• Title/Summary/Keyword: channel blockers

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Evaluation of T-Type Calcium Channel Blockers against Human Pancreatic MIA PaCa-2 Carcinoma Xenografts

  • Park, Jin Yeong;Choi, Heung Woo;Choi, Doo Li;Jang, Sun Jeong;Kim, Je Hak;Lee, Joo Han;Choo, Dong Joon;Kim, Jungahn;Lee, Kyung-Tae;Lee, Jae Yeol
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.482-488
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    • 2013
  • Two piperazine-containing 3,4-dihyroquinazolines (BK10007S/8S) have been synthesized, based on our previous work on the synthesis and antitumoral activity of 3,4-dihyroquinazolines. After evaluating them for T-type calcium channel blocking effect and in vitro anti-cancer effect, they were profiled for acute and repeat dose toxicity (40 mg/kg, 2 weeks) to BALB/c mice. BK10007S/8S were further in vivo evaluated against human pancreatic MIA PaCa-2 carcinoma in $BALB/c^{nu/nu}$ nude mice, which exhibited 54 and 61% tumor growth inhibition through 57-day oral administration of 2 mg/kg of body weight, respectively.

Pharmacological Action Mechanism(s) of Vasodilator Effect of Calcitonin Gene-related Peptide in Rat Basilar Arteries (흰쥐의 뇌 기저동맥에서 CGRP에 의한 혈관 이완반응의 기전에 대한 연구)

  • Rhim, Byung-Yong;Hong, Sun-Hwa;Kim, Chi-Dae;Lee, Won-Suk;Kim, Dong-Heon;Hong, Ki-Whan
    • The Korean Journal of Pharmacology
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    • v.32 no.1
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    • pp.39-49
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    • 1996
  • In the present study, we observed change in intracellular $Ca^{2+}$$([Ca^{2+}]_i)$ as measured with the fluorescent $Ca^{2+}-indicator$ fura-2 in association with force development of the rat basilar arteries during activation by$K^+$ depolarizing solution and U46619, a thromboxane analogue, in the absence and the presence of calcitonin-gent related peptide (CGRP). CGRP (30 and 100 nM) caused a concentration-dependent inhibition of U46619-induced contraction with decrease in $[Ca^{2+}]_i$, whereas it did not exert any effect on the $K^+$ (90 mM)-induced contraction and increase in $[Ca^{2+}]_i$, Further, $[Ca^{2+}]_i-force$ relationships were determined by plotting the ratio of $F_{340}/F_{380}$ $([Ca^{2+}]_i)$ as a function of the force induced by U46619, and the results were compared with those obtained in the presence of CGRP. The curves obtained in the presence of CGRP (30 and 100 nM) were significantly moved to downward without right shift of the curves suggesting that CGRP inhibited the U46619-induced contraction only by mediation of reduction in $[Ca^{2+}]_i$ with out any change in the sensitivity of contractile apparatus to $Ca^{2+}$. The CGRP-induced attenuation of $[Ca^{2+}]_i$ and force development was significantly inhibited under pretreatment with CGRP $(8{\sim}37)$ fragment (100 nM), a CGRP1 receptor antagonist. Both the reduced contraction and reduction in $[Ca^{2+}]_i$ caused by CGRP were fully reversed by pretreatment with charybdotoxin (100 nM) and iberiotoxin (100 nM), large conductance $Ca^{2+}-activated$ $K^+$ channel blockers, but not by apamin (300 nM), a small conductance $Ca^{2+}-activated$ $K^+$ channel blocker, and glibenclamide ( 1 ${\mu}M$), an ATP-sensitive $K^+$ channel blocker. In conclusion, it is suggested that the CGRP1 receptor, upon activation by CGRP, are coupled to opening of $Ca^{2+}-activated$ $K^+$ channel and cause to decrease in $[Ca^{2+}]_i$, thereby leading to vasodilation of the rat basilar artery. However, it is not defined that the mechanism underlying vasodilation whether the $K^+$ channel blockers, charybdotoxin and iberiotoxin directly block the CGRP receptors and that CGRP-evoked relaxation is dependent on the cyclic AMP or $K^+$ channel opening or both actions.

