• The Korean Journal of Physiology and Pharmacology
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• v.3 no.2
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• pp.223-230
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• 1999

Alterations of cardiovascular function associated with various thyroid states have been studied. In hyperthyroidism left ventricular contractility and relaxation velocity were increased, whereas these parameters were decreased in hypothyroidism. The mechanisms for these changes have been suggested to include alterations in the expression and/or activity levels of various proteins; ${\alpha}-myosin$ heavy chain, ${\beta}-myosin$ heavy chain, ${\beta}-receptors,$ the guanine nucleotide-binding regulatory protein, and the sarcolemmal $Ca^{2+}-ATPase.$ All these cellular alterations may be associated with changes in the intracellular $Ca^{2+}$ concentration. The most important regulator of intracellular $Ca^{2+}$ concentration is the sarcoplasmic reticulum (SR), which serves as a $Ca^{2+}$ sink during relaxation and as a $Ca^{2+}$ source during contraction. The $Ca^{2+}-ATPase$ and phospholamban are the most important proteins in the SR membrane for muscle relaxation. The dephosphorylated phospholamban inhibits the SR $Ca^{2+}-ATPase$ through a direct interaction, and phosphorylation of phospholamban relieves the inhibition. In the present study, quantitative changes of $Ca^{2+}-ATPase$ and phospholamban expression and the functional consequences of these changes in various thyroid states were investigated. The effects of thyroid hormones on (1) SR $Ca^{2+}$ uptake, (2) phosphorylation levels of phospholamban, (3) SR $Ca^{2+}-ATPase$ and phospholamban protein levels, (4) phospholamban mRNA levels were examined. Our findings indicate that hyperthyroidism is associated with increases in $Ca^{2+}-ATPase$ and decreases in phospholamban levels whereas opposite changes in these proteins occur in hypothyroidism.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.5
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• pp.423-431
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• 2001

Some recent investigations revealed that vasodilatory action of adenosine is mainly not mediated by surface A2 receptor and suggested the existence of an intracellular action site. In the present study, we tried to differentiate intracellular from extracellular site of adenosine action in the regulation of coronary flow. In perfused rabbit hearts, concentration-response curve of coronary flow to exogenous adenosine was constructed in the presence or absence of dipyridamole, an inhibitor of transmembrane purine transport. Inhibition of cellular adenosine uptake by dipyridamole suppressed the increase of flow rate while enhancing the decrease in heart rate induced by exogenous adenosine. In another series of experiments, perfused rabbit hearts were subjected to energy deprivation in order to increase the production of endogenous adenosine. Energy deprivation along with dipyridamole administration resulted in higher coronary flow rate. Lower perfusate adenosine concentration was observed along with higher tissue adenosine content in this group. These results implied that coronary flow rate is determined not by interstitial adenosine concentration but by intracellular activity of adenosine. To confirm the effects of dypiridamole in vivo, direct measurement of interstitial adenosine concentration by mycrodialysis along with the assay of intracellular adenosine content was performed after intranenous dipyridamole administration. After dipyridamole infusion, intracellular adenosine content was markedly increased while interstitial adenosine concentration was not altered. In another series of experiments, the right shift of concentration-response curve of adenosine-induced vasodilation by 8-phenyltheophilline, a representative adenosine receptor antagonist, was mostly abolished by prior administration of prazosin, indicating that the influence of 8-PT on the adenosine action is not attributed to the inhibition of A2 receptor but related to the suppression of ${\alpha}-adrenoceptor$ activation. From these results, we concluded that adenosine acts intracellularly to regulate the coronary blood flow.

