The effects of the prostaglandin E analogue Misoprostol and follicle-stimulating hormone on cervical penetrability in ewes during the peri-ovulatory period

A Review of Advances in Artificial Insemination (AI) and Embryo Transfer (ET) in Sheep, with the Special Reference to Hormonal Induction of Cervical Dilation and its Implications for Controlled Animal Reproduction and Surgical Techniques

“…Previous studies had indicated that 200-µg and 400-µg doses of misoprostol had been ineffective in inducing cervical relaxation 24-72 hours after administration. The higher dose seemed to confer better results with effective intrauterine penetration achieved at 54 hours post-treatment of cyclic ewes [59].…”

“…Leethongdee et al, [59] evaluated the usefulness of misoprostol, a synthetic analogue of prostaglandin E 1 (PGE 1 ), as a cervical relaxant for ewes. In that study, ewes were treated intracervically with 1 mg of misoprostol dissolved in 0.5 ml of 30% gelatin.…”

Traversing the ovine cervix – a challenge for cryopreserved semen and creative science

“…Receptors for all three hormones Figure 2 The effect of topical treatment of the os cervix of Scottish Blackface ewes on days 5 and 6 post oestrus with nitric oxide donor isosorbide-5-mononitrate, or prostaglandin E 2 (PGE 2 ) in combination with oestradiol (E 2 ), on the number and the percentage of ewes for which the cervix was successfully traversed and on the mean duration (in minutes) of successful attempts to traverse the cervix (Data source: Robinson et al, 1999). are abundantly expressed in the cervix at oestrus (Zhao et al, 1999 for progesterone and oestradiol;Ayad, 1994 andAyad et al, 2004 for oxytocin). There is now evidence that gonadotrophins are also involved in cervical relaxation at oestrus, as intracervically administered follicle stimulating hormone (FSH) either alone or in combination with prostaglandin E 1 (Misoprostol) resulted in increased penetrability (Leethongdee et al, 2007). Furthermore, judicious timing of their administration (24 and 48 h after progestagen pessary withdrawal for the FSH and prostaglandin E 1 , respectively) advanced the time of maximum cervical dilation from 72 h after pessary withdrawal in untreated ewes to coincide more closely with the preferred optimum time for insemination of 54 h. The amounts of FSH and Misoprostol administered per ewe intracervically were 2 and 1 mg, respectively.…”

“…An accompanying feature at this time is the abundant expression of the hyaluronan receptor, CD44, in the epithelial layer (Perry et al, 2010b). In view of the central role that peri-oestrous endocrine changes play in the collagen and elastin remodelling processes that promote cervical relaxation, the research emphasis in ewes in recent years has been on improving understanding of their mechanistic pathways (Mitchell et al, 2002 andKershaw et al, 2007;Leethongdee et al, 2007 andKershaw-Young et al, 2009 and. An overview of the findings from these studies is illustrated in Figure 3.…”

“…The overview incorporates the recent observation that gonadotrophins play a permissive role in the steroid-activated cervical relaxation process and that judicious timing of intracervical FSH administration may be a useful practical method for ensuring that maximum cervical relaxation coincides with the optimum time for transcervical insemination (Leethongdee et al, 2007 and. The overview also includes the role of IL and the inflammatory response in cervical softening and relaxation.…”