• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.1-8
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• 1994

Nerve conduction impairment in lead neuropathy has been empirically linked to altered nerve myo-inositol metabolism. In most cases of neuropathy, abnormal myo-inositol metabolism is associated with abnormal $Na^+/K^+$ATPase provides a potential mechanism to relate defects of the myo-inositol metabolism in the peripheral nerve treated with lead. Therefore, the effect of lead on the rat sciatic nerve $Na^+/K^+$ATPase and other ATPase of sciatic nerve was studied. ATPase activity was measured enzymatically in sciatic nerve homogenates from 2-wk lead treated neuropathy rats and age-mached controls administered myo-inositol. $Na^+/K^+$ATPase components were assessed by ouabain inhibition or the omission of sodium and potassium ions. Lead reduced 50% reduction in the $Na^+/K^+$ATPase activity in homogenates of sciatic nerve. The 50% reduction in the $Na^+/K^+$ ATPase activity was selectively prevented by myo-inositol treatment. This study suggests that the toxic mechanism of the lead on peripheral nerve may be through reduction in $Na^+/K^+$ATPase activity which has been linked to axonal transport slowing in the rat model of lead neuropathy, via direct changes by the perturbation of the intracelluar sodium or potasium level.

• The Journal of Korean Medicine
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• v.17 no.2 s.32
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• pp.264-276
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• 1996

This study was carried out to evaluate the effect of Samhwasan on the Na-K-ATPase activity of heart muscle. The Na-K-ATPase activity was prepared from rabbit heart ventricles. Samhwasan markedly inhibited the Na- K - ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.56%. Hill coefficient was 1.70, indicating that the enzyme has more than one binding site for the Samhwasan. Inhibition of enzyme activity by Samhwasan increased as pretreatment time was prolonged. Inhibition by the drug was not affected by a change in enzyme protein concentration. Kinetic studies of substrate activation of the enzyme indicated classical noncompetitive inhibition, showing significant reduction in Vmax without a change in Km value. Inhibitory effect by Samhwasan was not altered by changes in concentration of $Mg^{2+}$, $Na^+$ or $K^+$, dithiothreitol. a sulfhydryl reducing reagent, did not protect the inhibition of Na-K-ATPase activity by Samhwasan combination of Samhwasan and ouabain showed a cumulative inhibition fashion. These results suggest that Samhwasan inhibits Na-K-ATPase activity of heart ventricles with an unique binding site different from that of ATP, $Mg^{2+}$, $Na^+$ or $K^+$ and ouabain.

• Korean Journal of Pharmacognosy
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• v.16 no.2
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• pp.93-98
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• 1985

This investigation was performed to study the effect of Ginseng water extract on the cardiac sarcolemma $Na^+,\;K^+-ATPase$ activity of rat hearts. The Ginseng water extract (100mg/kg/day) was administered orally to Sprague-Dawley rats for one, four and seven days. The fragment of sarcolemma was prepared by the method of Matsui and Erdmann and the $Na^+,\;K^+-ATPase$ and $Mg^{++}-ATPase$ activity were measured by the method of Martins and Doty. $Na^+,\;K^+-ATPase$ activity in the rat heart treated with Ginseng water extract for 1 day was not significantly different from control value, but the activity was decreased by 13.4% in the rat heart treated for 4 days and was decreased by 20.4% in the 7 days treated group. $Mg^{++}-ATPase$ activity in the rat treated with ginseng water extract was similar to control value. It may be concluded that chronic administration of Ginseng may inhibit the $Na^+,\;K^+-ATPase$ enzyme activity, but single administration may not inhibit the activity.