• Toxicological Research
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• v.13 no.4
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• pp.359-365
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• 1997

Many factors are known to be responsible for cerebral ischemic injury, such as excitatory neurotransmitters, increased intraneuronal calcium, or disturbance of cellular energy metabolism. Recently, oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of ischemia/reperfusion injury. Therefore, to investigate the role of oxygen free radical during ischemia/reperfusion, in the present study the effect of endogenous oxygen free radical scavenger, superoxide dismutase / catalase(SOD / catalase) on the release of [$^3$H]-5-hydroxytryptamine([$^3$H]-5-HT) during hypoxia/reoxygenation in rat hippocampal slices was measured. The hippocampus was obtained from the rat brain and sliced 400 gm thickness with manual chopper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing [$^3$H]-5-HT(0.1 $\mu$M, 74 $\mu$Ci) for uptake, and washed. To measure the release of [$^3$H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Induction of hypoxia for 20 min (gassing it with 95% N$_2$/5% CO$_2$) was done in the 6th and 7th tube, and oxygen free radical scavenger, SOD / catalase was added 10 minutes prior to induction of hypoxia. The radioactivity in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. When slices were exposed to hypoxia for 20 min, [$^3$H]-5-HT release was markedly decreased and a rebound release of [$^3$H]-5-HT was observed on the post-hypoxic reoxygenation period. SOD / catalase did not changed the release of [$^3$H]-5-HT in control group, but inhibited the decrease of [$^3$H]-5-HT release in hypoxic period and rebound increase of [$^3$H]-5-HT in reoxygenation period. This result suggest that superoxide anion may play a role in the hypoxic-, and reoxygenation-induced change of [$^3$H]-5-HT release in rat hippocampal slices.

• Macromolecular Research
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• v.16 no.8
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• pp.695-703
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• 2008

Nanoparticles have tremendous potential in cancer prevention, detection and augmenting existing treatments. They can target tumors, carry imaging capability to document the presence of tumors, sense pathophysiological defects in tumor cells, deliver therapeutic genes or drugs based on the tumor characteristics, respond to external triggers to release an appropriate agent, document the tumor response, and identify the residual tumor cells. Nanoparticles < 30 nanometers in diameter show unexpected and unique properties. Furthermore, particles < 5 nanometers in size can easily penetrate cells as well as living tissues and organs. This study evaluated the safety of nano materials in a living body and the relationship between the living tissue and synthetic nano materials by examining the in-vitro cytotoxicity of poly(lactic-co-glycolic) acid (PLGA) nano-spheres and fluorescein isothiocynate(FITC)-labeled dendrimers as polymer nanoparticles. PLGA was chosen because it has been used extensively for biodegradable nanoparticles on account of its outstanding bio-compatibility and its acceptance as an FDA approved material. The dendrimer was chosen because it can carry a molecule that recognizes cancer cells, a therapeutic agent that can kill those cells, and a molecule that recognizes the signals of cell death. Cytotoxicity in L929 mouse fibroblasts was monitored using MTT assay. Microscopic observations were also carried out to observe cell growth. All assays yielded meaningful results and the PLGA nanoparticles showed less cytotoxicity than the dendrimer. These nano-particles ranged in size from 10 to 100 nm according to microscopy and spectroscopic methods.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.383-388
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• 1993

Pharmacokinetics of aucubin, an irdoid glucoside, was compared in rats of experimental hepatic failure(EHF). EHF was induced by CCI$_{4}$ or D-galactosamine pretreatment. This work was designed to find out any differences in the pharmacokinetics of aucubin that may explain the different protective effect of aucubin on CCI$_{4}$- and galactosamine-induced EHF : aucubin reportedly protected CCI$_{4}$-inducing hepatotoxicity effectively, but did not for galactosamine-hepatotoxicity. EHF was induced by intraperitoneal injection Of CCI$_{4}$(0.9ml/kg) or galactosamine(250 mg/kg) to Wistar rats 24 hr before the pharmacokinetic study. The rats were fasted during the 24 hr. Aucubin was iv injected at a dose of 15 mg/kg and the plasma aucubin was assayed by HPLC. There were no significant differences in the pathophysiologies(body weight, liver weight, GTP, hematocrit, blood cell distrbution and plasma protein binding of aucubin) between the two EHF models except GOP which was significantly (p<0.05) higher in CCI$_{4}$-than in galactosamine-EHF. On the other hand, pharmacokinetics of aucubin such as total cleatance(CL$_{t}$), distribution volume at steady-state(Vd$_{ss}$), and mean residence time(MRT) differed significantly(p<0.05) between the models : for example, CL$_{t}$ was increased two fold by CCI$_{4}$, but not by galaclosamine ; Vd$_{ss}$, in galactosamine-EHF was higher than that in CCI$_{4}$-EHF ; MRT was decreased by CCI$_{4}$, but increased conversely by galactosamine. The increase of CL$_{t}$(and decrease of MRT) in rats of CCI$_{4}$-EHF was contrary to the general expectation for the hepatic failure : most of the hepatic failures have been known to decrease CL$_{t}$ of the administered drugs. Whether the difference in the pharmacokinetics is responsible for the different protective effect of aucubin against the two EHF models is of interest. However, much more studies on biliary excretion, urinary excretion, and hepatic uptake in cellular level should be preceded before any conclusions are made on the role of different pharmacokinetics on the different pharmacology of aucubin.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.592-607
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• 1999

