• Toxicological Research
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• 제26권1호
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• pp.67-74
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• 2010

The present study was conducted to obtain information on the effects of amitraz on reproductive and developmental parameters in rats. The test chemical was administered via the drinking water containing 0, 40, 120, and 360 ppm to male rats from 2 weeks before mating to the end of 14-day mating period and to females from 2 weeks before mating, throughout mating, gestation and up to lactational day 4. During the study period, clinical signs, body weights, food intake, organ weights, reproductive and littering findings, necropsy findings, sperm parameters, and histopathology were examined. At 360 ppm, decreases in the body weight gain, food consumption, and the number of live pups and an increase in the post-implantation loss were observed. In addition, decreases in the seminal vesicle weight and sperm motility were found in males. At 120 ppm, a decrease in the food consumption was found transiently in both males and females, but no reproductive and developmental toxicity was observed in both sexes. There were no signs of either general or reproductive and developmental toxicity in the 40 ppm group. Based on these results, it was concluded that the repeated oral administration of amitraz to rats resulted in a decrease in the food consumption at 120 ppm and decreases in the seminal vesicle weight, sperm motility, and the number of live pups and an increase in the post-implantation loss at 360 ppm in rats. Under these experimental conditions, the no-observed-adverse-effect level (NOAEL) of amitraz for general and reproduction/developmental toxicity was believed to be 120 ppm, and the no-observed-effect level (NOEL) of amitraz was believed to be 40 ppm in rats.

• Clinical and Experimental Reproductive Medicine
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• 제38권3호
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• pp.135-141
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• 2011

Objective: Ovarian angiogenesis plays an important role in folliculogenesis. However, little is known about the expression of angiogenic factors during follicular development according to female age. Stromal cell derived factor-$1{\alpha}$ (SDF-$1{\alpha}$) plays a role in granulosa cell survival and embryo quality as an angiogenic chemokine. Leptin is also involved in folliculogenesis and angiogenesis. This study examined expression of SDF-$1{\alpha}$ and leptin, and their effects on the expression of angiogenic factors in the ovary during follicular development according to female age. Methods: Ovaries were collected from C57BL mice of two age groups (6-9 weeks and 24-26 weeks) at 6, 12, 24, and 48 hours after 5 IU pregnant mare's serum gonadotropin (PMSG) injection. The expression of ovarian SDF-$1{\alpha}$ and leptin mRNA was evaluated by RT-PCR. In the organ culture experiment, the ovaries were cultured in transwell permeable supports with Waymouth's medium treated with various doses of SDF-$1{\alpha}$(50-200 ng/mL) or leptin (0.01-1 ${\mu}g$/mL) for 7 days. Then, mRNA expression of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), and visfatin were examined in the cultured ovaries. Results: Expression of SDF-$1{\alpha}$ and leptin in the ovary was significantly lower in the aged mouse group compared to the young mouse group ($p$ <0.05). Expression of these two factors increased with follicular development after PMSG administration. SDF-$1{\alpha}$ treatment stimulated visfatin expression in a dose-dependent manner, while leptin treatment significantly increased eNOS expression. Conclusion: These results suggest that decrease of ovarian SDF-$1{\alpha}$ and leptin expression may be associated with aging-related reduction of ovarian function. SDF-$1{\alpha}$ and leptin may play a role in follicular development by regulating the expression of angiogenic factors in mouse ovaries.

• 대한예방한의학회지
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• 제12권1호
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• pp.89-102
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• 2008

Purpose : The experiments was undertaken to evaluate the effects of herbal medicine, Ojeoksan, in pregnant rats Methods : Female Sprague-Dawley rats were orally administered with the Ojeoksan at dose of 5mg/kg/day for 20 days. Pregnant rats were sacrificed at 20th day of gestation, and observed internal and reproductive organs. Approximately live fetuses in the 20th day of gestation were randomly selected and fixed in 95% ethanol. Results : Maternal body weight of Ojeoksan treated group has a tendency to increase compared to that of control group. There were no significant difference in internal and reproductive organs. There were no significant changes between two groups in blood chemistry and hematological values. There were no significant changes in number of corpus luteum, implantation, live fetuses and sex ratio. But Ojeoksan administered group showed higher delivery rate, early resorption rate than the control group. Also Ojeoksan administered group showed higher implantation rate, late resorption rate than the control group. Conclusion : From these results, it can be concluded that Ojeoksan showed no toxicity effects on maternal body weight and number of live fetuses. There were no significant changes in organ weight, hematological data, reproductive organs. We need more precise study to investigate the mechanism of early or late resoption by the herbal medicines such as Ojeoksan.

