O'Neill C
Human Reproduction Unit, Royal North Shore Hospital, St. Leonards, NSW, Australia.
Biol Reprod. 1995 May;52(5):965-71. doi: 10.1095/biolreprod52.5.965.
Platelet-activating factor (PAF) is a potent autacoid produced by the embryo and the endometrium during early pregnancy. Its actions in vivo are dependent upon its half-life, which in turn is largely governed by its metabolism. PAF:acetylhydrolase is a major metabolic enzyme for PAF and is widespread in body tissues and fluids. This study was an examination of the activity of this enzyme in the uterus (uterine luminal fluids and endometrial scrapings) of mice in the periovulatory period, throughout the preimplantation phase of pregnancy, and throughout the luteal phase of pseudopregnancy. PAF:acetylhydrolase activity was found in uterine washings and endometrial tissue; it was dependent upon incubation time and protein concentration and was destroyed by boiling. The activity was not affected by cations (Mg2+ and Ca2+) and was not inhibited by bromophenacyl bromide, a phospholipase A2 inhibitor. The specific and total activity changed dramatically throughout the reproductive cycle. Total tissue activity did not change significantly during the follicular phase. On the day after ovulation, tissue activity was lower in naturally mated mice and was maintained at this level until Day 4; there was no difference in this value between pregnant and pseudopregnant animals. On days 5 and 6 of pseudopregnancy the total tissue activity increased, reaching a peak on Day 6 of 4609 pmol acetate released.min-1, approximately 780% higher than the value obtained on Day 4. Activity then decreased so that by Day 8 it was not different from preovulatory levels. For uterine luminal fluids, total activity significantly decreased during the follicular phase. This continued throughout the preimplatation phase with minimum activity being reached on Days 3 and 4 (7.68 pmol acetate.min-1 on Day 4 pseudopregnancy).(ABSTRACT TRUNCATED AT 250 WORDS)
血小板活化因子（PAF）是胚胎和子宫内膜在妊娠早期产生的一种强效自分泌调节物质。其在体内的作用取决于其半衰期，而半衰期又在很大程度上受其代谢的调控。PAF：乙酰水解酶是PAF的一种主要代谢酶，广泛存在于身体组织和体液中。本研究检测了处于排卵期、整个植入前妊娠阶段以及整个假孕黄体期的小鼠子宫（子宫腔液和子宫内膜刮片）中该酶的活性。在子宫灌洗液和子宫内膜组织中发现了PAF：乙酰水解酶活性；它取决于孵育时间和蛋白质浓度，且煮沸后会被破坏。该活性不受阳离子（Mg2 +和Ca2 +）影响，也不受磷脂酶A2抑制剂溴苯甲酰溴的抑制。在整个生殖周期中，比活性和总活性发生了显著变化。在卵泡期，总组织活性没有显著变化。排卵后一天，自然交配小鼠的组织活性较低，并维持在该水平直至第4天；怀孕和假孕动物在该值上没有差异。在假孕的第5天和第6天，总组织活性增加，在第6天达到峰值，为每分钟释放4609 pmol乙酸盐，比第4天获得的值高出约780％。然后活性下降，到第8天与排卵前水平没有差异。对于子宫腔液，在卵泡期总活性显著降低。在整个植入前阶段这种情况持续存在，在第3天和第4天达到最低活性（假孕第4天为每分钟7.68 pmol乙酸盐）。（摘要截短于250字）
