ACTIVIN A IN HUMAN PREGNANCY

大约10%的孕妇会发生早产，有明显的 对围产期/新生儿发病率和死亡率的影响。早产儿 占新生儿死亡率的80%以上和90%以上 在美国的新生儿发病率。 在灵长类动物中观察到子宫收缩的昼夜节律 和人类。值得注意的是，宫缩的基本次数似乎在增加 随着孕龄的延长，特别容易患上 夜间子宫收缩能力。夜间催产素水平升高， 子宫收缩，已在恒河猴身上得到证实。 未结合的激活素A，被卵泡抑素灭活--其自然结合 蛋白质--在未怀孕的女性身上没有表现出来。然而，它是 在怀孕前三个月发现，显著升高 足月，尤其是在分娩时。在早产和早产的妊娠 随着时间的推移，激活素A水平也急剧增加。之后 递送，激活素A水平迅速下降，基本上不是 产后6小时后可检测到。激活素A也被证明是 直接给药后外周增加催产素 下丘脑室旁核，以及与 含有催产素的树突。当羊膜细胞与 激活素A、前列腺素E2a被诱导。PGE2a是一位知名的 子宫强直症。在这些条件下，激活素A可能会发挥重要作用 在启动真正的分娩的级联中，无论是病态的还是非病态的。 这项研究将集中在子宫收缩的昼夜规律上， 激活素A、卵泡抑素和催产素在24小时内的水平 不同孕龄的妇女，主要是25-27周，30-32周， 35-37周，40-42周。血液将以连续的间隔采集 在24小时内，控制暴露在光线下和 活动/压力体验。激活素A、卵泡抑素和 催产素和子宫收缩在不同的情况下会进行比较 孕龄。

Preterm delivery occurs in approximately 10% of pregnancies, with marked impact on perinatal/neonatal morbidity and mortality. Premature babies account for greater than 80% of neonatal mortalities and greater than 90% of neonatal morbidities in the U.S. A circadian rhythm of uterine contractions has been observed in primates and humans. Notably, a basal number of contractions seems to increase as gestational age inceases, with a particular predisposition to nighttime uterine contractility. Increased nighttime oxytocin levels, with uterine contractions, have been demonstrated in rhesus monkeys. Unbound activin A, inactivated by follistatin--its natural binding protein--is not demonstrated in the nonpregnant female. However, it is detected in the first trimester of pregnancy with marked elevation at term, particularly at parturition. In gestations with preterm labor and delivery, the activin A levels also increase dramatically. After delivery, the activin A level falls quickly and is essentially not detectable after 6 hours postpartum. Activin A has also been shown to increase oxytocin peripherally after direct administration into the paraventricular nucleus of the hypothalamus, as well as binding to oxytocin-containing dendrites. When amnion cells are incubated with Activin A, prostaglandin E2a is induced. PGE2a is a well-know uterotonic. Given these conditions, activin A may play and important role in the cascade that initiates true delivery, pathological or otherwise. This study will focus on the circadian pattern of uterine contractions, activin A, follistatin, and oxytocin levels over a 24 hour period in women of various gestational ages, primarily 25-27 weeks, 30-32 weeks, 35-37 weeks, 40-42 weeks. Blood will be collected at serial intervals over a 24 hour period, controlling exposure to light and amount of activity/stress experiences. The levels of Activin A, Follistatin, and Oxytocin, and uterine contractions will be compared in the different gestational ages.