• 치위생과학회지
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• 제2권1호
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• pp.47-51
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• 2002

Sprague-Dawley계 흰쥐의 악하선에서 선세포를 분리하여 fura-2/AM(fura-2)으로 염색한 후 spectrofluorometer로 세포내 $Ca^{2+}$농도를 측정하였다. 악하선 세포를 관류장치(perfusion chamber)에 넣고 표준용액을 관류시키면서 isoproterenol($1{\mu}M$)과 octanol(1mM)을 투여한 후 $Ca^{2+}$농도 변화를 측정하였는데 단독 투여시 $Ca^{2+}$농도는 거의 변화하지 않았으나 함께 투여한 경우 세포 내 $Ca^{2+}$농도가 증가함을 확인할 수 있었다. Adenylate-cyclase를 활성화 시키는 forskolin($10{\mu}M$)과 octanol을 함께 투여하였을 때도 isoproterenol의 경우와 유사한 증가 현상을 보이는 것으로 볼 때 octanol과 isoproterenol 또는 forskolin이 함께 작용할 때 세포 내 $Ca^{2+}$가 증가하는 것을 확인할 수 있었다. $Ca^{2+}$의 증가기전을 확인하고자 표준용액의 $Ca^{2+}$를 제거함은 물론 EGTA를 처리하여 세포외부의 $Ca^{2+}$를 제거한 후 상기한 바와 동일한 실험을 반복한 결과 $Ca^{2+}$농도의 증가를 보이지 않았다. 따라서 세포 내 $Ca^{2+}$의 증가는 세포 외부로부터의 $Ca^{2+}$유입 때문인 것으로 확인할 수 있었다. 이러한 $Ca^{2+}$의 유입 capacitative entry pathway를 이용하는지 확인코자 gadolinium($10{\mu}M$)을 처리하였을 때 $Ca^{2+}$농도의 증가가 완전히 억제되지는 않았지만 $Ca^{2+}$의 증가속도와 증가량이 감소되어 있음을 확인할 수 있었다. 이상의 실험결과들을 정리하면 세포 내 $Ca^{2+}$농도의 증가와 관련 ${\beta}$-아드레날린계 관련 약물과 옥탄올(octanol)을 함께 처리할 경우 세포 내 $Ca^{2+}$는 세포 외부에서 유입되어 증가되고 그 경로는 일부 capacitative entry pathway를 통함을 확인할 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권2호
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• pp.233-239
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• 2017

Intracellular calcium ($Ca^{2+}$) oscillation is an initial event in digestive enzyme secretion of pancreatic acinar cells. Reactive oxygen species are known to be associated with a variety of oxidative stress-induced cellular disorders including pancreatitis. In this study, we investigated the effect of hydrogen peroxide ($H_2O_2$) on intracellular $Ca^{2+}$ accumulation in mouse pancreatic acinar cells. Perfusion of $H_2O_2$ at $300{\mu}M$ resulted in additional elevation of intracellular $Ca^{2+}$ levels and termination of oscillatory $Ca^{2+}$ signals induced by carbamylcholine (CCh) in the presence of normal extracellular $Ca^{2+}$. Antioxidants, catalase or DTT, completely prevented $H_2O_2$-induced additional $Ca^{2+}$ increase and termination of $Ca^{2+}$ oscillation. In $Ca^{2+}$-free medium, $H_2O_2$ still enhanced CCh-induced intracellular $Ca^{2+}$ levels and thapsigargin (TG) mimicked $H_2O_2$-induced cytosolic $Ca^{2+}$ increase. Furthermore, $H_2O_2$-induced elevation of intracellular $Ca^{2+}$ levels was abolished under sarco/endoplasmic reticulum $Ca^{2+}$ ATPase-inactivated condition by TG pretreatment with CCh. $H_2O_2$ at $300{\mu}M$ failed to affect store-operated $Ca^{2+}$ entry or $Ca^{2+}$ extrusion through plasma membrane. Additionally, ruthenium red, a mitochondrial $Ca^{2+}$ uniporter blocker, failed to attenuate $H_2O_2$-induced intracellular $Ca^{2+}$ elevation. These results provide evidence that excessive generation of $H_2O_2$ in pathological conditions could accumulate intracellular $Ca^{2+}$ by attenuating refilling of internal $Ca^{2+}$ stores rather than by inhibiting $Ca^{2+}$ extrusion to extracellular fluid or enhancing $Ca^{2+}$ mobilization from extracellular medium in mouse pancreatic acinar cells.

