• 동의생리병리학회지
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• 제18권1호
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• pp.84-92
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• 2004

The present study examined the effects of Taekunyukmijiwhang-tang (TV) on blood pressure and renal function in nitric oxide (NO)-dependent hypertensive rats. A phamacological inhibition of nitric oxide synthase (NOS) for 4-6 weeks produces renal vasoconstriction, renal dysfunction, and progressive severe hypertension. Treatment of rats with NG-Nitro-L-arginie methylester (L-NAME) (100 mg/L, 6 weeks), which is a nonspecific NOS inhibitor, cause a sustained increase in systolic blood pressure (SBP), along with the decrease in expression of ecNOS in the kidney and thoracic aorta. The expression of Na, K-ATPase α1 subunit in the kidney was also reduced in the L-NAME induced hypertensive rats group. The renal functional parameters including urine osmolality (Uosm), creatinine clearance (Ccr), which is an index of glomerular filtration (GFR) were decreased in rat with L-NAME induced hypertension. while solute-free water reabsoption (TcH₂O) was unchanged in all experimental group. However, the group combined treated with TV and L-NAME did not develop hypertension and expression of ecNOS in the aorta was restored. The expression of Na/sup +/, K/sup +/-ATpase α1 subunit in the kidney was markedly restored in L-NAME-induced hypertension rats by administration of TV along with the restoration of urinary volume (UV) and sodium excretion (UNaV), whlie Na/sup +/, K/sup +/-ATPase /β1 subunit was not altered. These results suggest that TV attenuates an increase in SSP in the L-NAME induced hypertension and restores partially renal function, which seems to be caused by up-regulation of expression of Na/sup +/, K/sup +/-ATPase α1 subunit in the kidney and ecNOS in thoracic aorta.

• Korean Journal of Acupuncture
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• 제17권1호
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• pp.179-190
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• 2000

This study was undertaken to determine whether Juglandis semen extract solution (JLS solution) exerts protective effect against oxidant-induced inhibition of glutamate uptake by synaptosomes. Synaptosome was prepared from rabbit brain cortex. Glutamate uptake increased by incubation time during 10 minutes, which was significantly inhibited by 1mM t-buthylhydroperoxide(t-BHP). JLS solution prevented t-BHP-induced inhibition of glutamate uptake in a dose-dependent manner. t-BHP reduced glutamate uptake in dose-dependent fashion, which was significantly prevented by 2% JLS solution. t-BHP(1mM) and $ascorbate/Fe^{2+}(50/1{\mu}M)$ increased lipid peroxidation in synaptosomes by 5-fold, and it was significantly prevented by 2% JLS solution. $HgCl_2(0.1mM)$ inhibited glutamate uptake and increased lipid peroxidation. These changes were prevented by 2% JLS solution. Synaptosomal Na-K-ATPase activity was inhibited by t-BHP(1mM) and $H_2O_2(50mM)$, which was prevented by 2% JLS solution. The results indicate that JLS solution prevents oxidant-induced inhibition of glutamate by synaptosomes, and this may result from inhibition of lipid peroxidation induced by oxidants.

• 대한임상검사과학회지
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• 제41권2호
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• pp.83-92
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• 2009

This study was undertaken to examine the effect of oxidants on membrane transport function in renal epithelial cells. Hydrogen peroxide ($H_2O_2$) was used as a model oxidant and the membrane transport function was evaluated by measuring $Na^+$-dependent phosphate ($Na^+$-Pi) uptake in opossum kidney (OK) cells. $H_2O_2$ inhibited $Na^+$-Pi uptake in a dose-dependent manner. The oxidant also caused loss of cell viability in a dose-dependent fashion. However, the extent of inhibition of the uptake was larger than that in cell viability. $H_2O_2$ inhibited $Na^+$-dependent uptake without any effect on $Na^+$-independent uptake. $H_2O_2$-induced inhibition of $Na^+$-Pi uptake was prevented completely by catalase, dimethylthiourea, and deferoxamine, suggesting involvement of hydroxyl radical generated by an iron-dependent mechanism. In contrast, antioxidants Trolox, N,N'-diphenyl-p-phenylenediamine, and butylated hydroxyanisole did not affect the $H_2O_2$ inhibition. Kinetic analysis indicated that $H_2O_2$ decreased Vmax of $Na^+$-Pi uptake with no change in the Km value. Phosphonoformic acid binding assay did not show any difference between control and $H_2O_2$-treated cells. $H_2O_2$ also did not cause degradation of $Na^+$-Pi transporter protein. Reduction in $Na^+$-Pi uptake by $H_2O_2$ was associated with ATP depletion and direct inhibition of $Na^+$-$K^+$-ATPase activity. These results indicate that the effect of $H_2O_2$ on membrane transport function in OK cells is associated with reduction in functional $Na^+$-pump activity. In addition, the inhibitory effect of $H_2O_2$ was not associated with lipid peroxidation.

