• Biomolecules & Therapeutics
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• v.9 no.1
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• pp.26-32
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• 2001

This study was investigated about the effect of glibenclamide (GLY) which is $K^{+}$ channel blocker on renal function in rabbit, GLY, when given into the vein, produced the diuretic action accompanied with the increases of amounts of N $a^{+}$ and $K^{+}$ excreted into urine ( $E_{Na}$ , $E^{K}$), and then osmolar and negative free water clearances ( $C_{osm}$, $T^{C}$$_{H2O}$), fraction excretory rates of filtered N $a^{+}$ and $K^{+}$ ( $F_{Na}$ , $F_{K}$) and ratios of $E_{K}$ against $E_{Na}$ were augmented. Filtration fraction (FF) were reduced because renal plasma flow (RPF) were not changed but glomerular filtration rates (GFR) were diminished. GLY administered into a renal artery exhibited significant reduction of urine volume along with the decreases of GFR and RPF in only experimented kidney whereas changes of renal function was not observed in control kidney. GLY given intracerebroventricularly exhibited diuretic action along with the increase of $E_{Na}$ , $E_{K}$ and $F_{Na}$ , $F_{K}$ by small dose which was not affect on renal function when it given into the vein. Above results suggest that GLY given into the vein in rabbit produce the diuretic action by inhibition of electrolytes reabsorption in renal tubules through central function. function.n. function.ion.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.249-256
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• 1999

Glibenclamide(GLY)(1.0 and 3.0 mg/kg), an ATP-dependent $K^+$ channel blocker, when given into the vein in dogs, produced the diuretic action accompanied with the increase of osmolar clearance($C_{osm}$), urinary excretion of $Na^+$ and $K^+$ ($E_{Na}$, $E_K$), and with the decrease in reabsorption rates for $Na^+$ and $K^+$ in renal tubules ($R_{Na}$, $R_K$), and then ratios of $K^+$ against $Na^+$($K^+$/$Na^+$) were decreased. GLY did not affect mean arterial pressure at any doses used. At a low dose(0.1 mg/kg), GLY injected into a renal artery brought about the diurectic action in both experimental and control kidney, however at a higher dose(0.3 mg/kg), GLY appeared significant diuretic action in the control kidney, but not in experimental kidney and the decrease of glomerular filtration rates(GFR), renal plasma flow(RPF), $E_K$, and the increase in $E_{Na}$. In the control kidney, these changes in renal function exhibited the same aspect as shown in intravenous experiments. In experiments given into carotid artery of GLY(0.5 and 1.5 mg/kg), changes in all renal function included the increase in urine volume were the same pattern as shown in intravenous experiments. The above results suggest that glibenclamide produces diuretic action through central function and the action site of the GLY in kidney is the renal distal tubules in dogs.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.349-356
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• 2002

The present study was performed to examine the effect of fangchinoline, a bis- benzylisoquinoline alkaloid, which exhibits the characteristics of a $Ca^{2+}$ channel blocker, on cyanide-induced neurotoxicity using cultured rat cerebellar granule neurons. NaCN produced a concentration-dependent reduction of cell viability, which was blocked by MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, verapamil, L-type$Ca^{2+}$channel blocker, and L-NAME, a nitric oxide synthase inhibitor. Pretreatment with fangchinoline over a concentration range of 0.1 to 10 $\mu$M significantly decreased the NaCN-induced neuronal cell death, glutamate release into medium, and elevation of $[Ca^{2+}]_i$ and oxidants generation. These results suggest that fangchinoline may mitigate the harmful effects of cyanide-induced neuronal cell death by interfering with $[Ca^{2+}]_i$influx, due to its function as a $Ca^{2+}$ channel blocker, and then by inhibiting glutamate release and oxidants generation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.37-37
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• 1992

