• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.424-430
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• 2002

Vas deferens is a long tube and could be divided into four regions as its morphological characters: a short and slender proximal region, a convoluted region, a straight and more thick distal region, and an ejaculatory duct, It is connected with the posterior outer horns of the testis and runs to the gonopores opened on the coxa of the fifth walking legs, The proximal region consists almost entirely of simple cuboidal epithelial cells, $12\~28{\mu}$m in height, surrounded by a thin basal membrane. A small aggregation of high cuboidal epithelium is obsened from one side of the proximal region. The convoluted and distal region is composed of two kinds of epithelial cells; high cuboidal epithelial cells, $40\~120{\mu}m$ in height located in dorsal portion and simple cuboidal epithelial cells of $12\~28{\mu}$m in height located in ventral and lateral portion. The ejaculatory duct is surrounded with two kinds of muscle layers, inner longitudinal and outer circular muscle fibers, The lumen is lined with high and simple cuboidal epithelium in almost equal proportions. The proximal region contains mature sperm and basophilic substances. The eosinophilic substances appeared newly going toward the convoluted region and are laid along simple cuboidal epithelial cell layer. Tube-like content (spermatophore) of the vas deferens is ejaculated from a pair of genital pores at mating. Two masses of the content fuse together side by side and are usually deposited on the female thorax between the second and fourth or fifth pereiopods, The spermatophore formed measures $2.7\~4.0$ mm in length and $1.5\~2.7$ mm in width.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.170-177
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• 2006

Morphology and distribution of the minute tubercles projected on the skin surface of larvae with its development was observed in the Korean bitterling, Acheilognathus koreensis, known as an endemic freshwater fish. The epidermis of the larvae consisted of a thin single layer, having smaller basophilic flat or round-flattened basal cells. In between the single cell layer, two or three layers were added and they consisted mainly of large epidermal cells just above basal cells. These large unicellular epidermal cells were mainly scale-shaped and rarely cone-shaped, and do not give any histochemical tests for mucosubstances. They were present in anterior region and most region of yolk sac. Whereas, vestigial epidermal cells were distributed in the body region and the caudal fin-fold region. These two kinds of epidermal cells, called minute tubercles, increased in number and height from Just to 8 days after hatching, but as the larvae develop gradually, they became to reduce. At 31days after hatching of free swimming stage and absolute absorption stage of the yolk sac, the minute tubercles did not exist on the whole skin of the larvae.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.164-170
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• 2007

The concept of innate immunity in insects which refers to the first line of host defense constitutes the humoral and cellular components which are involved in recognition and actively participate in the elimination of the intruding foreign micro- or macro-organisms. Several recent studies suggest that juvenile hormone (JH) modulates the cellular immune reactions in response to pathogen. In this study, pyriproxyfen (a JH agonist as an insect growth regulator) was tested in its any inhibitory effect on the immune reactions of the beet armyworm, Spodoptera exigua. To this end, five different hemocyte morphotypes of final instar S. exigua were identified by phase contrast microscopy. Plasmatocytes and granular cells, which constitute about 90% of the total hemocyte count, were prominently distinguished based on their basophilic/acidophilic nature using Giemsa stain. The role of pyriproxyfen on the functional ability of hemocytes was analyzed using FITC-labeled Providencia vermicola for the phagocytic potential of the hemocytes. Both granular cells and plasmatocytes exhibited phagocytosis behavior. Pyriproxyfen significantly inhibited the phagocytosis of both cell types, proposing its novel action as an immunosuppressant.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.347-364
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• 2006

This study is concerned with assessment of diethylnitrosamine (DEN 0.01 %) induced liver cell carcinogenesis by measurement of changes preceding the development of neoplasms. Therefore, it was undertaken to investigate changes of liver-specific enzyme activities in Sprague-Dawley (SD) rats by ad libitum feeding of DEN. And also. the changes of hepatic morphology in SD rats were detected by haematoxylineosin stain and immunohistochemistry (PCNA). 5- Fluorouracil (5- FU) is one of the most widely used anticancer agents for digestive cancers including hepatocellular carcinoma, and is known to affect the cell cycle and induce apoptosis of cancer cells. In the present study, SD rats were given drinking water containing 0.01% diethylnitrosamine (DEN) for 8 weeks. Minor behavioral change, brittleness of hair and decreased amount of water and diet intake were observed in rats 4 weeks after DEN administration. The body and liver weights were significantly (p < 0.05) decreased in rats 11 weeks after DEN administration. The liver weight ratio to body weight was rather stable and not significantly decreased in the all treatment groups. The liver specific enzyme activities (AST, ALT, ${\gamma}$-GTP) were significantly increased in all treatment groups compared to control group (p < 0.05). Variable size of liver tumor and hepatomegaly were observed in rats treated with DEN after 10 weeks. Numerous vacuoles were seen on the midzonal and or peripheral areas of hepatic lobules. The large and polymorphological hepatocytes with eosinophilic cytoplasm or densely basophilic mitotic nucleoli were seen. Several proliferative small round cells were seen on vacuolated and necrotic areas in peripheral hepatic lobules or portal areas. PCNA-positive cells were seen on the vacuolated portal areas and peripheral areas of hepatic lobules in the areas of small round cells. We examined functional and morphological changes of livers by 5 - FU treatments on DEN -treated rat. The DEN -treated rats compared to 5 - FU -treated rats after DEN treatment for 8 weeks. The serum total protein and triglyceride were significantly (p < 0.05) decreased, and the liver enzyme activities of AST and ALT were significantly(p < 0.05) increased. After 8 weeks, in the non-5-FU -treated group, the size of liver tumor were varied and hepatomegaly were observed, hepatocellular vacuolization, necrosis and steatosis were observed on the midzonal and peripheral areas of hepatic lobules. The large and polymorphological hepatocytes were seen, the interlobular connective tissues were proliferated. PCNA positive cells were seen in the portal areas and peripheral areas of hepatic lobules in the non-5-FU-treated group. In hepatocytes, condensation of nuclear chromatin and vacuolization were observed, shape of the nuclei were irregular, the degraded nuclei and organelles were observed. The livers of rats in the 5 - FU treatment group were seen grossly brilliant, red-brown color, and the vacuolated and degenerated regions, hyperplastic nodules were not nearly observed. In the electron microscope, the cytoplasm of the hepatocytes contained a large number of mitochondria, rough endoplasmic reticulum, developed organelles surrounding nuclei. The above findings suggest that 5 - FU will be effective as anti -liver tumor drug.

