Biochemistry and Physiology of Oviductal Secretions

Stone, Sarah Lipford; Hamner, Charles E.

doi:10.1159/000301520

Cited by 31 publications

(11 citation statements)

References 17 publications

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“…Nevertheless, we ruled out an altered tubal migration because all uterine horns were perfused separately and no oocytes or embryos were collected. It is known that oocyte transport occurs in the opposite direction to the oviductal fluid current, which flows towards the peritoneal cavity, coinciding with the maximum secretion of oviductal fluid during oestrogen dominance [59], [60]. However, the oviduct ligated group ensures that no loss of oocytes occurs in the peritoneal cavity.…”

Section: Discussionmentioning

confidence: 99%

Live Birth from Slow-Frozen Rabbit Oocytes after In Vivo Fertilisation

2013

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In vivo fertilisation techniques such as intraoviductal oocyte transfer have been considered as alternatives to bypass the inadequacy of conventional in vitro fertilisation in rabbit. There is only one study in the literature, published in 1989, that reports live offspring from cryopreserved rabbit oocytes. The aim of the present study was to establish the in vivo fertilisation procedure to generate live offspring with frozen oocytes. First, the effect of two recipient models (i) ovariectomised or (ii) oviduct ligated immediately after transfer on the ability of fresh oocytes to fertilise were compared. Second, generation of live offspring from slow-frozen oocytes was carried out using the ligated oviduct recipient model. Throughout the experiment, recipients were artificially inseminated 9 hours prior to oocyte transfer. In the first experiment, two days after unilateral transfer of fresh oocytes, oviducts and uterine horns were flushed to assess embryo recovery rates. The embryo recovery rates were low compared to control in both ovariectomised and ligated oviduct groups. However, ligated oviduct recipient showed significantly (P<0.05) higher embryo recovery rates compared to ovariectomised and control-transferred. In the second experiment, using bilateral oviduct ligation model, all females that received slow-frozen oocytes became pregnant and delivered a total of 4 live young naturally. Thus, in vivo fertilisation is an effective technique to generate live offspring using slow-frozen oocytes in rabbits.

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Section: Discussionmentioning

confidence: 99%

Live Birth from Slow-Frozen Rabbit Oocytes after In Vivo Fertilisation

2013

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“…Although the protein composition of fallopian tube fluid has been characterized in different species (4,60), the regulation of the production and secretion of individual components remains largely unknown. In the present study, we focused on longterm estrogen-induced regulation of IGF-I and IGF-II in mouse fallopian tube tissues and fluid.…”

Section: Discussionmentioning

confidence: 99%

Dynamic regulation of estrogen receptor-α isoform expression in the mouse fallopian tube: mechanistic insight into estrogen-dependent production and secretion of insulin-like growth factors

