• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.251-259
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• 1988

Regional distribution and relative frequency of endocrine cells in ten portions of the gastrointestinal tract of the Korean native cattle were observed by immunocytochemical methods using specific antisera against chromogranin, serotonin, somatostatin, glucagon, bovine pancreatic polypeptide(BPP), motilin, gastric inhibitory polypeptide(GIP), neurotensin, secretin, gastrin and substance P. The results observed are summarized as follows: In the abomasum, chromogranin-, serotonin-, somatostatin-, motilin-, glucagon-, gastrin-, and substance P-immunoreactive cells were found. Chromogranin-and serotonin-immunoreactive cells were more numerous in the fundic region than pyloric region. Somatostatin- and gastrinimmunoreactive cells were numerous in the pyloric region than in the fundic region. In the small intestine, chromogranin-, serotonin-, somatostatin-, glucagon-, BPP-, motilin-, gastrin-, GIP-, neurotensin-, secretin-, and substance P-immunoreactive cells were detected. Chromogranin-, somatostatin-, GIP- and secretin-immunoreactive cells were most numerous in the duodenum, while BPP-, motilin-, glucagon-, neurotensin- and substance P-immunoreactive cells were rarely seen in the small intestine. In the large intestine, chromogranin-, serotonin- and BPP-immunoreactive cells were widely distributed and most numerous in the rectum. Somatostatin-, glucagon- and substance P-immunoreactive cells were rarely seen in the large intestine.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.9-13
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• 1997

The gastrointestinal endocrine cells of the African clawed toad, Xenopus laevis have been investigated immunohistochemically using the avidin-biotin method. Seven antisera were tested and three endocrine cell types immunoreacted with antisera to neurotensin, GRP and substance P. A moderate number of neurotensin-immunoreactive cells were weakly reacted in the small intestine. GRP-immunoreactive cells were mainly situated among the upper portion in the fundic glands, and the basal portion in the pyloric glands. These cells were oval and round in shape. On the other hand, in the intestine they were thin spindly cells with the epithelium. Substance P-immunoreactive cells were observed in among intestinal epithelium. However, no secretin-, motilin-, M-Enk- and PYY-immunoreactive cells were found in the GIT of the African clawed toads.

• Environmental Mutagens and Carcinogens
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• v.26 no.2
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• pp.53-58
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• 2006

Normally, environmental toxicants are classified as endocrine disruptors if they interfere with regulation of cellular function by endogeneous steroids through inhibition of receptor binding and/or transcriptional activation. So, many studies have been performed about agonist/antagonist of hormone receptor to study mechanisms of endocrine disruptors. If toxicants affect steroid biosynthesis and/or degradation and alter hormone homeostasis, these also are classified as endocrine disruptors. But there are not many studies of the mechanisms of endocrine disruptors on the basis of alteration of steroid biosynthesis and/or degradation. Isolation and culture of Leydig cells from testis is one of methods for the steroidogenesis screening assays to evaluate a substance for altering steroidogenesis. Leydig cells were harvested using the method described by Klinefelter with modifications. Leydig cells were purified by perfusion of testis and incubation ($34^{\circ}C$, 80cycles/minute, 20 minutes) with collagenase (0.25 mg/kg), centrifugal elutriation, percoll gradient centrifugation and BSA multidensity gradient centrifugation. To confirm if this method is one of appropriate tools to evaluate a substance for altering steroidogenesis, ketoconazole, positive control was administered to purified Leydig cells. Ketoconazole ($10^{-8}M$ and above) significantly reduced testosterone production in purified Leydig cells. From above results, we suggest that this method for steroidogenesis screening assay appears to be a appropriate tool to detect suspected compounds for altering steroidogenesis.

• Korean Journal of Veterinary Research
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• v.36 no.2
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• pp.297-303
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• 1996

The regional distribution and relative frequency of endocrine cells in the GIT of the snakehead, Channa(Oph icephalus) argus were studied immunohistochemically. Five kinds of endocrine cells and one kind of nerve cell were identified in this study. A few numbers of secretin-immunoreactive cells were restricted to the cardia and fundus of the stomach. Moti-lin- and GRP-immunoreactive cells were rare in the epithelium of the distal and proximal intestines. PYY-immunoreactive cells were found in a few number in the pyloric caeca and were rare in the distal intestine. Substance P-immunoreactive cells were distributed relatively numerous from the fundus to the distal intetsine. Also, their nerve cells were detected in occurrence in the lamina propria in the distal intestine. No neurotensin-, met-Enk- and GIP-immunoreactive cells were found in the GIT of the snakehead.

