• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.163-163
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• 2005

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.292.2-293
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• 2002

Pyrethroids are one of the most commonly used insecticides in worldwide. but it remains unclear whether pyrethroid compounds possess endocrine disrupting activity or not. T47D cells, an estrogen receptor positive human breast cancer cell line. is known to induce alkaline phosphatase (AlkP) only in response to progestins. Because the action of estrogen may be changed by the action of progestins (Kraus et al. 1995), it is important to examine the potential to produce progestin-mediated effects for determining endocrine disrupting activity of chemicals(LiLorenzo et al. 1991). (omitted)

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.373-381
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• 1990

Endocrine cells in the cardiac and fundic regions of the Korean hedgehog were studied ultrastructurally. Five types of endocrine cells classified as EC, ECL, $D_1$. G and A-like cells were identified in these regions. EC cells contained pleomorphic granules, 170~500nm in diameter, with high electron density and highly dense bodies in a dense matrix. ECL cells were characterized by the presence of round or oval granules, 220~450nm in diameter, with high electron density. Some granules of ECL cells showed a small amounts of contents or empty. $D_1$ cells contained round and relatively small granules, 140~400nm in diameter, with low to moderate electron density. G cells were characterized by the presence of round or oval granules, 200~400nm in diameter, with moderate electron density. Some granules of these cells showed a narrow halo between the limiting membrane and the granular matrix. A-like cells contained round granules, 170~260nm in diameter, With high electron density. The granules of these cells showed homogeneous matrix surrounded by the tight membrane.

• Journal of Environmental Science International
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• v.16 no.2
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• pp.219-225
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• 2007

Endocrine disrupting compounds (EDC's) are chemicals that either mimic endogenous hormones interfering with pharmacokinetics or act by other mechanisms. Some endocrine disrupters were reported to be chemical substances that cause apoptosis in cells. A number of reports have indicated that 1,3-DCP, one of the EDC's may act as an endocrine disrupter and also has possible carcinogenic effects. 1,3-DCP, present in commercial protein hydrolysates used for human nutrition, are genotoxic and 1,3-dichloro-2-propanol induced tumors in rats. In the present study, it was investigated whether 1,3-DCP induces ROS generation and apotosis in A549 adenocarcinoma cells. Here we show that 1,3-DCP inhibits the growth of lung cancer cell lines and generates reactive oxygen species (ROS), a major cause of DNA damage and genetic instability, It was investigated that 1,3-DCP increases G1 phase cells after 12 hours, thereafter abruptly draws A549 cells to G0 state after 24 hours by flow cytometric analysis. 1,3-DCP induces p53 and $p21^{Cip1/WAF1}$ activation time- and dose-dependently by 24 hours, while the level $p21^{Cip1/WAF1}$ was decreased after 48 hours. These results suggest that 1,3-DCP, an EDC's generates ROS and regulates genes involved with cell cycle and apoptosis.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.523-529
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• 1992

The GEP endocrine cells of the African clawed toad, Xenopus laevis, were studied immunohistochemically. Five kinds of the endocrine cells were identified in this study A moderated number of 5-HT-immunoreactive cells were detected throughout the gastro intestinal tract, being almost uniform frequency. Gas/CCK -immunoreactive cells were restricted to the basal portion of the pyloric gland and among the duodenal mucosa. A rare glucagon-immunoreactive cells were weakly reacted in the fundic region of the stomach and observed in the exocrine portions of the pancreas. Somatostatine-immunoreactive cells were distributed throughout the gastrointestinal tract with except for the rectum, and not only the periphery of the islets but also the exocrine portions in the pancreas. No CGs- and insulin-immunoreactive cells were found in the gastrointestinal tract, whereas in the pancreas, the later was seen in the central region of the islets and the exocrine portions.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.35-41
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• 2013

Metabolic analysis of CR6 interacting factor 1 (Crif1) deficient mouse embryonic fibroblasts with impaired oxidative phosphorylation has been carried out using LC-MS/MS and GC-MS methods. Metabolic profiles of the Crif1 deficient cells were comprehensively obtained for the first time. Loss of oxidative phosphorylation functions in mitochondria resulted in cancer-like metabolic reprogramming with consumption of majority of glucose carbon from up-regulated glycolysis to produce lactate, suppressed utilization of glucose carbon in the TCA cycle, increased amounts of amino acids. The changes in metabolic profile of the Crif1 deficient cells are most probably a consequence of metabolic reprogramming to meet the needs of energy balance and anabolic precursors in compensation for the loss of major oxidative phosphorylation functions.

