Division of Animal Sciences, University of Missouri, Columbia, MO, USA.
Biol Reprod. 2021 Jul 2;105(1):87-99. doi: 10.1093/biolre/ioab053.
In ruminants, conceptus elongation requires the endometrium and its secretions. The amino acid, carbohydrate, and protein composition of the uterine lumen during early pregnancy has been defined in sheep; however, a comprehensive understanding of metabolomic changes in the uterine lumen is lacking, particularly with respect to lipids. Here, the lipidome and primary metabolome of the uterine lumen, endometrium, and/or conceptus was determined on day 14 of the estrous cycle and pregnancy. Lipid droplets and select triglycerides were depleted in the endometrium of pregnant ewes. In contrast, select ceramides, diglycerides, and non-esterified fatty acids as well as several phospholipid classes (phosphatidylcholine, phosphatidylinositol, phosphatidylglycerols, and diacylglycerols) were elevated in the uterine lumen of pregnant ewes. Lipidomic analysis of the conceptus revealed that triglycerides are particularly abundant within the conceptus. Primary metabolite analyses found elevated amino acids, carbohydrates, and energy substrates, among others, in the uterine lumen of pregnant ewes. Collectively, this study supports the hypothesis that lipids are important components of the uterine lumen that govern conceptus elongation and growth during early pregnancy.
在反刍动物中，胚胎伸长需要子宫内膜及其分泌物。在绵羊中已经确定了妊娠早期子宫腔中的氨基酸、碳水化合物和蛋白质组成；然而，对于脂质，人们对子宫腔中的代谢组学变化缺乏全面的了解。在这里，在发情周期和妊娠的第 14 天确定了子宫腔、子宫内膜和/或胚胎的脂质组和主要代谢组。妊娠母羊的子宫内膜中脂质滴和选择的甘油三酯减少。相比之下，选择的神经酰胺、二甘油酯和非酯化脂肪酸以及几种磷脂类（磷脂酰胆碱、磷脂酰肌醇、磷脂酰甘油和二酰基甘油）在妊娠母羊的子宫腔中升高。胚胎的脂质组学分析表明，甘油三酯在胚胎中特别丰富。主要代谢产物分析发现，妊娠母羊的子宫腔中存在升高的氨基酸、碳水化合物和能量底物等。总的来说，这项研究支持了这样一种假设，即脂质是子宫腔的重要组成部分，它控制着妊娠早期胚胎的伸长和生长。
