Carvajal J A, Buhimschi I A, Thompson L P, Aguan K, Weiner C P
Perinatal Research Laboratory, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Hum Reprod. 2001 Apr;16(4):638-43. doi: 10.1093/humrep/16.4.638.
It was postulated that chorion releases a substance necessary for the maintenance of uterine quiescence during pregnancy. A decrease in the release of this substance at the end of the pregnancy would be necessary for normal myometrial activation. This hypothesis was tested by demonstrating the ability of chorion to inhibit oxytocin-stimulated myometrial contractility in vitro. Tissues were obtained from timed pregnant Duncan-Hartley guinea pigs either at pre-term or near-term gestation. Myometrial strips were placed in organ baths for isometric tension measurement and contractions stimulated by oxytocin (10(-8) mol/l). Fetal membranes or conditioned medium from chorion were added directly to the organ bath. Near-term chorion and chorion conditioned-medium decreased oxytocin-stimulated contractile activity to 39% and 49% respectively. Neither pre-term nor near-term amnion reduced oxytocin-stimulated myometrial contractile activity. Relaxation induced by pre-term chorion was greater than near-term chorion (23% and 41% of the oxytocin-induced basal level respectively; P < 0.05). Further, chorion-induced relaxation was independent of the gestational age of the myometrium. Human chorion from a term, not-in-labour woman also inhibited oxytocin-stimulated guinea pig myometrial contractility. It was concluded that the chorion releases a substance or substances that reduce oxytocin-stimulated myometrial contractility and may be involved in the maintenance of uterine quiescence during pregnancy.
据推测，绒毛膜会释放一种在孕期维持子宫静止状态所必需的物质。在妊娠末期，这种物质释放量的减少对于子宫肌层的正常激活是必要的。通过证明绒毛膜在体外抑制催产素刺激的子宫肌层收缩的能力，对这一假设进行了验证。组织取自定时妊娠的邓肯 - 哈特利豚鼠，分别处于早产或接近足月妊娠阶段。将子宫肌层条带置于器官浴槽中进行等长张力测量，并由催产素（10(-8)摩尔/升）刺激收缩。将胎膜或绒毛膜条件培养基直接添加到器官浴槽中。接近足月的绒毛膜和绒毛膜条件培养基分别将催产素刺激的收缩活性降低至39%和49%。早产或接近足月的羊膜均未降低催产素刺激的子宫肌层收缩活性。早产绒毛膜诱导的舒张大于接近足月的绒毛膜（分别为催产素诱导的基础水平的23%和41%；P < 0.05）。此外，绒毛膜诱导的舒张与子宫肌层的妊娠年龄无关。来自足月未临产妇女的人绒毛膜也抑制了催产素刺激的豚鼠子宫肌层收缩。得出的结论是，绒毛膜释放一种或多种物质，这些物质可降低催产素刺激的子宫肌层收缩性，可能参与孕期子宫静止状态的维持。
