Uterine activity in late pregnancy and during parturition in the rat.
Uterine activity in late pregnancy and during parturition in the rat.
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DOI：
10.1095/biolreprod1.4.344
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发表时间：
1969-01-01
影响因子：
3.6
通讯作者：
Fuchs, A. R.
中科院分区：
文献类型：
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作者：
Fuchs, A. R.
通过在之前的手术中插入宫内气球，记录 17 只未麻醉、不受约束的怀孕大鼠的子宫活动。从妊娠第 18 天开始以及整个自然分娩（妊娠第 22 或 23 天）期间记录子宫内压力变化。通过留置聚乙烯导管每隔一段时间静脉注射催产素。除了短时间外，怀孕大鼠的子宫从未静止过，并且在整个研究期间对中等剂量的催产素（10 mU）有反应。然而，在妊娠晚期和足月时，持续观察到宫缩模式和特征的变化，子宫对催产素的反应强度显着增加。分娩发生在子宫催产素敏感性最大的时候。在产仔排出之前，子宫会经历一段平均持续 2.5 小时的连续子宫活动期，并在第一个胎儿分娩前经历一段 5-30 毫米的用力期。连续同窝仔猪的分娩与持续的子宫活动和少量的腹部用力有关，平均持续 1.5 小时。最后一个胎儿和胎盘出生后，子宫活动迅速消失，在 10-30 毫米内，子宫完全静止，除了不常见的由 3-4 次宫缩组成的周期外。有节奏的规律活动在产后 8-12 小时开始。
Uterine activity was recorded in 17 unanesthetized, unrestrained pregnant rats by means of intrauterine balloons inserted at a previous operation. Recordings of intrauterine pressure changes were obtained from Day 18 of gestation onwards and throughout spontaneous delivery, which occurred on Days 22 or 23 of gestation. Oxytocin was injected intravenously through an indwelling polyethylene catheter at intervals. The uterus of the pregnant rat was never quiescent except for short periods of time and it responded to moderate doses of oxytocin(10 mU) throughout the period studied. However, a changing pattern and character of contractions was consistently observed in late pregnancy and toward term the intensity of the uterine response to oxytocin increased markedly. Parturition occurred at a time when the uterine oxytocin sensitivity was maximal. The expulsion of the litter was preceded by a period of continuous uterine activity lasting 2.5 hr on the average and by a period of 5-30 mm of bearing down efforts before the delivery of the first fetus. The deliver of successive littermates was associated with continuous uterine activity and only a few abdominal straining efforts, and lasted 1.5 hr on the average. After the last fetus and placenta were born the uterine activity disappeared quickly and in 10-30 mm the uterus was completely quiescent except for infrequently occurring cycles consisting of 3-4 contractions. Rhythmic regular activity started 8-12 hr postpartum.