• The Korean Journal of Physiology and Pharmacology
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• v.8 no.1
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• pp.57-63
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• 2004

Fluoxetine, a widely used anti-depressant compound, has several additional effects, including blockade of voltage-gated ion channels. We examined whether fluoxetine affects ATP-induced calcium signaling in PC12 cells by using fura-2-based digital calcium imaging and assay for $[^3H]-inositol$ phosphates (IPs). Treatment with ATP $(100\;{\mu}M)$ for 2 min induced $[Ca^{2+}]_i$ increases. The ATP-induced $[Ca^{2+}]_i$ increases were significantly decreased by removal of extracellular $Ca^{2+}$ and treatment with the inhibitor of endoplasmic reticulum $Ca^{2+}$ ATPase thapsigargin $(1\;{\mu}M)$. Treatment with fluoxetine for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase concentration-dependently. Treatment with fluoxetine $(30\;{\mu}M)$ for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase following removal of extracellular $Ca^{2+}$ and depletion of intracellular $Ca^{2+}$ stores. While treatment with the L-type $Ca^{2+}$ channel antagonist nimodipine for 10 min inhibited the ATP-induced $[Ca^{2+}]_i$ increases significantly, treatment with fluoxetine alone blocked the ATP-induced responses. Treatment with fluoxetine also inhibited the 50 mM $K^+-induced$ $[Ca^{2+}]_i$ increases completely. However, treatment with fluoxetine did not inhibit the ATP-induced $[^3H]-IPs$ formation. Collectively, we conclude that fluoxetine inhibits ATP-indueed $[Ca^{2+}]_i$ increases in PC12 cells by inhibiting both an influx of extracellular $Ca^{2+}$ and a release of $Ca^{2+}$ from intracellular stores without affecting IPs formation.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.65.2-65
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• 2003

To protect the plant against several soil-borne pathogens, we are currently constructing disease-resistant transgenic root stock for the growth of cucurbitaceae vegetable plants, watermelon and gourd. We made a watermelon cDNA library from Cladosporium cucumerinum-Infected leaves for substractive hybriazation and differential screening. We isolated the several pathogen inducible cDNA clones, such as caffeoyl-CoA-methyltransferase, LAA induced protein, receptor-like kinase homolog, hydroxyproline-rich glycoprotein, catalase, calmodulin binding protein, mitochondrial ATPase beta subunit, methyl tRNA synthetase and WRKY transcription factors. We previously obtained CaMADS in pepper and galactinol synthase ( CsGolS) in cucumber that were confirmed to be related with disease-resistance. CaMADS and CsGolS2 were transformed into the inbred line 'GO701-2' gourd, the inbred line '6-2-2' watermelon and the Kong-dye watermelon by Agrobacterium tumerfaciens LBA4404. Plant growth regulators (zeatin, BAP and IAA) were used for shoot regeneration and root induction for optimal condition. Putative transgenic plants were selected in medium containing 100mg/L kanamycin and integration of the CaMADS and CsGO/S2 into the genomic DNA were demonstrated by the PCR analysis. We isolated major soil-borne pathogens, such as Monosporascus cannonballus, Didymella bryoniae, Cladosporium cuvumerinum from the cultivation area of watermelon or root stock, and successfully established artificial inoculation method for each pathogen. This work was supported by a grant from BioGreen 21 program, Rural Development Administration, Republic of Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• International Journal of Molecular Medicine
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• v.44 no.3
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• pp.913-926
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• 2019

