Hormonal regulation of PGE2and COX-2 production in rabbit uterine cervical fibroblasts

Publisher Website
Google Scholar
Abstract
Prostaglandins (PGs) cause uterine contraction to initiate labor at term. We investigated the effect of progesterone and 17β-estradiol on the production of PGE2in rabbit uterine cervical fibroblasts. When the cervical fibroblasts were treated with interleukin-1α (IL-1α), the level of PGE2was augmented in a time- and dose-dependent manner. The IL-1α-augmented PGE2level was almost completely suppressed by progesterone and 17β-estradiol at the physiological concentration (0.01 μM), whereas a slight decrease in the basal level of PGE2was observed in the cervical fibroblasts treated with both hormones at a pharmacological concentration (1 μM). In addition, the level of PGE2augmented by IL-1α was due to the increase of cyclooxygenase (COX) activity, which was inhibited by progesterone and 17β-estradiol as well as by indomethacin and a specific COX-2 inhibitor, NS-398, but not by the well-known COX-1 inhibitor, aspirin. Furthermore, progesterone and 17β-estradiol suppressed the IL-1α-augmented COX-2 production but not the constitutive production of COX-1 in rabbit uterine cervical fibroblasts. These results suggest that progesterone and 17β-estradiol prevent the initiation of labor by inhibiting PGE2production after the suppression of COX-2 production during pregnancy in the rabbit.