Reciprocal expression of peroxisome proliferator-activated receptor-gamma and cyclooxygenase-2 in human term parturition.

Objective: The objective of this study was to test the hypothesis that peroxisome proliferator activated receptor-gamma (PPAR-gamma) is expressed in intrauterine tissues before active term human parturition, and that its repression is associated with up-regulation of cyclooxygenase-2 (COX-2).

Study Design: Specimens were collected from women with term singleton pregnancies after spontaneous labor or cesarean section before labor, prepared for immunoblot and immunohistochemical analysis, and probed for PPAR-gamma or COX-2.

Results: PPAR-gamma expression was prominent in fetal membranes and placenta before active labor.