• Toxicological Research
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• 제25권4호
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• pp.203-207
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• 2009

Present study was conducted to investigate potential effects of epichlorohydrin on testicular and epididymal function in male rats. The test chemical was administered to adult male rats by gavage at dose levels of 0, 3.125, 12.5, and 50 mg/kg/day for 7 days. Testicular and epididymal function were assessed by measurement of reproductive organ weight, testicular spermatid count, epididymal sperm count, motility and morphology, and histopathology in rats. At 50 mg/kg, a decrease in the sperm motility and an increase in the incidence of sperm abnormalities were observed. Histopathological examinations revealed an increase in the incidence of histopathological changes including cell debris in the ducts, vacuolization of the epithelial cells, oligospermia, and epithelial disruption in the proximal caput epididymidis. At 12.5 mg/kg, an increase in the incidence of histopathological changes of the epididymidis was found. There were no treatment-related effects at 3.125 mg/kg. These results show that 7-day repeated oral administration of epichlorohydrin to male rats results in adverse effects on sperm motility, sperm morphology, and epididymal histology at $\geq$ 12.5 mg/kg/day.

• Toxicological Research
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• 제19권1호
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• pp.13-19
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• 2003

GX-12 is a naked DNA vaccine developed by the DongA Pharmaceutical Co. Ltd. and Genexine for the treatment of HIV infection. This study was peformed to evaluate the biodistribution and expression of GX-12 mRNA in gonadal tissues, and to investigate the histopathological changes after the repeated intramuscular injection. GX-12 (400 $\mu\textrm{g}$/head) was injected into the left anterior tibialis once a week for four weeks. On day 1, 5, 15, 30 and 45 after the final administration, gonadal tissues (testes, epididymis, seminal vesicles, penis, prostate glands, ovaries, vagina, uterus) and the injection site (muscle) were harvested and examined for the expression of mRNA by RT-PCR. In addition, histopathological examination was peformed at each time point. At the injection site, mRNA expression of GX-12 was detected only at early time points (1 ~ 15 days after injection) but not thereafter. However, in gonadal tissues, mRNA expression was not identified at all time points both in male and female rats. There were no histopathological changes in all reproductive organs and muscle. Based on these results, it is unlikely that the plasmid DNAs of GX-12 was distributed to- and expressed in gonadal tissues, suggesting that the chance of germline integration and transmission is negligible.

• 한국작물학회지
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• 제48권1호
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• pp.8-12
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• 2003

To find out the relationship between pod development and cytokinin contents during reproductive stage of peanut, the cytokinin contents, trans-zeatin ribo-side (t-ZR) and dihydrozeatin riboside (diZR), were investigated at 0, 7, 14, 21 and 28 days after flowering (DAF). The amounts of t-ZR and diZR in cotyledon and first branch among primary branches were 3, 448 pmol/g (FW) and 4, 824 p/g (FW), respectively, which were higher than those of other branches. The t-ZR and diZR contents of lower parts on the branch from cotyledon node at 7 DAF were 579 pmol/g (FW) and 2, 028 pmol/g (FW), respectively, which were higher than those of upper parts. The cytokinin contents of reproductive organs as flowering progressed were increased at 0 and 14 DAF on branch and position of node. The cytokinin contents of upper part with pruning the lower part on the branch from cotyledon node were high 112-337% at 7 DAF and 14 DAF compared with those of the control. In case of remove the upper part of the first internode on main axis, t-ZR contents was 4.7 times higher than diZR contents at 7 DAF. The pod setting rate of flower and position on the branch from cotyledon node was closely related to the cytokinin contents during floral reproductive stage.

• Reproductive and Developmental Biology
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• 제34권2호
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• pp.103-109
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• 2010

Functional regulation of a specific tissue or organ is controlled by a number of ways, including local cell-cell interaction. Of several forms of cell-cell junctional complexes, gap junctions are caught a great attention due to a formation of direct linkage between neighboring cells. Gap junctions are consisted of connexin (Cx) isoforms. In the present study, we evaluated expressional profiling of Cx isoforms in the rat initial segment (IS) of the male reproductive tract at different postnatal ages. The presence and expression of 13 Cx isoform mRNAs were determined by semi-quantitative real-time PCR analyses. A total of 8 Cx isoform mRNAs were detected in the IS of the male rats during postnatal development. The highest level of Cx30.3 mRNA was found at 5 months of age, while abundance of Cx31 mRNA was the highest at 1 year of age. Expression of Cx31.1 gene was relatively consistent during the postnatal development. Fluctuation of Cx32 and 37 gene expression was observed during the postnatal period. Significant elevation of Cx40 mRNA abundance was detected at 25 days of age and older ages. Expression patterns of Cx43 and 45 genes were similar with the highest level at 2 weeks of age, followed by gradual decreases at older ages. These results indicate differential regulation on expression of Cx isoforms in the rat IS during postnatal development. A complicated regulation of gene expression of Cx isoforms in the IS at different postnatal ages is suggested.

