In horses, prostaglandin E₂ (PGE₂) is produced by embryos around Day 5 post-ovulation; PGE₂ functions directly at the oviduct promoting embryo transport into the uterus. Non-surgical collection of horse embryos for cryopreservation is recommended at Day 6.5–7 post-ovulation. It was proposed that misoprostol administered orally will hasten oviductal transport of horse embryos. In Experiment 1 (n = 15) there was comparison of time of embryo recovery (Day 6 and 6.5 post-ovulation) from mares administered misoprostol (Day 5 and 5.5) orally to that of untreated mares. On Day 6, embryo collections were attempted; if no embryo was collected, there was a second attempt on Day 6.5. In Experiment 2, (n = 16) misoprostol treatment was initiated on Day 4.5; there was the first embryo collection attempt on Day 5.5, followed by Day 6 and 6.5 if no embryo was collected. Blood samples were collected at 12 h intervals on Day 4.5 or 5, to Day 6.5. In Experiment 1, on days 6 and 6.5, respectively, there was collection of seven and one of a total of eight embryos detected at the time of collection per group (P = 1). In Experiment 2, 12 embryos were collected during 15 cycles with there being a total of three, two, and one collected from mares of both groups on Day 5.5, 6, and 6.5 post-ovulation, respectively (P = 1). Serum progesterone concentrations were not different (P ≥ 0.05). In conclusion, misoprostol, when administered orally, does not hasten oviductal transport of horse embryos.

在马中，排卵后第 5 天左右的胚胎会产生前列腺素 E ₂ (PGE ₂ )；PGE ₂直接作用于输卵管，促进胚胎运输到子宫中。建议在排卵后第 6.5-7 天采用非手术方式收集马胚胎进行冷冻保存。有人提出口服米索前列醇会加速马胚胎的输卵管运输。在实验 1 ( n = 15) 中，比较了母马口服米索前列醇（第 5 天和第 5.5 天）的胚胎恢复时间（排卵后第 6 天和第 6.5 天）与未经治疗的母马的胚胎恢复时间。在第 6 天，尝试收集胚胎；如果没有收集到胚胎，则在第 6.5 天进行第二次尝试。在实验 2 中， ( n= 16) 在第 4.5 天开始米索前列醇治疗；第 5.5 天进行了第一次胚胎收集尝试，如果没有收集胚胎，则在第 6 天和 6.5 天进行。从第 4.5 天或第 5 天到第 6.5 天，每隔 12 小时收集一次血样。在实验 1 中，分别在第 6 天和第 6.5 天，每组在收集时分别收集了 7 个和 8 个胚胎中的一个（P = 1）。在实验2中，在15个周期内收集了12个胚胎，在排卵后5.5、6和6.5天分别从两组母马中收集了3、2和1个胚胎（P = 1）。血清孕酮浓度无差异（P ≥0.05）。总之，当口服给药时，米索前列醇不会加速马胚胎的输卵管运输。