Pope W F, Maurer R R, Stormshak F
J Anim Sci. 1982 Nov;55(5):1169-78. doi: 10.2527/jas1982.5551169x.
Twenty-four pregnant Landrace and Yorkshire gilts were utilized to examine the relationship between myometrial activity and intrauterine embryo migration. On d 2 (1st day of estrus = d 0), embryos were flushed from one oviduct and transferred to the opposite oviduct. Uterine horns were ligated at the uterotubal junction on the flushed side and 40 and 50 cm posterior to the uterotubal junction on each side. On d 6, 9 or 12 (n = 8), embryo migration was determined by flushing segments of the excised uterus. Strips of myometrium from the pregnant and nonpregnant horn of each gilt were subsequently removed and assigned to one of the three in vitro experiments to examine the effects of the embryo and uterine flushings on myometrial contractility. Myometrial contractility increased concomitantly with embryo migration through the uterine ligations (day x side interaction, P less than .10). Uterine flushings from pregnant horns contained a short-acting substance that mimicked, in part, the stimulatory influence(s) of the in situ embryo on in vitro myometrial contractility. However, only flushings from the uterine segment containing the d 12 embryos could overcome the in vitro inhibitory effects of indomethacin (P less than .01) on myometrial contractility. The porcine embryo coincubated with myometrial strips could not directly stimulate contractions of the myometrium. Results of these experiments indicate that in gilts the stimulatory influence(s) of the migrating embryo on myometrial function may involve a "hormonal" factor of short half-life that does not directly affect the smooth muscle cell.
选用24头怀孕的长白猪和约克夏母猪来研究子宫肌层活动与子宫内胚胎迁移之间的关系。在第2天（发情第1天=d0），从一侧输卵管冲出胚胎并转移至对侧输卵管。在冲洗侧的子宫输卵管连接处以及两侧子宫输卵管连接处后方40和50厘米处结扎子宫角。在第6、9或12天（n=8），通过冲洗切除子宫的各段来确定胚胎迁移情况。随后从每头母猪的怀孕和未怀孕子宫角取下子宫肌层条带，并分配到三个体外实验之一，以研究胚胎和子宫冲洗液对子宫肌层收缩性的影响。随着胚胎通过子宫结扎处迁移，子宫肌层收缩性随之增加（日×侧交互作用，P<0.10）。来自怀孕子宫角的子宫冲洗液含有一种短效物质，该物质部分模拟了原位胚胎对体外子宫肌层收缩性的刺激作用。然而，只有来自含有第12天胚胎的子宫段的冲洗液能够克服吲哚美辛（P<0.01）对体外子宫肌层收缩性的抑制作用。与子宫肌层条带共同孵育的猪胚胎不能直接刺激子宫肌层收缩。这些实验结果表明，在母猪中，迁移胚胎对子宫肌层功能的刺激作用可能涉及一种半衰期短的“激素”因子，该因子不直接影响平滑肌细胞。