2-(1-Aryl-1-hydroxymethyl)-and 2-aroyl-DHAQ derivatives (DHAQ, 1,4-dihydroxy-,10-anthraquinone), and 2-(1-aryl-1-hydroxymethyl)-ATO derivatives (ATO, anthraceneactivity (T/C 125~128%), though their cytotoxicity was not further improved compared to that of 2-(1-aryl-1-dydroxymethyl)-1,4-dihydroxy-9,10-anthraquinones. They manifested no correlation between the cytotoxicity and the antitumor activity. In case of 2-[1-hydroxy-1-(4-propylphenyl)-methyl]-ATO, the most bioactive one in viv-1,4,9,10-tetraone) were synthesized and their antitumor activities were determined. 2-(1-Aryl-1-hydroxymethyl)-DHAQ derivatives showed a stronger cytotoxicity compared to the series of 2-(1-hydroxyalkyl)-1,4-dihydroxy-9,10-anthraquinone derivatives. It was suggested that the presence of aryl group at the side chain accelerated the bioreductive activation leading to cell death. 2-Aroyl-DHAQ derivatives, despite their higher electrophilicity, revealed smaller cytotoxicity and antitumor activity (expressed by T/C value) than 2-(1-aryl-1-hydroxymethyl)-DHAQ derivatives. Thus, no consistent relationship between the electronic effect on aromatic side chain and the cytotoxicity was observed. ATO series exhibited a higher antitumor o among the same series, it showed an $ED_{50}$ value of 10.2 mg/mL and a T/C value of 218%. It is assumed that the anthrancene1,4,9,10-tetraones after uptake into cellular tissues might be transformed to a cytotoxic metabolite(s).

• Molecules and Cells
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• v.40 no.8
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• pp.558-566
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• 2017

Regular monitoring on experimental animal management found the fluctuation of ART outcome, which showed a necessity to explore whether superovulation treatment is responsible for such unexpected outcome. This study was subsequently conducted to examine whether superovulation treatment can preserve ultrastructural integrity and developmental competence of oocytes following oocyte activation and embryo culture. A randomized study using mouse model was designed and in vitro development (experiment 1), ultrastructural morphology (experiment 2) and functional integrity of the oocytes (experiment 3) retrieved after PMSG/hCG injection (superovulation group) or not (natural ovulation; control group) were evaluated. In experiment 1, more oocytes were retrieved following superovulation than following natural ovulation, but natural ovulation yielded higher (p < 0.0563) maturation rate than superovulation. The capacity of mature oocytes to form pronucleus and to develop into blastocysts in vitro was similar. In experiment 2, a notable (p < 0.0186) increase in mitochondrial deformity, characterized by the formation of vacuolated mitochondria, was detected in the superovulation group. Multivesicular body formation was also increased, whereas early endosome formation was significantly decreased. No obvious changes in other microorganelles, however, were detected, which included the formation and distribution of mitochondria, cortical granules, microvilli, and smooth and rough endoplasmic reticulum. In experiment 3, significant decreases in mitochondrial activity, ATP production and dextran uptake were detected in the superovulation group. In conclusion, superovulation treatment may change both maturational status and functional and ultrastuctural integrity of oocytes. Superovulation effect on preimplantation development can be discussed.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.383-389
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• 2011