• The Journal of Korean Medicine
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• v.16 no.1 s.29
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• pp.281-294
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• 1995

The effect of Sam Hwa San on the Na-K-ATPase activity was evaluated in microsomal fraction prepared from rabbit cerebral cortex to determine whether Sam Hwa San affects Na-K-ATPase activity of nervous system. Sam Hwa San markedly inhibited the Na-K-ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.12%. Optimal pH for the Na-K-ATPase activity was at 7.5 in the presence or absence of Sam Hwa San. The degree of inhibition by the drug more increased at acidic and alkalic pHs than neutral pH. Kinetic studies of substrate and cationic activation of the enzyme indicate classic noncompetitive inhibition fashion for ATP, Na and K, showing significant reduction in Vmax without a change in Km. Dithiothreitol, a sulfhydryl reducing reagent, partially protects the inhibition of Na-K-ATPase activity by Sam Hwa San. Combination of Sam Hwa San and ouabain showed higher inhibition than cumulative inhibition. These results suggest that Sam Hwa San inhibits Na-K-ATPase activity in central nervous system by reacting with, at least a part, sulfhydryl group and ouabain binding site of the enzyme protein, but with different binding site from those of ATP, Na and K.

• The Korean Journal of Physiology
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• v.11 no.1
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• pp.1-9
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• 1977

Action of anthraquinone on the sodium plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated and the experiments were also designed to determine the mechanism of action of anthraquinone on the ATPase activity. The following results were obtained 1. The activity of the NaK ATPase from red cell membrane is inhibited by anthraquinone and the concentration of anthraquinone for maximal inhibition is about 5mM. 2. The ratio of inhibition of NaK ATPase by anthraquinone, with a giving concentration of sodium in the medium, is increased by raising the potassium concentration. 3. The ratio of inhibition of NaK ATPase by anthraquinone, with a given concentration of potassium in the medium, is increased by raising the sodium concentration. 4. The action of anthraquinone on the NaK ATPase activity is inhibited by calcium ions and the ratio of inhibition is increased by small amounts of calcium but almost constant by larger amounts. 5. The inhibitory action of anthraquinone on the NaK ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine or the imidazole group of histidine. 6. The inhibitory action of anthraquinone on the ATPase activity is due to sulfhydryl group or the carboxyl group of the enzyme of NaK ATPase.

• The Korean Journal of Pharmacology
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• v.18 no.2
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• pp.69-77
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• 1982

$Na^+,\;K^+-ATPase$ is a component of plasma membrane in almost all animal cell, and maintains ionic distribution and membrane potential of normal cell. In the mechanism of adrenergic transmission, it is relatively well known that drug-receptor combination leads to stimulate adenylate cyclase and so on. In the cholinergic transmisison, the mechanism is not well known but is simply interpreted as the change of membrane permeability results from acetylcholine receptor interaction. To study the relationship between cholinergic transmission and membrane $Na^+,\;K^+-ATPase$, the effect of carbachol on $Na^+,\;K^+-ATPase$ activity in rabbit erythrocyte membrane is studied. The results are summarized as follows. 1) Total ATPase, $Mg^{+2}-ATPase$ and $Na^+,\;K^+-ATPase$ of rabbit erythrocyte membrane show maximum activities at 1mM of tris-ATP. 2) Total ATPase activity tends to increase when treated with carbachol $(10-^{-9}M-10^{-3}M)$. 3) The $Mg^{+2}-ATPase$ activity also tends to increase when treated with carbachol $(10-^{-9}M-10^{-3}M)$. 4) The $Na^+,\;K^+-ATPase$ activity is inhibited when treated with carbachol $(10-^{-9}M-10^{-7}M)$. It is suggested that the inhibition of $Na^+,\;K^+-ATPase$ by cholinergic drugs may be considered as one part of mechanism of cholinergic transmission.

• The Korean Journal of Physiology
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• v.6 no.1
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• pp.27-31
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• 1972

The activity of Mg and Na-K activated ATPase of homogenate from rat brain cortex was measured in vitro under the variety of conditions. The effects of various hypnotic and tranquilizer such as phenobarbital, amobarbital, diazepam, promazine and chlorpromazine on the activities of both ATPase was investigated and the results was summarized as follows. 1. Na-K ATPase was slightly inhibited by phenobarbital and amobarbital while Mg ATPase was moderately activated by these drugs. 2. Both Mg and Na-K ATPase activities were markedly inhibited by diazepam. 3. Promazine and chlorpromazine markedly inhibited both Mg and Na-K ATPase activities. These findings indicate that remarkable correlation between hypnotic or tranquilizing potency and ATPase inhibition could be observed.

