• Journal of Acupuncture Research
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• v.18 no.2
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• pp.150-160
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• 2001

Objectives ; This study was undertaken to determine whether Carthami-Flos aquacapuncture (CFA) exerts protective effect against oxidant-induced inhibition of $Na^+-K^+$-ATPase activity in cerebral synaptosomes. Methods and Results ; The enzyme activity was dependent on incubation time and enzyme protein concentrations. An oxidant t-butylhydroperoxide (tBHP) at 1 mM concentration caused a significant inhibition of $Na^+-K^+$-ATPase activity, which was prevented by addition of 0.01% CFA. tBHP inhibition and CFA protection were independent on incubation time or enzyme protein concentrations. The enzyme activity was increased by ATP in a dose dependent manner. Effects of tBHP and CFA were not affected by ATP cocentrations. tBHP (1 mM) produced a significant increase in lipid peroxidation in cerebral synaptosomes, which was prevented by 0.01% CFA. CFA decreased oxygen free radicals generated induced by the phorbol-ester in a dose-dependent manner in human neutrophil. Conclusions ; These results suggest that CFA exerts protective effect against tBHP-induced inhibition of $Na^+-K^+$-ATPase activity, which is due to by an antioxidant action resulting from a direct scavenging effect of oxygen free radicals in the cerebral synaptosomes.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.202-208
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• 1997

In order to investigate the mechanisms of epithelial ion transports, microsomes of soybean roots were prepared and the activity of microsomal ATPases was measured by an enzyme-coupled assay. The effects of various ions were evaluated on the total activity of microsomal ATPases and the average activity was 190 nmol/min/mg protein in the control solution containing $10\;mM\;Na^+\;and\;120\;mM\;K^+$. The activities were increased to 150% and decreased to 63% of the control activity in the solution containing $130\;mM\;K^+$ without $Na^+$ and in the solution containing $130\;mM{\;}Na^+$ without $K^+$, respectively. In general, the activity of microsomal ATPase was increased by$K^+$ in a concentration-dependent manner The activity was also increased at lower pH and relatively higher activities were observed in the pH range of $6{\sim}7$. However, the activity was decreased at weak alkaline $pH\;and{\sim}80%$ of the activity was inhibited at pH 9. Since intracellular $Ca^{2+}$ has been known to control the activity of various enzymes, we have investigated the effects of intra-and extrarnicrosomal $Ca^{2+}$ on the activity of microsomal ATPases. The maximal activity was obtained at the extrarnicrosomal $Ca^{2+}$ concentrations below 1 nM. The activity was gradually decreased by increasing $‘Ca^{2+}’$ concentration and 50% inhibition was observed at ${\sim}500{\;}{\mu}M{\;}Ca^{2+}$. The increase in luminal $Ca^{2+}$ concentration also inhibited the activity of microsomal ATPase. When the influx of external $Ca^{2+}$ was induced by $Ca^{2+}$ ionophore A23187 treatment, the activity was decreased by 30%; however, it was recovered by EGTA-induced chelation of $Ca^{2+}$. These results suggest that the presence of $Ca^{2+}$ regulation sites on both cytoplasmi and luminal sides of microsomal ATPases.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.260-266
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• 2005

IgE-dependent histamine releasing factor (HRF), previously known as P23/P21 or translationally controlled tumor protein (TCTP), induces the degranulation of histamine in mast cell and basophil. Yeast two hybrid results showed that HRF interacts with the alpha subunit of Na, K-ATPase, suggesting that HRF is a regulator for governing the activity of Na, K-ATPase. In this study, we examined the interaction of HRF and Wa,K-ATPase after treatments of various PKC isotype inhibitors. Membrane fractionation, pull-down assay and immunoprecipitation results showed that PKC $\alpha,\;PKC\;\beta,\;\delta$ subunits are involved in the phosphorylation of HRF. However, these results did not correlate with the results of histamine release assay since histamine release assay results suggested that some PKC isotype inhibitors induced the histamine release in RBL-2H3 cell.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.203-213
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• 1985

