Li W I, Chen C L, Hansen P J, Bazer F W
Endocrinology. 1987 Sep;121(3):1111-5. doi: 10.1210/endo-121-3-1111.
Levels of beta-endorphin-like immunoreactivity (beta END-LI) in uterine secretions were studied in pseudopregnant and ovariectomized gilts treated with ovarian steroids. Pseudopregnancy was induced in 7 gilts by daily injection of estradiol valerate (5 mg/day) between days 11 and 15 of the estrous cycle. Between days 60 and 90 of pseudopregnancy, uterine secretions were collected by flushing the uterus with 0.9% saline. Uterine flushings were extracted with a Sep-Pak C-18 column and assayed for beta END-LI by a specific RIA. The RIA cross-reacted only with beta-lipotropin (15%). Significant amounts of total immunoreactive beta END-LI were detected in the uterine flushings. The inhibition curve for extracts was parallel to the standard END inhibition curve. Extracted uterine flushings were applied to a Sephadex G-50 column. Three peaks of immunoreactive beta END-LI were detected. One peak eluted at the void volume. The second peak eluted at a Kav of 0.21, which was near the Kav of a lipotropin standard (0.23). The highest peak (Kav = 0.53) eluted similar to standard END (Kav = 0.51). In the second experiment, 12 gilts were ovariectomized on day 4 of the estrous cycle and randomly assigned to 4 groups of 3 gilts each. Each group received 1 of the following daily injections: vehicle (corn oil), 0.1 mg 17 beta-estradiol (E2), 200 mg progesterone (Prog), or a combination of E2 and Prog (E2 + Prog). After treatment for 30 days, beginning on the day of ovariectomy, the uterine flushings were assayed for beta END-LI and total protein. Treatment with Prog increased (P less than 0.05) total beta END-LI 532% (12.4 ng) compared to corn oil treatment (2.3 ng), and levels were significantly higher than with E2 (2.9 ng) or E2 + Prog treatment (5.1 ng). Opiate receptor assay showed that extracts of uterine flushing had a displacement curve parallel to that of standard porcine beta END. Results suggest that significant amounts of immunoreactive beta END-LI are present in uterine secretions of gilts and that the accumulation of beta END-LI is influenced by ovarian steroids.
在接受卵巢类固醇处理的假孕和去卵巢后备母猪中，研究了子宫分泌物中β-内啡肽样免疫反应性（β END-LI）的水平。通过在发情周期的第11至15天每天注射戊酸雌二醇（5毫克/天），诱导7头后备母猪假孕。在假孕的第60至90天，用0.9%生理盐水冲洗子宫收集子宫分泌物。子宫冲洗液用Sep-Pak C-18柱提取，并用特异性放射免疫分析（RIA）测定β END-LI。该RIA仅与β-促脂素发生15%的交叉反应。在子宫冲洗液中检测到大量的总免疫反应性β END-LI。提取物的抑制曲线与标准内啡肽抑制曲线平行。将提取的子宫冲洗液应用于Sephadex G-50柱。检测到三个免疫反应性β END-LI峰。一个峰在空体积处洗脱。第二个峰在Kav为0.21处洗脱，接近促脂素标准品的Kav（0.23）。最高的峰（Kav = 0.53）洗脱情况与标准内啡肽（Kav = 0.51）相似。在第二个实验中，12头后备母猪在发情周期的第4天进行去卵巢手术，并随机分为4组，每组3头。每组每天接受以下注射之一：赋形剂（玉米油）、0.1毫克17β-雌二醇（E2）、200毫克孕酮（Prog）或E2与Prog的组合（E2 + Prog）。从去卵巢手术当天开始处理30天后，对子宫冲洗液进行β END-LI和总蛋白测定。与玉米油处理（2.3纳克）相比，Prog处理使总β END-LI增加了532%（12.4纳克）（P小于0.05），且水平显著高于E2处理（2.9纳克）或E2 + Prog处理（5.1纳克）。阿片受体分析表明，子宫冲洗液提取物具有与标准猪β END平行的置换曲线。结果表明，后备母猪的子宫分泌物中存在大量免疫反应性β END-LI，且β END-LI的积累受卵巢类固醇的影响。