• Journal of Photoscience
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• 제4권2호
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• pp.35-40
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• 1997

The sensory transduction processes of blue light in guard cells have been suggested the involvement of Ca$^{2+}$/calmodulin-dependent myosin light chain kinase (MLCK) or MLCK-like proteins. The source of Ca$^{2+}$ required for the signal transduction process was investigated in guard cell protoplasts (GCPs). The GCPs showed the typical H$^+$ pumping activity by blue light (200 $\mu$mol m$^{-2}$ s$^{-1}$) and fusicoccin (10 $\mu$M) under background red light (600 $\mu$mol m$^{-2}$ s$^{-1}$). The blue light-dependent H$^+$ pumping was not significantly affected by the externally changed Ca$^{2+}$ concentrations. The addition of 1 mM Ca$^{2+}$ in the bathing medium ratherly inhibited the H$^+$ pumping. In contrast, the blue light-dependent H$^+$ pumping was inhibited by caffeine and 2,5-di-(tert-butyl)-1,4-benzohydroquinone (BHQ), inhibitor of C$^{2+}$-ATPase in endoplasmic reticulum (ER) without inhibiting the H $^+$ pump. The inhibition by caffeine and BHQ was fully reversible. The extent of inhibition by caffeine and BHQ was larger when they were added together than when added separately. The results suggest that Ca$^{2+}$ required for the blue light-dependent H$^+$ pumping may be released from the intracellular Ca$^{2+}$ stores, probably ER in guard cells.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.184-184
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• 1998

Aldose reductase(AR), a rate-limiting enzyme in the polyol pathway, has been demonstrated to cause the intracellular accumulation of sorbitol or galactitol and hence to play key roles not only in the cataract formation in the lens but also in the pathogenesis of diabetic complications such as neuropathy, retinopathy and nephropathy, etc. In a series of investigations to evaluate potential AR inhibitors from medicinal plants, we have shown that some hot water extracts exhibited a significant inhibition of a significant inhibition of bovine lens AR in vitro. Among active plants, the roots of Angelica dahuria (Umbelliferae) were shown to have relatively potent AR inhibitory activity. Systematic fractionation of the ether soluble fraction monitored by bioassay led to isolation of two furanocoumarins, byakangelicin(I) and ter-O-methyl byakangelicin( II), were identified as potential AR inhibitors, their $IC_{50}$ values being 6.2 M and 2.8 M, respectively.

• Journal of Microbiology
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• 제37권2호
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• pp.59-65
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• 1999

RecA protein can promote strand assimilation, homologous pairing, and strand exchange. All these reactions require DNA-dependent ATP hydrolysis by recA protein, and the activities of recA protein are affected by the ionic environment. In this experiment, DNA-dependent ATPase activity showed different sensitivity to anionic species. ATP hydrolysis and strand exchange were relatively sensitive to salt in the reactions with NaCl, strongly inhibited at 100 mM NaCl. However, the inhibition by sodium acetate or sodium glutamate was not observed at 50∼100 mM concentration. Addition of sodium glutamate to the standard reaction condition increased the apparent efficiency of ATP hydrolysis during strand exchange. The condition including 50∼100 mM sodium-glutamate might be similar to the physiological condition.