This study was carried out to investigate whether the K-pNPPase activity in renal cortical slices can be used as an index for measuring the activity of $Na^+-K^+$ exchange pump. The K-pNPPase activity, Ouabain-sensitive oxygen consumption add intracellular electrolytes content in slices, and Na-K-ATPase activity in microsome were measured and the effects of ouabain and vanadate on these were observed. The results are as follows : 1) p-NPPase activity in slices increased linearly with incubation time during 60 minutes, and $K^+$-dependent, ouabain-sensitive fraction was about 55% of total p-NPPase activity. This value was almost the same through out the incubation time. 2) The concentrations of ouabain and vanadate for 50f inhibition of K-pNPPase activity were$7.0{\times}10^{-6}M$ and $1.3{\times}10^{-5}M$, respectively. 3) The ouabain-sensitive oxygen consumption in slices was reduced to 50% of control value by $6.3{\times}10^{-6}M$ ouabain or $2.5{\times}10^{-5}M$ vanadate. These concentrations were similar to those for 50% inhibition of K-pNPPase activity. 4) The trends of intracellular electrolytes change by ouabain and vanadate were similar to those of the change in K-pNPPase activity. 5) The Na-K-ATPase activity in microsome prepared from renal cortex was completely inhibited by $10^{-3}M$ ouabain or $10^{-3}M$ vanadate and the concentration for 50% inhibition was $1.2{\times}10^{-6}M$ in ouabain and $1.6{\times}10^{-6}M$ in vanadate, which were much lower than those for K-pNPPase activity or ouabain-sensitive oxygen consumption in slices. These results indicate that K-pNPPase activity measured in renal cortical slices is a better index for evaluating $Na^+-K^+$ exchange pump activity than Na-K-ATPase activity measured in microsome.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.279-286
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• 2004

Although numerous studies have shown that cadmium disturbs the normal biological processes in central nervous system, the mechanism of toxicity is not well understood. The present study has investigated the effect of cadmium on oxidative stress, Na$^{+}$K$^{+}$ ATPase activity and the aggregation of amyloid beta peptide ($\beta$-amyloid) in neuronal cell line, HT22 cell. LC$_{5}$ and LC$_{50}$ of cadmium for HT22 cell resulted from MTT assay was 4.1 uM and 9.5 uM, respectively. Cadmium (2 to 8 uM) dose-dependently increased the lipid peroxidation and decreased the content of glutathione. Cadmium 4 uM showed a significant decrease in Na$^{+}$/K $^{+}$ ATPase activity as compared with control group. The aggregation of $\beta$-amyloid was accelerated in a dose-dependent manner by the treatment with 2 to 8 uM cadmium. These results suggest that the neurotoxicity of cadmium can be mediated by the increase in oxidative stress and decrease in Na$^{+}$/K$^{+}$ ATPase activity.se activity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.300-300
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• 1994

$Na^{+}$,$K^{+}$-ATPase activity, $Na^{+}$-dependent phosphorylalion, and [$^3$〕ouabain binding in sarcolemma prepared from 4 week old spontaneously hypertensive rat(SHR) ventricles were compared to the same parameters in sarcolemma from age matched normotensive Wistar-Kyoto(WKY) rat ventricles to examine whether the reduced myocardial $Na^{+}$-pump activity in SHR is an inherited enzymatic defect or a second phenomenon due to sustained hypertension. The total body weights, ventricular weights, and blood pressures were the same for SHR and WKY. No significant differences in sarcolemmal protein content and protein recovery were noted between the two pups. Sarcolemma isolated from SHR ventricles showed sigificantly less $Na^{+}$,$K^{+}$-ATPase activity and number of phosphorylation sites when compared to snrcolemma 1mm the WKY ventricles. Equilibrium binding of [$^3H$〕ouabain and the turnovcr number of myocardial $Na^{+}$,$K^{+}$-ATPast however, wee the same for both groups. These results. indicate that the low affinity(${\alpha}$, or ${\alpha}_1$) isoform for ouabain is reduced in SHR compared to WKY but that the high affinity(${\alpha}$+, or ${\alpha}_2$) isoform is the same in ventricles of SHR and WKY. The reduced amount of at isoform of the $Na^{+}$,$K^{+}$-ATPasc in prehypertensive SHR ventricles may play some pole in the development of hypertension.

