• Title/Summary/Keyword: blocker

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Nitric Oxide Production Ability and its Formation Mechanisms in Macrophage TIB 71 Cell Line by Polysaccharide Extracted from Ganoderma lucidum (영지버섯 다당체의 Nitric Oxide 생성능 및 생성기전 연구)

  • 김성환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.2
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    • pp.333-337
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    • 1998
  • This study was carried out to get infomation on the nitric oxide production ability and its formation mechanisms of polysaccharides extracted from Ganoderma lucidum(PSG) by using murine macrophage cell line. The cultured mycelial cells of Ganoderma lucidum were extracted by alkali, and than neutralized by acid. The extract were passed through the column of DEAE cellulose for more purification. The neutral fraction was concentrated and precipitated with 95% ethanol. The precipitate was lyophilized and PSG was obtained. The immunomodulating effects of PSG on macrophage were performed by using murine macrophage cell line ATCC TIB 71 cells with PSG 0.5mg. PSG alone could not induce the production of nitrite, but it had a significant potential effect on nitrite secretion when the cells were primed and triggered with BCG and Interferon(IFN)-${\gamma}$. Also it was prominent by using calcium channel blocker(verapamil) and adenylate cyclase activator(forskolin).

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Effect of Renal Denervation and Glibenclamide, a selective ATP-sensitive $K^+$ Channel Blocker, on Renal Action of BRL 34915, a ATP-sensitive $K^+$ Channel Opener, in Dog ($K^+$ Channel 개방제인 BRL 34915의 신장작용에 대한 신장 신경제거 와 선택성 ATP-의존성 $K^+$Channel 차단제인 Glibenclamide의 영향)

  • 고석태;최홍석
    • YAKHAK HOEJI
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    • v.44 no.4
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    • pp.362-370
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    • 2000
  • In anesthetized dogs, antidiuretic action of intravenously administered BRL 34915 (10.0~30.0 $\mu$/kg) was blocked by renal denervation, whereas it was not affected by glibenclamide, a selective $K_{ATP}$ blocker, given into renal artery. Diuretic action in ipsilateral kidney produced by intrarenal administration of BRL 34915 was not influenced by renal denervation, but blocked completely by glibenclamide given into the vein. Above results suggest that the antidiuretic action of BRL 34915 is mediated by renal sympathetic nerves and the diuretic action is caused by opening of $K^+$ channel within kidney.

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Bisphenol A and 4-tert-Octylphenol Inhibit Cx46 Hemichannel Currents

  • Oh, Seunghoon
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.1
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    • pp.73-79
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    • 2015
  • Connexins (Cx) are membrane proteins and monomers for forming gap junction (GJ) channels. Cx46 and Cx50 are also known to function as conductive hemichannels. As part of an ongoing effort to find GJ-specific blocker(s), endocrine disruptors were used to examine their effect on Cx46 hemichannels expressed in Xenopus oocytes. Voltage-dependent gating of Cx46 hemichannels was characterized by slowly activating outward currents and relatively fast inward tail currents. Bisphenol A (BPA, 10 nM) reduced outward currents of Cx46 hemichannels up to ~18% of control, and its effect was reversible (n=5). 4-tert-Octylphenol (OP, $1{\mu}M$) reversibly reduced outward hemichannel currents up to ~28% (n=4). However, overall shapes of Cx46 hemichannel current traces (outward and inward currents) were not changed by these drugs. These results suggest that BPA and OP are likely to occupy the pore of Cx46 hemichannels and thus obstruct the ionic fluxes. This finding provides that BPA and OP are potential candidates for GJ channel blockers.

