• Journal of Embryo Transfer
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• v.24 no.1
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• pp.1-14
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• 2009

Ovarian cancer is a significant cause of cancer-related death in women, but the main biological causes remain open questions. Hormonal factors have been considered to be an important determinant causing ovarian cancer. Recent studies have shown that gonadotropin-releasing hormone (GnRH)-I and its analogs have clinically therapeutic value in the treatment of ovarian cancer. In addition, numerous studies have shown that the potential of GnRH-II in normal reproductive system or reproductive disorder. GnRH-I receptors have been detected in approximately 80% of ovarian cancer biopsy specimens as well as normal ovarian epithelial cells and immortalized ovarian surface epithelium cells. GnRH-II receptors have also been found to be more widely expressed than GnRH-I receptors in mammals, suggesting that GnRH receptors may have additional functions in reproductive system including ovarian cancer. The signal transduction pathway following the binding of GnRH to GnRH receptor has been extensively studied. The activation of protein kinase A/C (PKA/PKC) pathway is involved in the GnRH-I induced anti-proliferative effect in ovarian cancer cells. In addition, GnRH-I induced mitogen-activated protein kinase (MAPK) activation plays a role in anti-proliferative effect and apoptosis in ovarian cancer cells and the activation of transcriptional factors related to cellular responses. However, the role of GnRH-I and II receptors, there are discrepancies between previous reports. In this review, the role of GnRH in ovarian cancer and the mechanisms to induce anti-proliferation were evaluated.

• Safety and Health at Work
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• v.11 no.2
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• pp.152-158
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• 2020

Background: The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) was developed to enhance chemical classification and hazard communication systems worldwide. However, some of the elements such as building blocks and data sources have the potential to cause "disharmony" to the GHS, particularly in its classification results. It is known that some countries have developed their own lists of classified chemicals in accordance with the GHS to "standardize" the classification results within their respective countries. However, the lists of classified chemicals may not be consistent among these countries. Method: In this study, the lists of classified chemicals developed by the European Union, Japan, Malaysia, and New Zealand were selected for comparison of classification results for carcinogenicity, germ cell mutagenicity, and reproductive toxicity. Results: The findings show that only 54%, 66%, and 37% of the classification results for each Carcinogen, Mutagen and Reproductive toxicants hazard classes, respectively are the same among the selected countries. This indicates a "moderate" level of consistency among the classified chemicals lists. Conclusion: By using classification results for the carcinogenicity, germ cell mutagenicity, and reproductive toxicity hazard classes, this study demonstrates the "disharmony" in the classification results among the selected countries. We believe that the findings of this study deserve the attention of the relevant international bodies.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.2
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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.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.2
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• pp.125-134
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• 2024

Objective: Vitamin D deficiency is a major problem for human health worldwide. The mechanisms of vitamin D in the male reproductive system are unknown. After coronavirus disease 2019 (COVID-19) vaccines were developed, doubts were raised about their possible effects on male fertility. Based on vitamin D's function in the immune system, its potential role as an adjuvant for COVID-19 vaccines is intriguing. The aims of this study were to assess the effects of vitamin D first on sperm parameters and sex hormones, and then as an immune adjuvant on sperm parameters and sex hormones after study participants had received their second doses of COVID-19 vaccines. Methods: Phase 1 (before the COVID-19 pandemic) included 72 men with idiopathic infertility, and phase 2 had 64 participants who received two doses of COVID-19 vaccines. Both groups were instructed to take 50,000 IU of vitamin D twice monthly for 3 months. Sperm parameters and sex hormones were assessed pre-and post-supplementation. Results: Regular vitamin D intake for 3 months significantly increased the participants' vitamin D levels (p=0.0001). Both phases showed a positive correlation between vitamin D intake and sperm parameters. Vaccination had no negative effects on sperm parameters and sex hormones. Vitamin D was associated with follicle-stimulating hormone (p=0.02) and testosterone (p=0.0001) in phase 2 after treatment. Conclusion: Our results support vitamin D supplementation as an immune adjunct to COVID-19 vaccination for improving sperm parameters and hormone levels. COVID-19 vaccination is not harmful for male fertility potential, and vitamin D is an effective factor for male fertility.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.366-378
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• 2024

Application of commercial hormone failed to promote breeding in certain Pangasius species due to the differences of gonadotropin-releasing hormone specific peptide with species-specific bioactivities. Gonadotropin-releasing hormone (GnRH) is a hypothalamic decapeptide in the reproductive system that plays a crucial role in the regulation of reproductive processes. This study was performed to determine and analyse the GnRH genes from commercially important Pangasius sp., Pangasianodon hypophthalmus and Pangasius nasutus. The GnRH1 and GnRH2 genes were amplified and cloned into TOPO vector, followed by phylogenetic analysis of a complete open reading frame (ORF) of GnRH genes. The GnRH1 and GnRH2 genes of P. hypophthalmus and P. nasutus were detected at 300 bp and 360 bp, encoded for 81 and 87 amino acids, respectively. Amino acid sequence identities revealed high homology of P. hypophthalmus and P. nasutus GnRH1 and GnRH2 genes in comparison with other fish and vertebrates. Phylogenetic tree showed that fish from various families were aggregated into a group of the same order due to their highest identity similarities. It revealed that the vertebrate formed clusters and are grouped according to their GnRH decapeptide and GnRH-associated peptide (GAP) region, indicating a close relationship among GnRH decapeptide and GAP in different vertebrate species.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.283.1-283.1
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• 2002

The adverse health effects on humans and domestic and wildlife species by exposing to environmental contaminants. which interact with the endocrine system. have he en treated as an important issue without hesitation throughout the 1990s. The chemicals with practical and/or potential interfering actions with the endocrine system functions are called endocrine disrupting chemicals (EDCs). (omitted)

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.89-90
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• 2004

• 대한생식의학회:학술대회논문집
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• 2001.11a
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• pp.86.1-86.1
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• 2001

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.123-124
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• 2003

• 대한생식의학회:학술대회논문집
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• 2003.12a
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• pp.99.1-99.1
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• 2003