• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.289-289
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• 1994

흰쥐 적출 대동맥을 이용하여 혈관근의 $Na^{+}$/$Ca^{2+}$ 교환계의 기능과 성질을 구명코자 $Na^{+}$/$Ca^{2+}$ 교환계를 통한 수축 반응을 관찰하고 이때의 조직내 $Ca^{2+}$ 농도, cGMP 농도 및 이 수축에 대한 차단제와 저산소 처리의 영향을 조사하였다. 흰쥐 적출 대동맥은 $Na^{+}$ free 영양액하에서 수축반응을 일으켰고 이 수축 반응 ($Na^{+}$ free 수축반응)은 KCl 농도 증가에 비례하여 증가하였다. KCI 21.6mM 하의 $Na^{+}$ free유발 수축반응은 amiloride전처리하에서 용량-의존성으로 억제되었고 특히 tonic 수축반응이 예민하게 소실되었으며, benzamil과 verapamil 전처리하에서도 유의하게 억제되었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.542-548
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• 2018

We investigated the effects of Na-alginates's average molecular weight (AMW), their concentrations and divalent metal ions on hydrophobic interaction of solution of Na-alginates in sea tangle produced Saccharina japonicus in East Coast of Korea. As the AMWs of Na-alginates decreased, the formations rates of hydrophobic micro domains and pre-micelles between intermoleculars of Na-alginates were increased. The pre-micelles between Na-alginates chains fully were formed when their concentrations reached 0.2%. In the effects of $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ on the hydrophobicity of Na-alginates solution, when the AMWs of Na-alginates were increased, the formation rates of hydrophobic micro domains produced by $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ in alginates chains were increased. When $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ concentrations that were needed to form gels of alginates solutions were insufficient, the formations of pre-micelle in alginates having large AMW were more incomplete than those of small AMW. In the increasing range from 0.01 to 0.1 mM in divalent metal ion concentration, the formation rate of pre-micelle in alginates solution added $Ca^{{+}{+}}$ were more faster than that of $Mg^{{+}{+}}$.

• The Korean Journal of Physiology
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• v.22 no.1
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• pp.13-29
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• 1988

In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.3
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• pp.219-225
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• 2022

Glucagon like peptide-1 (GLP-1) released from enteroendocine L-cells in the intestine has incretin effects due to its ability to amplify glucose-dependent insulin secretion. Promotion of an endogenous release of GLP-1 is one of therapeutic targets for type 2 diabetes mellitus. Although the secretion of GLP-1 in response to nutrient or neural stimuli can be triggered by cytosolic Ca²⁺ elevation, the stimulus-secretion pathway is not completely understood yet. Therefore, the aim of this study was to investigate the role of reverse Na⁺/Ca²⁺ exchanger (rNCX) in Ca²⁺ entry induced by muscarinic stimulation in NCI-H716 cells, a human enteroendocrine GLP-1 secreting cell line. Intracellular Ca²⁺ was repetitively oscillated by the perfusion of carbamylcholine (CCh), a muscarinic agonist. The oscillation of cytosolic Ca²⁺ was ceased by substituting extracellular Na⁺ with Li⁺ or NMG⁺. KB-R7943, a specific rNCX blocker, completely diminished CCh-induced cytosolic Ca²⁺ oscillation. Type 1 Na⁺/Ca²⁺ exchanger (NCX₁) proteins were expressed in NCI-H716 cells. These results suggest that rNCX might play a crucial role in Ca²⁺ entry induced by cholinergic stimulation in NCI-H716 cells, a GLP-1 secreting cell line.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.110-114
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• 2004

Formation behavior of aragonite precipitated calcium carbonate was investigated with changed the concentration of $Na_2CO_3$ solution and addition method which added in the $Ca(OH)_2$ slurry at $75^{\circ}C$. In this reaction, we found that $Na^+$ ions were substituted into $Ca^{2+}$ion site then disturb the growth of calcite, and while proceed the crystal growth in a certain direction and promote the formation of aragonite. Also, a decrease of reaction rate by control the concentration of $CO_3^{2-}$ ion, induce the homogeneous precipitate reaction and increase substitution ability of $Na^+$ ions, consequently it was promote the formation and growth of aragonite.