Leonurus sibiricus L. (LS) is a medicinal plant used in East Asia, Europe and the USA. LS is primarily used in the treatment of gynecological diseases, and recent studies have demonstrated that it exerts anti-inflammatory and antioxidant effects. To the best of our knowledge, the present study demonstrated for the first time that LS may promote osteoblast differentiation and suppress osteoclast differentiation in vitro, and that it inhibited lipopolysaccharide (LPS)-induced bone loss in a mouse model. LS was observed to promote the osteoblast differentiation of MC3T3-E1 cells and upregulate the expression of runt-related transcription factor 2 (RUNX2), a key gene involved in osteoblast differentiation. This resulted in the induction of the expression of various osteogenic genes, including alkaline phosphatase (ALP), osteonectin (OSN), osteopontin (OPN), type I collagen (COL1) and bone sialoprotein (BSP). LS was also observed to inhibit osteoclast differentiation and bone resorption. The expression levels of nuclear factor of activated T-cells 1 (NFATc1) and c-Fos were inhibited following LS treatment. NFATc1 and c-Fos are key markers of osteoclast differentiation that inhibit receptor activator of nuclear factor-κB ligand (RANKL)-induced mitogen-activated protein kinase (MAPKs) and nuclear factor (NF)-κB. As a result, LS suppressed the expression of osteoclast-associated genes, such as matrix metallopeptidase-9 (MMP-9), cathepsin K (Ctsk), tartrate-resistant acid phosphatase (TRAP), osteoclast-associated immunoglobulin-like receptor (OSCAR), c-src, c-myc, osteoclast stimulatory transmembrane protein (OC-STAMP) and ATPase H+ transporting V0 subunit d2 (ATP6v0d2). Consistent with the in vitro results, LS inhibited the reduction in bone mineral density and the bone volume/total volume ratio in a mouse model of LPS-induced osteoporosis. These results suggest that LS may be a valuable agent for the treatment of osteoporosis and additional bone metabolic diseases.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.236-249
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• 1993

Background: Among the injurious agents to which the lung airspaces are constantly exposed are reactive species of oxygen. It has been widely believed that reactive oxygen species may be implicated in the etiology of lung injuries. In order to elucidated how this oxidant causes lung cell injury, we investigated the effects of exogenous $H_2O_2$ on alveolar epithelial barrier characteristics. Methods: Rat type II alveolar epithelial cells were plated onto tissue culture-treated polycarbonate membrane filters. The resulting confluent monolayers on days 3 and 4 were mounted in a modified Ussing chamber and bathed on both sides with HEPES-buffered Ringer solution. The changes in short-circuit current (Isc) and monolayer resistance (R) in response to the exogenous hydroperoxide were measured. To determine the degree of cellular catalase participation in protection against $H_2O_2$ injury to the barrier, experiments were repeated in the presence of 20 mM aminotriazole (ATAZ, an inhibitor of catalase) in the same bathing fluid as the hydroperoxide. Results: These monolayers have a high transepithelial resistance (>2000 ohm-$cm^2$) and actively transport $Na^+$ from apical fluid. $H_2O_2$(0-100 mM) was then delivered to either apical or basolateral fluid. Resulting indicated that $H_2O_2$ decreased Isc and R gradually in dose-dependent manner. The effective concentration of apical $H_2O_2$ at which Isc (or R) was decreased by 50% at one hour ($ED_{50}$) was about 4 mM. However, basolateral $H_2O_2$ exposure led to $ED_{50}$ for Isc (and R) of about 0.04 mM. Inhibition of cellular catalase yielded $ED_{50}$ for Isc (and R) of about 0.4 mM when $H_2O_2$ was given apically, while $ED_{50}$ for basolateral exposure to $H_2O_2$ did not change in the presence of ATAZ. The rate of $H_2O_2$ consumption in apical and basolateral bathing fluids was the same, while cellualr catalase activity rose gradually with time in culture. Conclusion: Our data suggest that basolateral $H_2O_2$ may affect directly membrane component (e.g., $Na^+,\;K^+$-ATPase) located on the basolateral cell surface. Apical $H_2O_2$, on the other hand, may be largely degraded by catalase as it passes through the cells before reaching these membrane components. We conclude that alveolar epithelial barrier integrity as measured by Isc and R are compromised by $H_2O_2$ being relatively sensitive to basolateral (and insensitive to apical) $H_2O_2$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.280-290
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• 1984

