• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.149-157
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• 2009

Larvae and juveniles of the filefish Thamnaconus modestus were reared for 64 days after hatching (DAH) in order to determine the activity of four enzymes (trypsin, pepsin-like enzyme, lipase, amylase) during ontogeny. Larvae were fed on rotifer Brachionus plicatilis from 2 to 26 DAH, Artemia nauplii from 10 to 64 DAH, and then gradually changed to pelleted feed from 40 DAH. Temperature was kept between $21.5{\sim}24.2^{\circ}C$ Activity of trypsin and lipase was found in larvae 4 DAH ($6.0{\pm}1.4unit$) and 6 DAH ($4.5{\pm}1.4unit$), respectively. The evolution of activity in both enzymes showed a profile marked by drastic increases between late larval and early juvenile stages. Pepsin-like enzyme activity was found at 10 DAH and drastically increased from 28 DAH, corresponding with the early juvenile stage of T. modestus. Interestingly, developmental changes in the pepsin-like enzyme activity coincided well with increases in the number of gastric glands. Amylase activity was found at 10 DAH and was maintained at a low level up to 28 DAH, followed by a drastic increase from 28 DAH to 40 DAH. It might be concluded that a drastic increase in trypsin and pepsin-like enzyme activities, and a corresponding increase in the number of gastric glands reflects a higher somatic growth of T. modestus during the early juvenile period.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.653-660
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• 2000

In order to study the regional distribution and relative frequency of the immunoreactive endocrine cells in the gastrointestinal tract of the Mongolian gerbil, Meriones unguiculatus, the gastrointestinal tract was divided into 9 portions (cardia, fundus, pylorus, duodenum, jejunum, ileum, cecum, colon and rectum) and immunostained by immunohistochemical (PAP) method using 8 types of specific antisera against cholecystokinin (CCK)-8, gastrin, secretin, pancreatic polypeptide(PP), somatostatin, serotonin, glucagon and insulin. CCK-8-, gastrin-, somatostatin- and serotonin-immunoreactive cells were demonstrated in this study. These immunoreactive cells were found in the gastric gland regions of the pylorus or between parietal and chief cells of the fundus with round to spherical shaped, and in the interepithelial regions of the intestinal tract with spherical to spindle shaped except for jejunum where some of immunoreactive cells were also observed in the intestinal glands with round to spherical shaped. CCK-8-immunoreactive cells were restricted to the pylorus and duodenum with numerous and a few frequency, respectively. Gastrin-immunoreactive cells were restricted to the pylorus with numerous frequency. Similar to those of gastrin-immunoreactive cells, somatostatin-immunoreactive cells were restricted to pylorus with moderate frequency. Serotonin-immunoreactive cells were detected throughout whole gastrointestinal tract except for cardia and cecum with moderate or numerous frequency. However, no secretin-, PP-, glucagon- and insulin-immunoreactive cells were observed in this study. From these results, the appearance type, regional distribution and relative frequency of immunoreactive endocrine cells in the gastrointestinal tract of the Mongolian gerbils were somewhat lowered or restricted compared to those of other mammals and these differences were might be caused by feeding habits and species specification.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.793-807
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• 1995