• The Korean Journal of Physiology
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• v.18 no.2
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• pp.125-137
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• 1984

The effects of external $Ca^{2+}$ ana the inhibition of Na-pump on vanadate-induced contraction in isolated human and rat uterine smooth muscle were studied and the following results were observed. 1) Vanadate induced contraction in rat uterine muscle and showed maximal contraction at concentration of $5{\times}10^{-4}$M, and the contractile response to vanadate was more sensitive in human than rat uterine muscle. 2) Vanadate-induced contraction was not completely inhibited by $Ca^{2+}$ removal from PSS and the response to $Ca^{2+}$ removal was more sensitive in human than rat uterine muscle. 3) Vanadate-induced contraction decreased with increasing concentration of verapamil, but even in the presence of $3{\times}10^{-5}M$ verapamil which inhibited 100 K-induced contraction completely. about 40% of maximal contraction remained, and its amplitude was similar to that of contraction in $Ca^{2+}$-free solution. 4) Vanadate-induced contraction was increased by the inhibition of Na-pump and this increase also could be observed in the presence of $3{\times}10^{-5}M$ verapamil. 5) After pretreatment with $Ca^{2+}$-free PSS containing ouabain Vanadate-induced contraction was not increased, but the contractile response of these tissues to the addition of external $Ca^{2+}$ was remarkably increased in the presence of vanadate. 6) $3{\times}10^{-5}$M verapamil inhibited vanadate-induced $Ca^{45}$ influx completely, but after pretreatment with ouabain vanadate could induce remarkable $Ca^{45}$ influx even in the presence of verapmil. 7) With increasing the time of pretreatment with ouabain or $K^+$-free solution, the degree of increase in contraction by vanadate was more remarkable. 8) $10^{-4}M$ papaverine stowed a considerable inhibition of the increase in the vanadate-induced contraction by pretreatment with ouabain. 9) Acetylcholine-induced contraction increased with lengthening the duration of Na-pump inhibition even in the presence of verapamil. Considering above results it seems that the uterine muscle of human is more sensitive to vanadate than that of rat, and both internal and external $Ca^{2+}$ is utilized in vanadate·induced contraction. In the case of Na-pump inhibition several smooth muscle contracting agents seems to induce $Ca^{2+}$ influx which is not inhibited by verapamil. This $Ca^{2+}$ influx seems to be inhibited by papaverine and to be associated with membrane potential, although its precise characteristics is not certain.

• The Korean Journal of Pharmacology
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• v.2 no.2
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• pp.35-42
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• 1966

The author investigated the effect of $Mg^#$, $Ca^#$, $Na^+$, $K^+$ and creatine phosphate on the ATPase activity of microsomal fraction isolated from rabbit uterus and obtained the following results : 1) The uterine microsomal fraction contained the $Na^+-$ and $K^+-$ activated ATPase in the presence of $Mg^#$. The ATPase activity increased with protein content in the fraction. 2) The maximum ATPase activity was obtained at $Na^+$ and $K^+$ concentraction of 100 mM respectively. 3) In the absence of $Mg^#$, the ATPase was not activated by $Na^+$ and $K^+$, but inhibited. 4) Car stimulated the $Na^+-$ and $K^+-$ activated ATPase in the presence of $Mg^#$. However, in the absence of $Mg^#$, the ATPase was not activated by $Ca^#$. 5) The $K^+-$ activated ATPase activity was greater than the $Na^+-activated$ ATPase under all conditions. 6) The $Na^+-$ and $K^+$ activated ATPase activity was increased by addition of creatine phosphokinase and creatine phosphate to the reaction mixture.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.250-255
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• 2012

