Bartol F F, Roberts R M, Bazer F W, Thatcher W W
Biol Reprod. 1985 Oct;33(3):745-59. doi: 10.1095/biolreprod33.3.745.
Endometrial tissues were obtained from 17 pregnant (P, estrus/mating = Day 0; Day 16, n = 4; Day 19, n = 6; Day 22, n = 3; Day 24, n = 4) and six nonpregnant (NP; Day 16, n = 4; Day 19, n = 2) cattle, as well as from one cyclic (nonbred) cow (Day 4), one later-pregnant cow (Day 69), and both ligated and pregnant uterine horns of three unilaterally pregnant cattle (UP; Day 270). Tissues (approximately equal to 500 mg wet tissue/explant) were cultured for 24 or 48 h in modified minimal essential medium (MEM), in the presence of radioactive amino acid and/or amino sugar substrate(s) (L-[3H] leucine, L-[14C] leucine, and D-[3H] glucosamine), in order to characterize substrate uptake and de novo synthesis and release of proteins and polypeptides in vitro. Endometrial explants from all cattle produced proteins de novo from radiolabeled substrates. Chromatographic (gel filtration, cation, and anion exchange) and two-dimensional polyacrylamide gel electrophoretic analyses revealed complex patterns of primarily acidic radiolabeled polypeptides in dialyzed MEM, which were absent from endometrial tissue homogenates. No qualitative differences were noted in the array of proteins released into MEM associated with either pregnancy status (P vs. NP, UP) or stage of gestation (Days 16, 19, 22, 24, 69, and 270). Medium from all endometrial explants was enriched in polypeptides in four Mr (X 10(3)/pH classes (I, approximately equal to 14/greater than 7.2; II, 19-24/5.4-6.3; III, 28-31/6.9-7.3; and IV, greater than or equal to 150/less than or equal to 5.1).
从17头怀孕母牛（P，发情/配种日为第0天；第16天，n = 4；第19天，n = 6；第22天，n = 3；第24天，n = 4）、6头未怀孕母牛（NP；第16天，n = 4；第19天，n = 2）、1头处于发情周期（未配种）的母牛（第4天）、1头怀孕后期的母牛（第69天）以及3头单侧怀孕母牛（UP；第270天）的结扎且怀孕的子宫角获取子宫内膜组织。将组织（约500毫克湿组织/外植体）在改良的最低必需培养基（MEM）中培养24或48小时，培养基中含有放射性氨基酸和/或氨基糖底物（L-[³H]亮氨酸、L-[¹⁴C]亮氨酸和D-[³H]葡糖胺），以便在体外表征底物摄取以及蛋白质和多肽的从头合成与释放。所有母牛的子宫内膜外植体均能利用放射性标记底物从头合成蛋白质。色谱分析（凝胶过滤、阳离子和阴离子交换）以及二维聚丙烯酰胺凝胶电泳分析显示，透析后的MEM中主要是酸性放射性标记多肽的复杂图谱，而子宫内膜组织匀浆中没有这些图谱。在与妊娠状态（怀孕与未怀孕、单侧怀孕）或妊娠阶段（第16、19、22、24、69和270天）相关的释放到MEM中的蛋白质阵列中未发现定性差异。来自所有子宫内膜外植体的培养基在四个Mr（×10³/pH类别）中富含多肽（I，约等于14/大于7.2；II，19 - 24/5.4 - 6.3；III，28 - 31/6.9 - 7.3；IV，大于或等于150/小于或等于5.1）。