This study was carried out to investigate the effects of diethyl maleate(DEM) on the carcinogenesis of forestomach and pyloric glandular stomach in rats caused by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). A total of 60 male 6-week-old Wistar rats were given twice intragastric injection of MMNG(200mg/kg BW), then were given diets containing 5% NaCl for 3 weeks until 4th week of the experiment. And then the animals of groups of 1 and 2 were placed on diets containing 0.2% DEM for 16 weeks until the end of 20 weeks of the experiment. On the other hand, the animals of groups of 3 and 4 were placed on basal diets for the same periods. The tissues of forestomach and liver of each group were frozen in liquid nitrogen and the activities of quinone reductase(QR) were determined by measurement of the dicoumarol-sensitive reduction of dichloro-indophenol by NADPH at 600nm. All rats were sacrificed at the end of 20 weeks of the experiment. Every animal was fasted for 24 hrs prior to sacrifice. The forestomach was fixed in 10% neutral phosphate buffered formalin for histology and the pyloric gland was fixed in sublimated formalin for immunohistochemistry of pepsinogen 1 altered pyloric gland(PAPG). The final body weight of the group given MNNG and treated with 5% NaCI and DEM was significantly decreased compared with that of the group 4(p<0.05). Food and water consumption rates were not significantly changed. The preneoplastic and neoplastic lesions of the forestomach given MNNG and treated with 5% NaCI and DEM were significantly increased compared to those of the group 4(p<0.0l). The incidence of PAPG in the groups treated with 0.2% DEM was significantly increased compared with that of the group 4(group 1:p<0.01, group 2:p<0.05). The activities of QR of forestomach in the groups treated with 0.2% DEM were significanitly increased compared with those of the group 4(p<0.001), but those of liver were not significant. These results indicate that DEM exert the enhancing effect of forestomach and glandular stomach carcinogenesis in rats pretreated with MNNG and NaCl.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.19-27
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• 2016

The RLG (relative length of gut) is 1.52 (n=12) in the sablefish, Anoplopoma fimbria. The digestive tract has five or six pyloric caeca in the posterior region of stomach. Morphology of mucosal fold is unbranched type in the esophagus and stomach, but branched type in the intestine. The histological structure of digestive tract can be divided into mucosal layer, submucosal layer, muscular layer and serous membrane in the cross section. In the esophagus, mucosal epithelial layer is a simple, and consists of ciliated columnar epithelia and mucous cells. In the stomach, gastric gland of mucosal epithelial layer is a tubular, and is composed of chief cell, parietal cell and mucin secreting cell, which is columnar and contained secretory granules of red and blue colors in the AB-PAS (pH 2.5) reaction. In the intestine, mucosal epithelial layer is a simple, and consists of ciliated columnar epithelia and goblet cells. The submucosal layer is composed mainly of collagen fibers, and well developed in the esophagus. And the muscular layer of digestive tract is divided into longitudinal and circular muscle layer, and well developed in the stomach. The liver is composed of numerous lobular structure and bile canaliculi. Stainability of hepatocyte cytoplasm was eosinophilic, and nucleus and nucleolus showed basophilic in the H-E stain. The pancreatic tissue was scattered in the fatty tissue near the digestive tract, and acinar gland consisting of numerous exocrine cells. And cytoplasmic stainability of exocrine cell was basophilic, and contained numerous zymogen granules of eosinophilic in the H-E stain.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.2
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• pp.89-94
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• 2014

DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces $Ca^{2+}$ signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in $Ca^{2+}$ signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated $Ca^{2+}$-activated $Cl^-$ channels (CaCCs) and increased intracellular calcium concentrations ($[Ca^{2+}]_i$) in primary cultured human conjunctival cells. DA-6034 also increased $[Ca^{2+}]_i$ in mouse salivary gland cells and human corneal epithelial cells. $[Ca^{2+}]_i$ increase of DA-6034 was dependent on the $Ca^{2+}$ entry from extracellular and $Ca^{2+}$ release from internal $Ca^{2+}$ stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate ($IP_3$) pathway and lysosomal $Ca^{2+}$ stores. These results suggest that DA-6034 induces $Ca^{2+}$ signaling via extracellular $Ca^{2+}$ entry and RyRs-sensitive $Ca^{2+}$ release from internal $Ca^{2+}$ stores in epithelial cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.195-204
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• 2011

