• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.47-54
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• 2011

Endocrine disruptors bind to hormone receptors on sperm membrane, therefore spermatozoa are potentially a useful model for examining estrogenic activities of endocrine disruptors. The objective of this study was to compare the effects of two xenoestrogenic compounds [genistein (Gen) and 4-tert-octylphenol (OP)] to those of two steroids [estrogen ($E_2$) and progesterone ($P_4$)] on boar sperm % motility and motion kinematics of in vitro. Porcine spermatozoa were incubated with various concentrations ($0.001{\sim}100\;{\mu}M$) of each chemical for 15 or 30 min, and then assessed % motility and sperm motion kinematics using computer assisted sperm analyzer (CASA). Each chemical decreased sperm % motility, and OP decreased VSL and VAP compared with untreated control(p<0.05). $E_2$ stimulated the motion kinematic changes except VCL. Moreover, Gen had effects on VCL and VAP alterations after 30 min incubation. In summary, since all chemicals studied effectively altered sperm % motility and motion kinematics, it was concluded that porcine spermatozoa could be a useful model for in vitro screening of potential endocrine disruptors.

• Toxicological Research
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• v.18 no.4
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• pp.331-339
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• 2002

Phenoxy compounds, 2,4-Dichlorophenol acetoxy acid (2,4-D) and 2,4-dichlorophenol (DCP), are widely used as a hormonal herbicide and intermediate for pesticide manufacturing, respectively. In order to assess the potential of these compounds as endocrine disruptors, we studied the androgenicity of them wing in vivo and in vitro androgenicity assay system. Administration of 2,4-D (50 mg/kg/day, p.o.) or DCP (100 mg/kg/day, p.o.) to rats caused an increase in the tissue weight of ventral prostate, Cowpers gland and glands penis. These increase of androgen-dependent tissues were additively potentiated when rats were simultaneously treated with low dose of testosterone (1 g/kg, s.c.). 2,4-D increased about 350% of the luciferase activity in the PC cells transiently cotransfected phAR and pMMTV-Luc at concentration of $10^{-9}$ M. In 2,4-D or DCP-treated castrated rats, testosterone 6$\beta$-hydroxylase activity was not significantly modulated even when rats were co-treated with testosterone. In vitro incubation of 2,4-D and DCP with microsomes at 50 $\mu$M inhibited testosterone 6$\beta$-hydroxylase activity about 27% and 66% in rat liver microsomes, about 44% and 54% in human liver microsomes and about 50% and 45% in recombinant CYP3A4 system, respectively. The amounts of total testosterone metabolites were reduced about 33% and 75% in rat liver microsomes, 69% and 73% in human liver microsomes and 54% and 64% in recombinant CYP3A4 by 2,4-D or DCP, respectively. Therefore, the additive androgenic effect of 2,4-D or DCP by the co-administration of the low dose of testosterone may be due to the increased plasma level of testosterone by inhibiting the cytochrome P450-mediated metabolism of testosterone. These results collectively suggested that 2,4-D and DCP may act as androgenic endocrine disrupter by binding to the androgen receptor as well as by inhibiting the metabolism of testosterone.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4711-4715
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• 2013

Aim: The aim of this study was to evaluate acute adverse events and efficacy of three-dimensional intensitymodulated radiotherapy (IMRT) combined with endocrine therapy for intermediate and advanced prostate cancer. Methods: Sixty-seven patients were treated with three-dimensional IMRT combined with maximum androgen blockade. The correlation between radiation-induced rectal injury and clinical factors was further analyzed. Results: After treatment, 21 patients had complete remission (CR), 37 had partial remission (PR), and nine had stable disease (SD), with an overall response rate of 86.5%. The follow-up period ranged from 12.5 to 99.6 months. Thirty-nine patients had a follow-up time of ${\geq}$ five years. In this group, three-year and five-year overall survival rates were 89% and 89.5%, respectively; three-year and five-year progression-free survival rates were 72% and 63%. In univariate analyses, gross tumor volume was found to be prognostic for survival ($X^2$ = 5.70, P = 0.037). Rates of leucopenia and anemia were 91.1% and 89.5%, respectively. Two patients developed acute liver injury, and a majority of patients developed acute radiation proctitis and cystitis, mainly grade 1/2. Tumor volume before treatment was the only prognostic factor influencing the severity of acute radiation proctitis (P < 0.05). Conclusions: IMRT combined with endocrine therapy demonstrated promising efficacy and was well tolerated in patients with intermediate and advanced prostate cancer.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.10-13
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• 2008