• 한국콘텐츠학회논문지
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• 제9권12호
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• pp.339-347
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• 2009

연구목적: 64 절편 MDCT를 이용한 심장 CT의 진단일치도를 알아보고, 심박동수와 관상동맥 석회화가 진단일치도에 영향을 미치는지 확인하여 심장 CT 검사 시 기초 자료로 활용하고자 함이다. 연구방법: 심장 CT와 관상동맥 조영술을 함께 시행한 178명(남자 84명, 여자 94명)을 대상으로 심장 CT에서 관상동맥 협착과 심박동수, 석회화 수치를 측정하였고, 관상동맥조영술에서 좌전하행동맥, 좌회선동맥, 우관상동맥의 유의한 협착($\geq50%$)이 있는지 확인하였다. 관상동맥 조영술의 결과를 표준으로 심장 CT의 민감도, 특이도, 양성예측도, 음성예측도, kappa index($\kappa$)를 계산하였다. 연구결과: 환자별 협착의 정도를 평가한 결과 심장 CT의 정확도는 96.6%였다. 혈관별로는 LAD, LCX, RCA 각각 86.5%, 84.3%, 92.1%로 높은 진단일치도를 보였다. 체질량지수와 혈압은 심장 CT의 진단일치도에 영향을 미치지 않았다. 심박동수는 60/min 미만에서 정확도 90.1%, $\kappa$값 0.78이었고, 70/min 이상에서는 정확도가 75.8%, $\kappa$값 0.52이었다. 관상동맥 석회화지수 100 미만에서는 정확도가 91.3%, $\kappa$값 0.81이었고, 석회화지수 400 이상에서는 정확도 68.6%, $\kappa$값 0.33으로 떨어졌다. 결론: 64 절편 MDCT를 이용한 심장 CT는 관상동맥 조영술과 거의 비슷한 진단일치도를 나타냈다. 하지만 심박동수 70/min 이상, 관상동맥 석회화지수 400 이상에서는 진단일치도가 저하되었기 때문에 심장 CT 검사 시 심박동수와 관상동맥 석회화지수를 확인하여 검사하여야 하고, 심박동수가 70/min 이상이면 베타차단제를 사용하여 심박동수를 조절하여야 한다.

• 대한환경공학회지
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• 제31권9호
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• pp.783-792
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• 2009

서울 인근의 하수처리장에서 채취한 유입/유출수에 내포되어 있는 31개의 미량 EDC/PPCPs(내분비계장애물질/의 약 개인관리용품물질)의 발현 특성에 대한 조사 연구를 수행하였다. 유입수에서 검출된 EDC/PPCPs의 용도별 분류에 따른 총농도 관점의 발현 비율은 각성제(59.67%), X선 조영제(20.20%), 난연제(9.00%), 기타 등의 순으로 나타났으며, 유출수의 경우에는 베타 차단제(30.54%), 난연제(20.49%), X선 조영제(18.17%), 기타 등의 순으로 발현 빈도가 나타났다. 본 연구에서 검출된 대상 미량물질의 전반적인 농도 검출 범위는 다른 국내 선행연구에 비해 다소 낮은 것으로 나타났으며, 국외의 연구결과와 비교해서는 상당한 낮은 수준으로 검출되는 것으로 나타났다. 특히 유럽 지역의 연구결과와 비 교하면 일부 의약물질항목에 따라서는 수천 배의 농도차이를 보여주는 것으로 나타났다. 한편, 선택된 9개의 의약물질에 대해 유입수와 유출수의 예상환경농도(PEC)를 계산하고 실제 측정된 농도(MEC)와 비교한 결과 물질별 발현 농도 수치 관점에서는 큰 편차를 보였으나, 물질별 상대적 발현 빈도 순서 관점에서는 대체적으로 유사한 것으로 나타났다.

