• 대한약리학회지
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• 제8권1호
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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.

• The Korean Journal of Physiology
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• 제8권1호
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• pp.67-76
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• 1974

The effect of saponin on the sodium plus potassium activated ATPase activity was studied in the rabbit red cell ghosts and the experiments were also designed to determine the mechanism of action of saponin on the APTase activity. The following results were observed. 1. The ATPase activity of rabbit red cell ghosts is inhibited by low concentration of saponin but increased by high concentration. The activating effect of saponin on the $Na^{+}-K^{+}-ATPase$ activity is inhibited by ouabain but the stimulation of the $Mg^{++}-ATPase$ by high concentration of saponin is not inhibited by ouabain. 2. The activity ratio of $Na^{+}-K^{+}-ATPase$ by high concentration of saponin is decreased by raising the potassium concentration, and is increased by raising the sodium concentration. 3. The ATPase activity is increased by small amounts of calcium but inhibited by larger amounts. The activity ratio of the enzyme by saponin is decreased by raising the calcium concertration 4. The action on the ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine, the imidazole group of histidine, or the carboxyl group of aspartic acid. 5. The action of saponin on the ATPase activity is due to sulfhydryl group of the enzyme of $Na^{+}-K^{+}-ATPase$.

• The Korean Journal of Physiology
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• 제12권1_2호
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• pp.25-34
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• 1978

The action of theobromine on the sodium plus potassium activated ATPase activity In the rabbit red cell membrane has teen investigated and the experiments were also designed to determine the mechanism of action of theobromine on the ATPase activity. The following results were observed. 1. The activity of the NaK ATPase from red fell membrane is stimulated by theobromine, and the concentration of theobromine for maximal activity is about 3mM. 2. The activating effect of theobromine on the ATPase, with a given concentration of potassium in the medium, is increased by raising the sodium concentration but activity ratio is decreased. 3. The activating effect of theobromine on the ATPase, with a given concentration of sodium in the medium. is increased by the raising the potassium concentration but activity ratio is decreased. 4. The NaK ATPase activity is increased by small amounts of calcium but decreased by larger amounts. The activity of the enzyme by theobromine is increased by small amounts of calcium but decreased by larger amounts. 5. The activating effect of theobromine on the ATPase was not related to the hydroxyl group of threonine and imidazole group of histicline. 6. The activating effect of theobromine on the ATPase is due to sulfhydryl group, amino group and carboxyl group of the enzyme of NaK ATPase.

• The Korean Journal of Physiology
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• 제11권1호
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• pp.11-20
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• 1977

The action of pilocarpine 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 pilocarpine on the ATPase activity. The following results were observed. 1. The activity of the NaK ATPase from red cell membrane is stimulated by pilocarpine, and the concentration of pilocarpine for maximal activity is about 3 mM. The pH optimum for the pilocarpine sensitive component is 8.0. 2. The activating effect of pilocarpine on the ATPase, with a given concentration of sodium .in the medium, is increased by raising the potassium concentration but activity ratio is decreased 3. The activating effect of pilocarpine on the ATPase, with a given concentration of Potassium in the medium, is increased by raising the sodium concentration but activity ratio is decreased 4. The NaK ATPase activity is increased by small amounts of calcium but decreased by 'larger amounts. The activity ratio of the enzyme by pilocarpine is decreased by small amounts .of calcium but decreased by larger amounts. 5. The activating effect of pilocarpine on the ATPase was not related to the sulfhydryl group of cysteine, the hydroxyl group of threonine or the imidazole group of histidine. 6. The activating effect of pilocarpine on the ATPase is due to amino group and carboxyl group of the enzyme of NaK ATPase

• The Korean Journal of Physiology
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• 제1권2호
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• pp.141-150
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• 1967

The present investigation was initially undertaken to see if there exists $Na^+-K^+$ activated ATPase in the microsome fraction of the kidney. Having confirmed the presence of such an enzyme, further attempts have been made to characterize its nature and the following conclusions were obtained: (1) The ATPase activity was greatest at the $Na^+$ concentration of 100 mM as well as at $K^+$ concentration of 10 mM. Moreover, the ATPase activity was found to be depressed by $Ca^{++}$ in the presence of $Mg^{++}$. (2) While the ATPase activity was depressed by Ouabain, the magnitude of inhibition was greater in the Na medium than in the K medium. (3) NaCN augmented the ATPase activity whereas NaF and IAA depressed it. On the other hand, DNP had little influence on the ATPase activity. (4) Diamox, vasopressin and aldosterone had no effect while $HgCl_2$ markedly depressed the ATPase activity These findings indicate that the nature of ATPase isolated from the microsome fraction of the rabbit kidney is quite similar to that from other organs such as the heart and the muscle, although there are certain features specific to the type of organs.

