Garfield R E, Beier S
Department of Neurosciences, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada.
Am J Obstet Gynecol. 1989 Aug;161(2):454-61. doi: 10.1016/0002-9378(89)90541-3.
The contractile effects of oxytocin on the longitudinal and circular muscle of rat uteri from animals undergoing term and preterm labor were studied in vitro to define the action of the hormone. The maximal tension and slopes of oxytocin dose contractile-response curves, but not the pD2 values (-log ED50), were higher in both muscle layers at term delivery and also during preterm delivery induced with antiprogesterones compared with responses from tissues of nondelivering animals. These data indicate that the myometrium is hyperresponsive and hyperreactive to oxytocin during term and preterm birth but not hypersensitive. The increase in oxytocin responsiveness of the myometrium may be fundamental to the initiation of labor and regulated by the increases in oxytocin receptors and postreceptor events, including gap junctions.
为明确催产素的作用，我们对足月分娩和早产大鼠子宫的纵肌和环肌进行了体外研究，观察催产素对其收缩的影响。与未分娩动物组织的反应相比，足月分娩时以及用抗孕激素诱导早产时，两层肌肉中催产素剂量收缩反应曲线的最大张力和斜率均较高，但pD2值（-log ED50）无差异。这些数据表明，在足月和早产期间，子宫肌层对催产素反应性增强且反应活跃，但并非过敏。子宫肌层对催产素反应性的增加可能是分娩发动的基础，并受催产素受体增加及包括缝隙连接在内的受体后事件调控。
