Responsivity to PGE2 labor induction involves concomitant differential prostaglandin E receptor gene expression in cervix and myometrium

Prostaglandin E2 (dinoprostone) is largely used for labor induction. However, one-third of patients do not respond to treatment. One cause of this poor response may be associated with changes in regulation of prostaglandin E receptors (EP1-4). In this study, we investigated EP mRNA expression in the uterine cervix and lower uterine segment myometrium for term births. Biopsies were obtained from women with successful (responders) and failed (non-responders) dinoprostone labor induction, while women that underwent spontaneous labor were included as controls. EP1 mRNA was upregulated in the cervical tissue of women who did not respond to dinoprostone induction. In addition, in the myometrium, significantly higher levels of EP3 mRNA were observed in women treated with dinoprostone, independent of their responsiveness. Dinoprostone-responders presented 3.6-fold higher levels of EP3 mRNA expression than the spontaneous labor group. Significantly higher levels of EP3 mRNA in the myometrium of the dinoprostone-treated group indicated that dinoprostone may regulate the EP3 gene on the transcriptional level. These results highlight the relationship between EP gene expression and delivery and indicate that understanding the regulation of prostaglandin E receptors may lead to improved labor induction.

Maternal serum progesterone, estradiol and estriol levels in successful dinoprostone-induced labor

Hormone-mediated quiescence involves the maintenance of a decreased inflammatory responsiveness. However, no study has investigated whether labor induction with prostanoids is associated with changes in the levels of maternal serum hormones. The objective of this study was to determine whether labor induction with dinoprostone is associated with changes in maternal serum progesterone, estradiol, and estriol levels. Blood samples were obtained from 81 pregnant women at term. Sixteen patients had vaginal birth after spontaneous labor, 12 required cesarean section after spontaneous labor and 16 underwent elective cesarean. Thirty-seven patients had labor induction with dinoprostone. Eligible patients received a vaginal insert of dinoprostone (10 mg) and were followed until delivery. Serum progesterone (P4), estradiol (E2) and estriol (E3) levels and changes in P4/E2, P4/E3 and E3/E2 ratios were monitored from admission to immediately before birth, and the association of these measures with the resulting clinical classification outcome (route of delivery and induction responsiveness) was assessed. Progesterone levels decreased from admission to birth in patients who underwent successful labor induction with dinoprostone [vaginal and cesarean birth after induced labor: 23% (P < 0.001) and 18% (P < 0.025) decrease, respectively], but not in those whose induction failed (6.4% decrease, P > 0.05). Estriol and estradiol levels, P4/E2, P4/E3 and E3/E2 ratios did not differ between groups. Successful dinoprostone-induced labor was associated with reduced maternal progesterone levels from induction to birth. While a causal relationship between progesterone decrease and effective dinoprostone-induced labor cannot be established, it is tempting to propose that dinoprostone may contribute to progesterone withdrawal and favor labor induction in humans.

The effect of proximal gastric vagotomy plus duodenoplasty on duodenogastric reflux

Alkaline reflux gastritis is a clinical syndrome that results from a mucosal injury by duodenal contents. In this study, the amount of duodenogastric reflux was assessed in patients who previously underwent proximal gastric vagotomy (PGV group; n = 11) and PGV plus duodenoplasty (PGV+D group; n = 10) as a treatment for duodenal ulcer. The control group (A) consisted of 11 healthy volunteers without endoscopic abnormalities. A quantitative index of duodenogastric reflux was obtained in each case by determining the percentage of the injected dose of 99mTechnetium-DISIDA that was recovered by continuous aspiration of gastric juice in fasting subjects. In the PGV group, the percentage of administered 99mTechnetium-DISIDA recovered from the stomach (median: 0.69%; range: 0.09%-3.61%) did not differ significantly (P > 0.05) from that of the PGV+D group (median: 0.49%; range: 0.09%-3.91%) and from that of the A group (median: 1.47%; range: 0.22%-3.01%). The results show that proximal gastric vagotomy plus duodenoplasty did not increase duodenogastric reflux.