Effect of pregnancy on oxytocin-induced release of prostaglandin F2 alpha in heifers.
Effect of pregnancy on oxytocin-induced release of prostaglandin F2 alpha in heifers.
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怀孕对催产素诱导的小母牛前列腺素 F2 α 释放的影响。
DOI：
10.1095/biolreprod33.5.1113
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发表时间：
1985
影响因子：
3.6
通讯作者：
A. Goff
中科院分区：
文献类型：
--
作者：
M. Lafrance;A. Goff
已经检查了妊娠对催产素 (OT) 反应中前列腺素 F2 α (PGF2 α) 释放的影响。 14 头周期性小母牛在发情开始后（第 0 天）17、18 或 19 天（第 17-19 天）接受一次 1 IU OT（n = 6）或 100 IU OT（n = 8）静脉注射。其中 5 只动物还在第 6 天和第 13 天接受了 100 IU OT，以确定 OT 在周期不同时间的效果。 OT注射前60分钟和注射后90分钟频繁采集血样，通过放射免疫测定法测量15-酮-13,14-二氢-PGF2α（PGFM）。然后在怀孕第 17-19 天使用相同的动物重复该实验（通过 OT 注射后第二天胚胎的恢复来证实）。注射1 IU OT后，血浆PGFM在30分钟内达到峰值，怀孕动物的血浆PGFM增加值（1.13+/-0.10倍）显着低于非怀孕动物（2.07+/-0.27倍）（P小于0.05）。然而，由于 6 只周期性动物中只有 3 只对 1 IU OT 表现出反应，因此在后续实验中剂量增加至 100 IU。在第 6 天和第 13 天接受 100 IU 的动物 PGFM 浓度没有显着增加（分别为 1.18 +/- 0.05 倍和 1.01 +/- 0.04 倍）。在第 17-19 天，血浆 PGFM 的增加在 100 IU OT 后 5-15 分钟达到峰值，非妊娠小母牛的增加量（3.23 +/- 0.17 倍）显着高于怀孕小母牛（1.21 +/- 0.02 倍；P = 0.003）。在周期第 17-19 天注射的 11 只动物中，有 6 只在 OT 给药后第二天显示黄体酮 (P4) 下降。这些数据表明，在怀孕动物体内，PGF2 α 响应 OT 的释放受到抑制，这表明胚胎在黄体稳态中具有抗黄体溶解作用。
The effect of pregnancy on the release of prostaglandin F2 alpha (PGF2 alpha) in response to oxytocin (OT) has been examined. Fourteen cyclic heifers received one intravenous injection of 1 IU OT (n = 6) or 100 IU OT (n = 8) 17, 18, or 19 days (Day 17-19) after the onset of estrus (Day 0). Five of these animals also received 100 IU OT at Days 6 and 13 to determine the effect of OT at different times of the cycle. Frequent blood samples were taken for 60 min before and for 90 min after OT injection for the measurement of 15-keto-13,14-dihydro-PGF2 alpha (PGFM) by radioimmunoassay. The experiment was then repeated using the same animals at Day 17-19 of pregnancy (confirmed by the recovery of an embryo the day after OT injection). Following the injection of 1 IU OT, plasma PGFM reached its peak within 30 min with the increase significantly lower (P less than 0.05) in pregnant (1.13 +/- 0.10-fold) than in nonpregnant animals (2.07 +/- 0.27-fold). However, because only 3 of the 6 cyclic animals showed a response to 1 IU OT, the dose was increased to 100 IU in subsequent experiments. The animals that received 100 IU at Days 6 and 13 had no significant increase in PGFM concentrations (1.18 +/- 0.05-fold and 1.01 +/- 0.04-fold, respectively). At Day 17-19 the increase in plasma PGFM reached its peak 5-15 min after 100 IU OT and the increase was significantly greater in nonpregnant (3.23 +/- 0.17-fold) than in pregnant (1.21 +/- 0.02-fold; P = 0.003) heifers. Six of 11 animals injected at Day 17-19 of the cycle showed a decrease in progesterone (P4) the day after OT administration. These data show that the release of PGF2 alpha in response to OT is suppressed in pregnant animals in vivo, suggesting an antiluteolytic role for the embryo in luteostasis.