• Journal of Embryo Transfer
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• v.28 no.3
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• pp.237-241
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• 2013

It is generally accepted that chronic stress impairs female reproduction. It negatively affects ovarian function and the number of ovulated oocytes. Chronic stress lowers the number of retrieved oocytes. Ovarian follicular development is regulated by both pituitary-derived gonadotropins and intraovarian regulatory factors. The main corticosteroids are cortisol, cortisone, 11-deoxycortisol and corticosterone, cortisol being one of the most commonly used welfare and stress physiological indicator. In this study, we investigated the effect of cortisol level on progesterone patterns and ovulation in the dog. Cortisol and progesterone level of serum were analyzed by radioimmunoassay. The day of ovulation was considered as the day when serum progesterone concentration was 6.0~8.0 ng/ml. In vivo dog oocytes were collected by flushing oviducts of mixed-breed bitches at three days after ovulation. We classified dogs as having group 1 (cortisol level, 0 ${\leq}$ or < $2{\mu}g/dl$), group 2 (corisol level, 2 ${\leq}$ or < $4{\mu}g/dl$), group 3 (cortisol level, 4 ${\leq}$ or < $6{\mu}g/dl$) and group 4 (cortisol level, $6{\mu}g/dl$ ${\leq}$). The patterns of progesterone were not different in four cortisol groups. The average numbers of retrieved oocytes was not different in four cortisol groups. These results suggest that different cortisol levels on estrus dogs do not affect ovulation, number of ovulated oocytes and progesterone changes.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.181-186
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• 2007

Inhibitor of DNA binding protein or inhibitor of differentiation(Id) is largely considered as positive and/or negative regulators of proliferation, differentiation, angiogeneisis, and apoptosis. The four Id genes(Id1, Id2, Id3, and Id4) were known in mammals. However, little is known about the expression and function of these genes in reproductive physiology. Among them, this study was conducted to analyze the expression pattern of Id3 mRNA on folliculogenesis in rat ovary. After PMSG administration, the ovaries were obtained at 3, 6, 12, 24, 36, and 48hrs, fixed, dehydrated, and paraffin embedded. For in situ hybridization, anti-sense and sense Id3 cRNA probes were prepared and applied to the ovarian section. The ovarian sections were coated with NTB-2 emulsion. After that, the slides were developed and counterstained with hematoxylin and eosin staining. The hybridization signal was estimated on a scale of 1+ to 4+. In oocyte, the intensity of Id3 mRNA in primordial and primary follicles was scored at ${\geq}2+$, but the intensity was less than 1+ in secondary, dominant, and preovulatory follicles. In granulosa cells, the Id3 mRNA was strongly expressed(3+ or 4+) in dominant and preovulatory follicles. Taken together, Id3 mRNA was expressed specifically at follicle stages and follicular tissue and might be closely related with follicle development.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.3
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• pp.155-168
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• 2004

Objective: Melatonin, which is secreted by pineal gland play an important role in the regulation of ovarian function via seasonal rhythm and sleep in most mammals. It also has a role in the protection of cells by removing toxic oxygen free radicals brought about by metabolism. In the present study, effects of melatonin on the mouse oocyte maturation were examined using two different culture conditions provided with 5% or 21% oxygen concentration. Material and Method: Immature mouse oocytes were obtained from the ovarian follicles of $3{\sim}4$ weeks old ICR strain mice intraperitoneally injected with 5 I.U. PMSG 44 hour before. Under stereomicroscope, morphologically healthy oocytes with distinct germinal vesicle (GV) were liberated from the graafian follicles and collected using mouth-controlled micropipette. They were then cultured for 17 hour at $37^{circ}C$, 5% $CO_2$ and 21% $O_2$ (95% air) or 5% $CO_2$, 5% $O_2$ and 90% $N_2$. New modified Hank's balanced salt solution (New MHBS) was used as a culture medium throughout the experiments. Effects of melatonin were examined at a concentration of $0.0001{\mu}M$, $0.01{\mu}M$ or $1.0{\mu}M$. For the prevention of spontaneous maturation of immature oocytes during culture, dibutyryl cyclic AMP (dbcAMP) and/or hypoxanthine were included in the medium. Results: Under 21% oxygen condition, oocytes cultured in the presence of $0.01{\mu}M$ melatonin showed a significantly higher maturation rates, in terms of germinal vesicle breakdown (95.0% vs 89.0%) and polar body formation (88.1% vs 75.4%), compared to those cultured with $0.0001{\mu}M$ or $1.0{\mu}M$ melatonin. However, no difference was observed in oocytes cultured under 5% oxygen whether they were treated with melatonin or not. In the presence of $0.01{\mu}M$ melatonin, oocytes either cultured under 21% or 5% oxygen exhibited no difference in the polar body formation (85.6% vs 86.7%). However, in the absence of melatonin, oocytes cultured under 21% oxygen exhibited lower polar body formation (74.7%). When oocytes were cultured in the presence of dbcAMP alone or with varying concentrations of melatonin, those treated with both compounds always showed better maturation, i.e., germinal vesicle breakdown and polar body formation, compared to those cultured with dbcAMP alone. At the same concentration of melatonin, however, oocytes exposed to 21% oxygen showed poor maturation than those to 5% oxygen. Similar results were obtained from the experiments using hypoxanthine instead of dbcAMP. Conclusion: Based upon these results, it is suggested that melatonin could enhance the meiotic maturation of mouse oocytes under 21% oxygen concentration, and release oocytes from the meiotic arrest by dbcAMP or hypoxanthine regardless of the concentration of oxygen, probably via the removal of oxygen free radicals.

