They may also regulate COX-2 gene transcription in the maternal compartment of the bovine placenta. Directional transport of cytokines from uterine epithelial cells into underlying stromal cells to induce COX-2 expression has been demonstrated in pregnant mice. In accordance with this hypothesis, fetal cotyledons accumulated COX-2 transcripts earlier in gestation than maternal caruncles. Contamination with villous tissue from cotyledons possibly accounts for some of the COX-2 mRNA found in caruncles, because some fetal tissue remained attached to the caruncle when the fetal and maternal sides of the placentome were torn apart; however, the proportion of fetal tissue remaining in caruncles was small and could not account for almost equal concentration of COX-2 mRNA in total RNA from the two tissues at term. Cheap Diskus Advair
In contrast to endometrium in vivo, bovine endometrial epithelial cells, obtained from nonpregnant cows in early luteal phase and kept in culture for several days, express COX-1 mRNA in addition to COX-2 mRNA. This discrepancy between the in vitro and our in vivo results may be due to the morphological differences between the two sets of tissues. The in vitro experiments were done with purified epithelial cells, which are the COX-2 gene-expressing cells, whereas intact endometrium used in the in vivo experiments consists of several cell types in addition to epithelial cells.