The Relationship of in vitro Dissolution and Intestinal Membrane Permeability with in vivo Bioavailability (시험관내 용출 및 장관막 투과도와 생체이용률과의 상관성)

  • 서수경;손수정;박인숙;최기환;김순선;유태무;조혜영;이용복;김동섭
    • YAKHAK HOEJI
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    • v.44 no.5
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    • pp.424-431
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    • 2000
  • A biopharmaceutics drug classification system for correlation between in vitro dissolution and in vivo bioavailability is proposed based on recognizing that drug dissolution and gastrointestinal permeability are the fundamental parameters controlling the rate and extent of drug absorption. The objective of this study was to assess whether in vitro dissolution profiles of immediate-release beta-blocker tablets can be correlated with intestinal membrane permeability and/or in vivo bioavailability In vitro dissolution of the beta-blocker tablets was examined using KP VII Apparatus II methods at various pH. Intestinal membrane permeability was determined in vitro using the diffusion chamber method. Bioavailablity parameters were cited from literatures. The dissolution profiles did not accurately represent the in vivo bioavailablity However there were good correlations between intestinal membrane permeability and log P (noctanol/buffer). The correlations obtained in this study indicated that in vitro diffusion chamber method could be used to predict intestinal absorption in vivo.

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MYH9 nephropathy

  • Oh, Taehoon;Seo, Hyun Jung;Lee, Kyu Taek;Kim, Han Jo;Kim, Hwi Jun;Lee, Ji-Hye;Cheong, Hae Il;Lee, Eun Young
    • Kidney Research and Clinical Practice
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    • v.34 no.1
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    • pp.53-56
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    • 2015
  • MYH9-related disorder is an autosomal dominant disease caused by a mutation in the MYH9 gene, which encodes nonmuscle myosin heavy chain IIA (NMMHC-IIA). This disease is characterized by giant platelets, thrombocytopenia, granulocyte inclusion bodies, proteinuria, and high-pitch sensorineural deafness. Nephropathy has been observed in 30% of patients with MYH9-related disorder. The characteristic features are early onset proteinuria and rapidly progressing renal disorder. However, the prognosis of MYH9 nephropathy remains unclear. Herein, we describe a 36-year-old woman who presented with proteinuria and was diagnosed with MYH9 nephropathy via renal biopsy and gene analysis. Her proteinuria improved after administration of an angiotensin II receptor blocker, but was aggravated after changing to a calcium channel blocker.

The Intoxication of Beta Blocker with Psychiatric Drugs Focused on the Cardiovascular Adverse Effects (베타차단제를 포함한 정신과적 약물 중독: 심혈관계 영향을 중심으로)

  • Joo, Sung Woo;Min, Young-Gi;Choi, Sang-Cheon;Park, Eun Jung
    • Journal of The Korean Society of Clinical Toxicology
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    • v.14 no.2
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    • pp.100-106
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    • 2016
  • Purpose: Beta blocker (BB) has been prescribed for anxiety and panic disorder. Patients intoxicated by psychiatric drugs have often been exposed to BB. Moreover, BB overdose has adverse effects including cardiovascular effects, which can be life-threatening. This study was conducted to identify the characteristics of BB intoxication with psychiatric drugs and the adverse effects on the cardiovascular system. Methods: A single center, retrospective study was performed from January 2010 to December 2015. A total of 4,192 patients visited the emergency department (ED) with intoxication, and 69 with BB intoxication were enrolled. Results: Overall, 64 patients (92.8%) of enrolled patients were intoxicated with drugs prescribed for the purpose of psychiatric disorders. Propranolol was the most common BB (62 cases, 96.2%), and the median dose was 140.0 mg (25%-75% 80.0-260.0). Twenty-four patients (37.5%) had experienced cardiovascular events, and these patients tended to have decreased mentality, hypotension and coingestion with quetiapine. An initial mean arterial pressure (MAP) below 65 mmHg (odds ratio 10.069, 95% confidence interval 1.572-64.481, p=0.015) was identified as a factor of cardiovascular event upon multiple logistic regression analysis. Conclusion: Initial MAP below 65 mmHg was a factor of cardiovascular adverse effect in patients of BB intoxication with psychiatric drugs.