• Animal Bioscience
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• v.34 no.6
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• pp.975-984
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• 2021

Objective: Inbreeding depression of reproduction is a major concern in the conservation of native chicken genetic resources. Here, based on the successful development of strongly inbred (Sinb) and weakly inbred (Winb) Langshan chickens, we aimed to evaluate inbreeding effects on reproductive traits and identify candidate genes involved in inbreeding depression of reproduction in Langshan chickens. Methods: A two-sample t-test was performed to estimate the differences in phenotypic values of reproductive traits between Sinb and Winb chicken groups. Three healthy chickens with reproductive trait values around the group mean values were selected from each of the groups. Differences in ovarian and hypothalamus transcriptomes between the two groups of chickens were analyzed by RNA sequencing (RNA-Seq). Results: The Sinb chicken group showed an obvious inbreeding depression in reproduction, especially for traits of age at the first egg and egg number at 300 days (p<0.01). Furthermore, 68 and 618 differentially expressed genes (DEGs) were obtained in the hypothalamus and ovary between the two chicken groups, respectively. In the hypothalamus, DEGs were mainly enriched in the pathways related to vitamin metabolism, signal transduction and development of the reproductive system, such as the riboflavin metabolism, Wnt signaling pathway, extracellular matrix-receptor interaction and focal adhesion pathways, including stimulated by retinoic acid 6, serpin family F member 1, secreted frizzled related protein 2, Wnt family member 6, and frizzled class receptor 4 genes. In the ovary, DEGs were significantly enriched in pathways associated with basic metabolism, including amino acid metabolism, oxidative phosphorylation, and glycosaminoglycan degradation. A series of key DEGs involved in folate biosynthesis (gamma-glutamyl hydrolase, guanosine triphosphate cyclohydrolase 1), oocyte meiosis and ovarian function (cytoplasmic polyadenylation element binding protein 1, structural maintenance of chromosomes 1B, and speedy/RINGO cell cycle regulator family member A), spermatogenesis and male fertility (prostaglandin D2 synthase 21 kDa), Mov10 RISC complex RNA helicase like 1, and deuterosome assembly protein 1) were identified, and these may play important roles in inbreeding depression in reproduction. Conclusion: The results improve our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction and provide a theoretical basis for the conservation of species resources.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.314-329
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• 2022