• The Korean Journal of Physiology and Pharmacology
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• 제8권5호
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• pp.265-272
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• 2004

The present study was attempted to investigate the effect of cilnidipine (FRC-8635), which is a newly synthesised novel dihydropyridine (DHP) type of organic $Ca^{2+}$ channel blockers, on secretion of catecholamines (CA) evoked by acetylcholine (ACh), high $K^+$, DMPP and McN-A-343 from the isolated perfused rat adrenal gland. Cilnidipine $(1{\sim}10{\mu}M)$ perfused into an adrenal vein for 60 min produced relatively dose- and time-dependent inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}M),\;DMPP\;(10^{-4}M\;for\;2\;min)$ and McN-A-343 $(10^{-4}M\;for\;2\;min)$. However, lower dose of cilnidipine did not affect CA secretion by high $K^+\;(5.6{\times}10^{-2}\;M)$, higher dose of it reduced greatly CA secretion of high $K^{+}$. Cilnidipine itself did fail to affect basal catecholamine output. In the presence of cilnidipine $(10{\mu}M)$, the CA secretory responses evoked by Bay-K-8644 $(10{\mu}M)$, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid $(10{\mu}M)$, an inhibitor of cytoplasmic $Ca^{2+}$-ATPase were also inhibited. Moreover, ${\omega}-conotoxin\;GVIA\;(1{\mu}M)$, a selective blocker of the N-type $Ca^{2+}$ channels, given into the adrenal gland for 60 min, also inhibited time-dependently CA secretory responses evoked by Ach, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid. Taken together, these results demostrate that cilnidipine inhibits CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors from the isolated perfused rat adrenal gland without affecting the basal release. However, at lower dose, cilnidipine did not affect CA release by membrane depolarization while at larger dose inhibited that. It seems likely that this inhibitory effect of cilnidipine is exerted by blocking both L- and N-type voltage-dependent $Ca^{2+}$ channels (VDCCs) on the rat adrenomedullary chromaffin cells, which is relevant to inhibition of both the $Ca^{2+}$ influx into the adrenal chromaffin cells and intracellular $Ca^{2+}$ release from the cytoplasmic store. It is thought that N-type VDCCs may play an important role in regulation of CA release from the rat adrenal medulla.

• 대한약리학회지
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• 제30권2호
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• pp.191-203
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• 1994

$K^+$ channel openers (KCOs) are known to have a wide range of effects by opening the $K^+$ channel in plasma membranes of various smooth muscles, cardiac muscle and pancreatic ${\beta}-cell$. In the present study, we investigated the effects of 5 types of KCOs, cromakalim, RP49356, pinacidil, nicorandil and diazoxide on the contractility of isolated rat uterus. All KCOs tested inhibited the uterine contraction induced by 0.2 nM oxytocin in a dose-dependent manner. Individual KCO and its $pD_2$ values were cromakalim 6.5, RP49356 6.3, pinacidil 5.92, nicorandil 4.43 and diazoxide 4.18. The relaxant effects of KCO were inhibited by glibenclamide (0.3, 1 and $10\;{\mu}M$) with $pA_2$ values of cromakalim 6.91, RP49356 6.59, pinacidil 6.55, nicorandil 5.97 and diazoxide 6.37. In addition, the relaxant effect of cromakalim or pinacidil was antagonised by TEA, a non-selective $K^+$ channel blocker, but not by apamin. Contractions induced by low concentration of KCI (< 40 mM) were inhibited by cromakalim $(100{\mu}M)$ and nicorandil $(300{\mu}M)$, but those evoked by higher concentration (> 40 mM) of KCI were little affected. In ovariectomized rat uterus, cromakalim dose-dependently inhibited oxytocin-induced contraction and glibenclamide $(10{\mu}M)$ inhibited the relaxant effect of cromakalim with $pD_2$ and $K_B$ values of 7.48 and $1.26{\times}10^{-7}M$, respectively. In estrogen-primed rat uterus, these values were 6.51 and $1.57{\times}10^{-7}M$, respectively, indicating that the cromakalim is less effective on the estrogen-treated uterine smooth muscle. Our results suggest that the KCO-sensitive $K^+$ channels participate in the motility of uterine smooth muscle and such channels are, at least in part, under the control of estrogen. In addition, our data Indicate that the type of $K^+$ channels activated by KCO is ATP-sensitive $K^+$ channels which is blocked by glibenclamide.