• 대한한의학회지
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• 제18권1호
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• pp.198-207
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• 1997

To explore the action mechanism of Ijintang in the brain, the authors investigated the effects of Ijintang fractions on MgNaK ATPase and MgCa ATPase in rat brain synaptosomes prepared from cerebral cortex. The activities of MgNaK ATPase and MgCa ATPase were assayed by the level of inorganic phosphate liberated from the hydrolysis of ATP. Fraction WH-95-7 at the concentration of $10^{-2}%$ decreased the activity of MgNaK ATPase about 34.1% and also reduced the activity of MgCa ATPase about 49.3% But, other fractions (WB-95-7, WC-95-7, MB-95-7, MC-95-7, MH-95-7) did not significantly changed the activities of the MgNaK ATPase and MgCa ATPase The decreased activity of MgNaK ATPase by WH-95-7 will decrease the rate of $Ca^{2+}$ efflux, probably via an Na-Ca exchange mechanism and will increase the rate of $Ca^{2+}$ entry by the depolarization of nerve terminals. The reduced activity of MgCa ATPase by WH-95-7 will result in the decreased efflux of $Ca^{2+}$. As a conclusion, it can be speculated that lithium elevates the intrasynaptosomal $Ca^{2+}$ concentration via inhibition of the activities of MgNaK ATPase and MgCa ATPase. and this increased $[Ca^{2+}]i$ will cause the release of neurotransmitters.

• 대한한방내과학회지
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• 제19권1호
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• pp.431-441
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• 1998

This study was undertaken to determine whether Buthus exract(BTE) affects Na^+-K^+-ATPase$ activity of nervous tissues. The enzym activity was measured in synaptosomal fraction prepared from rabbit brain cortex. Na^+-K^+-ATPase$ activity was inhibited by BTE over concentration range of 0.05-0.5% in a dose-dependent manner. The enzyme activity was increased by an increase in $Na^+$ concentration from 5 to 100mM, $K^+$ concentration from 0.5 to 10mM, and $Mg^{2+}$ concentration from 0.2 to 5mM. These changes in ion concentrations did not produce any effect on the inhibitory effect of BTE on $Na^+-K^+-ATPase$ activity. An increase in ATP concentration from 0.1 to 3mM caused an increase in the enzyme activity. The inhibition of the enzyme activity by BTE were not different between two ATP concentrations. A sulfhydryl group protector DTT prevented PCMB-induced inhibition of $Na^+-K^+-ATPase$ activity, but the BTE-induced inhibition was not altered by DTT. The inhibition of enzyme activity by combination of ouabain and BTE was not different from that by Buthus alone. These results suggest that Buthus exerts inhibitory effect on $Na^+-K^+-ATPase$ activity in cerebral synaptosomes, and the action mechansim is similar to that of ouabain.

• 대한약리학회지
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• 제26권1호
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• pp.35-49
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• 1990

A highly purified $(Na^+,\;K^+)-ATPase$ from the rectal gland of Squalus acanthias and from the electric organ of Electrophorus electricus has been used to raise antibodies in rabbits. The 97,000 dalton catalytic subunit and glycoprotein derived from the rectal gland of spiny shark were also used as antigens. The two $(Na^+,\;K^+)-ATPase$ holoenzymes and the two shark subunits were antigenic. In Ouchterlony double diffusion experiments, these antibodies formed precipitation bands with their antigens. Antibodies prepared against the two subunits of shark holoenzyme also formed precipitation bands with their antigens and shark holoenzyme, but not with eel holoenzyme. These observations are in good agreement with inhibitory effect of these antibodies on the catalytic activity of $(Na^+,\;K^+)-ATPase$ both from the shark and the eel, since there is very little cross-reaction between the shark anticatalytic subunit antibodies and the eel holoenzyme. The maximum antibodies titer of the anticatalytic subunit antibodies is found to be 6 weeks after the initial single exposure to this antigen. Multiple injections of the antigen increased the antibody titer. However, the time required to produce the maximum antibody titer was approximately the same. These antibodies also inhibit catalytic activity of $(Na^+,\;K^+)-ATPase$ vesicles reconstituted by a slow dialysis of cholate after solubilization of the enzyme in a presonicated mixture of cholate and phospholipid. In these reconstituted $(Na^+,\;K^+)-ATPase$ vesicles, effects of these antibodies on the fluxes of $Na^+$, $Rb^+$, and $K^+$ were investigated. Control or preimmune serum had no effect on the influx of $^{22}Na^+$ or the efflux of $^{86}Rb^+$. Immunized sera against the shark $(Na^+,\;K^+)-ATPase$ holoenzyme, its glycoprotein or catalytic subunit did inhibit the influx of $^{22}Na^+$ and the efflux of $^{86}Rb^+$. It was also demonstrated that these antibodies inhibit the coupled counter-transport of $Na^+$ and $K^+$ as studied by means of dual labeling experiments. However, this inhibitory effect of the antibodies on transport of ions in the $(Na^+,\;K^+)-ATPase$ vesicles is manifested only on the portion of energy and temperature dependent alkali metal fluxes, not on the portion of ATP and ouabain insensitive ion movement. Simultaneous determination of effects of the antibodies on ion fluxes and vesicular catalytic activity indicates that an inhibition of active ion transport in reconstituted $(Na^+,\;K^+)-ATPase$ vesicles appears to be due to the inhibitory action of the antibodies on the enzymatic activity of $(Na^+,\;K^+)-ATPase$ molecules incorporated in the vesicles. These findings that the inhibitory effects of the antibodies specific to $(Na^+,\;K^+)-ATPase$ or to its subunits on ATP and temperature sensitive monovalent cation transport in parallel with the inhibitory effect of vesicular catalytic activity by these antibodies provide direct evidence that $(Na^+,\;K^+)-ATPase$ is the molecular machinery of active cation transport in this reconstituted $(Na^+,\;K^+)-ATPase$ vesicular system.

• 대한수의학회지
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• 제23권1호
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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.

• 대한약리학회지
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• 제18권2호
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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.