• Journal of Environmental Health Sciences
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• v.41 no.3
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• pp.147-162
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• 2015

Objectives: The objective of this review was to summarize the primary role of three representative endocrine axes in aquatic vertebrates and discuss the effects on endocrine systems and their interactions in teleost fish after exposure to environmental contaminants. Methods: We summarized individual traits and mechanisms for hormonal and transcriptional interactions between the hypothalamic-pituitary-gonad (HPG), hypothalamic-pituitary-thyroid (HPT), and hypothalamic-pituitary-adrenal (HPA) axes in fish. We also provided a brief discussion on the effects of nonylphenol-induced toxicity on endocrine systems and their interactions in fish as a demonstration of holistic explanation. Results: Currently-available data showed that thyroid dysfunction is associated with reproductive toxicity due to changes in steroidogenic gene expressions and sex hormone levels as well as gonad glands in fish. As an example, we demonstrated that exposure to nonylphenol could induce estrogenicity in male fish by decreasing thyroid hormones, which contributes to increased aromatase expression. Although the mechanisms are complicated and involved in multiple ways, a number of studies have shown that sex steroids influence the HPT axis or the HPA axis in fish, indicating bi-directional crosstalk. Critically missing is information on the primary target or toxicity mechanisms of environmental contaminants among the three endocrine axes, so further studies are needed to explore those possibilities. Conclusions: This review highlights the interactions between the HPG, HPT, and HPA axes in fish in order to better understand how these endocrine systems could interact with each other in situations of exposure to endocrine disrupting chemicals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.41-47
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• 2017

Perhaps the most common type of reproductive dysfunction in captive fish is failure of females to undergo final oocyte maturation and thus to ovulate and spawn. The success of aquaculture could therefore be improved by developing techniques to enhance natural spawning, artificial maturation, and/or to induce ovulation in farmed fish. This study aimed to investigate the effects of prostaglandin $E_2$ ($PGE_2$) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) on in vitro oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation in the marine fish Chasmichthys dolichognathus. Post-vitellogenic follicles (0.80-0.94 mm diameter oocytes) were incubated with $PGE_2$ or $PGF_{2{\alpha}}$ at concentrations of 5, 50, or 500 ng/mL for 24 hours. A significant increase in GVBD was seen in 0.84 mm and 0.94 mm oocytes incubated with 50 ng/mL $PGE_2$ compared with the control. There was no significant increase in GVBD in any of the other experimental conditions (5 or 500 ng/mL $PGE_2$ or 5, 50, or 500 ng/mL $PGF_{2{\alpha}}$). Neither of the prostaglandins induced ovulation at the concentrations tested.These results suggest that GVBD was induced by incubation with 50 ng/mL $PGE_2$.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.515-523
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• 1990

Plasma progesterone concentrations in 44 suckling Korean native cows were determined to monitor ovarian activity postpartum by radioimmunoassay. Blood samples were collected in 3 day intervals from 15 to 80 days postpartum. The ovaries and uterus were examined in 6 day intervals by rectal palpation. Results are summaried as follows: 1. The cows were qualified into four categories; Type I(normal): cyclic changes in plasma progesterone concentrations appear within 45 days postpartum(35 cows, 79.5%), Type II(cycle delayed): delayed resumption of ovarian activity by 55 days postpartum(5 cows, 11. 4%), Type III(cycle ceased with low progesterone): plasma progesterone concentrations remained low(${\leq}1ng/ml$) until 80 days postpartum(3 cows, 6.8%), Type IV(cycle ceased with high progesterone): plasma progesterone concentrations after 30 days remained high(${\geq}4.0ng/ml$) until 80 days postpartum(1 cow, 2.3%). 2. Out of the cows classified Type II and III, 7 cows had inactive ovaries and a cow had follicular cyst by rectal palpation. The cow of Type IV was diagnosed as bearing persistent corpus luteum by rectal palpation. 3. About 82% of the cows showed significant rises in plasma progesterone concentrations prior to 50 days postpartum and the cows of Type II and III resumed cycles in 31. 6(range 17~55) days after calving. However, 43.2% resumed cycles in 50 days postpartum by estrus signs. These results indicated that plasma progesterone concentrations assessed by radioimmunoassay can be utilized for monitoring postpartum ovarian activity and would be helpful for the early detection of ovarian dysfunction in the Korean native cow.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.4
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• pp.341-354
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• 2021

