EP3-2 receptor mRNA expression is reduced and EP3-6 receptor mRNA expression is increased in gravid human myometrium.

OBJECTIVE

To assess relative expression levels of mRNA for EP3 isoforms EP3-2, EP3-3, and EP3-6 in human myometrium in various physiologic states.

METHODS

Using semiquantitative reverse transcriptase-polymerase chain reaction, we analyzed myometrial samples from 46 women (ten menopausal, ten nongravid premenopausal, 19 gravidas, seven premenopausal misoprostol-treated nongravid women) for the specific expression of mRNA messages for the EP3 receptor isoforms EP3-2, EP3-3, and EP3-6.

RESULTS

We found that the expression of EP3-2 was significantly lower in gravid than nongravid myometrium (P < .0001). Levels of the EP3-6 message were higher in gravid samples than in nongravid specimens (P < .02). EP3-3 mRNA was present in higher levels in menopausal samples compared with the other groups.

CONCLUSIONS

The selective fluctuation of mRNA expression of the different EP3 isoforms suggests the possibility of an important regulatory role for these receptors in myometrial contractility. Additional studies are necessary to evaluate the exact mechanism of action of EP3 receptor isoforms in human myometrium.