* Marcoleta 391, Centro de Investigaciones Médicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
Exp Physiol. 2014 Mar;99(3):489-94. doi: 10.1113/expphysiol.2013.077446. Epub 2014 Jan 17.
Myometrial quiescence is a physiological stage of the myometrium during pregnancy. It is a period of active relaxation of the myometrial smooth muscle cells; myometrial quiescence is responsible for maintaining pregnancy. The precise mechanisms underlying myometrial quiescence have not been completely elucidated, although many mediators and cellular pathways have been described as playing a role. Fetal membranes (chorion and amnion) produce and release one or more substances that inhibit myometrial contractions, playing a central role in the maintenance of myometrial quiescence. Brain natriuretic peptide (BNP) is more potent than any other natriuretic peptide in inhibiting myometrial contractions in vitro. Brain natriuretic peptide is produced by the chorion and amnion, mainly during myometrial quiescence, and decreasing towards the end of pregnancy. Production of BNP is reduced in fetal membranes obtained from women in preterm labour. It is postulated that BNP, acting in a paracrine fashion, plays a key role in the maintaining myometrial quiescence and, therefore, controlling the duration of pregnancy. Furthermore, it is postulated that a premature decrease of BNP production by the fetal membranes may cause preterm labour and preterm birth.
子宫静止是妊娠期间子宫的一种生理阶段。它是子宫平滑肌细胞活跃放松的时期；子宫静止负责维持妊娠。尽管已经描述了许多介质和细胞途径在起作用，但子宫静止的确切机制尚未完全阐明。胎儿膜（绒毛膜和羊膜）产生和释放一种或多种抑制子宫收缩的物质，在维持子宫静止中起核心作用。脑利钠肽（BNP）在体外抑制子宫收缩的作用比任何其他利钠肽都强。脑利钠肽由绒毛膜和羊膜产生，主要在子宫静止期间产生，并在妊娠末期减少。从早产妇女的胎儿膜中获得的 BNP 产量减少。据推测，BNP 以旁分泌的方式发挥作用，在维持子宫静止和控制妊娠持续时间方面发挥关键作用。此外，据推测，胎儿膜中 BNP 产生的过早减少可能导致早产和早产。