• The Korean Journal of Zoology
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• v.23 no.2
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• pp.61-68
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• 1980

Quantitative analysis of the activities of transport ATPases as well as alkaline phosphatase of the mouse uterus was carried out during the estrous cycle. Even though the proportional patterns of the enzyme activities were similar each another between the stages of estrous cycle, the absolute activities of the enzymes except $K^+$-dependent and $Na^+$, $K^+$-activated ATPases at the time of estrus were significantly (p<0.025) higher than that at any other time of the estrous cycle. That is, the activities of $K^+$-dependent and $Na^+$, $K^+$-activated ATPases were negligible during the period of time from diestrus to estrus while the little activities (0.04 $\\sim$ 0.05$\\mu$M/mg protein/hr in average, $6\\sim7$% of the total enzyme activity) of these enzymes appeared at the time of metaestrus. On the other hand, at the time of estrus, the activities of $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase were rapidly and tremendously increased to be 0.69 (35%), 0.42 (21%) and 1.58 (79%), respectively. The activity of alkaline phosphatase was in the range of 0.60 $\\sim$ 1.58 (79 $\\sim$ 90%) and predominant throughout the estrous cycle. The activity of $Mg^++$-dependent alkaline phosphatase was estimated as 12 $\\sim$ 16% of the total enzyme activity. Therefore, it is assumed likely that $K^+$-dependent and $Na^+$, $K^+$-activated ATPases are not the main factors to control the fluid accumulation at the time of estrus, but may be the factors to reabsorb the luminal fluid into the uterine epithelium at the time of metaestrus, and that $Mg^++$-dependent phosphatase, transport ATPase and alkaline phosphatase must be closely involved in the secretion of luminal fluid from the epithelial cells of the mouse uterus.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.97-106
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• 2016

$Na^+/K^+$-ATPase is a membrane protein and plays a key role in osmotic regulation in living organisms. In the present study, a cDNA sequence encoding the $Na^+/K^+$-ATPase alpha subunit from the monogonont rotifer, Brachionus koreanus was cloned by rapid amplification of cDNA ends technique. To investigate the role of this enzyme in osmotic stress, enzymatic activities of $Na^+/K^+$-ATPase were measured after exposure to different salinities for 48 h. The full-length Bk $Na^+/K^+$-ATPase cDNA was 3069 bp-long, encoding a 1022-amino acid polypeptide. Bk $Na^+/K^+$-ATPase possesses eight membrane spanning regions and five conserved domains. Phylogenetic analysis showed that Bk $Na^+/K^+$-ATPase had high identity with those of other species, and was closely clustered with other Brachionus sp. These findings indicate that this protein was conserved both structurally and functionally. B. koreanus $Na^+/K^+$-ATPase activity was stimulated in both hyposaline (6 psu) and hypersaline (32 psu) conditions, suggesting that this protein may play a role in osmoregulation. This study would provide better understanding of the physiology of B. koreanus and this enzyme may be useful as a molecular marker for evaluation of osmotic stress in aquatic environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.64-70
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• 2015

We investigated the branchial osmoregulatory response of black sea bream Acanthopagrus schlegelii to short-term (3-48 h) exposure to a hyposaline environment (5 psu). Gill $Na^+/K^+$-ATPase (NKA) activity was decreased after 3 h in fish transferred to 5 psu compared to salt water-acclimated (control) fish, but the level of activity returned to that observed in the control fish at 6 h after transfer. NKA activity increased significantly at 24 h after transfer, but it returned to the level observed in the control fish at 48 h after transfer. Immunohistochemical staining revealed that gill NKA was localized to chloride cells. The number of chloride cells tended to change in parallel with NKA activity. Substantial decreases in plasma $Na^+$, $Cl^-$, and osmolality were observed after 12 h of exposure to 5 psu; however, these parameters began to recover to the values detected in the controls at 24 h after transfer. In conclusion, our results suggest that black sea bream are able to adjust their osmoregulatory mechanisms to shift from hypo- to hyperosmoregulation within 6 h of exposure to a hypoosmotic environment.

• Korean Journal of Environmental Agriculture
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• v.17 no.4
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• pp.296-300
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• 1998

The analysis of biochemical changes in tobacco plant as increase of NaCl concentraion was conducted. Total protein content and soluble protein content were decreased as NaCl concentration was increased, in that steady decreased until 120mM NaCl and largely decreased at 150mM NaCl. The expression of 74Kd subunit was increased until 60mM NaCl. However, the amount of 74Kd protein was decreased from 90mM NaCl. There was no difference for expression of other protein subunits. Chlorophyll a content was significantly decrease as NaCl concentration was increased, but chlorophyll b content was not much decreased. The slow increase up to 120mM NaCl and large increase at 150mM NaCl for ATPase and peroxidase activities indicated that 120mM NaCl could be a limiting concentration for salt injury.