Background: EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. Methods: C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of cytokine secretion. Normal myeloid-dendritic cell (DC) was ex vivo cultured from bone marrow hematopoietic stem cells of C57BL/6 mice with GM-CSF and IL-4 to analyze the DC uptake of dead tumor cells and to observe the effect of EY-6 on the normal DC. Results: EY-6 killed the MC38 tumor cells in a dose dependent manner (25, 50 and $100{\mu}M$) with carleticulin induction. And EY-6 induced the secretion of IFN-${\gamma}$ but not of TNF-${\alpha}$ from the MC38 tumor cells. EY-6 did not kill the ex-vivo cultured DCs at the dose killing tumor cells and did slightly but not significantly induced the DC maturation. The OVA-specific cross-presentation ability of DC was not induced by chemical treatment (both MHC II and MHC I-restricted antigen presentation). Conclusion: Data indicate that the EY-6 induced tumor cell specific and immunological cell death by modulation of tumor cell phenotype and cytokine secretion favoring induction of specific immunity eliminating tumor cells.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.483-489
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• 2004

Fexofenadine HCl is non-sedating histamine H1 receptor antagonist that can be used for the treatment of seasonal allergic rhinitis. The objective of this study was to investigate whether the carriers of deformable liposomes can enhance the transepithelial permeability of fexofenadine HCl across the in vitro ALI human nasal monolayer model. Characterization of this model was achieved by bioelectric measurements and morphological studies. The passage 2 and 3 of cell monolayers exhibited the TEER value of $2852\;{\pm}\;482\;ohm\;{\times}\;cm^2$ on 11 days of seeding and maintained high TEER value for 5 days. The deformable liposome of fexofenadine HCl was prepared with phosphatidylcholine (PC) and cholic acid using extruder method. The mean particle size was about 200 nm and the maximum entrapment efficiency of 33.0% was obtained in the formulation of 1% PC and $100\;{\mu}g/ml$ fexofenadine HCl. The toxicity of the deformable liposome to human nasal monolayers was evaluated by MTT assay and TEER value change. MTT assay showed that it has no toxic effect on the nasal epithelial cells in 2-hour incubation when the PC concentration was below 1%. However, deformable liposome could not enhance the transepithelial permeability $(P_{app})$ and cellular uptake of fexofenadine HCl. In conclusion, the in vitro model could be used in nasal drug transport studies and evaluation of transepithelial permeability of formulations.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1639-1648
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• 2017

Curcumin is a natural polyphenolic compound, widely acclaimed for its antioxidant, anti-inflammatory, antibacterial, and anticancerous properties. However, its use has been limited due to its low-aqueous solubility and poor bioavailability, rapid clearance, and low cellular uptake. In order to assess the effect of glycosylation on the pharmacological properties of curcumin, one-pot multienzyme (OPME) chemoenzymatic glycosylation reactions with UDP-${\alpha}-{\text\tiny{D}}$-glucose or UDP-${\alpha}-{\text\tiny{D}}$-2-deoxyglucose as donor substrate were employed. The result indicated significant conversion of curcumin to its glycosylated derivatives: curcumin 4'-O-${\beta}$-glucoside, curcumin 4',4"-di-O-${\beta}$-glucoside, curcumin 4'-O-${\beta}$-2-deoxyglucoside, and curcumin 4',4"-di-O-${\beta}$-2-deoxyglucoside. The products were characterized by ultra-fast performance liquid chromatography, high-resolution quadruple-time-of-flight electrospray ionization-mass spectrometry, and NMR analyses. All the products showed improved water solubility and comparable antibacterial activities. Additionally, the curcumin 4'-O-${\beta}$-glucoside and curcumin 4'-O-${\beta}$-2-deoxyglucoside showed enhanced anticancer activities compared with the parent aglycone and diglycoside derivatives. This result indicates that glycosylation can be an effective approach for enhancing the pharmaceutical properties of different natural products, such as curcumin.