Role of $Na^+/Ca^{2+}$ Exchange in the Control of Contractility in Rabbit Basilar Arterial Smooth Muscle

  • Kim, Eui-Yong;Han, Jin
    • The Korean Journal of Physiology
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    • v.28 no.2
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    • pp.159-167
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    • 1994
  • The contraction of rabbit basilar artery was examined as a function of changes in the $Na^+$ electrochemical gradient in order to determine the contribution of $Na^+/Ca^{2+}$ exchange to the modulation of contractility. Ouabain $(10^{-5}\;M)$ or $K^+-free$ Tyrode solution caused an increase in tonic tension even in the presence of a $Ca^{2+}$ channel blocker $(10^{-6}\;M\;verapamil)$ and an ${\alpha}-receptor$ blocker $(10^{-5}\;M\;phentolamine)$. After treatment with ouabain $(10^{-5}\;M)$, contractions were augmented by reduction of external $Na^+$ concentration. The longer the treatment with ouabain $(10^{-5}\;M)$ was, the larger the amplitude of $Na^+-free$ contracture was. $Na^+-free$ contracture wag induced by either substitution of equimolar Tris for $Na^+$ or substitution of equimolar $Li^+\;for\;Na^+$. The competition between $Na^+\;and\;Ca^{2+}$ for the $Na^+/Ca^{2+}$ exchange carrier would exist, because it was observed that contractility was dependent on the $Na^+$ electrochemical gradient or the extracellular $Ca^{2+}$ concentration (2 mM, 4 mM). Ryanodine $(10^{-7}\;M)$, the blocker of intracellular $Ca^{2+}$ release from the sarcoplasmic reticulum, did not suppress the development of $Na^+-free$ contracture. The contractile response to norepinephrine $(10^{-6}\;M)$ was augmented by reducing the extracellular $Na^+$ concentration. The relaxation rate from caffeine-induced contraction was dependent on the extracellular $Na^+$ concentration (0 mM, 140 mM). From the above results, it could be suggested that $Na^+/Ca^{2+}$ exchange can move $Ca^{2+}$ either into or out of rabbit basilar arterial smooth muscle. $Ca^{2+}$ entry or extrusion is dependent upon the $Na^+$ electrochemical gradient. $Na^+/Ca^{2+}$ exchange plays a significant role in the regulation of contractility in rabbit basilar arterial smooth muscle.

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Traditional oriental herbal medicine, Jukyeoondam-tang, occludes aconitine-induced ventricular arrhythmia in hearts

  • Ha, Ki-Chan;Chae, Han-Jung;Piao, Cheng-Shi;Chae, Soo-Uk;Kim, Hyung-Ryong;Chae, Soo-Wan
    • Advances in Traditional Medicine
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    • v.4 no.3
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    • pp.157-161
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    • 2004
  • We showed the effects of the traditional herbal medicine, Jukyeoondam-tang (JO-T, Zhu-ru-Wen-Dan-Tang in Chinese), on ventricular arrhythmia induced by aconitine. Electrophysiological experiments with conventional microelectrode techniques revealed that JO-T potently suppressed the aconitine-induced arrhythmias in ventricular strips of the rat. In the aconitine-induced arrhythmia model of the rat, pretreatment with JO-T $(100\;{\mu}g/ml)$ completely occluded the appearance of ventricular tachyarrhythmia (VT) or ventricular fibrillation (VF) induced by aconitine. Furthermore, the aconitine-induced ventricular arrhythmia was occluded by $Na^+$ channel blocker quinidine but was not occluded by $K^+$ channel blocker glibenclamide $(3\;{\mu}mol/L)\;and\;Ca^{2+}$ channel blocker nifedipine $(10\;{\mu}mol/L)$. We also confirmed the effect of JO-T in the ischemia-reperfusion (I/R)-induced arrhythmia model of the rat. JO-T did not affect the I/R-induced arrhythmias in rats. JO-T may alleviate the risk of ventricular arrhythmias following aconitine. These results suggest that JO-T is a potent antiarrhythmic drug having a$Na^+$ channel-blocking action.