-21 after breeding; additional groups were ovariectomized on Day 19 of pregnancy, and the cervix obtained on Day 20 of pregnancy before birth or the next day at about 24 h after birth. On Days 18-19 of pregnancy, macrophage numbers and nerve fiber density increased more than 3-fold compared with findings in nonpregnant or Day 15 or 21 pregnant Ptgfr(-/-) mice. The magnitude and time course of these changes were comparable to those found in wild-type controls that delivered on Day 19 after breeding. Thus, the mechanism regulating macrophage immigration, innervation, and cervical remodeling in Ptgfr(-/-) mice with delayed parturition is similar to wild-type controls that deliver at term. By contrast, ovariectomy forestalled the decrease in cervical macrophages in Ptgfr(-/-) mice. By Day 21 after breeding, macrophage numbers more than double those after ovariectomy, relative to those found in pregnant Ptgfr(-/-) mice, whereas nerve fiber density was the same regardless of birth. Density of collagen structure in these mice directly matched macrophage traffic in the cervix. The findings indicate that the prostaglandin F(2alpha) receptor and progesterone withdrawal are a necessary part of the final common pathway for ripening of the cervix and the process of parturition.

Cyclic mechanical stretch augments hyaluronan production in cultured human uterine cervical fibroblast cells

Hyaluronan (HA) a glycosaminoglycan with high affinity for water molecules stimulates local inflammatory reactions. Parturition causes a dramatic increase in the amount of HA fragments in the uterine cervix, thereby contributing to a rapid softening as well as opening of the cervical canal, i.e. cervical ripening. The aim of this study was to investigate the possible involvement of cyclic distension caused by labour in the augmentation of HA production during cervical ripening. Immunohistochemistry and/or RT-PCR detected hyaluronan synthase (HAS)1, 2 and 3 in samples of human cervical tissue obtained from pregnant women. Labour-like cyclic mechanical stretch for 24, 36 and 48 h significantly enhanced the secretion of HA, from cultured human uterine cervical fibroblast (CxF) cells, 128.7, 151.4 and 173.2%, respectively, concomitant with a significant augmentation of HAS1 (36, 48 h), HAS2 (24, 36 and 48 h) and HAS3 (48 h) mRNA expression. Cyclic mechanical stretch for 12, 36 and 48 h increased molecular size of the HA secreted from CxF cells. In conclusion, cyclic mechanical stretch of the uterine cervix caused by the presenting part of the fetus in labour may contribute to the increase in the secretion of HA during the process of cervical ripening.