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Involvement of Ca2+ and K+ channels in the action of NO on gastric circular muscle (기니피그 유문부 윤상근의 자발적 수축 및 서파에 대한 nitric oxide의 억제적 작용과 Ca2+ 및 K+ 통로의 관련성)

  • Kim, Tae-wan;La, Jun-ho;Yang, Il-suk
    • Korean Journal of Veterinary Research
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    • v.41 no.4
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    • pp.485-495
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    • 2001
  • It was investigated whether $Ca^{2+}$ and $K^+$ channels were involved in the inhibitory action of nitric oxide (NO) on the contractile and slow wave activity of guinea pig gastric antral circular muscle. The gastric antral circular muscle showed spontaneous phasic contraction and slow wave. NO donors, 3-morpholinosydnonimine hydrochloride (SIN-1, $0.01{\sim}100{\mu}M$) and S-nitroso-L-cysteine (CysNO, $0.001{\sim}10{\mu}M$), reduced not only the amplitude of phasic contraction but also that of slow wave in a concentration-dependent manner. Both the perfusion of $Ca^{2+}$-free solution and the administration of $Ni^{2+}$, a nonselective $Ca^{2+}$ channel blocker, reduced the phasic contraction as well as the amplitude and frequency of the slow wave. The effects of these treatments were similar to those of NO donors. Nifedipine ($10{\mu}M$), a specific L-type $Ca^{2+}$ channel blocker, abolished the phasic contraction and remarkably reduced the plateau of slow wave but had no profound effect on the upstroke of slow wave. In the whole-cell patch clamp mode, CysNO shifted the steady-state activation curve for L-type $Ca^{2+}$ current to the right and the steady-state inactivation curve to the left. Pretreatment of various $K^+$ channel blockers such as tetraethylammonium (1 mM), 4-aminopyridine (0.5 mM), glibenclamide (10 mM), apamin ($0.1{\mu}M$), and iberiotoxin ($0.1{\mu}M$) did not affect the inhibitory action of SIN-1. These results suggest that NO donors suppress mechanical and electrical activity of guinea pig gastric antral circular muscle by inhibition of L-type $Ca^{2+}$ channel rather than by activation of $K^+$ channels.

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Two-Dimensional Echocardiographic Preoperative Prediction of Prosthetic Valve Size (이면성 심초음파도로 구한 대동맥판륜부 크기와 실제 치환된 판막크기와의 비교연구)

  • 정태은
    • Journal of Chest Surgery
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    • v.21 no.6
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    • pp.979-983
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    • 1988
  • Calcium channel blockers may prevent myocardial injury during cardioplegia and reperfusion. This study was done to evaluate the effects of diltiazem cardioplegia on myocardial protection during ischemic arrest and recovery of myocardial function after reperfusion. Four formulations of crystalloid cardioplegic solutions, GIK solution[group I, n=12], diltiazem[lug/ml GIK] in GIK solution[group II, n=7], ],diltiazem[2ug/ml GIK] in GIK solution[group III, n=6] and diltiazem[4ug/ml GIK] in GIK solution[group IV, n=6] were compared in isolated working rat heart subjected to a long period [2 hours] of hypothermic arrest with multi-dose infusion. Diltiazem cardioplegia[group II, III and IV]was found to be superior in nearly all aspects. Diltiazem cardioplegia showed faster recovery of regular rhythm and lower incidence of ventricular fibrillation than group I did. In comparing mechanical function in all experimental hearts, the mean postischemic recoveries of aortic flow, cardiac output, peak aortic pressure, stroke volume and stroke work[expressed as a percentage of its preischemic control] were significantly greater in group II, III and IV[diltiazem cardioplegia] than in group I. The infused amount of cardioplegic solution was more increased by the addition of diltiazem to GI K solution. [p < 0.01] Creatine kinase leakage tended to be lower in hearts receiving diltiazem cardioplegia, especially in group III and IV[p<0.05] than in those receiving GIK solution only[group I]. Diltiazem cardioplegia results in the increased flow of cardioplegic solution and the decreased ischemic injury of myocardium during ischemic arrest and the improved recovery of myocardial function after reperfusion, and a dose-response relation must be established before clinical use.

