• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.32-42
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• 2009

The purpose of the present study was to examine the effect of dihydrexidine, a full $D_1$ receptor agonist, on the secretion of catecholamines (CA) from the perfused model of the rat adrenal gland, and to establish its mechanism of action. Dihydrexidine (10-100 ${\mu}M$), perfused into an adrenal vein for 60 min, relatively produced dose- and time-dependent inhibition in the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (56 mM), DMPP (100 ${\mu}M$) and McN-A-343 (100 ${\mu}M$). Dihydrexidine itself did fail to affect basal CA output. Also, in adrenal glands loaded with dihydrexidine (30 ${\mu}M$), the CA secretory responses evoked by Bay-K-8644 (10 ${\mu}M$), an activator of L-type $Ca^{2+}$ channels, cyclopiazonic acid (10 ${\mu}M$), an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, and veratridine, an activator of voltage-dependent $Na+$ channels (10 ${\mu}M$), were also markedly inhibited, respectively. However, in the simultaneous presence of dihydrexidine (30 ${\mu}M$) and R (+)-SCH23390 (a selective antagonist of $D_1$ receptor, 3 ${\mu}M$), the CA secretory responses evoked by ACh, high K+, DMPP, McN-A-343, Bay-K-8644, cyclopiazonic acid and veratridine were considerably recovered to the extent of the corresponding control secretion compared with the inhibitory responses by dihydrexidinetreatment alone. In conclusion, these experimental results suggest that dihydrexidine significantly inhibits the CA secretion evoked by cholinergic stimulation (both nicotinic and muscarinic receptors) and membrane depolarization from the rat adrenal medulla. It seems that this inhibitory effect of dihydrexidine may be mediated by inhibiting influx of both $Ca^{2+}$ and $Na^+$ into the cytoplasm as well as by suppression of $Ca^{2+}$ release from cytoplasmic calcium store through activation of dopaminergic $D_1$ receptors located on the rat adrenomedullary chromaffin cells.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.13-18
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• 1999

This study was undertaken to find out the effect of dropwort on histopathological changes of cadmium toxicity in mice. Thirty two mice of BALB/c strain were divided into a control group (A) and three experimental groups (B, C, D). Each group was consisted of four males and four females : group A received tap water and basal diet, group B received tap water and diet supplemented with 100 mg/kg of cadmium, group C received dropwort juice and diet supplemented with 100 mg/kg of cadmium, group D received dropwort juice and basal diet. All mice were dissected on the 35th day. Pathological changes in liver, kidney, spleen, heart, lung, stomach and muscle were observed. Group D showed no significant change as the control group. But group B showed many cytoplasmic vacuoles and necrosis of hepatocytes, glomerular swelling, and degeneration and necrosis of convoluted tubules in kidney, marked congestion and hemorrhage, and a large number of variably sized alveolar macrophages appearance in lung and swelling in some part of muscle fiber. On the other hand, group C showed a little convalescent changes and maintained their normal architectures in liver, kidney, lung and muscle.

• IMMUNE NETWORK
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• v.5 no.3
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• pp.144-149
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• 2005

Background: Fc receptor-mediated phagocytosis is a complex process involving the activation of kinases and phosphatases. FcgammaRIIB has been known to transduces inhibitory signals through an immunoreceptor tyrosine-based inhibitory motif (ITIM) in cytoplasmic domains. In this study, we examined the involvement of inositol-phosphatase in the Fc receptor-mediated phagocytosis. Methods: J774 cells were infected using vaccinia viral vector containing SH2 domain-containing inositol-phosphatase (SHIP) cDNA and stimulated with the sensitized sheep red blood cells. Results: Stimulation of J774 cells induced the tyrosine phosphorylation of SHIP which was maximal at 5 minutes. Phosphatidylinositol-3 (PI-3) kinase inhibitor (wortmannin) inhibits J774 cell phagocytosis of sensitized sheep red blood cells in a dose-dependent manner. Heterologious expression of SHIP in J774 cells inhibits phagocytosis of sensitized sheep red blood cells in a dose-dependency manner, but catalytically dead mutants of SHIP has no effect on phagocytosis. Conclusion: These results strongly suggest that the active signals mediated by PI-3 kinase are opposed by inhibitory signals through SHIP in the regulation of Fc receptor-mediated phagocytosis.

