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Fertilization and normal embryonic and early fetal development
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Asim Kurjak, Ritsuko K. Pooh, Aida Salihagic-Kadic, Iva Lausin, Lara Spalldi-Barisic
Transfer of the oocyte is facilitated by the changing endocrine milieu of the early luteal phase with its rising ratio of progesterone to estrogen, which affects the oviductal and uterine musculature and relaxes the isthmic sphincter. It is probable, however, that the cilia, rather than the musculature, are the primary active transporters of the conceptus. Thus, pharmacologic inhibition of oviductal muscles does not prevent transfer of the conceptus. Furthermore, if a segment of oviduct is excised, turned around, and replaced such that cilia beat away from the uterus, the conceptus moves to that part of the oviduct and then it stops (Figs. 7–9) (4).
Capacitation, the Acrosome Reaction, and Motility in Mammalian Sperm
Published in Claude Gagnon, Controls of Sperm Motility, 2020
Susan S. Suarez, John W. Pollard
After passing through the cervix, spermatozoa traverse the length of the uterus, either by their own flagellar activity or by some action of the uterus itself. At the anterior end of the uterus or uterine horns, they enter the oviducts through the uterotubal junction. The junction and/or the caudal portion of the oviductal isthmus apparently acts as a sperm reservoir, preventing most of the spermatozoa from continuing on to the ampulla.44 Although the uterine environment is capable of fully capacitating spermatozoa,45 the primary site for the completion of capacitation is thought to be the oviduct.33 In fact, capacitation may not even be initiated in spermatozoa destined to fertilize until they enter the oviduct, especially in species having uterine insemination sites. In some species, spermatozoa have been observed to be immobilized in the caudal isthmus.12,46 Perhaps they are inhibited from continuing or completing capacitation at this time as well. Capacitation could resume when they are released or release themselves from the isthmic reservoir. The isthmic sperm reservoir is discussed in greater detail in the chapter in this volume by Overstreet and Katz.
Histogenesis of Irreversible Changes in the Female Genital Tract After Perinatal Exposure to Hormones and Related Substances
Published in Takao Mori, Hiroshi Nagasawa, Toxicity of Hormones in Perinatal Life, 2020
The oviduct structure was similar to that found in normal fetuses: oviduct uncoiled, short, adherent to and wrapped around the ovary. The authors interpreted the findings as a developmental arrest of the oviduct.144,145 Microscopically, the incidence of salpingitis was increased; the epithelium was of a secretory type and sometimes hyperplastic with mucosal folds extending through the muscularis. The mucosa of the isthmus region was lined by numerous abnormal nonciliated cells, while the ciliated cells were normal. Large cysts adjacent to the ovary and oviduct could be related to both Miillerian and Wolffian duct alterations.144 A progressive epithelial hyperplasia and pseudogland formation also occurred after neonatal DES treatment.147
Efficacy of polyvinylpyrrolidone-capped gold nanorods against 7,12 dimethylbenz(a)anthracene-induced oviduct and endometrial cancers in albino rats
Published in Egyptian Journal of Basic and Applied Sciences, 2023
Hend Gamal, Walid Tawfik, Hassan H El-Sayyad, Heba Mohamed Fahmy, Ahmed N. Emam, Heba A El-Ghaweet
The oviduct from the negative control group was examined histologically. It revealed normal mucosa in the proximal portion of the oviduct that was flung into a sequence of branched longitudinal folds and extended past the oviduct’s open cranial end as finger-like processes known as fimbria. As one gets closer to the uterus, the creases become less noticeable. The mucosa is a straightforward columnar epithelium with secretory cells that are both ciliated and unciliated. Large lymphatic capillaries are found in the highly vascular lamina propria that lies beneath the epithelium (Figure 5a). An acquired circular or spiral layer of smooth muscle (the muscular) and a less well-improved outer layer of longitudinally oriented smooth muscle were visible in the oviduct of the PVP-capped AuNRs positive control group (Figure 5b). In the DMBA carcinogenesis group, the oviduct revealed degenerated mucosal folds with loss of both ciliated and unciliated secretory cells. Palpable abnormality in lamina propria and disorganization of circular and longitudinal smooth muscle is presented in Figure 5c. The DMBA carcinogenesis group treated with PVP-capped AuNRs exhibited modest improvement, but the mucosal folds remained aberrant in morphology and lacked vascular lamina propria differentiation (Figure 5d).
Bu-Shen-Ning-Xin decoction alleviates premature ovarian insufficiency (POI) by regulating autophagy of granule cells through activating PI3K/AKT/mTOR pathway
Published in Gynecological Endocrinology, 2022
Xiaoqing Dou, Xin Jin, Xingbei Chen, Qun Zhou, Hanyu Chen, Mingxiao Wen, Wenjun Chen
Ovulation was induced as described previously [14]. Briefly, after treatments, rats were super-ovulated with 50 IU pregnant mare serum gonadotropin (Sansheng Pharmaceutical Co., Ltd., China). After 48 h, 50 IU human chorionic gonadotropin (Sansheng Pharmaceutical Co., Ltd., China) was administered intraperitoneally to trigger oocytes maturation. Oviducts were harvested 24 h later, followed by being teared with a needle to release oocytes into pre-heated G-MOPSplus medium (Vitrolife, Sweden). Cumulus-free oocytes were harvested from the oocyte-corona-cumulus complex after removing granulosa cells with the addition of 0.3 mg/mL hyaluronidase (Sigma, USA), which were washed thrice with G-MOPSplus and finally incubated at 37 °C in G-IVFplus medium (Vitrolife, Sweden), followed by counting using a flow cytometer (ACEA Biosciences, USA).
The effect of low and ultra-low oxygen tensions on mammalian embryo culture and development in experimental and clinical IVF
Published in Systems Biology in Reproductive Medicine, 2020
Manuel Belli, Sevastiani Antonouli, Maria Grazia Palmerini, Serena Bianchi, Sara Bernardi, Mohammad Ali Khalili, Orlando Donfrancesco, Stefania Annarita Nottola, Guido Macchiarelli
The debate is regarding the effects of physiological and atmospheric O2 levels in embryo culture continues. Time-lapse monitoring studies on the developmental arrest in human and mouse preimplantation embryo culture found delayed/arrested embryo development under atmospheric O2 with respect to those using low O2 (Kirkegaard et al. 2013; Ma et al. 2017). Mouse embryos cultured from zygote to blastocysts under different O2 (3% and 20%) gave higher blastocyst developmental (92.3% vs. 79.4%) and hatching rates (80% vs. 70.4%) when embryos were cultured in 3% O2, suggesting that low O2 utilization in IVC may improve embryo viability with increased expression of antioxidant enzymes and glucose transporter activities (Ma et al. 2017). According to these findings, most of the modern IVF laboratories accepted the superiority of using physiologic O2, arguments regarding whether a further reduction in O2 after E3 of embryo development represents the most physiologic system still exists (Morin 2017). These arguments deserve two considerations: 1) O2 levels are lower in the uterus than in the oviduct, and 2) the embryo usually crosses the uterus-tubal junction on day 3. A few recent studies using ultra-low O2 (2%) in embryo culture after E3 of development, suggested that the best O2 level may be stage-dependent (Morin 2017; Crawford and Ledger 2019). However, the mechanism by which low O2 could improve in vitro embryo development is still not fully understood.