Cardamonin (CARD) is a chalconoid with anti-inflammatory and antioxidant properties, and it is present in several plants. We sought to explore whether CARD exerts any positive effects against hyperglycemia-induced testicular dysfunction caused by type 2 diabetes and aimed to identify its possible intracellular pathways. Adult male rats were subdivided into six groups: control, CARD, diabetic (DM), DM + glibenclamide (GLIB), DM + CARD and DM + GLIB + CARD. Type 2 DM induced a significant increase in blood glucose and insulin resistance, along with diminished serum insulin, testosterone and gonadotropins levels, which were associated with the impairment of key testicular androgenic enzymes and cellular redox balance. Administration of CARD at a dose of 80 mg/kg for 4 weeks effectively normalized all of these alterations, and the improvement was confirmed by epididymal sperm analysis. After treatment with CARD, the pathological changes in spermatogenic tubules were markedly improved. Significantly, CARD upregulated testicular glucose transporter-8 (GLUT-8) expression and had inhibitory effects on elevated autophagy markers and caspase-3 immunoreactive cells. Furthermore, our results revealed that CARD was able to attenuate damage via activation of Nrf2 through the p62-dependent degradation of testicular anti-Kelch-like ECH-associated protein-1 (Keap-1). In conclusion, this study suggests that CARD provides protection against diabetic stress-mediated testicular damage. The use of CARD with conventional anti-diabetic therapy was associated with improved efficacy compared with conventional therapy alone.

• Mycobiology
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• v.50 no.1
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• pp.86-95
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• 2022

Inflammaging in male reproductive organs covers a wide variety of problems, including sexual dysfunction and infertility. In this study, the beneficial effects of cordycepin (COR), isolated from potential medicinal fungi Cordyceps militaris, in aging-associated testicular inflammation and serum biochemical changes in naturally aged rats were investigated. Male Sprague Dawley rats were divided into young control (YC), aged control (AC), and COR (5, 10, and 20 mg/kg) treated aged rat groups. Aging-associated serum biochemical changes and inflammatory parameters were analyzed by biochemical assay kits, Western blotting, and real-time RT-PCR. Results showed a significant (p < 0.05) alteration in the total blood cell count, lipid metabolism, and liver functional parameters in AC group when compared with YC group. However, COR-treated aged rats ameliorated the altered biochemical parameters significantly (p < 0.05 and p < 0.01 at 5, 10, and 20 mg/kg, respectively). Furthermore, the increase in the expression of inflammatory mediators (COX-2, interleukin (IL)-6, IL-1β, and tissue necrosis factor-alpha) in aged rat testis was significant (p < 0.05) when compared with YC group. Treatment with COR at 20 mg/kg to aged rats attenuated the increased expression of inflammatory mediators significantly (p < 0.05). Mechanistic studies revealed that the potential attenuating effects exhibited by COR in aged rats was mediated by regulation of NF-κB activation and MAPKs (c-Jun N-terminal kinase, extracellular signal-regulated kinase 1/2, and p38) signaling. In conclusion, COR restored the altered serum biochemical parameters in aged rats and ameliorated the aging-associated testicular inflammation proving the therapeutic benefits of COR targeting inflammaging-associated male sexual dysfunctions.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.526-537
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• 2023

Hepatitis C virus (HCV) infection is a major health problem worldwide and its eradication is mandatory. Direct acting HCV polymerase inhibitors, such as Sofosbuvir (SOF), is an effective regimen. However, it has some side effects like mutagenesis, carcinogenesis, and the impairment of testicular function. It is important to evaluate the safety of SOF on the ovary, as there are no studies yet. Increasing the production of Reactive Oxygen Species (ROS), causes oxidative stress, which affects ovulation process, female reproduction, and fertility. Accumulation of SOF in the cells was demonstrated to promote ROS generation. Vitamin E (Vit E) is an antioxidant agent that has an essential role in the female reproductive system, its deficiency can cause infertility. We explored the effect of SOF treatment alone and co-treated with Vit E on ovarian ROS level and ovarian morphology experimentally using biochemical and immunohistochemical studies. Significant changes in oxidative stress markers; nitric oxide and malondialdehyde lipid peroxidation, antioxidant enzymes; catalase, super oxide dismutase, and reduced glutathione, proliferating markers; proliferation cell nuclear antigen and Ki-67 antigen and caspase 3 apoptotic marker were demonstrated. It was shown that where SOF induced oxidative stress, it also aggravated ovarian dysfunction. The essential role of Vit E as an antioxidant agent in protecting the ovarian tissue from the effect of oxidative stress markers and preserving its function was also displayed. This could be guidance to add Vit E supplements to SOF regimens to limit its injurious effect on ovarian function.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.236-251
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• 2023