• Journal of Sericultural and Entomological Science
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• v.18 no.2
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• pp.79-81
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• 1976

Experiments on the disinfection of the silkworm larvae by the application of Neo-PPS fumigation have been carried out for the control of virus diseases. The results obtained are summarized as follows. The disinfection of 2, 4 and 6 hours'fumigation with Neo-PPS (para-formaldehyde) showed an outstanding effect on the inactivation of the both viruses, nuclear polyhedrosis virus and cytoplasmic polyhedrosis virus, without significance in the 2. 4. and 6 hours' treatment.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.75-81
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• 1976

High ionic strength is expected to enhance dissociation of Ca-DPA from spores and to contribute to a detrimental effect on spore stability or on spore heat resistance with a combined treatment of gamma-radiation. From this study, this hypothesis has become apparent as as follows; 1) Ca-DPA dissociation contributes to loss of stability of bacterial spores with respect to heat resistance, survival during storage, and 2) the cytoplasmic membrane plays a role in maintaining the stability of DPA-Ca-spore complex, apparently by serving as a permeability barrier.

• Journal of Sericultural and Entomological Science
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• v.16 no.1
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• pp.85-92
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• 1974

Many of studies on the transovarial transmission of occult virus and their activation due to various stresses such as cold or heat treatment, chemical feeding, and nutritional deficiency, etc., in the silkworm, Bombyx mori L. have been made, but any attempts have been not made to control virus diseases by detection of the occult virus-carried moths in the production of silkworm egg of hybrids, because of difficulty to detect occult virus in any stage. Therefore, it may be worth while to disclose whether a sublethal infection of the moths from which active virus are detectable, has the same level of induction rate as that of occult virus activation, thus to apply its results for the reduction of the occurence of virus diseases in silkworm rearing. For these purposes, the following experiment was conducted as one of preliminary steps. In this study, investigations on the generation-to-generation transmission of occult virus and a sublethal infection, and the role of chromosomal gene of the host, Jam 103 and Jam 104 in the Previous generation, and Jam 103 x Jam 103 and Jam 104 f Jam 104 in the next generation were made for the induction of virus diseases due to the transmitted virus. The frequency of cytoplasmic polyhedrosis due to the induction in the F$_1$ generation was markedly higher in the cross-batches, male$\times$female and male$\times$female in which inoculated individuals were used as fem ale parents than in the cross-batches, male$\times$female and male$\times$female in which virus has been not inoculated or inoculated only to male in the previous generation. The tendency of increasing rate was observed in any treatments; such as the inoculations of cytoplasmic polyhedrosis virus (10$\^$5/, 10$\^$6/ 10$\^$7, and 10$\^$8//ml ill different concentration of inocula) , cold-treatment (5$^{\circ}C$, 12hrs or 24hrs), and formalin-feeding treatment (2％ or 3％). The shape of polyhedra (tetragonal in outline) examined in the F, larvae was identified as that of the inoculated polyhedra with partial application of immunofluorescent techniques. These results suggests that the cytoplasmic polyhedrosis virus in B. meri L. are transmitted to the next generation through the egg, apparently in the occult state. And the experimental results of various cross-batches revealed the egg cytoplasm plays an important part i the transmission of the occult virus of the cytoplasmic polyhedrosis virus,

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.101-118
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• 1975