• Animal cells and systems
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• v.2 no.3
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• pp.395-401
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• 1998

The regional distribution and relative frequency of endocrine cells were studied immunohistochemically in the gastrointestinal tract (GIT) of the Manchurian chipmunk, Tamias sibiricus asiaticus. Six kinds of endocrine cells were identified in this study. 5-hydroxytryptamine (5-HT)-immunoreactive cells were detected throughout the GIT. These cells were observed in moderate numbers in the pylorus, duodenum, jejunum, ileum, fundus, colon, and rectum. Somatostatin- and bovine pancreatic polypeptide (BPP)-immunoreactive cells were also identified throughout the GIT. The former were abundant in the pylorus region while the latter were scattered In ileum and colon. Motilin-immunoreactive cells were rarely detected in the small intestine. A few neurotensin-immunoreactive cells were detected in jejunum, ileum and colon. Also, a few substance P-immunoreactive cells were observed to be restricted to duodenum and jejunum.

• Journal of Veterinary Clinics
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• v.14 no.2
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• pp.208-214
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• 1997

The objective of this study was (a) to examine the change of bloodchemistry and (b) to investigate the secretion trend of endocrinological substance in a dog model after laser-beam radiation at different level of frequency (250 Hz, 2,000 Hz, 5,000 Hz and 8,000 Hz). The experimental groups were divided into four groups were divided into four groups on the basis of the level of frequency radiated and stimulated for five minutes. Before stimulation and after a lapse of time (10-minute, 30-minute and 60-minute) all dogs were checked the following parameters; cortisol, ACTH, RBC, hemoglobin, hematocrit, WBC, Ca, P, ALT, AST and creatinine. The results were as follow: ten minutes after stimulation, cortisol level of 250 Hz group, 2,000 Hz group, 5,000 Hz group and 8,000 Hz group was increased 18.8%, 20.5%, 23.2% and 309%, respectively. Ten minutes after stimulation, ACTH level of 250 Hz group, 2,000 Hz group, 5,000 Hz group and 8,000 Hz group was increased 26.7%, 26.6%, 30.5% and 29.5%, respectively. It began to decrease and at 30-minute after stimulation resturned to pre-stimulation level at 60-minute after stimulation. In blood examination RBC, hemaoglobin, hematocrit and WBC level showed slight increase and decrease and returned to pre-stimulation level at 60-minute after radiation. In bloodchemical examination serum calcium, inorganic phosphorus, ALT, AST and creatinine level were within normal physiological ranges.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.17-26
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• 2000

The regional distribution and relative frequencies of endocrine cells were studied immunohistochemically (PAP methods) in the alimentary tract and pancreas of the toad, Bufo bufo gargarizans Cantor using specific antisera against bovine Sp-1/chromogranin (BCG), serotonin, bombesin, gastrin, substance P (SP), somatostatin, insulin, glucagon, pancreatic polypeptide (PP), vasoactive intestinal polypeptide (VIP) and secretin. Nine kinds of endocrine cells were identified in this study. Spherical or spindleshaped immunoreactive (IR) cells were located in the gastric glands of stomach regions, in the basal portion of the epithelium of intestinal tract or esophagus, and in the exocrine or pancreatic islets with variable frequencies. In the alimentary tract, BCG-IR cells were found in the fundus and pylorus with rare and a few frequencies, respectively. Serotonin-IR cells were demonstrated in the whole alimentary tract including the esophagus. Bombesin- and SP-IR cells were restricted to the stomach regions and gastrin-IR cells were restricted to the pylorus. Somatostatin-IR cells were detected throughout the whole alimentary tract except for the large intestine, However, insulin-, glucagon-, PP-, VIP- and secretin-IR cells were not detected in the alimentary tract. In the pancreas of toad, the distribution and relative frequency of endocrine cells were similar to those of other mammals. Insulin-IR cells were located in the central portion of the pancreatic islets and interspaces of exocrine portions, and glucagon-, somatostatin- and PP-IR cells were detected in the marginal regions of the pancreatic islets and interspaces of exocrine. However, other IR cells were not found in the pancreas. In conclusion, the regional distribution and relative frequency of the endocrine cells in the alimentary tract and pancreas of the toad were similar to other anuran species but some differences which might be caused by feeding habits and species specification were also observed.