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Effect of Na, K, Ca and Mg ions on the Action Potential of the Sinoatrial Node in the Rabbit (토끼 동방결절 활동전압에 대한 Na, K, Ca 및 Mg 이온의 영향)

  • Lee, Jeong-Ryeol;Eom, Yung-Ui
    • Journal of Chest Surgery
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    • v.18 no.1
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    • pp.1-6
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    • 1985
  • Isolated sinus node cells of the rabbit were used to assess the effects of extracellular Na, K, Ca and Mg concentrations on cardiac pacemaker activity. With intracellular glass micro-electrodes spontaneous action potentials of SA node were recorded and the effects of various ions and their blockers were analyzed in terms of the cycle length, the amplitude and the duration of action potentials, the results obtained were as follows. 1. Sodium reduction [up to 30%] decreased the amplitude of action potential and lengthened the cycle length. TTX, specific blocker of Na channel slightly lengthened the cycle length. 2. Increasing potassium ion concentration, the duration of action potential decreased and the frequency increased in 6mM, however, spontaneous action potential was stopped in 24 mM. Barium ion known to be decreasing K conductance increased the duration of action potential but no significant change in the cycle length was noticed. 3. Calcium ion has shortening effect on the duration and the cycle length of action potential but not with dose-dependent manner. Cadmium ion .[0.02mM] lengthened cycle length and the duration of action potential. 4. Increasing the concentration of magnesium ion the cycle length was lengthened, significantly.

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Progressive Manifestations of Reversible Cerebral Vasoconstriction Syndrome Presenting with Subarachnoid Hemorrhage, Intracerebral Hemorrhage, and Cerebral Infarction

  • Choi, Kyu-Sun;Yi, Hyeong-Joong
    • Journal of Korean Neurosurgical Society
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    • v.56 no.5
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    • pp.419-422
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    • 2014
  • Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden-onset headache with focal neurologic deficit and prolonged but reversible multifocal narrowing of the distal cerebral arteries. Stroke, either hemorrhagic or ischemic, is a relatively frequent presentation in RCVS, but progressive manifestations of subarachnoid hemorrhage, intracerebral hemorrhage, cerebral infarction in a patient is seldom described. We report a rare case of a 56-year-old woman with reversible cerebral vasoconstriction syndrome consecutively presenting as cortical subarachnoid hemorrhage, intracerebral hemorrhage, and cerebral infarction. When she complained of severe headache with subtle cortical subarachnoid hemorrhage, her angiography was non-specific. But, computed tomographic angiography showed typical angiographic features of this syndrome after four days. Day 12, she suffered mental deterioration and hemiplegia due to contralateral intracerebral hematoma, and she was surgically treated. For recurrent attacks of headache, medical management with calcium channel blockers has been instituted. Normalized angiographic features were documented after 8 weeks. Reversible cerebral vasoconstriction syndrome should be considered as differential diagnosis of non-aneurysmal subarachnoid hemorrhage, and repeated angiography is recommended for the diagnosis of this under-recognized syndrome.

Relation of Paeonia lactiflora Pallas to Nifedipine-induced Gingival Hyperplasia and Impaired Submandibular Glands Function in Rats (흰쥐에서 nifedipine으로 유발된 치은 증식증 및 하악선 분비기능에 대한 작약 추출물 저해효과)