The pathogenicity of hexagonal and tetragonal cytoplasmic polyhedron virus to one of present leading silkworm varieties, Jam 103${\times}$Jam 104, and its parents, Jam 103 and Jam 104, was investigated. The activation of occult virus by oral inoculation of foreign virus as well as the interference phenomena between the activated and inoculated cytoplasmic polyhedron viruses was observed and the results obtained are as follows. 1. The pathogenicity of cytoplasmic polyhedrosis viruses. 1) There was a high significant difference in the pathogenicity of hexagonal polyhedron virus between the hybrid and its parents showing the lowest infection rate in the hybrid (Jam 103${\times}$Jam 104), medium infection rate in the Japanese line (Jam 103) and the highest infection rate in the Chinese line (Jam 104). In the pathogenicityof tetragonal polyhedron virus, a significant difference was observed only between the hybrid (Jam 103${\times}$Jam 104) and the Chinese line (Jam 104) by showing a higher infection rate in the Chinese line than in the hybrid. 2) The pathogenicity of both hexagonal and tetragonal polyhedron viruses showed a high significant difference in different silkworm instars inoculated by showing a higher infection rate at the second instar than at the fourth instar. 3) The pathogenicity of both hexagonal and tetragonal polyhedron viruses was increased as the concentration of viruses inoculated increased. 2. The phenomena of induction and interference by oral inoculation of foreign virus. 1) The induction rate of cytoplasmic polyhedrosis virus was higher in the parents than in the hybrid. In the parents. a higher rate in the Chinese line than in the Japanese line was observed. 2) The effect of inoculation at different instars on the induction was studied and the induction rate was higher at the second instar inoculated than at the fourth instar inoculated. 3) The degree of activation of hexagonal polyhedron virus with inoculation of tetragonal polyhedron virus was very high when a lower concentration of virus was inoculated and it was very low when a higher concentration of virus was inoculated 4) The degree of activation of tetragonal polyhedron virus with inoculation of hexagonal polyhedron virus was very low when a lower concentration of virus was inoculated and it was not observed when a higher concentration of virus was inoculated. 5) The mixed infection rate with hexagonal and tetragonal polyhedron viruses was higher at the second instar inoculated than at the fourth instar inoculated. 6) It was observed that the secondary hexagonal pc]yhedron virus activated interfered with the primary tetragonal polyhedron virus inoculated when the inoculated concentration of the primary virus is low and the primary virus inoculated interfered with the secondary virus activated when the inoculated concentration of the primary virus is high.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.5
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• pp.1243-1249
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• 2007

The aim of this study was to investigate the effect of ethanol extract of Fagopyrum esculentum on the melanogenesis. To determine whether ethanol extract of Fagopyrum esculentum suppress melanin synthesis in cellular level, B16F10 melanoma cells were cultured in the presence of different concentrations of Fagopyrum esculentum ethanol extract. In the present study, we examined the effects of Fagopyrum esculentum ethanol extract on cell proliferation, melanin contents, tyrosinase activity, expression of melanogenic enzyme proteins including tyrosinase, tyrosinase-related protein 1 (TRP-1) and tyrosinase-related protein 2 (TRP-2). Cell proliferation was slightly increased by treatment with ethanol extract of Fagopyrum esculentum $(25-200 {\mu}g/m{\ell}).$ The ethanol extract of Fagopyrum esculentum effectively suppressed melanin contents at a dose of $100 {\mu}g/m{\ell}).$ It was observed that the color of cell pellets was totally whitened compared with the control. The ethanol extract of Fagopyrum esculentum inhibited tyrosinase activity, regulate melanin biosynthesis as the key enzyme in melanogenesis. Using western blot analysis, the ethanol extract of Fagopyrum esculentum dose-dependently decreased tyrosinase and TRP-1 protein levels, and tyrosinase and TRP-1 were detected in similar manner. ${\alpha}-MSH$ leads to a stimulation of melanin synthesis through increase of tyrosinase activity, melanin contents and cytoplasmic dendricity. In this study, ethanol extract of Fagopyrum esculentum down-regulated the ${\alpha}-MSH$-induced tyrosinase activity, melanin contents and cytoplasmic dendricity. Regarding protein levels of the melanogenic enzymes, the amounts of tyrosinase and TRP-1 was increased after incubation with a-MSH. The treatment of ethanol extract of Fagopyrum esculentum decreased the ${\alpha}-MSH$-induced expression levels of tyrosinase and TRP-1. These results suggest that the ethanol extract of Fagopyrum esculentum exerts its depigmenting effects through the suppression of tyrosinase, TRP-1 and cytoplasmic dendricity. And it may be a potent depigmetation agent in hyperpigmentation condition.