• Korean Journal of Animal Reproduction
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• v.23 no.1
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• pp.1-12
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• 1999

The present study was conducted to find the effects of different cadmium(Cd) levels in diets on clinical toxicity, sperm capacity and histopathological changes in rats. Thirty male rats of Sprague-Dawley weighing 125.3$\pm$15.2g were randomly blocked into five groups according to body weights. Five levels of Cd in AIN-76 purified diet(0, 25, 50, 100 and 250 ppm) had been fed for 8 weeks. Cadmium was supplemented with a form of CdCl$_2$. 1. After 8 weeks of Cd intake had resulted in apparent cadmium intoxication; reduced growth rate, enlarged kidney and testis, decreased hematocrit value and hemoglobin content in response to supplemented Cd levels in the diets. 2. Cadmium accumulation in liver and kidney showed a tendency to increase in cadmium-exposed groups. The levels of metallothionein were also significantly elevated in the tissues of liver in response to the levels of Cd supplemented(P＜0.05). 3. Although sperm motility was not significantly different among treatments, rats fed Cd tended to have reduced sperm motility but sperm concentration of Cd supplemented groups were significantly lower than that of control(p＜0.05). 4. Based on the findings from gross lesion, rats fed 250ppm of Cd were externally emaciated, had exposed penis and observed atrophies of kidney and testis. Histopathological observation seemed that the liver of groups feeding Cd supplemented diets showed cellular degeneration and accumulation of eosinophilic materials in the capillaries. In kidney, rats fed Cd diets had shown tubular epithelium degeneration and lesions of basophilic materials, while testes were weakened in numbers of spermatid and sporadically enlarged of giant cells.

• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.43-49
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• 2012

Stimulation of mast cells through the high affinity IgE receptor (Fc${\varepsilon}$RI) induces degranulation, lipid mediator release, and cytokine secretion leading to allergic reactions. Although various signaling pathways have been characterized to be involved in the Fc${\varepsilon}$RI-mediated responses, little is known about the precious mechanism for the expression of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in mast cells. Here, we report that rapamycin, a specific inhibitor of mammalian target of rapamycin (mTOR), reduces the expression of TNF-${\alpha}$ in rat basophilic leukemia (RBL-2H3) cells. IgE or specific antigen stimulation of RBL-2H3 cells increases the expression of TNF-${\alpha}$ and activates various signaling molecules including S6K1, Akt and p38 MAPK. Rapamycin specifically inhibits antigeninduced TNF-${\alpha}$ mRNA level, while other kinase inhibitors have no effect on TNF-${\alpha}$ mRNA level. These data indicate that mTOR signaling pathway is the main regulation mechanism for antigen-induced TNF-${\alpha}$ expression. TNF-${\alpha}$ mRNA stability analysis using reporter construct containing TNF-${\alpha}$ adenylate/uridylate-rich elements (AREs) shows that rapamycin destabilizes TNF-${\alpha}$ mRNA via regulating the AU-rich element of TNF-${\alpha}$ mRNA. The antigen-induced activation of S6K1 is inhibited by specific kinase inhibitors including mTOR, PI3K, PKC and $Ca^{2+}$chelator inhibitor, while TNF-${\alpha}$ mRNA level is reduced only by rapamycin treatment. These data suggest that the effects of rapamycin on the expression of TNF-${\alpha}$ mRNA are not mediated by S6K1 but regulated by mTOR. Taken together, our results reveal that mTOR signaling pathway is a novel regulation mechanism for antigen-induced TNF-${\alpha}$ expression in RBL-2H3 cells.