세포의 흥분성과 막전위의 조절에 있어서 $K^{+}$ channel의 역할이 크다는 사실이 인정 됨으로서 (Rudy, 1988) $K^{+}$ channel 개방 약물의 약리학적 연구와 임상적 응용에 대한 관심은 높아졌다. Cromakalim, nicorandil 및 pinacidil등이 혈관 평활근을 특히 예민하게 이완시킨다. 작용기전으로서는 세포의 원형질 막을 통한 $K^{+}$ 전도의 항진과 $K^{+}$ outward current의 증가가 막 과분극을 일으킨다. 이러한 결과는 막흥분에 의한 voltage-dependent $Ca^{++}$ channel을 닫게하고 세포내 free $Ca^{++}$의 농도를 감소시켜 혈관의 흥분성과 수축력의 감소를 야기하여 근이완을 야기한다. 한편, 평활근 세포막의 $Na^{+}$-$K^{+}$ ATPase도 활성화하면 electrogenic pump를 가동하여 막 과분극을 일으키고 막 흥분성을 저하시킨다. $Na^{+}$-$K^{+}$ pump는 세포 바깥의 $K^{+}$과 세포안의 $Na^{+}$농도에 의하여 활성화한다.

• KSBB Journal
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• v.14 no.1
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• pp.1-8
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• 1999

It confirmed the facilitated diffusion of $Na^+$ of frog bladder membrane which is a tissue membrane. The mechanism was explained in $Na^+$ channel model and its referred to the $Na^+$ channel obstruction ingredient which was contained in the reference to the $Na^+$ channel obstruction ingredient and son on, e.g., seaweed, shellfish, pufferfish, phytoplankton and chinese drug. Also, it introduces the result which studied from the barrier point of the application of the tissue biosensor to the trade friction on Korea or Japan pufferfish and the marine environment in the one with high dependance. It was possible for the poison quantity of small amount pufferfish toxin (TTX), paralytic shellfish poisoning (PSP) to be measured and also to measure poison quantity in the cultivation poisonous toxin phytoplankton individual. In future, as for this tissue biosensor, it expects that it is possible to contribute widely until environment watch and also monitoring to the scene.

• Biomolecules & Therapeutics
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• v.8 no.1
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• pp.44-52
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• 2000

SKP-450 which is $K^{+}$ channel opener, When given into duodenum, exhibited the decline of urine flow accompanied with the decrease of glomerular filtration rates (GFR), renal plasma flow (RPF), N $a^{+}$ and $K^{+}$ excreated in the urine ( $E_{Na}$ , $E_{K}$) and the increase of $K^{+}$N $a^{+}$ratios, and then appeared the significant fall of mean arterial pressure (MAP) and unchanged of reabsorption rates of N $a^{+}$, $K^{+}$ in renal tubules ( $R_{Na}$ , $R_{K}$). SKP- 450 injected into the vein elicited the decline of urine flow along with the reduction of $E_{Na}$ , $E_{K}$, and the increase of $R_{Na}$ , $R_{K}$ and $K^{+}$M $a^{+}$ ratios. SKP-450 administered into a renal artery produced diuretic action along with the increase of $E_{Na}$ , $E_{K}$ and the decrease of $R_{Na}$ , $R_{K}$ in experimental kidney, whereas produced the same aspect to intravenous SKP-450 in the control kidney. Above results suggest that SKP-450 possess both diuretic action in the kidney and central antidiuretic action in dog.tic action in dog.tion in dog.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.36-36
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• 1992

기니픽심장에서 유두근을 적출하여 valve 쪽은 silver wire에 연결하여 수축력을 측정하고 mural end는 sylgard floor에 pin으로 고정하여 1Hz로 자극하였다. 이때 사용된 영양액은 Tyrode Ringer로 bath내 은도는 36$^{\circ}C$이고 97% 0$_2$, 3% $CO_2$로 포화시켜 사용하였다. 수축력이 일정해진 후 막전위는 conventional electrode를 이용해서 기록하고, 세포내 $Na^{＋}$ 이온 활성도( $a_{Na}$ $^{i}$ )는 $Na^{＋}$ 선택적 전극을 이용해서 기록하였다. 적출 기니픽 심근에서 pinacidil, cromakalim, RP49356 둥의 $K^{＋}$ channel opener는 활동전위 기간(APD)과 수축력 감소을 일으켰고, pinacidil과 cromakalim에 의한 APD 감소는 glibenclamide (10 $\mu$M)에 의해 거의 억제되었다. Pinacidil, RP49356 및 cromakalim에 의한 수축력 감소시 세포내 $Na^{＋}$ 이온농도( $a_{Na}$ $^{i}$ )의 감소가 나타났으며 glibenclamide(10 $\mu$M)에 의한 APD의 감소는 거의 차단되었으나 $a_{Na}$ $^{i}$ 감소는 일부 나타났으며 이때 수축력의 감소도 나타났다.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.119-127
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• 2016