An extensive study has been made on the relationship between the freshness and the compositions of the muscle protein of prawn, Pandalus japonica during the storage under partially frozen condition. The variations of the subunit distribution for sarcoplasmic protein and myofibrillar protein extracted from the samples by changes of freshness were discussed by sodium dodecylsulfate-poly-acrylamide gel (SDS-PAG) electrophoresis. On the other hand, the denaturation constant ($K_D$) of the myofibrillar protein extracted from the prawn stored at $-3^{\circ}C\;and\;-20^{\circ}C$ were successively compared. The prawn muscle contained about $18\%$ of protein with the composition of $32\%$ in sarcoplasmic protein, $56\%$ in myofibrillar protein, $10\%$ in residual intracellular protein and $2\%$ in stroma. The indices for estimating freshness of the muscle were approached to the early stage of putrefaction on the 26th day of the storage with $25.29mg\%$ of total volatile basic nitrogen, $31.36\%$ of K-value and 8.83 of pH. The content of the myofibrillar protein was remarkably decreased with the time during the storage while that of residual intracellular protein was increased. The $K_D$ values of the myofibrillar protein were $9.03{\times}10^{-6}sec^{-1}\;at\;-3^{\circ}C\;and\;4.42{\times}10^{-6}sec^{-1}\;at\;-20^{\circ}C$. The results of the analysis of SDS-PAG electrophoretograms indicated that the sarcoplasmic protein and the myofibrillar protein were composed of 12 subunits and 17 subunits in the muscle of instantaneously killed prawn ana were changed into 8 subunits and 22 subunits in the muscle stored for 26 days, respectively. It is noticeable that 30,000, 41,000, 107,000, 136,000, 170,000 173,000, 185,000, and 198,000 daltons of the newly appeared 8 subunits were found in the myofibrillar protein from the prawn muscle stored for 26 days. The amino acid composition of the muscle protein showed that the most of amino acids were slightly decreased with the days of the storage. With respect to the free amino acid composition of the muscle of instantaneously killed prawn, glycine, proline, arginine, alanine and taurine comprised $93\%$ of the total free amino acids. Taurine, valine, leucine, phenylalanine, serine, lysine, methionine, isoleucine and histidine were increased during the storage period but exceptionally proline was decreased.

• Parasites, Hosts and Diseases
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• v.23 no.2
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• pp.269-284
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• 1985

The metabolism of Entamoeba histolytica would be affected by various environmental factors, and alteration of the environment was known to afEect the fine structure of 5. histolytica. The present study was designed electronmicroscopically to investigate the ultrastructure and enzyme activities in the aEonic and conventional strains of 5. histolytica. The trophozoites of axenically cultivated HK-9 strain and conventional YS-27 and YS-49 strains of 5. histolytica were collected and liKed with 4% paraformaldehyde/0.1M cacodylate buffier(pH 74), After washing them by centrifugation, 1% warm agar was added in the sediment. Solidified agar with the trophozoites was cut into $lmm^3$ cubes, and incubated in the various substrates to observe enzyme activities. Then, the specimen was post-fixed with 3% glutaraldehyde/0.1M cacodylate buffer (PH 7.4) and 1% osmium tetroBide/0.1M cacodylate buffier (pH 7.4) , dehydrated in ascending ethanol series and embedded in epoxy resin. These were sectioned on an ultramicrotome and observed with a transmission electronmicroscope. The procedures for the observation of the fine structure were same as the above, except for the incubation in the substrate. The sections were stained with uranyl acetate and lead citrate. For the observation of the surface of the amoebae, scanning-electronmicroscopy was carried out. The results obtained in the present study are summarized as follows: 1. The fuzzy coat around double-layered plasma membrane of 5. histolytica was more irregularly and densely distributed in the conventional strains (YS-27, YS-49 strains) than in the axonic strain (HK-9 strain). 2. The endosomes, button bodies and chromatin material were surrounded by a double-layered nuclear membrane having scattered nuclear fores. The paranuclear body, mono- or double-layered vacuoles, vacuolar membrane whorls, rosette-like cylindrical bodies, aggregation of cylindrical bodies and helical bodies were found in the cytoplasm of the amoebae. Helical bodies and glycogen granules were generally abundant, while a few smooth endoplasmic reticula were observed in the cytoplasm. 3. Alkaline phosphatase activity was mainly demonstrated in the plasma membrane, limiting membranes of vacuoles and smooth endoplasmic reticula. ATPase activity was observed in the nucleus, limiting membranes of vacuoles and vacuolar membrane whorls. 4. Acid phosphatase activity was commonly demonstrated in the limiting membranes an contents of vacuoles, Iysosome-like organelles, plasma membrane and the button bodies in the nucleus. The activity was more weakly demonstrated in the HK-9 strain than in the other conventional strains of 5. histolytica. No peroBidase activity was observed in the amoeba strains employed in the present study. 5. With a scanning electron-microscope, no distinct structural differences were observed between the amoeba strains. All the trophozoite forms of the amoebae showed crater-like depressions and rugged features on the outer surface.

