Markenson G R, Foley K, Maslow A S, Kopelman J N
Maternal-Fetal Medicine Division, Madigan Army Medical Center, Tacoma, Washington, USA.
Am J Obstet Gynecol. 1995 Oct;173(4):1143-7. doi: 10.1016/0002-9378(95)91341-6.
Our purpose was to investigate pressure changes induced by angiotensin II on placental vasculature pretreated with atrial natriuretic factor.
A dual-perfused cotyledon model was used. Two cotyledons from each placenta were perfused. One cotyledon was infused with atrial natriuretic factor for 30 minutes while the other received an equal volume of saline solution. Three atrial natriuretic factor concentrations were studied: 50 pg/ml, 150 pg/ml, and 15 ng/ml. Both cotyledons received injections of angiotensin II, at the following doses: 1 x 10(-11.5), 1 x 10(-11), 1 x 10(-10.5), and 1 x 10(-10) mol.
Cotyledons subjected to 50 pg/ml and 150 pg/ml concentrations of atrial natriuretic factor did not differ in pressure responses to angiotensin II, compared with the saline-infused cotyledons (p > 0.05). The 15 ng/ml concentration of atrial natriuretic factor, however, decreased the pressor response of angiotensin II (p < 0.034).
Atrial natriuretic factor decreases vasoconstriction caused by angiotensin II. However, this was seen only at a supraphysiologic concentration. No effect was noted at normal fetal concentrations of atrial natriuretic factor.
我们的目的是研究血管紧张素II对经心钠素预处理的胎盘血管系统所诱导的压力变化。
采用双灌注子叶模型。对每个胎盘的两个子叶进行灌注。一个子叶灌注心钠素30分钟，而另一个接受等量的盐溶液。研究了三种心钠素浓度：50 pg/ml、150 pg/ml和15 ng/ml。两个子叶均接受以下剂量的血管紧张素II注射：1×10⁻¹¹.⁵、1×10⁻¹¹、1×10⁻¹⁰.⁵和1×10⁻¹⁰摩尔。
与灌注盐溶液的子叶相比，接受50 pg/ml和150 pg/ml浓度心钠素的子叶对血管紧张素II的压力反应无差异（p>0.05）。然而，15 ng/ml浓度的心钠素降低了血管紧张素II的升压反应（p<0.034）。
心钠素可降低血管紧张素II引起的血管收缩。然而，这仅在超生理浓度时出现。在正常胎儿心钠素浓度下未观察到效果。