Endocrine disrupting chemicals (EDCs) are hard to be degraded in nature, and are also accumulated in diverse organisms. They finally give negative effects to human through the food web. White rot fungi which have lignin-degrading enzymes have high potentials for degradation of recalcitrant compounds, and a white rot fungus, Phlebia tremellosa, isolated in Korea show good degrading activity against the endocrine disrupting phthalates. We have isolated a laccase cDNA which was involved in the degradation of EDCs, and constructed a laccase expression vector to use in the genetic transformation of P. tremellosa. The expression vector was stably integrated into the chromosomal DNAs and showed increased laccase activity in transformants. One of transformants showed not only increased degradation of several EDCs but also faster estrogenic decreasing activities generated by the EDCs.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.82-85
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• 2009

Endocrine disrupting chemicals (EDCs) disturb animal hormonal system even at very low concentrations, and finally give harmful effects to human through the food web. A white rot fungus Phlebia tremellosa isolated in Korea, was reported to have good degrading activity against the endocrine disrupting phthalates. However, this fungus has very low manganese peroxidase (MnP) activity under various culture conditions while laccase and lignin peroxidase activities were high. We have isolated an MnP cDNA from Trametes versicolor which was involved in the degradation of EDCs, and constructed an MnP expression vector to use in the genetic transformation of P. tremellosa in order to get higher MnP producing strains. Many transformants had integrated expression vector in their chromosomal DNAs, and showed increased MnP activity. One of two transformants showed increased degradation of 4 EDCs (70${\sim}$88%) than the wild type (30${\sim}$45% degradation rates), and showed twice better removal of estrogenic activities generated by the EDCs than the wild type.

• The Journal of Pediatrics of Korean Medicine
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• v.15 no.1
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• pp.105-115
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• 2001

The relation of endocrine in the western medicine and zangfu-organ functions in Korean medicine, related to growth disturbance, was studied and derived the following results. 1. The hormone most related to growth disturbance is, directly secreted from the anterior pituitary or is stimulated and secreted in the target grands, growth hormone, thyroid, adrenocortical hormone, gonadial hormone and is insulin secreted from $\beta$ cell of langerhans' slands of pancreas. 2. the pituitary has the most close relation with the kidney in the five zang-organ. Because the kidney is innate origin(先天之本) and promotes qi and blood(生化氣血), stores the essence of life(藏精), dominates the bones(主骨) and promotes the marrow(生骨髓). Especially it is connected with brain(通於腦). 3. In the children growth, the endocrine action in the pituitary has the most close relation with the kidney, As in the reports of the brain and spinal cord, bone, store essence of life, sexual maturation and decline(kidney-qi, sexual functions of both sexes(天癸)) etc, and cause of cretinism, dwarf in the main subject. 4. Somatomedin is the most important factor of the growth factors, IGF in another word. The unification of IGF and secretion is controlled firstly according to growth hormone, however is very closely related to the nutrition status in the non-hormonic causes. Also, it is affected very much by the insulin. 5. Insulin is one of the important hormone related to the growth and is secreted from the pancreas. Pancreas belongs to the functional system of spleen in oriental medicine, thus the growth disturbance, occurred due to error in insulin secretion and nutrition(in another words, the lack of postnatal essential substance from food-stuff(水穀精氣)), is closely related to the spleen. 6. From the results driven above, the hormone action of endocrine and problem in secretion, related to the growth disturbance, must be focused on the differentiation of symptoms and signs of the kidney and the spleen in oriental medicine.

• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.27-32
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• 1991

The pancreatic endocrine cells of the cat-shark, S. torazame, were studied using immunohistochemical method. Five kinds of endocrine cells (glucagon-, somatostatin-, insulin-, 5-HT-and BPP-immunoreactive cells) identified in this study. The chracteristic findings of the distributions of five immunoreactive cells were as follows. Glucagon-immunoreactive cells were detected as clustering group in the epithelia of the interlobular duct and singly the pancreatic acini, respectively. Insulin -immunoreactive cells were moderately observed in the epithelia of the interlobular duct or in the periphery of the islet. Somatostatin-immunoreactive cells were distributed in single or mass groups in the epithelia of the interlobular duct and the exocrine gland of the pancreas. A very few 5-HTimmunoreactive cells were seen in the periphery of the islet and the acini of the pancreas-BPP-immunoreactive cell was singly located in the periphery of the pancreatic islet, but GAS/CCK-and Chromogranin-immunoreactive cells were not found in this study.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.137-142
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• 2011

Extremely low frequency magnetic fields (ELF-MF) have the ability to produce a variety of behavioral and physiological changes in animals. The stomach, as the most sensitive part of the neuroendocrine organ of the gastrointestinal tract, is crucial for the initiation of a full stress response against all harmful stress. Thus, the purpose of this study was to examine whether ELF-MF stimuli induce changes in the activity of neuroendocrine cells, considering their involvement in endocrine or paracrine effect on surrounding cells. The exposure to ELF-MF (durations of 24 h and 1 or 2 weeks, 60 Hz frequency, 0.1 mT intensity) altered the distribution and occurrence of gastrin, ghrelin and somatostatinpositive endocrine cells in the stomach of rats. The change, however, in the secretion of those hormones into blood from endocrine cells did not appear significantly with ELF-MF exposure. Comparing with sham control, ELF-MF exposure for 1 and 2 week induced an increase in $BaSO_4$ suspension propelling ratio of gastrointestinal tract, indicating that ELF-MF affects gastrointestinal motility. Our study revealed that ELF-MF exposure might influence the activity of endocrine cells, an important element of the intrinsic regulatory system in the digestive tract. The pathophysiological character of these changes and the mechanism responsible for neuroendocrine cell are still unclear and require further studies.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.667-674
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• 2017

Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%. Ang-(4-8) (0.01, 0.1, and $1{\mu}M$) suppressed high stretch-induced ANP secretion in a dose-dependent manner. Ang-(4-8) ($0.1{\mu}M$)-induced suppression of ANP secretion was attenuated by the pretreatment with an antagonist of Ang type 1 receptor ($AT_1R$) but not by an antagonist of $AT_2R$ or $AT_4R$. Ang-(4-8)-induced suppression of ANP secretion was attenuated by the pretreatment with inhibitor of phospholipase (PLC), inositol triphosphate ($IP_3$) receptor, or nonspecific protein kinase C (PKC). The potency of Ang-(4-8) to inhibit ANP secretion was similar to Ang II. However, Ang-(4-8) $10{\mu}M$ caused an increased mean arterial pressure which was similar to that by 1 nM Ang II. Therefore, we suggest that Ang-(4-8) suppresses high stretch-induced ANP secretion through the $AT_1R$ and $PLC/IP_3/PKC$ pathway. Ang-(4-8) is a biologically active peptide which functions as an inhibition mechanism of ANP secretion and an increment of blood pressure.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.417-425
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• 1995

The regional distribution and relative frequencies of gastrointestinal endocrine cells were studied immunohistochemically in the GIT of the cat-shark. Five kinds of endocrine cells were identified in this study. Mostly these cells were of open types, except for glucagon-, BPP- and somatostatin-immunoreactive cells in the stomach which seemed to be of closed type. 5-HT-immunoreactive cells were detected throughout the GIT, and were more freguent than of the other regions. Glucagon-and BPP-immunoreactive cells were demonstrated in the entire GIT except for the duodenum an the rectum, and occurred in various frequencies. A few numbers of Gas/CCK-immunoreactive cells were restricted to the duodenum. Somatostatin-immunoreactive cells were distributed in the whole GIT, and were a few in numbers in the stomach and rare in the intestine, respectly. These results suggest that the pattern of the regional distribution is rather similar to that reported fur previously, but relative number was less frequent than that of other species.