• Archives of Pharmacal Research
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• v.29 no.5
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• pp.375-383
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• 2006

The anti platelet effects of a novel guanidine derivative, KR-32570 ([5-(2-methoxy-5-chlorophenyl) furan-2-ylcarbonyl]guanidine), were investigated with an emphasis on the mechanisms underlying its inhibition of collagen-induced platelet aggregation. KR-32570 significantly inhibited the aggregation of washed rabbit platelets induced by collagen $(10{\mu}g/mL)$, thrombin (0.05 U/mL), arachidonic acid $(100{\mu}M)$, a thromboxane (TX) $A_2$ mimetic agent U46619 (9,11-dideoxy-9,11-methanoepoxy-prostaglandin $F_2,\;1{\mu}M$) and a $Ca^{2+}$ ATPase inhibitor thapsigargin $(0.5{\mu}M)$ ($IC_{50}$ values: $13.8{\pm}1.8,\;26.3{\pm}1.2,\;8.5{\pm}0.9,\;4.3{\pm}1.7\;and\;49.8{\pm}1.4{\mu}M$, respectively). KR-32570 inhibited the collagen-induced liberation of $[^3H]$arachidonic acid from the platelets in a concentration dependent manner with complete inhibition being observed at $50{\mu}M$. The $TXA_2$ synthase assay showed that KR-32570 also inhibited the conversion of the substrate $PGH_2$ to $TXB_2$ at all concentrations. Furthermore, KR-32570 significantly inhibited the $[Ca^{2+}]_i$ mobilization induced by collagen at $50{\mu}M$, which is the concentration that completely inhibits platelet aggregation. KR-32570 also decreased the level of collagen $(10{\mu}g/mL)$induced secretion of serotonin from the dense-granule contents of platelets, and inhibited the NHE-1-mediated rabbit platelet swelling induced by intracellular acidification. These results suggest that the antiplatelet activity of KR-32570 against collagen-induced platelet aggregation is mediated mainly by inhibiting the release of arachidonic acid, $TXA_2$ synthase, the mobilization of cytosolic $Ca^{2+}$ and NHE-1.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1897-1906
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• 2019

Objective: An experiment was conducted to investigate the effects of dietary non-phytate phosphorus (nPP) deficiency on intestinal pH value, digestive enzyme activity, morphology, nutrient utilization, and gene expression of NaPi-IIb in meat ducks from 1 to 21 d of age. Methods: A total of 525 one-d-old Cherry Valley ducklings were fed diets (with 7 pens of 15 ducklings, or 105 total ducklings, on each diet) with five levels of nPP (0.22%, 0.34%, 0.40%, 0.46%, or 0.58%) for 21 d in a completely randomized design. Five experimental diets contained a constant calcium (Ca) content of approximately 0.9%. Body weight (BW), body weight gain (BWG), feed intake (FI), and feed to gain ratio (F:G) were measured at 14 and 21 d of age. Ducks were sampled for duodenum and jejunum digestion and absorption function on 14 and 21 d. Nutrient utilization was assessed using 25- to 27-d-old ducks. Results: The results showed ducks fed 0.22% nPP had lower (p<0.05) growth performance and nutrient utilization and higher (p<0.05) serum Ca content and alkaline phosphatase (ALP) activity. When dietary nPP levels were increased, BW (d 14 and 21), BWG and FI (all intervals), and the serum phosphorus (P) content linearly and quadratically increased (p<0.05); and the jejunal pH value (d 14), duodenal muscle layer thickness (d 14), excreta dry matter, crude protein, energy, Ca and total P utilization linearly increased (p<0.05); however, the serum ALP activity, jejunal $Na^+-K^+$-ATPase activity, and duodenal NaPi-IIb mRNA level (d 21) linearly decreased (p<0.05). Conclusion: The results indicated that ducks aged from 1 to 21 d fed diets with 0.22% nPP had poor growth performance related to poor intestinal digestion and absorption ability; but when fed diets with 0.40%, 0.46%, and 0.58% nPP, ducks presented a better growth performance, intestinal digestion and absorption function.