Alcohol consumption alongside combination antiretroviral therapy (cART) has attracted research interest, especially because of increasing male infertility. This study investigated the combined effects of alcohol and cART on testicular morphology, biomarkers of oxidative stress, inflammation, and apoptosis. Rats, weighing 330-370 g, were divided into four groups of six animals each; control, alcohol treated (A), cART, and alcohol plus cART treated (A+cART). Following 90 days treatment period, animals were euthanized, testis extracted, and routinely processed for histology and immunohistochemical analysis. Significantly decreased epithelial area fraction, increased luminal and connective tissue area fractions, and reduction of epithelial height and spermatocyte number, were recorded in the treated groups compared to control. Extensive seminiferous epithelial lesions including widened intercellular space, karyolysis, and sloughing of germinal epithelium were recorded in all the treated groups. Furthermore, upregulation of inducible nitric oxide synthase and 8-hydroxydeoxyguanosine, interleukin-6, and caspase 3 recorded in treated animals, was more significant in A+cART group. Also, the levels of interleukin-1β and tumor necrosis factor-α were more elevated in A and cART treated groups than in A+cART, while MDA was significantly elevated in cART and A+cART treated groups compared to control group. Altogether, the results indicate testicular toxicity of the treatments. It is concluded that consuming alcohol or cART induces oxidative stress, inflammation, and apoptosis in testis of rats, which lead to testicular structural and functional derangements, which are exacerbated when alcohol and cART are consumed concurrently. The result will invaluably assist clinicians in management of reproductive dysfunctions in male HIV/AIDS-alcoholic patients on cART.

• Korean Circulation Journal
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• v.53 no.10
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• pp.655-676
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• 2023

Interest in sex differences in coronary artery disease (CAD) has been steadily increasing. Concurrently, most of the data on these differences have primarily been Western-oriented. The KoRean wOmen'S chest pain rEgistry (KoROSE), started in 2011, has since published numerous research findings. This review aims to summarize the reported differences between men and women in CAD, integrating data from KoROSE. Cardiovascular risk in postmenopausal women escalates dramatically due to the decrease in estrogen levels, which normally offer cardiovascular protective effects. Lower estrogen levels can lead to abdominal obesity, insulin resistance, increased blood pressure, and endothelial dysfunction in older women. Upon analyzing patients with CAD, women are typically older and exhibit more cardiovascular risk factors than men. Diagnosing CAD in women tends to be delayed due to their symptoms being more atypical than men's. While in-hospital outcome was similar between sexes, bleeding complications after percutaneous coronary intervention occur more frequently in women. The differences in long-term prognosis for CAD patients between men and women are still a subject of ongoing debate. Pregnancy and reproductive factors also play a significant role as risk factors for cardiovascular disease in women. A notable sex disparity exists, with women found to use fewer cardiovascular protective drugs and undergo fewer interventional or surgical procedures than men. Additionally, women participate less frequently than men in clinical research. Through concerted efforts to increase awareness of sex differences and mitigate sex disparity, personalized treatment can be provided. This approach can ultimately improve patient prognosis.

• Development and Reproduction
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• v.6 no.2
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• pp.111-115
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• 2002

5-Hydroxytryptamine(5-HT; serotonin) system has been implicated in the modulation of male sexual behaviors and the secretion of reproductive hormones. In human males, selective serotonin re-uptake inhibitors(SSRIs) are known to improve the major male sexual dysfunction, premature ejaculation, through the central nervous system-mediated pathways. As numerous hormone and local factors, 5-HT may have peripheral role in the regulation of male sexual function. The expression of 5-HT receptor subtypes in the target tissue, however, has not been explored yet. The present study was undertaken to test whether the 5-HT receptor subtypes are expressed in the reproductive tissues of male rat, especially in ejaculatory machinery such as seminal vesicle and vas deferens. To do this, reverse transcription-polymerase chain reaction(RT-PCR) and Southern blot analysis were employed. The transcripts for the 1A, 1B and 2C subtypes of 5-HT receptor were amplified in all the tested tissues. The present study demonstrated the expression of 5-HT receptor in the rat ejaculatory machinery, suggesting that 5-HT may play a pivotal role in the male sexual function via not only central pathway but also peripheral route. Further study on the receptor subtype-specific effect and their harmonized mode of action will be needed to establish the understanding of ejaculation mechanism and drug design.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.394-402
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• 2014

The objective of this study was to investigate the effect of chronic unpredictable stress on the reproductive function and ovarian luteinizing hormone receptor (LHR) expression. 9-week-old C57BL/6 female mice were randomly divided into two groups: control group and stressed group. Mice have been stressed twice a day for 35 days with 12 different stressors which were randomly selected. The results demonstrate that there is significant increase in the anxiety-related behaviors (P < 0.05), decrease body weight gain rate (P < 0.01) and decrease in the average of litter size in stressed mice compared with control group (P < 0.01). Furthermore, the rate of primary, secondary and early antral follicles in stressed mice significantly decreased (P < 0.05), whereas that of atretic follicles significantly increased compared with control mice (P < 0.01). The immunohistochemical analysis revealed that reduced LHR expression in granulosa cells of follicle and luteal cells of corpus luteum in response to chronic unpredictable stress. The western blot analysis revealed significantly decrease in LHR expression in the stressed mice ovaries compared with the control (P < 0.05). These results suggest that ovarian LHR expression affected by chronic unpredictable stress and the modulated ovarian LHR is responsible for ovarian follicular maldevelopment and reproductive dysfunction.