Levine M G, Miodovnik M, Clark K E
Am J Obstet Gynecol. 1984 Mar 15;148(6):735-8. doi: 10.1016/0002-9378(84)90557-x.
Estetrol is produced by the fetal liver and has been suggested to be a sensitive indicator of fetal well-being. Although the uterine vascular effects of estrogens (17 beta-estradiol, estriol, and estrone) have been extensively investigated in our laboratory and those of others, the ability of estetrol to dilate the ovine uterine vasculature is not presently known. The present experiment was designed to compare the vasoactivity of estetrol to that of a second pregnancy-associated estrogen, estriol. Five nonpregnant oophorectomized ewes were chronically instrumented with catheters in the femoral artery, femoral vein, uterine arteries, and electromagnetic flow probes on both uterine arteries. Upon recovering from operation, animals received unilateral intra-arterial (uterine) injections of either estriol (0.1, 0.3, 1, and 3 micrograms) or estetrol (1, 3, 10, and 30 micrograms). Ewes received only one dose of either estetrol or estriol daily and all doses were given in a randomized order. Uterine blood flow responses were continuously monitored and the time of onset, peak, and duration were recorded. The time of onset (38 +/- 2 minutes), time of peak response (75 +/- 1 minute), and duration (189 +/- 7 minutes) were approximately equal to those observed for estriol. On the basis of the data obtained in the present study we have determined that estetrol is 15 to 30 times less potent than estriol as a uterine vasodilator.
雌三醇由胎儿肝脏产生，被认为是胎儿健康的敏感指标。尽管雌激素（17β-雌二醇、雌三醇和雌酮）对子宫血管的作用已在我们实验室及其他实验室中得到广泛研究，但目前尚不清楚雌三醇扩张绵羊子宫血管的能力。本实验旨在比较雌三醇与另一种与妊娠相关的雌激素——雌三醇的血管活性。对五只非妊娠的去卵巢母羊进行长期手术，在股动脉、股静脉、子宫动脉中插入导管，并在两侧子宫动脉上安装电磁血流探头。术后恢复后，动物接受单侧动脉内（子宫）注射雌三醇（0.1、0.3、1和3微克）或雌三醇（1、3、10和30微克）。母羊每天仅接受一剂雌三醇或雌三醇，所有剂量均按随机顺序给药。持续监测子宫血流反应，并记录起效时间、峰值时间和持续时间。起效时间（38±2分钟）、峰值反应时间（75±1分钟）和持续时间（189±7分钟）与雌三醇观察到的时间大致相等。根据本研究获得的数据，我们确定，作为子宫血管扩张剂，雌三醇的效力比雌三醇低15至30倍。
