THE EXPRESSION OF CYCLOOXYGENASE-2 (COX-2) IN AMNION AND DECIDUA FOLLOWING SPONTANEOUS LABOR

Objective: Prostaglandins production rises dramatically during term an d preterm labor. The source of this production is thought to be the fe tal membranes and maternal decidua. The enzyme responsible for the con version of arachidonic acid to the prostaglandins and related endopero xides is variously known as prostaglandin synthase or cyclooxygenase ( COX). An inducible form of this enzyme, COX-2, has been described in s everal tissues. The purpose of this study was to investigate a possibl e role for COX-2 in labor by comparing the COX-2 content in amnion and decidua from laboring and non-laboring patients. Study Design: Fetal membranes from seven normal labor and ten elective cesarean section at term were collected immediately following delivery. The maternal age and gravity were similar between the groups. The amnion and decidua we re identified, washed in sterile saline, frozen in liquid nitrogen and stored in -70 degrees C. COX-2 expression was determined using Wester n Blot analysis with a purified COX-2 antibody. A scanning densitomete r was used to quantify the bands. Results were expressed as mean +/- S .D. ng/50 mu g protein. Results: The concentration of COX-2 in amnion of laboring women showed a twofold increase (240.0 +/- 17.6 vs. 120.7 +/- 5.1) compared to the non-labored group (p<0.05). The concentration in the decidua showed no significant increase during labor (38.1 +/- 7.5 vs. 26.4 +/- 2.1, p>0.05). Conclusion: We evaluated the role of CO X-2 in normal labor. Our study demonstrates that COX-2 is significantl y induced in the amnion following spontaneous labor. These findings su ggest that the induction of amnion COX-2 may be involved in the proces s of human labor.