• Korean Journal of Microbiology
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• v.7 no.1
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• pp.10-21
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• 1969

The effect of glucose and 2-thiobarbituric acid on the biosynthesis of cell constituents such as protein, carbohydrate, DNA, RNA, phospholipid and PCA-soluble phosphate compounds in Chlorella duing the life cycle was measured, and the changes in the content of these main cellular components of the algal cell were analyzed in connection with the nuclear and cytoplasmic divison. In the normal autotrophic synchronous culture the contents of protein, RNA, and DNA in the cell showed a chracteristic changes according to the progress of cell development, increasing more or less throughout all the life cycle. The synthesis of protein is more prominent in the division period nad that of DNA is more active in the ripening period, while the synthesis of RNA is more rapid in the growing and ripening periods than other developmental stages. The period of division cycle was little affected by glucose in the medium, although the synchrony of the growth and cellular division was disturbed and the n value increased. The cotents of protein, carbohydrate, RNA nad DNA of the cell were increased by the glucose treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment. The synthesis of protein, carbohydrate, DNA, RNA and phospholipid of the cell was also retarded by 2-thiobarbituric acid. In the autotrophic, mixotrophic and 2-thiobarbituric acid-treated cultures, each having different mode cytoplasmic division, a common general schema occurring in the cell during the life cycle may be drawn as follows. The ratio of RNA to protein attains maximum value in the $L_1$-cell stage prior to the nuclear division and thereafter decreases during the periods of ripening and division. The ratio of PCA-soluble phosphate compounds to protein increased from the begining of the culture to $L_4$-cell stage successively and thereafter decreased gradually during the division period, while the ratio of protein to DNA kept almost constant up to the division period and thereafter increased during the division period. Therefore, it is presumed that the increase in the ratio of RNA to protein is to be an inducer of nuclear division and that the cytoplasmic division is induced by the increase in the ratio of protein to DNA.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.155-164
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• 2008

Resveratrol has been known to possess various potent cardiovascular effects in animal, but there is little information on its functional effect on the secretion of catecholamines (CA) from the perfused model of the adrenal medulla. Therefore, the aim of the present study was to determine the effect of resveratrol on the CA secretion from the isolated perfused model of the normotensive rat adrenal gland, and to elucidate its mechanism of action. Resveratrol (10${\sim}100{\mu}$M) during perfusion into an adrenal vein for 90 min inhibited the CA secretory responses evoked by ACh (5.32 mM), high $K^+$ (a direct membrane-depolarizer, 56 mM), DMPP (a selective neuronal nicotinic $N_n$ receptor agonist, 100${\mu}$M) and McN-A-343 (a selective muscarinic $M_1$ receptor agonist, 100${\mu}$M) in both a time- and dose- dependent fashion. Also, in the presence of resveratrol (30${\mu}$M), the secretory responses of CA evoked by veratridine 8644 (an activator of voltage-dependent$Na^+$ channels, 100${\mu}$M), Bay-K-8644 (a L-type dihydropyridine $Ca^{2+}$ channel activator, 10${\mu}$M), and cyc1opiazonic acid (a cytoplasmic $Ca^{2+}$-ATPase inhibitor, 10${\mu}$M) were significantly reduced. In the simultaneous presence of resveratrol (30${\mu}$M) and L-NAME (an inhibitor of NO synthase, 30${\mu}$M), the CA secretory evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyc1opiazonic acid were recovered to a considerable extent of the corresponding control secretion compared with the inhibitory effect of resveratrol alone. Interestingly, the amount of nitric oxide (NO) released from the adrenal medulla was greatly increased in comparison to its basal release. Taken together, these experimental results demonstrate that resveratrol can inhibit the CA secretory responses evoked by stimulation of cholinergic nicotinic receptors, as well as by direct membrane-depolarization in the isolated perfused model of the rat adrenal gland. It seems that this inhibitory effect of resveratrol is exerted by inhibiting an influx of both ions through $Na^+$ and $Ca^{2+}$ channels into the adrenomedullary cells as well as by blocking the release of $Ca^{2+}$ from the cytoplasmic calcium store, which are mediated at least partly by the increased NO production due to the activation of NO synthase.