BACKGROUND/OBJECTIVES: Oocyte lipid droplets play a crucial role in meiosis and embryo development. Biotin is associated with fatty acid synthesis and is the coenzyme for acetyl-CoA carboxylase (ACC). The effects of a biotin deficiency on the oocyte lipid metabolism remain unknown. This study examined the effects of a biotin deficiency and its replenishment on murine 1) oocyte lipid droplet levels, 2) ovary lipid metabolism, and 3) oocyte meiosis. MATERIALS/METHODS: Mice were divided into 3 groups: control, biotin deficient (BD), and recovery groups. The control and BD groups were fed a control diet or BD diet (0.004 or 0 g biotin/kg), respectively. The recovery group mice were fed a BD diet until day 21, and were then fed the control diet from days 22 to 64. This study then quantified the oocyte lipid droplet levels, assessed the oocyte mitochondrial function, and examined the ability of oocytes to undergo meiosis. Ovarian phosphorylated ACC (p-ACC), lipogenesis, β-oxidation, and ATP production-related genes were evaluated. RESULTS: The BD group showed a decrease in lipid droplets and mitochondrial membrane potential and increased p-ACC levels. In the recovery group, the hepatic biotin concentration, ovarian p-ACC levels, and mitochondrial membrane potential were restored to the control group levels. On the other hand, the quantity of lipid droplets in the recovery group was not restored to the control levels. Furthermore, the percentage of oocytes with meiotic abnormalities was higher in the recovery group than in the control group. CONCLUSIONS: A biotin deficiency reduced the oocyte lipid droplet levels by downregulating lipogenesis. The decreased lipid droplets and increased oocyte meiosis failure were not fully restored, even though the biotin nutrition status and gene expression of lipid metabolism was resumed. These results suggest that a biotin deficiency remains robust and can be long-lasting. Biotin might play a crucial role in maintaining the oocyte quality.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.307-322
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• 1996

The corpus luteum (CL) is formed by the action of a surge of luteinizing hormone (LH) on the pre-ovulatory follicle. Luteal cells derived from granulosa and theca interna cells continue to secrete progesterone for about two weeks. LH in domestic animals is essential for the normal secretion of progesterone at all stages of the luteal phase. For this process in the rodents, 20$\alpha$-hydroxysteroid dehydrogenase (20$\alpha$-HSD) is indispensable. 20$\alpha$-HSD is an enzyme to be a biologically inactive steroid. This enzyme plays a critical role in the regulation of the rat luteal function and reported to be present in steroid-producing tissues such as the testis and adrenal gland. We have purified 20$\alpha$-HSD and found two distinct 20$\alpha$-HSD molecules (HSD-1 and HSD-2). Their molecular weights are both estimated to be 33kd.The amino acid compositions of HSD-1 and HSD-2 are mostly similar, but there is a slight difference in the content of lysine. We demonstrated that 1) CL of previous generations contribute more to whole ovarian 20$\alpha$-HSD activity, 2) newly formed corpora lutea contain only 20$\alpha$-HSD-1 activity, and 3) old CL express activities of each HSD isozyme as shown in the luteal tissue of cycling rats on the day of diestrus where only degenerating old CL exist. The increase in 20$\alpha$-HSD activity identified seems to be related to the increase in the numbers of 20$\alpha$-HSD-positive cells. Interestingly, 20$\alpha$-HSD-1 activities were strongly found in the follicle fluids and theca interna cells by immunohistochemical study. Thus, the activity of 20$\alpha$-HSD may be related to a survival mechanism of those luteal cells and follicles remaining in the ovaries. Luteal cells arise from two sources. The small luteal cells are all of theca cell origin, while the large luteal cells are mainly of granulosa cell origin. CL of Korean Native Cattle, as those of other animal species, contains two morphologycally and functionally distinct luteal cell populations, such as small and large luteal cells as well as nonluteal cells. In all reproductive states except in the late luteal phase, the bovine CL also contained more small luteal cells than large luteal cells. Luteal tissue secretes a variety of growth factors (proteins) and the pattern of secretion changes during all stages of the luteal phase. These growth factors could be important in regulating the function of the bovine corpus luteum and may act in a potential endocrine autocrine and paracrine mechanisms. Therefore, further work has to be done to elucidate the role of growth factors in the ovary, especially in the corpus luterum. Interest should be focussed on interaction of these growth factors in the regulation of luteal cell and the localization of cytokine synthesis in differnet luteal cells.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5445-5450
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• 2012

