Delayed effect of low progesterone concentrations on bovine uterine PGF(2alpha) secretion in the subsequent oestrous cycle.
Delayed effect of low progesterone concentrations on bovine uterine PGF(2alpha) secretion in the subsequent oestrous cycle.
复制标题
低孕酮浓度对随后发情周期牛子宫 PGF(2α) 分泌的延迟影响。
DOI：
10.1530/rep.0.1220643
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发表时间：
2001
期刊：
影响因子：
3.8
通讯作者：
D. Wolfenson
中科院分区：
文献类型：
--
作者：
A. Shaham;Y. Folman;M. Kaim;M. Rosenberg;D. Wolfenson
牛发情周期中孕酮浓度较低时，黄体期黄体晚期对催产素攻击的反应增强。通过测定发情周期中主要PGF(2α)代谢物(13，14-二氢-15-酮-PGF(2α)；PGFM)的浓度，研究了发情周期中低孕酮浓度对催产素刺激后子宫PGF(2α)分泌的延迟效应。进行了两个实验，不同的孕酮处理类型和低孕酮浓度曲线的形状不同。在实验1中，在有或不有活动黄体的情况下，阴道内补充孕酮分别用于获得高、低和恒定的血浆孕酮浓度。在实验2中，未处理的奶牛代表高孕酮处理，与血浆孕酮浓度低但升高的奶牛进行比较，后者是通过控制黄体内源性孕酮分泌而实现的。这两个实验都没有显示在随后的发情周期中，高孕酮组和低孕酮组之间的血浆孕酮浓度有任何差异。在这两个实验中，两组在随后发情周期的第15天(试验1)或第16天(试验2)，即黄体酮治疗结束后18天，两组动物的PGFM基础浓度相似。在这两个实验中，催产素攻击后低孕酮组的PGFM浓度的增加明显高于高孕酮组。这些结果表明，发情周期中低孕酮浓度对下一个发情周期黄体晚期子宫对催产素的反应有延迟刺激作用。由此导致的前列腺素F(2α)分泌的增加可能会干扰怀孕早期黄体的维持。
Low progesterone concentrations during the bovine oestrous cycle induce enhanced responsiveness to oxytocin challenge late in the luteal phase of the same cycle. The delayed effect of low progesterone concentrations during one oestrous cycle on uterine PGF(2alpha) secretion after oxytocin challenge on day 15 or 16 of the subsequent cycle was studied by measuring the concentrations of the major PGF(2alpha) metabolite (13,14-dihydro-15-keto PGF(2alpha); PGFM) in plasma. Two experiments were conducted, differing in the type of progesterone treatment and in the shape of the low progesterone concentration curves. In Expt 1, progesterone supplementation with intravaginal progesterone inserts, with or without an active corpus luteum, was used to obtain high, or low and constant plasma progesterone concentrations, respectively. In Expt 2, untreated cows, representing high progesterone treatment, were compared with cows that had low but increasing plasma progesterone concentrations that were achieved by manipulating endogenous progesterone secretion of the corpus luteum. Neither experiment revealed any differences in plasma progesterone concentrations between the high and low progesterone groups in the subsequent oestrous cycle. In both experiments, both groups had similar basal concentrations of PGFM on day 15 (Expt 1) or 16 (Expt 2) of the subsequent oestrous cycle, 18 days after progesterone treatments had ended. In both experiments, the increases in PGFM concentrations in the low progesterone groups after an oxytocin challenge were markedly higher than in the high progesterone groups. These results indicate that low progesterone concentrations during an oestrous cycle have a delayed stimulatory effect on uterine responsiveness to oxytocin during the late luteal phase of the subsequent cycle. This resulting increase in PGF(2alpha) secretion may interfere with luteal maintenance during the early stages of pregnancy.