Morin F C, Egan E A, Lundgren C E, Swartz D D
Department of Pediatrics, University at Buffalo, S.U.N.Y. 14214.
Prostaglandins Leukot Essent Fatty Acids. 1988 Jun;32(3):139-44.
The role of prostacyclin in mediating the increase in pulmonary blood flow caused by an increase in oxygen tension in the fetal lamb was investigated. Plasma concentrations of 6-keto-PGF1 alpha, the hydrolysis product of prostacyclin, were measured during an increase in pulmonary blood flow caused by a rise in oxygen tension in eight intrauterine fetal lambs. Fetal oxygen tension was increased by placing the pregnant ewes in a hyperbaric chamber and having them breathe 100% oxygen at three atmospheres absolute pressure. This increased fetal PaO2 from 27 +/- 3 to 60 +/- 6 torr (mean +/- S.E., p less than or equal to 0.0001) and increased the proportion of right ventricular output distributed to the fetal lungs from 6 +/- 2 to 45 +/- 7% (mean +/- S.E., p less than or equal to 0.001). However, the fetal plasma concentration of 6-keto-PGF1 alpha did not change, 186 +/- 26 to 208 +/- 40 pg/ml (mean +/- S.E.). Indomethacin decreased plasma concentrations of 6-keto-PGF1 alpha in each of three fetuses but did not decrease the proportion of right ventricular output distributed to their lungs. The increase in pulmonary blood flow caused by an increase in oxygen tension in the fetal lamb is not associated with an increase in plasma concentrations of 6-keto-PGF1 alpha. Prostacyclin does not appear to be involved in the increase in pulmonary blood flow caused by the increase in oxygen tension at birth.
研究了前列环素在介导胎羊因氧分压升高引起的肺血流量增加中的作用。在8只宫内胎羊因氧分压升高导致肺血流量增加的过程中，测量了前列环素的水解产物6-酮-前列腺素F1α的血浆浓度。通过将怀孕母羊置于高压舱中，并让它们在3个绝对大气压下呼吸100%氧气，来提高胎儿的氧分压。这使胎儿的动脉血氧分压从27±3升至60±6托（平均值±标准误，p≤0.0001），并使右心室输出量分配到胎儿肺部的比例从6±2%增至45±7%（平均值±标准误，p≤0.001）。然而，胎儿血浆中6-酮-前列腺素F1α的浓度并未改变，从186±26 pg/ml升至208±40 pg/ml（平均值±标准误）。吲哚美辛降低了3只胎儿中每只胎儿血浆中6-酮-前列腺素F1α的浓度，但并未降低右心室输出量分配到其肺部的比例。胎羊因氧分压升高引起的肺血流量增加与血浆中6-酮-前列腺素F1α浓度的增加无关。前列环素似乎不参与出生时因氧分压升高引起的肺血流量增加。
