Oxytocin and Estrogen Receptor Expression in the Myometrium of Pregnant Relaxin-Deficient (Rlx~(-/-)) Mice

摘要

Relaxin decreases oxytocin-stimulated rat myometrial contractions in vitro. This study used pregnant relaxin-deficient (Rlx~(-/-)) mice to investigate the interaction between relaxin, oxytocin receptor (OTR), and estrogen receptor (ER) expression in the myometrium. Myometrial OTRs were significantly decreased on gestation day 18.5 in Rlx~(-/-) mice than in Rlx~(+/+) mice. An increase in ERα in Rlx~(+/+) mice at term was correlated with a decrease in ERβ, which was not observed in Rlx~(-/-) mice. Treatment of Rlx~(-/-) mice with relaxin had no effect on OTR, LGR7, or ERα expression, but it caused a significant decrease in ERβs.