Introduction: This study examined the regulatory mechanism underlying the meal-induced changes in the hypothalamic-pituitary-adrenal gland (HPA) axis activity. Materials and Methods: Male Sprague-Dawley rats (250-300 g) were hired for two different experiments as follows; 1) rats received either 8% sucrose or 0.2% saccharin ad libitum after 48 h of food deprivation with the gastric fistula closed (real feeding) or opened (sham feeding). 2). rats received 5 ml of intra-oral infusion with 0.2% saccharin or distilled water after 48 h of food deprivation. One hour after food access, all rats were sacrificed by a transcardiac perfusion with 4% paraformaldehyde. The brains were processed for c-Fos immunohistochemistry and the cardiac blood was collected for the plasma corticosterone assay. Results: Real feedings with sucrose or saccharin and sham feeding saccharin but not sucrose, following food deprivation decreased the plasma corticosterone level. c-Fos expression in the nucleus tractus of solitarius (NTS) of the fasted rats was increased by the consumption of sucrose but not saccharin, regardless of the feeding method. On the other hand, the consumption of sucrose or saccharin with real feeding but not the sham, induced c-Fos expression in the paraventricular nucleus (PVN) of the fasted rats. The intra-oral infusion with saccharin or water decreased the plasma corticosterone level of the fasted rats. Intra-oral water infusion increased c-Fos expression in both the PVN and NTS, but saccharin only in the NTS in the fasted rats. Conclusion: Neither restoration of the fasting-induced elevation of plasma corticosterone nor the activation of neurons in the PVN and NTS after refeeding requires the palatability of food or the post-ingestive satiety and caloric load. In addition, neuronal activation in the hypothalamic PVN may not be an implication in the restoration of the fasting-induced elevation of the plasma corticosterone by oropharyngeal stimuli of palatable food.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.247-256
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• 2000

The regional distributions and relative frequencies of endocrine cells were studied histochemically (Grimelius and Masson-Hamperl (M-H) silver methods) in the alimentary tract of the red-eared slider, Trachemys scripta elegans. Samples were taken from the esophagus, fundus, pylorus, duodenum, jejunum, ileum and large intestine. Argyrophil (Grimelius-positive) cells and argentaffin (M-H-positive) cells were found in the whole alimentary tract in this study. Spherical to spindle and/or oval to round-shaped argyrophil or argentaffin cells were located in the gastric glands of the stomach regions, in the basal portion of the epithelium of intestinal tract or the esophagus with variable frequencies. Argentaffin cells were more numerously detected in the whole alimentary tract compared with those of argyrophil cells in this study. Argyrophil cells were observed in the whole alimentary tract including the esophagus and the most predominant region was the rectum with moderate frequency. The relative frequency of these cells was rare in the esophagus, fundus, duodenum, jejunum and ileum, respectively and a few frequency in the pylorus. Argentaffin cells were also observed in the whole alimentary tract including the esophagus and the most numerously demonstrated region was the rectum with numerous frequency. They were observed with a few frequencies in the remaining regions of the alimentary tract except for the rectum, respectively. However, to know the exact type of the argyrophil cells and argentaffin cells that were observed in this study, more developmental methods such as immunohistochemistry were needed.

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.347-356
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• 2006

It is reported that a fermented soybean food, Doenjang, has srong antimutagenic and cytotoxic effect on cancer cells. This study investigated the effect of Chungkookjang, another traditional popular Korean soybean fermented food, on growth of cancer cells: HL-60, SNU-638 and MCF-7, and also its in vivo antitumorigenic effect in DMBA-induced mammary tumor rat model. For the in vitro study, Chungkookjang and steamed soybeans were extracted with ethanol and sequentially fractioned with 5 kinds of solvents differing in grades of polarity such as hexane, dichloromethane, ethylacetate, butanol and water. Almost all Chungkookjang extracts significantly inhibited the growth of HL-60 (human leukemic cancer cell), SNU-638 (human gastric cancer cell) and MCF-7 (human breast cancer cell) when compared to steamed soybean extracts. Butanol fraction of Chungkookjang extract especially showed a remarkable inhibitory effect in all the three kinds of cancer cells. To induce a mammary gland tumor, DMBA (50 mg/BW) was administered to 50 day-old female rats and followed by Chungkookjang or steamed soybean supplemented diets. Freezedried Chungkookjang powder (20% of diet in wet weight) was added to AIN-93G based diet for the Chungkookjang group of rats. Likewise, steamed soybean powder containing equal protein content to that of Chungkookjang powder was supplemented to soybean group of rats. At 13 weeks later, the mammary tumor incidence, average tumor number and tumor weight a rat were lower in Chungkookjang group compared to the control or soybean group. In conclusion, Chungkookjang showed a strong inhibitory effect on cancer cell growth in vitro, as well as a more preventive effect against chemically induced mammary tumorigenesis in vivo, while steamed soybeans did not. Therefore, these results suggest that Chungkookjang acquire its anticancer activity through the fermentation process.

