Abramowicz J S, Phillips D B, Jessee L N, Levene H, Parker K J, Miller R K
Department of Obstetrics and Gynecology, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642, USA.
J Clin Ultrasound. 1999 Nov-Dec;27(9):513-22. doi: 10.1002/(sici)1097-0096(199911/12)27:9<513::aid-jcu5>3.0.co;2-a.
Our objective was to demonstrate sonographically the flow distribution in the circulation of human placentae as well as the sensitivity of the human fetal capillary bed to vasoconstriction and dilatation.
Five human full-term placental lobules were maintained in vitro with fetal and maternal flow. Commercial ultrasound scanners were used for imaging. Albunex (1 ml bolus) was administered to the fetal "artery" to monitor patterns of flow. U46619 (1 ml, 10(-6) M; a thromboxane agonist and potent vasoconstrictor) and/or nitroglycerin (a potent vasodilator) were added to the fetal artery.
Following the addition of U46619, mean "fetal pressures" rapidly rose from 23.2 +/- 0.8 to 118 +/- 2. 9 mm Hg (mean +/- standard error of mean; p < 0.001); venous flow rates decreased. As demonstrated by color Doppler imaging, flow markedly changed from a pattern of general distribution throughout the lobule to flow only near the chorionic plate. Color persistence was 94.4 +/- 6.5 seconds with Albunex after nitroglycerin and 39.8 +/- 3.4 seconds with Albunex after injection of U46619 (p < 0.001). Nitroglycerin had no effect when injected by itself but returned "constricted" flow to a "normal" pattern when injected after U46619.
The contrast medium Albunex improved visualization of the fetal circulation throughout the lobule. Flow in the human placental capillary bed can be regionally manipulated throughout the placental lobule by vasomodulators and monitored by Albunex-enhanced sonographic examination.
我们的目标是通过超声检查来展示人类胎盘循环中的血流分布情况，以及人类胎儿毛细血管床对血管收缩和扩张的敏感性。
将五个足月的人类胎盘小叶在体外维持胎儿和母体血流状态。使用商用超声扫描仪进行成像。向胎儿“动脉”注射阿尔布奈克斯（1毫升推注剂量）以监测血流模式。向胎儿动脉中添加U46619（1毫升，10⁻⁶ M；一种血栓素激动剂和强效血管收缩剂）和/或硝酸甘油（一种强效血管扩张剂）。
添加U46619后，平均“胎儿压力”迅速从23.2±0.8毫米汞柱升至118±2.9毫米汞柱（平均值±平均标准误差；p<0.001）；静脉血流速度降低。如彩色多普勒成像所示，血流模式从整个小叶的普遍分布明显改变为仅在绒毛膜板附近流动。硝酸甘油注射后使用阿尔布奈克斯时，彩色持续时间为94.4±6.5秒，注射U46619后使用阿尔布奈克斯时为39.8±3.4秒（p<0.001）。硝酸甘油单独注射时无作用，但在U46619注射后注射可使“收缩”的血流恢复到“正常”模式。
造影剂阿尔布奈克斯改善了整个小叶内胎儿循环的可视化。人类胎盘毛细血管床中的血流可通过血管调节剂在整个胎盘小叶区域进行调控，并通过阿尔布奈克斯增强的超声检查进行监测。