Dihydropyridine (DHP) calcium channel blockers (CCBs) have been widely used to treat of several cardiovascular diseases. An excessive shortening of action potential duration (APD) due to the reduction of $Ca^{2+}$ channel current ($I_{Ca}$) might increase the risk of arrhythmia. In this study we investigated the electrophysiological effects of nicardipine (NIC), isradipine (ISR), and amlodipine (AML) on the cardiac APD in rabbit Purkinje fibers, voltage-gated $K^+$ channel currents ($I_{Kr}$, $I_{Ks}$) and voltage-gated $Na^+$ channel current ($I_{Na}$). The concentration-dependent inhibition of $Ca^{2+}$ channel currents ($I_{Ca}$) was examined in rat cardiomyocytes; these CCBs have similar potency on $I_{Ca}$ channel blocking with $IC_{50}$ (the half-maximum inhibiting concentration) values of 0.142, 0.229, and 0.227 nM on NIC, ISR, and AML, respectively. However, ISR shortened both $APD_{50}$ and $APD_{90}$ already at $1{\mu}M$ whereas NIC and AML shortened $APD_{50}$ but not $APD_{90}$ up to $30{\mu}M$. According to ion channel studies, NIC and AML concentration-dependently inhibited $I_{Kr}$ and $I_{Ks}$ while ISR had only partial inhibitory effects (<50% at $30{\mu}M$). Inhibition of $I_{Na}$ was similarly observed in the three CCBs. Since the $I_{Kr}$ and $I_{Ks}$ mainly contribute to cardiac repolarization, their inhibition by NIC and AML could compensate for the AP shortening effects due to the block of $I_{Ca}$.

• Korean Journal of Optics and Photonics
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• v.12 no.4
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• pp.320-326
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• 2001

In this paper, we have fabricated asymmetric Y-branch optical power splitters with various optical power splitting ratios by changing the width of one of the output waveguides using $Ag^+-Na^+$ ion change method in BK7 glass. The transmission characteristics of asymmetric Y-branch optical power splitters with different output waveguide width have been investigated using the finitedifference beam propagation method (FD-BPM). We have found the index of the channel waveguide formed by Ag+-Na+ ion change method in BK7 glass and have fabricated channel waveguides to examine the transmission characteristics of channel waveguide. And we have fabricated asymmetric Y-branch optical power splitters with output waveguide width from TEX>$4{\mu}m$ to $6{\mu}m$. /TEX>.

• YAKHAK HOEJI
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• v.44 no.3
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• pp.205-212
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• 2000

The effect of BRL 34915, a $K^{+}$ channe$Na^{+}$l opener, on renal function was investigated in anesthetized dog. BRL 34915, when given into the vein, elicited the decrease of urine volume accompanied with the reduction of renal plasma flow (RPF), osmolar clearance ($C_{osm}$) and amounts of sodium excreted into urine ($E_{na}$), whereas reabsorption rate of sodium in renal tubules ($R_{na}$), ratio of $K^{+}$ against $Na^{+}$ in urine ($K^{+}$ /$Na^{+}$) were elevated significantly with a partial fall of mean arterial pressure (MAP). BRL 34915 injected into a renal artery produced the diuretic action along with the increase in RPF $C_{osm}$, $E_{na}$ and amounts of potassium excreted in urine ($E_{k}$), and the decrease in $R_{na}$, reabsorption rate of potassium in renal tubules ($R_{k}$), free water clearance ($C_{H20}$) and $K^{+}/Na^{+}$ ratio in only ipsilateral kidney, however changes of the renal function were not observed in control kidney. BRL 34915 given into carotid artery exhibited the same aspect as changes of renal function induced by intravenous BRL 34915. These results suggest that BRL 34915 has dual effects, renally acting diuretic and centrally acting antidiuretic action.n.