• Journal of Aquaculture
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• v.17 no.3
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• pp.215-220
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• 2004

Using light microscopy, the digestive tract of the parrot fish, Oplegnathus fasciatus was studied histologically. The tract consists of esophagus, stomach, intestine and fifty or sixty pyloric caecae. Each pyloric caecum is a blind sac of banana shape, and is originated from pyloric end of the stomach. The relative length of gut (RLG), that is length of digestive tract to standard length, is 1.78 (n=30). Esophagus has an undeveloped submucosa and a well developed muscularis mucosae. Its mucosa displays primary and secondary folds lined with a cuboidal or columnar epithelium and numerous acidic mucous secretory cells. The stomach has muscularis, which consists of longitudinal and circular muscular layers; its submucosa and muscularis mucosae are well developed. Only primary folds are present in the stomach. Microvilli are present in the epithelial layer. The stomach has a well-developed gastric gland and relatively more secretory granules. Mucosal epithelium of the pyloric caeca is composed of neutral mucous secretory cells and columnar epithelium with developed microvilli in the apical portion. Using the morphological and histological features, the intestine may be divided into anterior, mid and posterior parts. It has an advanced striated border and abundant acidic mucous secretory cells and some neutral mucous secretory cells. The mid intestine has more abundant acidic mucous secretory cells than the anterior and posterior parts. A thick longitudinal muscle is formed in the intestine and its thickness is progressively increased towards the posterior end.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.115-127
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• 1998

The digestive tract of the rockfish, Sebastes schlegeli composed of pharynx, esophagus, stomach, intestine, anus and ten or eleven pyloric caeca. Pyloric caeca is blind sac of banana shape, and that is originated from pyloric portion of the stomach. The relative length of gut(RLG), that is length of digestive tract to standard length, is about 1.56(n=10). Esophageal muscularis consists of thin outer layer of longitudinal muscle and thick inner layer of circular muscle. Mucosal epithelium consists of columnar epithelium with short microvilli and contains numerous mucous secretory cell. The mucosal folds of the stomach are regular, and the muscularis consists of longitudinal, oblique and circular muscle layer. The chief cell of the gastric gland have a tubular mitochondria, endoplasmic reticula and numerous secretory granules in electron-dense. However, parietal cell contains small mitochondria, endoplasmic reticula and vacuoles in low electron density. Mucosal epithelium of the pyloric caeca and intestine composed of columnar epithelium, goblet cell, rodlet cell and dark cell. Columnar absorptive cell in the pyloric caeca and intestine contains well developed mitochondria, endoplasmic reticula, vesiculated granules in high electron density, pinocytotic vesicles and multivesicular body. Rodlet cell have a well developed cytoplasmic capsule and the endoplasmic reticula in the cytoplasm. Dark cell showing a high electron density in the cytoplasm and contains well developed mitochondria. Columnar epithelium of the intestine have a well developed intercellular junction and the microvilli which contains actin filament originated from the cytoplasm. Mucosal epithelium of the intestine have a longer microvilli and more abundant goblet cells than in the pyloric caeca.