• 대한약리학회지
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• 제31권1호
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• pp.27-37
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• 1995

본 연구에서는 콜린성 기전에 반응하여 분비되는 내피 의존성 이완물질(endothelium-derived relaxing factor, EDRF)나 nitric oxide(NO)가 마취 흰쥐의 뇌혈류 자가조절기전에 관여할 가능성을 관찰하였다. Acetylcholine($10^{-9}-10^{-6}M$)을 포함한 mock 뇌척수액(CSF)을 관류시 뇌연막 동맥은 농도에 의존하여 이완반응 나타내었고(평균; $19.3{\pm}1.7{\mu}m$, n=36), 이러한 이완반응은 $N{\omega}$-nitro-L-arginine(L-NNA, $10^{-5}M$)에 의해서 억제되었을 뿐 아니라 methylene blue($10^{-6}M$)나 oxyhemoglobin($10^{-6}M$)에 의하여도 억제되었다. 한편 이러한 acethlcholine에 의한 뇌연막동맥의 이완반응을 매게하는 무스카린 수용체는 무스카린 수용체 길항제의 봉쇄효과를 관찰한 실험에서 $M_1$과 $M_3$ 아형으로 생각되었다. L-Arginine을 함유한 mock CSF로 관류시 일어나는 일시적인 혈관이완반응은 NY 83583 ($10^{-5}M$)에 강력히 억제되었으나 L-NNA ($10^{-5}M$)에 의해서는 억제되지 아니하였다. 한편 acetylcholine과 L-arginine에 의한 혈관이완반응은 ATP-sensitive $K^+$ 통로 봉쇄제인 glibenclamide에 의해 유의하게 봉쇄되었다. 나아가 뇌연막동맥의 직경 변화를 동맥압의 변화에 대하여 검정한 결과 혈관이완과 혈관수축의 희귀 직선의 경사도는 $10^{-5}M$ L-NNA의 전처치에 의하여 영향을 받지 아니하였으나, $3{\times}10^{-6}M$ glibenclamide에 의해 유의하게 감소되었다. 이러한 결과로 보아 혈압하강에 대해 쥐의 뇌연막동맥에 나타나는 혈관이완반응은 EDRF(NO)에 의해 매개되지 않는다고 사료된다.

• BMB Reports
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• 제40권4호
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• pp.467-474
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• 2007

Autosomal recessive polycystic kidney disease (ARPKD) is one of the important genetic disorders in pediatric practice. Mutation of the polycystic kidney and hepatic disease gene 1 (PKHD1) was identified as the cause of ARPKD. The gene encodes a 67-exon transcript for a large protein of 4074 amino acids termed fibrocystin, but its function remains unknown. The neoplastic-like in cystic epithelial proliferation and the epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) axis overactivity are known as the most important characteristics of ARPKD. Since the misregulation of $Ca^{2+}$ signaling may lead to aberrant structure and function of the collecting ducts in kidney of rat with ARPKD, present study aimed to investigate the further mechanisms of abnormal proliferation of cystic cells by inhibition of PKHD1 expression. For this, a stable PKHD1-silenced HEK-293T cell line was established. Then cell proliferation rates, intracellular $Ca^{2+}$ concentration and extracellular signal-regulated kinase 1/2 (ERK1/2) activity were assessed after treatment with EGF, a calcium channel blocker and agonist, verapamil and Bay K8644. It was found that PKHD1-silenced HEK-293T cell lines were hyperproliferative to EGF stimulation. Also PKHD1-silencing lowered the intracellular $Ca^{2+}$ and caused EGF-induced ERK1/2 overactivation in the cells. An increase of intracellular $Ca^{2+}$ in PKHD1-silenced cells repressed the EGF-dependent ERK1/2 activation and the hyperproliferative response to EGF stimulation. Thus, inhibition of PKHD1 can cause EGF-induced excessive proliferation through decreasing intracellular $Ca^{2+}$ resulting in EGF-induced ERK1/2 activation. Our results suggest that the loss of fibrocystin may lead to abnormal proliferation in kidney epithelial cells and cyst formation in ARPKD by modulation of intracellular $Ca^{2+}$.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.215-224
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• 1994