• Applied Microscopy
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• v.18 no.2
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• pp.59-76
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• 1988

In order to know the distribution, relative frequencies, types and morphology, endocrine cells in the intestinal tract of the hedgehog(Erinaceus koreanus) were studied by light microscopy, immunohistochemistry and electron microscopy. The results obtained are summarized as follows: 1. Two kinds of endocrine cells were demonstrated with two specific staining methods. Argyrophil cells(reactive cells for Grimelius method) were found most frequently in the intestinal region, and were infrequent in the rectum, whereas argentaffin cells (reactive cells for Masson-Hamperl method) were found most frequently in the rectum and in the other legions were infrequent. These reacting cells were mainly found in the intestinal glands, whereas a small number in the mucosa. 2. Twelve kinds of endocrine cells, gastrin(Gas)-, somatostatin (Som)-, serotonin(5-HT)-, glucagon(Glu)-, bovine pancreatic polypeptide(Bpp)-, cholecystokinin(Cck)-, secretin(Sec)-, motilin(Mot)-, glicentin(Gli)-, gastric inhibitor polypeptide(GIp)-, substance P(Sp)-, and neurotensin(Neu)-immunoreactive cells, were identified by immunohistochemical method. Gas-, Som-, 5-HT-, Glu-, Cck-, Sec-, Mot-, Gli-, Sp-, and Neu-reactive cells were observed in the duodenum, and among these Gas- and 5-HT-reactive cells were moderately found while the others were infrequent. In the jejunoileum Gas-, Som-, 5-HT-, Glu-, Cck-, Mot-, Gli-, GIp-, SP-, and Neu-reactive cells were found, and among these 5-HT- and GIp-reactive cells were moderately found while the others were infrequent. In the colon Sec-reactive cell was not detected. 5-HT-reactive cells were found most frequently and the others were infrequent in this region. 5-HT-, Bpp-, GIi- and Neu-reactive cells were found in the rectum. Among these 5-HT-reactive cells were found most frequently. 3. Electron microscopically, five types of endocrine cells, EC, ECL, D, G, A-like cell, were identified in the intestinal region. EC and ECL cells in the duodenum, EC, D and G cells in the jejuno-ileum, EC and A-like cells in the colon and EC cell in the rectum were observed respectively.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.321-331
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• 1992

The regional distribution and relative frequency of gastrointestinal endocrine cells were studied immunohistochemically in the gastrointestinal mucosa and pancreas of the fresh water turtle. Ten kinds of endocrine cells were identified in the gastrointestinal tract. Cholecystokinin-8-, bovine pancreatic polypetide-and glucagon-immunoreactive cells were seen throughout the gastrointestinal tract, also among them cholecystokinin-8-immunoreactive cells were most predominant in segment III. Although gastrin- and gastrin/cholecystokinin-immunoreactive cells were found from segment III to VI and X, respectively, they were numerous in segment III. Somatostatin-immunoreactive cells were observed from segment I to VII. 5-hydroxytryptamine- immunoreactive cells were detected in segment I, III, VIII, IX and X. Human pancreatic polypeptide-immunoreactive cells were demonstrated in segment V, VI, VIII, IX and X. Insulin-immunoreactive cells were found from segment III to X except for segment VIII, but rare in segment VII. Neurotensin-immunoreactive cells were found to be restricted to segment VIII, IX and X. No porcine chromogranin-, substance P- and bombesin-immunoreactive cells were detected throughout the gastrointestinal tract of the fresh water turtle. Although typical mammalian pancreatic islets encapsulated by connective tissue were not present in this species, five kinds of endocrine cells-glucagon, insulin, somatostatin, bovine pancreatic polypeptide and 5-hydroxytryptamine-were found in forming small or large groups and scattered in the exocrine gland region. However porcine chromogranin- and motilin-immunoreactive cells could not be demonstrated in the pancreas.

• Toxicological Research
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• v.16 no.1
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• pp.27-31
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. EPA and OECD are developing screening programs using validated test systems to determine whether certain substances may have an effect on humans. In the present study, the establishment of in vivo short-term test system for pubertal female assay with thyroid to detect endocrine disrupting chemicals was tried using a model substance, methoxychlor (MC), a chlorinated hydrocarbon insencticide. Forty female rats were assigned to four groups. MC was administered at dose levels of 0, 8, 40 and 200mg/kg by gavage to female rats from day 21 post partum to the completion of vaginal opening. We evaluated body weight change, age at vaginal opening, onset of estrous cyclicity, age at first esturs, ovary weight, and serum concentrations of thyroxine and thyroid stimulating hormone in female rats. The age at vaginal opening of females receiving 40 200mg/kg was significantly younger than control. The onset of estrus cyclicity and age at first estrus of females receiving 200mg/kg was also younger than controls. There was no effect of treatment on body weight, ovary weight, and hormone concentration. Based on these results, it can be concluded that application of MC at dose level of 40mg/kg affects the vaginal opening and application of MC at dose level of 200mg/kg accelerates the vaginal opening and the onset of estrus cylicity.