• Animal cells and systems
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• v.3 no.1
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• pp.97-102
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• 1999

In order to investigate the regional distribution and relative frequency of the serotonin-, somatostatin- and motilin-immunoreactive cells in the gastrointestinal tract GIT) of the bullfrog (Rana catesbeiana) with developmental stages, group of bullfrogs subdivided into the tadpole with hindlegs, metamorphosed bullfrog with tail, 2 wk after metamorphosed bullfrog and adult bullfrog, were stained by immunohistochemical methods (PAP methods). Multifarious changes of the regional distribution and relative frequency of the gastrointestinal endocrine cells were observed as developmental stages but motilin-immunoreactive cell ere not detected in this study. Serotonin-immunoreactive cells were detected from 2 wk after metamorphosed bullfrog in the whole GIT. The positive cells were predominant in the pylorus regions. In the adult bullfrog, these cells increased in fundus. On the other hand, somatostatin-immunoreactive cells were observed from the tadpole with hindlegs in the stomach regions. In the metamorphosed bullfrog with tail, they were found in the whole GIT except for the ileum, and increased with developmental stages except for rectum. In the rectum, these cells were not detected after that period. Our results show that most of the immunoreactive cells appear from completed metamorphosed periods when the histological structure of GIT is completely differentiated.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.654-670
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• 2022

Spermatogenesis and testis development are highly structured physiological processes responsible for post-pubertal fertility in stallions. Spermatogenesis comprises spermatocytogenesis, meiosis, and spermiogenesis. Although germ cell degeneration is a continuous process, its effects are more pronounced during spermatocytogenesis and meiosis. The productivity and efficiency of spermatogenesis are directly linked to pubertal development, degenerated germ cell populations, aging, nutrition, and season of the year in stallions. The multiplex interplay of germ cells with somatic cells, endocrine and paracrine factors, growth factors, and signaling molecules contributes to the regulation of spermatogenesis. A cell-tocell communication within the testes of these factors is a fundamental requirement of normal spermatogenesis. A noteworthy development has been made recently on discovering the effects of different somatic cells including Leydig, Sertoli, and peritubular myoid cells on manipulation the fate of spermatogonial stem cells. In this review, we discuss the self-renewal, differentiation, and apoptotic roles of somatic cells and the relationship between somatic and germ cells during normal spermatogenesis. We also summarize the roles of different growth factors, their paracrine/endocrine/autocrine pathways, and the different cytokines associated with spermatogenesis. Furthermore, we highlight important matters for further studies on the regulation of spermatogenesis. This review presents an insight into the mechanism of spermatogenesis, and helpful in developing better understanding of the functions of somatic cells, particularly in stallions and would offer new research goals for developing curative techniques to address infertility/subfertility in stallions.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.258-262
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• 2006

To investigate additive effects of endocrine disruptors, we have histopathologically studied the exchanges of the reproductive organ to ovariectomized ICR mice. Female ICR mice were ovariectomized and then treated with endocrine disruptors after two weeks. Macroscopic exchanges, which were body weight, feed and water intake, of all groups were not seen during experiment period. Histopathological changes of uterine epithelial cells, vaginal epithelial cells, mammary glands and the diameter in uterine tubles were observed. In the results, the histopathological sensitivity to endocrine disruptors effect was more seen to the vaginal epithelial cell height than others. The additive estrogenic effects of endocrine disruptors, which were combinations of DEHP, DBP and BPA, were seen with E2 and BPA treatments. These results offers a sysmatic and mechanistically informative approach to assessing estrogenicity. It provides a useful profile of activity using a reasonable amount of resources and is compatible with the study of individual chemicals as well as the investigation of interactions among combinations of chemicals.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.19-30
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• 1986

Endocrine cells were observed in the gastrointestinal tract of the squirrels by light microscopy using Grimelius and Masson-Hamperl silver impregnation, and in the stomach and duodenum by electron microscopy. Light microscopically, argyrophil cell decreased gradually in number in the pyloric region and ileum, stomach, duodenum and jejunum and rectum in the order listed. Argentaffin cells were moderately distributed in the stomach, pyloric region and duodenum, while absent in the jejunum, ileum and rectum. Five kinds of cell types, EC, ECL, D, $D_1$ and G cells were identified in the stomach and three kinds of cell types, S, $EC_1$ and $EC_2$ were also identified in the duodenum by electron microscopy. A cilium noted in the cytoplasm of $D_1$-type cell. The species differences in the distribution, size and structure of the secretory granules were discussed.