Although benign uterine leiomyomata (LMA) is the most common reproductive tumor in premenopausal women, its etiology is largely unknown. We aimed in the present study to demonstrate the potential role of environmental factors with estrogenic activity in tumor etiology by focusing on the role of aryl hydrocarbon receptor (AhR) which mediates the effects of many environmental endocrine disruptors and contributes to the loss of normal ovarian function in polluted environments. This case-control study aimed to compare the interactions between AhR and lifestyle factors in a clinical setting for the first time among 138 newly diagnosed LMA patients and 138 normal controls who lived in Tehran and Mashhad, respectively, during the last 10 years. To conduct immunohistochemical studies using appropriate monoclonal antibodies, 30 cases were selected retrospectively from 2009-2011 from the pathology departments of two university hospitals in Tehran. Although the levels of sex steroid receptors were similar in adjacent myometrium and uterine leiomyomas of all cases, AhR was significantly overexpressed (p=0.034, OR=1.667) in uterine LMA and this overexpression was correlated with living in Tehran [(p=0.04, OR=16 (1.216-210.58)], smoking[P=0.04, OR=2.085 (1.29-3.371)], living near polycyclic aromative hydrocarbon producing companies [p=0.007, OR=2.22 (1.256-3.926)] and eating grilled meat [p=0.042, OR=1.28 (1.92-3.842)]. Our study contributes to the understanding of the effects of EDCs on AhR levels as well as women's health and points out possible risk factors for the development and growth of uterine LMA. It seems that the development of LMA could be the result of interactions between hormonal and environmental factors.

• Journal of Embryo Transfer
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• v.26 no.1
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• pp.53-56
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• 2011

Infertility of the pig is directly affects on economic loss and failure of the embryo transfer. In the present case report, we show one rare case of porcine infertility resulted from oviductal obstruction. A gilt showing normal heat behaviors was selected as a recipient of embryo transfer. During the laparotomy surgery, abnormality of the reproductive tract was founded. Several large sized cyst-like structures were founded on infundibulum and body of uterus. Severe enlargement of oviduct represents that obstruction of the oviduct. Sign of fibrosis on the surface of uterus and other internal organs revealed that the obstruction was come arise from prior peritonitis. Mild neutropenia and elevated number of monocytes, eosinophils and platelets in blood smear represent that the peritonitis might be due to chronic parasitic infection. Ovarian function was seems to be normal due to blood progesterone concentration was higher than basal level. The pig was culled because she cannot be recovered by surgical or hormonal treatment.

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.917-924
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• 1997

Estrus cycle of cow, season and follicldar stimulating treatment, having an effect on the number of follicle, are investigated for the oocyte recovery rate in ovum pick-up(OPU). The number of follicle aspirated and oocyte collected on the different days of estrus cycle(D 4~5, D 9~10 and D 14~15) were not significantly different among the groups. The higher number of viable oocytes were produced on Jan-May(79.0%) than Jun-Aug(33.3%) by OPU in cow. The number of follicle and aspirated oocyte in cows treated FSH or PMSG combined with bovine somatotropin(bST) were 1.2~1.5 times higher than in cows treated alone follicular stimulating hormone(FSH) or pregnant mare serum gonadotropin(PMSG). In conclusion, OPU can be repeatedly practiced 2 or 3 times in an estrus cycle. In addition, the high environmental temperature is not good for ovarian function of cow and the bST co-treatment with FSH or PMSG is increasing the number of aspiratable follicle.

• Clinical and Experimental Pediatrics
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• v.58 no.1
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• pp.1-7
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• 2015

Gonadotropin-releasing hormone analogs (GnRHa) are widely used to treat central precocious puberty (CPP). The efficacy and safety of GnRHa treatment are known, but concerns regarding long-term complications are increasing. Follow-up observation results after GnRHa treatment cessation in female CPP patients up to adulthood showed that treatment (especially <6 years) was beneficial for final adult height relative to that of pretreated or untreated patients. Puberty was recovered within 1 year after GnRHa treatment discontinuation, and there were no abnormalities in reproductive function. CPP patients had a relatively high body mass index (BMI) at the time of CPP diagnosis, but BMI standard deviation score maintenance during GnRHa treatment seemed to prevent the aggravation of obesity in many cases. Bone mineral density decreases during GnRHa treatment but recovers to normal afterwards, and peak bone mass formation through bone mineral accretion during puberty is not affected. Recent studies reported a high prevalence of polycystic ovarian syndrome in CPP patients after GnRHa treatment, but it remains unclear whether the cause is the reproductive mechanism of CPP or GnRHa treatment itself. Studies of the psychosocial effects on CPP patients after GnRHa treatment are very limited. Some studies have reported decreases in psychosocial problems after GnRHa treatment. Overall, GnRHa seems effective and safe for CPP patients, based on long-term follow-up studies. There have been only a few long-term studies on GnRHa treatment in CPP patients in Korea; therefore, additional long-term follow-up investigations are needed to establish the efficacy and safety of GnRHa in the Korean population.