• 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 Pharmacology
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• v.8 no.1
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• pp.31-40
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• 1972

The author studied the actions of ouabain and diphenylhydantoin sodium on the ATPase activity in mitochondrial fraction isolated from rabbit heart and compared with that of quinidine. The results obtained are as follows: 1) In studying the $(Na^++K^+)-activated$ ATPase activity, the rabbit heart isolated was immediately frozen for 7-9 days (ageing of preparation) and thereafter the mitochondria1 fraction obtained by differential centrifugation technic was treated with solution A containing 0.15% deoxycholate for 24-48 hours at $-10^{\circ}C$ before using in experiment. These methods increased the activity ratio to 0.87-0.98. 2) The $(Na^++K^+)-activated$ ATPase activity in mitochondrial fraction of rabbit heart was not completely but markedly inhibited by ouabain. This inhibitory action of ouabain was moderately antagonised by $K^+$ concentration at constant Na concentration. 3) Diphenylhydantoin sodium in concentration of $5{\times}10^{-4}{\sim}10^{-3}M$ stimulated markedly not only $Mg^{++}-dependent$ ATPase activity but also $(Na^++K^+)$-activated ATPase activity and in concentration lower than $10^{-6}M$ had little effect. However, this effect of diphenylhydantoin was markedly increased in the presence of $Na^+$ alone rather than $K^+$ alone, but lesser than that effect in the presence of both $Na^+$ and $K^+$, together. The stimulating effect of diphenylhydantoin was specifically antagonized by ouabaion. 4) When the rabbits were intravenously injected with ouabain and diphenylhydantion respectively, $(Na^++K^+)-activated$ ATPase activity of rabbit heart of ouabain-treated group was much decreased and both $(Na^++K^+)-activated$ ATPase and $Mg^{++}-activated$ ATPase activity were moderately increased in diphenylhydantoin-treated rabbit group. 5) The $(Na^++K^+)-activated$ ATPase activity in mitochondrial fraction of rabbit heart was slightly inhibited by quinidine in high concentration of $10^{-4}M$, but nearly little effect was observed below the concentration of $5{\times}10^{-5}M$. 6) It might be possible to conclude that diphenylhydantoin specifically antagonised the action of ouabain on the membrane ATPase, which is different from the action of quinidine.

• Korean Journal of Veterinary Research
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• v.23 no.1
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• pp.9-16
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• 1983

The effects of ethanol on Na-K-ATPase activity were investigated with cat kidney homogenate. The results were summarized as follows: 1. Na-K-ATPase activity was inhibited with dose-dependent manner by ethanol of higher concentration than 1%, and showed an estimated $I_{50}$ (the inhibitor concentration to cause 50% inhibition) of 7.5%. 2. Hydrolysis of ATP was linear with the incubation time in the absence and presence of 8% ethanol, whereas it was different with preincubation time in the presence of 15% ethanol. 3. Inhibition of Na-K-ATPase activity by ethanol was not affected by increased enzyme concentration, and showed the reversibility of the inhibitory pattern. 4. Kinetic studies of cationic-substrate activation of Na-K-ATPase showed that ethanol had both properties of classical competitive inhibition for $Mg^{{+}{+}}$ or $K^+ and non-competitive inhibition for ATP or $Na^+$. 5. Arrhenius plot yield two break point at $21^{\circ}$ and $30^{\circ}C$ in the absence of ethanol, whereas showing only one break point at $18^{\circ}C$ in the presence of 8% ethanol. These results suggested that ethanol inhibited Na-K-ATPase activity reversible through a disturbance of microenvironment of lipids associated with the enzyme.