Shao

Egecioglu²,

Weijdegård³

et al. 2007

American Journal of Physiology-Endocrinology and Metabolism

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Estrogen receptors (ERs) are members of the nuclear receptor superfamily and are involved in regulation of fallopian tube functions (i.e., enhancement of protein secretion, formation of tubal fluid, and regulation of gamete transport). However, the ER subtype-mediated mechanisms underlying these processes have not been completely clarified. Recently, we identified ER␤ expression and localization in rat fallopian tubes, suggesting a potential biological function of ER␤ related to calcium-dependent ciliated beating. Here we provide for the first time insight into the less studied ER␣ isoforms, which mediate estrogen-dependent production and secretion of IGFs in vivo. First, Western blot studies revealed that three ER␣ isoforms were expressed in mouse fallopian tubes. Subsequent immunohistochemical analysis showed that ER␣ was detected in all cell types, whereas ER␤ was mainly localized in ciliated epithelial cells. Second, ER␣ isoform levels were dramatically downregulated in mouse fallopian tubes by treatment with E2 or PPT, an ER␣ agonist, in a time-dependent manner. Third, the presence of ICI 182,780, an ER antagonist, blocked the E2-or PPT-induced downregulation of tubal ER␣ isoform expression in mice. However, alteration of ER␣ immunoreactivity following ICI 182,780 treatment was only detected in epithelial cells of the ampullary region. Fourth, changes in ER␣ isoform expression were found to be coupled to multiple E2 effects on tubal growth, protein synthesis, and secretion in mouse fallopian tube tissues and fluid. In particular, E 2 exhibited positive regulation of IGF-I and IGF-II protein levels. Finally, using growth hormone receptor (GHR) gene-disrupted mice, we showed that regulation by E 2 of IGF production was independent of GHinduced GHR signaling in mouse fallopian tubes in vivo. These data, together with previous studies from our laboratory, suggest that the long-term effects of estrogen agonist promote IGF synthesis and secretion in mouse tubal epithelial cells and fallopian tube fluid via stimulation of ER␣.estrogen receptor-␣ isoforms; tubal epithelial cells A CRITICAL FUNCTION of the mammalian fallopian tube (24) is to provide an optimal microenvironment for the necessary transport and maturation of gametes and the establishment of pregnancy. It excretes the intraluminal tubal fluid, containing a number of growth factors (1,4,29,30,34). Compelling evidence suggests that estrogen may be involved in the regulation of biological processes in the fallopian tube. Studies have shown that ovarian-derived estradiol (E 2 ), the principal bioactive estrogen, is involved in the regulation of tubal protein secretion in human fallopian tubes in vivo (34) and in vitro (63). Insulin-like growth factors (IGFs) have been identified in human and rodent fallopian tube fluid (4). Accumulating data suggest that IGF-I may support embryonic development and survival (1). Moreover, E 2 has been shown to increase endogenous IGF-I mRNA levels in rat fallopian tube and uterus (5, 46), and estrogen-responsive elements are...

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“…It is unclear whether mouse eggs are exposed to low pH under physiological conditions within the ovarian follicle or oviduct, as direct measurements have not been reported. In larger species, follicular fluid and oviduct pH is generally in the range of 7-8 [reviewed by Edwards (1974); Stone and Hamner (1975)], but pH has been measured as low as 6.8 in bovine follicles and pig oviducts (Smiljakovićet al, 2008;Zachariae and Jensen, 1958). In addition, follicle or oviductal pH could drop during an inflammatory process as has been observed in inflamed airways (Liu et al, 2013).…”

Section: Acidic Ph Induces a Rise In Intracellular Camentioning

confidence: 99%

Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs

et al. 2015

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During oocyte maturation, capacity and sensitivity of Ca 2+ signaling machinery increases dramatically, preparing the metaphase II (MII)-arrested egg for fertilization. Upon sperm-egg fusion, Ca 2+ release from IP 3 -sensitive endoplasmic reticulum stores results in cytoplasmic Ca 2+ oscillations that drive egg activation and initiate early embryo development. Premature Ca 2+ release can cause parthenogenetic activation prior to fertilization; thus, preventing inappropriate Ca 2+ signaling is crucial for ensuring robust MII arrest. Here, we show that regulator of G-protein signaling 2 (RGS2) suppresses Ca 2+ release in MII eggs. Rgs2 mRNA was recruited for translation during oocyte maturation, resulting in ∼20-fold more RGS2 protein in MII eggs than in fully grown immature oocytes. Rgs2-siRNA-injected oocytes matured to MII; however, they had increased sensitivity to low pH and acetylcholine (ACh), which caused inappropriate Ca 2+ release and premature egg activation. When matured in vitro, RGS2-depleted eggs underwent spontaneous Ca 2+ increases that were sufficient to cause premature zona pellucida conversion. Rgs2 −/− females had reduced litter sizes, and their eggs had increased sensitivity to low pH and ACh. Rgs2 −/− eggs also underwent premature zona pellucida conversion in vivo. These findings indicate that RGS2 functions as a brake to suppress premature Ca 2+ release in eggs that are poised on the brink of development.

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Biochemistry and Physiology of Oviductal Secretions

Cited by 31 publications

References 17 publications

Live Birth from Slow-Frozen Rabbit Oocytes after In Vivo Fertilisation

Live Birth from Slow-Frozen Rabbit Oocytes after In Vivo Fertilisation

Dynamic regulation of estrogen receptor-α isoform expression in the mouse fallopian tube: mechanistic insight into estrogen-dependent production and secretion of insulin-like growth factors

Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs

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