• Clinical and Experimental Reproductive Medicine
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• 제13권2호
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• pp.187-193
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• 1986

The purpose of this study was to establish optimal conditions for progesterone receptor assay using rat uterus, therby applying this system to understand action mechanism of progesterone in female reproductive organ and to evaluate physiological and pathological conditions in female reproduction. The results obtained were as follows 1. $^3H-R5020$ seemed to be more stable than 3H-progesterone as a ligand. 2. Optimal incubation time for ligand and receptor binding was 4-5 hrs at $4^{\circ}C$. 3. For the separation of bond and free ligand, optimal charcoal incubation time was 20 mins. 4. 2-3 mg cytosolic protein/ml was optimal for the binding of ligand. 5. Endogenous progesterone did not influence binding of ligand and receptor unless endogenous progesterone levels were extremely high as in case of pregnancy. 6. Dissociation rate for progesterone receptor was 1.22 nM. 7. $^3H-R5020$ did not bind to corticoid binding globulin (CBG), suggesting that addition of cortisol is saturate CBG was, not necessary as far as $^3H-R5020$ was used as a radioligand. It is, therefore, considered that this assay system established with these conditions might be used for the research as well as clinical routine purposes.

• Journal of Veterinary Science
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• 제25권3호
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• pp.40.1-40.19
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• 2024

Importance: The creation of robust maternal-embryonic interactions and implantation models is important for comprehending the early stages of embryonic development and reproductive disorders. Traditional two-dimensional (2D) cell culture systems often fail to accurately mimic the highly complex in vivo conditions. The employment of three-dimensional (3D) organoids has emerged as a promising strategy to overcome these limitations in recent years. The advancements in the field of organoid technology have opened new avenues for studying the physiology and diseases affecting female reproductive tract. Observations: This review summarizes the current strategies and advancements in the field of 3D organoids to establish maternal-embryonic interaction and implantation models for use in research and personalized medicine in assisted reproductive technology. The concepts of endometrial organoids, menstrual blood flow organoids, placental trophoblast organoids, stem cell-derived blastoids, and in vitro-generated embryo models are discussed in detail. We show the incorportaion of organoid systems and microfluidic technology to enhance tissue performance and precise management of the cellular surroundings. Conclusions and Relevance: This review provides insights into the future direction of modeling maternal-embryonic interaction research and its combination with other powerful technologies to interfere with this dialogue either by promoting or hindering it for improving fertility or methods for contraception, respectively. The merging of organoid systems with microfluidics facilitates the creation of sophisticated and functional organoid models, enhancing insights into organ development, disease mechanisms, and personalized medical investigations.

• 한국발생생물학회지:발생과생식
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• 제28권1호
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• pp.1-12
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• 2024

Gonadotropin-releasing hormone (GnRH), a critical hormone produced in the hypothalamus, is essential for regulating reproductive processes. It has also been demonstrated the presence of GnRH and its receptors (GnRHR) in ovarian and uterine tissues, but little was known about the regulation mechanism of their expression in these organs and ovarian aging. Therefore, the aim of this study was to investigate the expression of GnRHR in the ovary and uterus of mice, particularly after high-dose gonadotropin treatments and in relation to aging. Quantitative real-time-PCR (qRT-PCR) revealed that pituitary gland had the highest GnRHR expression in both young and aged mice. In addition, liver expression was higher in young mice, whereas thymus expression was higher in aged mice. GnRHR mRNA was present in the ovaries of both young and aged mice but nearly undetectable in the uterus of aged mice. We next examined the expression of GnRHR in the ovary and uterus in response to high-dose administration of pregnant mare serum gonadotropin (PMSG). After PMSG administration, GnRH mRNA levels were significantly decreased in the ovary but increased in the uterus. The expression of GnRH mRNA in these organs showed opposite trends to that of GnRHR expression. These results suggest the involvement of GnRH in age-related reproductive decline and the potential effects of high-dose gonadotropin treatments on reproductive organ function.