• Toxicological Research
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• 제11권1호
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• pp.103-108
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• 1995

Rat renal proximal tubule suspension was prepared from adult male Sprague Dawley rat (250-300g) by mechanical (non-enzymatical) method and evaluated as a pontential model for mechanistic studies and early screening of nephrotoxicity, using anionic antibiotics (cephaloridine). Cephaloridine (CPL) produced an increase in LDH release into media. This release results from decrease a proximal tubule cell viability and subsequently increase the permeability of cell viability and subsequently increase the permeability of cell membrane. Since loss of intracellular potassium and ATP into media is the sign of disruption of cell membrane, especially basolateral membrane (BLM), CPL induced proximal tubule cell compromise also appear be associated with BLM, maybe $Na^+-K^+$ ATPase. Also seen was significant depression in brush border membrane (BBM) ALP activity and no significantly increase in BBM GGT activities. The inhibition of typical anion, PAH accumulation (especially, CPL 5 mM) and cation, TEA (especially, 4hours incubation) were seen dose dependently. This is because of CPL accumulation in renal proximal tubule and increase of cytotoxicity.

• 한국양식학회지
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• 제11권2호
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• pp.279-282
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• 1998

Effects of high concentration of intracellular calcium on estradiol-induced vitellogenin(VTG) induction were examined using ouabain in Primary hepatocyte culture in the rainbow trout Oncorhynchus mykiss. Ouabain increases cytosolic free calcium as a result of inhibition of $Na^+ - Ca^{2+}$ exchanger. Ouabain markedly reduced VTG production to the control level, despite of calcium concentrations in the incubatin medium. Therefore, ouabain would reduce VTG production not by increasing intracellular calcium bt directly by inhibiting $Na^+ - K^+$ ATPase.

• Journal of Plant Biology
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• 제37권3호
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• pp.271-276
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• 1994

The possibility that 1-aminocyclopropane-1-carboxylic acid (ACC)-uptake may be dependent on the H+-gradient established across the plsma membrane was tested in protoplasts isolated from 2.5 day old mungbean hypocotyls. The ACC-induced ethylene production was inhibited when the H+-gradient was collapsed by the treatment with carbonycyamide-p-trifluro-methoxy-phenylhydrazone (FCCP). Moreover, the treatment with o-vanadate, a specific inhibitor of plasma membrane H+-ATPase, caused the inhibition of ethylene production. The ACC-induced ethylene production was inhibited by the treatemnt with verapamil (Ca2+-channel blocker), or ethylene glycol-bis($\beta$-aminoethyl ether) N, N, N', N'-tetraacetic acid (EGTA) (Ca2+-chelator). In contrast, the ehtylene production was stimulated by the application of A23187 (Ca2+ ionophore). The inhibitory effect of EGTA in the ethylene producton was magnified in the presence of A23187. From these results, we suggest that the external Ca2+ influx to the cytosol resulted in the stimulatin of ACC oxidase activity after ACC-uptake resulting from a H+-gradient across the plasma membrane.

• 약학회지
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• 제28권3호
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• pp.129-138
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• 1984

Specific [$^{3}H$] ouabain binding and $Ca^{2+}$ -uptake were measured to elucidate the role of high affinity [$^{3}H$] ouabain binding site in rat cardiac myocytes which contain 65% of rod cells. High affinity [$^{3}$H] ouabain binding site, which is about 3% of total pump sites, with apparent dissociation constant ($K_{D}$) of $1.1{\times}10^{-7}M$ and maximum binding site concentration (Bmax) of 1.2 pmol/mg protein ($1.754{\times}10^{5}cells$) were identified. At the concentration of $10^{-7}M$ to $10^{-4}M$, ouabain produced concentration dependent increase in $Ca^{2+}$-uptake of myocytes. The effect of ouabain on $Ca^{2+}$-uptake was not effected by membrane depolarization (elevated K+ in incubation medium) or verapamil. These results suggest that in rat ventricular myocytes the ouabain receptor complex to high affinity site may increase Na+ - $Ca^{2+}$ exchange across the sarcolemmal membrane by inhibition of Na+, K+ - ATPase.