The effect of different source silicon ($CaSiO_3$, $K_2SiO_3$, and $NaSiO_3$) and their application methods (foliar application and subirrigation) on the growth of potted kalanchoe was investigated. Rooted terminal cuttings of Kalanchoe blossfeldiana 'Peperu' were transplanted into 10.5 cm plastic pots containing a commercial growing medium. Then, a nutrient solution, containing 0 or $50mg{\cdot}L^{-1}$ Si as $K_2SiO_3$, $Na_2SiO_3$, or $CaSiO_3$ and adjusted to EC 1.4-$1.6mS{\cdot}cm^{-1}$ and pH 6.0, was supplied through subirrigation along with the nutrient solution or by a foliar application. Plants were grown in a glasshouse under a mean temperature of $23^{\circ}C$ and RH of 70-80%. After 12 weeks of cultivation, plant growth characteristics and leaf tissue contents of P, K, Ca, Mg, Na, S, and Si were measured. Both subirrigational supply and foliar application of Si decreased the plant height and flower stem length. However, the plant condition in the foliar application resulted in disease-like soft rot on the leaf. Among three silicon sources tested, $CaSiO_3$ supplied through a subirrigation system increased shoot tissue contents of Si and chlorophyll as compared to the $Na_2SiO_3$ or $K_2SiO_3$ treatment. Shoot tissue contents of Ca, K, and Na increased when the plant was supplied with $CaSiO_3$, $K_2SiO_3$, and $Na_2SiO_3$, respectively. Subirrigational supply of $K_2SiO_3$ and $NaSiO_3$ decreased the shoot tissue contents of Ca and Mg, and K and Ca, respectively. Therefore, $CaSiO_3$ supplied through a subirrigation system could improve plant quality of kalanchoe 'Peperu' making compact potted plants.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.5
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• pp.417-425
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• 2000

The underlying mechanism commonly applicable for both the positive and negative force-frequency relationships (FFR) was pursued in left atria (LA) of rat and rabbit. The species differences in the roles of $Na^+/Ca^{2+}$ exchanger and sarcoplasmic reticulum (SR), which are major intracellular $Ca^{2+}$ regulatory mechanisms in the heart, were examined in the amplitude accommodation to the frequency that changed from 3 Hz to the variable test frequencies for 5 minutes in the electrically field stimulated left atria (LA) of rat and rabbit. Norepinephrine strongly increased the frequency-related amplitude accommodation in both of rat and rabbit LA, while monensin, oubain or the reduced $Na^+$ and 0 mM $Ca^{2+}$ containing Tyrode solution increased the frequency-related amplitude accommodation only in the rabbit LA. Monenisn was also able to increase the frequency-related amplitude accommodation only in 1-day old rat LA but not in 4-week old rat LA that had 75% less $Na^+/Ca^{2+}$ exchanger with 97% higher SR than 1-day old rat LA. Taken together, it is concluded that the differences in the prevalence between myocardial $Na^+/Ca^{2+}$ exchanger and SR in the amplitude accommodation to the frequency-change determine the difference in the FFR between rat and rabbit heart.

• Nuclear Engineering and Technology
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• v.28 no.3
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• pp.274-279
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• 1996

Diffusion coefficient is a critical parameter for predicting radiological source term(migration rate and flux of radionuclide) through given near field conditions in spent fuel or high level waste repository. The effect of exchangeable cation-$Na^+$ and $Ca^{2+} - on the diffusion of $I^- \;and^3H$ (as HTO) in compacted bentonite was examined using a through-diffusion method. Bentonite material used here was compacted to a density of 1.3 Mg/m$^3$, and Na-bentonite was saturated with a solution of 100 mol NaCl/m$^3$ and Ca-bentonite with 50 $mol\;CaCl_2$/m$^3$. The results show that effective diffusion coefficients are generally higher by a factor of two to five in Ca-than Na-clay. This is attributed to the larger particle size of Ca-compared to Na-bentonite; hence, Ca-bentonite has a greater proportion of relatively large pores, which make a greater contribution to mass transport than small pores. Although the nature of the exchangeable cation affects mass diffusion in compacted bentonite, the effect is small and not likely to influence performance assessment modeling of compacted bentonite-based barriers.