The presence of a calcium current $(i_{Ca^{2+}})$ passed via a specific channel was examined in the unfertilized hamster egg using the whole-cell voltage clamp technique. Pure inward current was isolated using a $Ca^{2+}-rich$ pipette solution containing 10 mM TEA. This current was independent of external $Na^+$ and was highly sensitive to the $Ca^{2+}$ concentration in the bathing solution, indicating that the inward current is carried by $Ca^{2+}$. The maximal amplitude was $-4.12{\pm}0.58nA\;(n=12)$ with 10mM $Ca^{2+}$ at -3OmV from a holding potential of -8OmV. This current reached its maximum within 20ms beyond -3OmV and decayed rapidly with an inactivation time constant $({\tau})$ of 15ms. Activation and inactivation of this $i_{Ca^{2+}}$ was steeply dependent on the membrane potential. The $i_{Ca^{2+}}$ began to activate at the lower voltage of -55 mV and reached its peak at -35 mV, being completely inactivated at potentials more positive than -40 mV. These result suggest that $i_{Ca^{2+}}$ in hamster eggs passes through channels with electrical properties similar to low voltage-activated T-type channels. Other results from the present study support this suggestion; First, the inhibitory effect of $Ni^{2+}\;(IC_{50}=13.7\;{\mu}M)$ was more potent than $Cd^{2+}\;(IC_{50}=123\;{\mu}M)$. Second, $Ba^{2+}$ conductance was equal to or below that of $Ca^{2+}$. Third, $i_{Ca^{2+}}$ in hamster eggs was relatively insensitive to nifedipine $(IC_{50}=96.6\;{\mu}M)$, known to be a specific t-type blocker. The physiological role of $i_{Ca^{2+}}$ in the unfertilized hamster eggs remains unclear. Analysis from steady-state inactivation activation curves reveals that only a small amount of this current will pass in the voltage range $(-70{\sim}-30\;mV)$ which partially overlaps with the resting membrane potential. This current has the property that it can be easily activated by a weak depolarization, thus it may trigger a certain kind of a intracellular event following fertilization which may cause oscillations in the membrane potential.

• 대한한방내과학회지
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• 제21권3호
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• pp.377-388
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• 2000

Objective : This study was undertaken to evaluate the effect of Sunghyangchungisan (SHCS) on the regulation of vascular tone and $Ca^{2+}$ metabolism in arterial tissues. Vascular rings isolated from rabbit carotid artery were myographed isometrically in isolated organ baths and the effect of SHCS on contractile activities, endothelial function and $Ca^{2+}$ metabolism were determined. Methods : In phentobarbital sodium-anesthetized rabbits, SHCS administered through ear vein (100 mg/Kg body wt.) or intragastric dwelling tube (300 mg/Kg body wt.) attenuated phenylephrine (PE, 10 ${\mu}g$/Kg, i.v.)-induced increases in both systolic and diastolic cartoid arterial blood pressure. Results : In experiments with isolated arterial strips, SHCS relaxed arterial rings which were pre-contracted by phenylephrine (PE, 1 ${\mu}M$). The responses to SHCS were partially dose-dependent at concentrations lower than 0.5 mg/ml. When SHCS was applied prior to the exposure to PE, it inhibited the PE-induced contraction by a similar magnitude which was comparable to the relaxation of pre-contracted arterial rings. Washout of SHCS after observing its relaxant effect resulted in a full recovery of PE-induced contractions, indicating that the action mechanism is reversible. The observation that SHCS did not change the $ED_{50)$ of PE oh its dose-response curve ruled out the possible interaction of SHCS with ${\alpha}$-receptors. The relaxant effect of SHCS was not affected by removal of endothelium or a nitric oxide synthase inhibitor, L-NAME. Methylene blue, an inhibitor of the soluble guanylate cyclase, did not affect the relaxant effect of SHCS. These results suggest that the action of SHCS is not mediated by the endothelium nor soluble guanylate cyclase. Constant cGMP production determined in arterial strips in the presence or absence of SHCS is consistent with this conclusion. When contraction was induced by additive application of $Ca^{2+}$ in arterial rings which were pre-depolarized by high $K^+$ in a $Ca^{2+}$-free solution, the relaxant effect of SHCS was attenuated by increasing the $Ca^{2+}$ concentration. SHCS, when applied to the arterial rings pre-contracted by PE and then relaxed by nifedipine, a $Ca^{2+}$ channel blocker, did not show additive relaxation. SHCS partially blocked $Ca^{2+}$ influx stimulated by PE and high $K^+$ which was determined by 5-min ^{45}Ca$ uptake, while it did not affect $Ca^{2+}$ efflux. Conclusions : From above results, it is suggested that SHCS relax PE-induced contraction of rabbit carotid artery in an endothelium independent manner, andinhibition of $Ca^{2+}$ influx may contribute to the underling mechanism.