  • Kim, Sung-Hoon;Choi, Jong-Won
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.3
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    • pp.470-475
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    • 2010
  • Calcium-channel blockers such as nifedipine could be associated with gingival overgrowth. The aim of this study was to examine the role of Paeonia lactiflora Pallas(PLP) on nifedipine-induced gingival hyperplasia along with submandibular secretory function in rats. Animals in divided groups received nifedipine (250 mg/kg) alone and in PLP(100, 200 mg/kg) in orally administration for 3 weeks. Pure submandibular saliva was collected intraorally by micropolyethylene cannula and the mandibular gingiva was examined by means of dissecting microscope for signs of redness, tickness, inflammation and exuda. Twenty-one days nifedipine treatment induced gingival hyperplasia accompanied with reduced salivary flow rate and concentrations total protein, epidermal growth factor(EGF) and calcium in comparison with normals. Co-treatment of animals with nifedifine and PLP protected from gingival hyperplasia and retained flow rate, and concentrations of total protein, EGF and calcium in normal levels.

Inhibitory Effect of Fangchinoline on Excitatory Amino Acids. Induced Neurotoxicity in Cultured Rat Cerebellar Granule Cells

  • Kim, Su-Don;Oh, Sei-Kwan;Kim, Hack-Seang;Seong, Yeon-Hee
    • Archives of Pharmacal Research
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    • v.24 no.2
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    • pp.164-170
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    • 2001
  • Glutamate receptors-mediated excitoxicity is believed to play a role in the pathophysiology of neurodegenerative diseases. The present study was performed to evaluate the inhibitory effect of fanschinoline, a bis-benzylisoquinoline alkaloid, which has a characteristic as a $Ca^{2+}$channel blockers on excitatory amino acids (EAAS)-induced neurotoxicity in cultured rat cerebellar granule neuron. Fangchinoline (1 and 5$\mu\textrm{m}$) inhibited glutamate (1 ${m}M$), N-methyl-D-aspartate (NMDA; 1 ${m}M$) and kainate (100$\mu\textrm{m}$)-induced neuronal cell death which was measured by trypan blue exclusion test. Fangchinoline (1 and 5$\mu\textrm{m}$) inhibited glutamate release into medium induced by NMDA (1 ${m}M$) and kainate (100$\mu\textrm{m}$), which was measured by HPLC. And fangchinoline (5$\mu\textrm{m}$) inhibited glutamate (1 ${m}M$)-induced elevation of intracellular calcium concentration. These results suggest that inhibition of $Ca^{2+}$influx by fangchinoline may contribute to the beneficial effects on neurodegenerative effect of glutamate in pathophysiological conditions.

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The effect of non-surgical treatment in gingival enlargement (치은비대에서 비외과적 치료의 효과)

  • Kim, Sang-Jun;Lee, Jae-Kwan;Um, Heung-Sik;Chang, Beom-Seok
    • Journal of Periodontal and Implant Science
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    • v.39 no.1
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    • pp.103-108
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    • 2009
  • Purpose: It is well recognized that gingival enlargement is induced by unwanted effect associated with three major drugs/drug groups - phenytoin, cyclosporine, and the calcium channel blockers. The present case report describes the effect and limitation of non-surgical treatment in gingival enlargement cases. Materials and methods: Three cases included 2 drug-influenced gingival enlargement patients and a idiopathic gingival fibromatosis patient. For the drug-influenced gingival enlargement patients, the medication was replaced with other medication. And then, all the patients were treated non-surgically. Results: Drug-influenced gingival enlargements had been reduced after non-surgical treatment and the results were well-maintained. In the idiopathic gingival fibromatosis case, non-surgical treatment resulted in only limited reduction of gingival enlargement, and surgical periodontal treatment was unavoidable. Conclusion: These case reports indicated that non-surgical periodontal treatment with change in medication was effective in the treatment of drug-influenced gingival enlargements. Non-surgical approach can be considered as the primary management to reduce the gingival enlargement. If non-surgical treatment encounters a limitation, surgical treatment should be considered.

Protective Effect of Right Ventricular Mitochondrial Damage by Cyclosporine A in Monocrotaline-induced Pulmonary Hypertension

  • Lee, Dong Seok;Jung, Yong Wook
    • Korean Circulation Journal
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    • v.48 no.12
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    • pp.1135-1144
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    • 2018
  • Background and Objectives: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). Methods: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. Results: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. Conclusions: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.