Gerber J G, Payne N A, Murphy R C, Nies A S
J Clin Invest. 1981 Mar;67(3):632-6. doi: 10.1172/JCI110077.
Uterine production of PGI2 (prostacyclin) was quantitated in late pregnant dogs to evaluate if PGI2 could act as circulating vasodepressor substance in pregnancy. In five anesthetized, laparotomized dogs, the uterine venous plasma concentration of 6-keto PGF1 alpha (the in vitro hydrolysis product of PGI2) was 6.7 +/- 1.9 ng/ml and the arterial plasma concentration was 2.6 +/0 0.8 ng/ml. In four nonpregnant female dogs the arterial plasma concentration of 6-keto PGF1 alpha was consistently below 0.2 ng/ml. In eight pregnant dogs we also evaluated the ability of the pregnant uterus to inactivate PGI2 by comparing the hypotensive response to increasing doses of PGI2 infused into the uterine artery to the hypotensive response to increasing doses of PGI2 infused into the inferior vena cava. In addition, the effect of PGI2 infused into the uterine artery on uterine blood flow and intraamniotic fluid pressure was evaluated. The dose-response curves of intrauterine and intravenous PGI2 in causing systemic hypotension were identical suggesting that the pregnant uterus does not inactivate infused PGI2. Intrauterine PGI2 had no consistent effect on uterine hemodynamics although it did increase intraamniotic fluid pressure significantly. These data demonstrate that the pregnant uterus has the capacity to produce large quantities of PGI2 which is not inactivated in the uterus and therefore can appear in the arterial blood to exert a systemic vasodepressor effect.
为评估前列腺素I2（前列环素）是否可作为妊娠期循环血管舒张物质，对妊娠晚期母犬子宫产生的前列腺素I2进行了定量分析。在5只麻醉并开腹的母犬中，子宫静脉血浆中6-酮-前列腺素F1α（前列腺素I2的体外水解产物）的浓度为6.7±1.9 ng/ml，动脉血浆浓度为2.6±0.8 ng/ml。在4只未孕母犬中，动脉血浆中6-酮-前列腺素F1α的浓度始终低于0.2 ng/ml。在8只妊娠母犬中，我们还通过比较注入子宫动脉的不同剂量前列腺素I2引起的降压反应与注入下腔静脉的不同剂量前列腺素I2引起的降压反应，评估了妊娠子宫使前列腺素I2失活的能力。此外，还评估了注入子宫动脉的前列腺素I2对子宫血流量和羊膜腔内压力的影响。子宫内和静脉内注射前列腺素I2引起全身低血压的剂量反应曲线相同，表明妊娠子宫不会使注入的前列腺素I2失活。子宫内注射前列腺素I2对子宫血流动力学没有一致影响，尽管它确实显著增加了羊膜腔内压力。这些数据表明，妊娠子宫有能力产生大量前列腺素I2，其在子宫内不会失活，因此可出现在动脉血中发挥全身血管舒张作用。
