• Title/Summary/Keyword: Blocker

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Xenopus Oocyte의 $K^{+}$ Channel에 관한 연구

  • 채수완
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.160-160
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    • 1993
  • 목적: Guinea pig heart의 ATP sensitive $K^{+}$ channel xenopus oocyte에 발현시켜 연구하고져 본 실험을 행하였다. 실험방법: 기니픽 심장으로부터 ,RNA를 분리하여 50ng/$\mu$l의 농도로 50nl를 xenopusdp 주입하였다. Xenpus oocyte에서 conventional electrode를 이용 막전휘를 측정하였고, pH selective 미세전극으로 세포내 pH를 측정하였다. 막전위에 미치는 potassium channel opener, blocker, KCN의 작용을 관찰하였다. 결과: 기니픽 심장 mRNA를 주입하거나 주입하지 않은 xenopus oocyte에서 $K^{+}$channel opener인 cromakalin, RP49356등은 과분극을 일으키지 못하였다. 그러나 세포내 ATP 감소제인 KCN은 농도 의존적으로 과분극을 일으켰으나 ,glibenclamide에 의해 차단되는 않았다. mRNA를 주입한 oocyte에서 Na-H 자극제인 NH$_4$Cl은 pH 변동을 일으켜 NA-H exchange를 expression 시켰다. 결론: Xenopus oocyte는 cromakalin등에 의해 open되는 $K^{+}$channel 은 없었고, 기니픽 심근의 ATP sensitive $K^{+}$channel로 expression 되지 않았으나 Na-H exchange 는 expression 됨을 알 수 있었다. KCN으로 open 되는 $K^{+}$channel이 있었으나 glibenclamide에는 차단되지 않는 channel이였다.

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The responsiveness to amitraz in isolated porcine myometrial strips (척출 돼지 자궁근의 amitraz에 대한 반응성)

  • Shin, Dong-ho
    • Korean Journal of Veterinary Research
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    • v.33 no.3
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    • pp.381-385
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    • 1993
  • 수의학 및 농업분야에서 널리 사용되고 있는 살충제인 amitraz의 효과를 척출 돼지 자궁근에서 검토하였다. Amitraz($10^{-8}{\sim}10^{-6}M$)는 발정정지기의 자궁근 수축성을 용량의존적으로 증가시켰다. Amitroaz의 이 효과는 yohimbine($10^{-8}{\sim}10^{-7}M$)에 의해 용량의존적으로 차단되었으나, prazosin($10^{-6}M$)에 의해서는 억제되지 않았다. 또한 $Ca^{2+}$-free Tyrode's solution에서나 verapamil($3{\times}10^{-5}M$)의 전처치에 의해서 amitraz의 수축효과는 완전히 억제되었다. 따라서 amitraz에 의한 발정정지기 돼지 자궁근의 수축은 ${\alpha}_2$-adrenoceptor가 중개하며 이 효과는 주로 $Ca^{2+}$ entry blocker에 감수성이 있는 $Ca^{2+}$ channel을 통한 extracellular $Ca^{2+}$ influx의 증가에 의한 것으로 여겨진다.

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$Ca^{2+}$ Effect on Conversion of Exogenous 1-Aminocyclopropane-1-Carboxylic Acid to Ethylene in Vigna radiata Protoplasts

  • Seung-Eun Oh
    • Journal of Plant Biology
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    • v.37 no.3
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    • pp.271-276
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    • 1994
  • The possibility that 1-aminocyclopropane-1-carboxylic acid (ACC)-uptake may be dependent on the H+-gradient established across the plsma membrane was tested in protoplasts isolated from 2.5 day old mungbean hypocotyls. The ACC-induced ethylene production was inhibited when the H+-gradient was collapsed by the treatment with carbonycyamide-p-trifluro-methoxy-phenylhydrazone (FCCP). Moreover, the treatment with o-vanadate, a specific inhibitor of plasma membrane H+-ATPase, caused the inhibition of ethylene production. The ACC-induced ethylene production was inhibited by the treatemnt with verapamil (Ca2+-channel blocker), or ethylene glycol-bis($\beta$-aminoethyl ether) N, N, N', N'-tetraacetic acid (EGTA) (Ca2+-chelator). In contrast, the ehtylene production was stimulated by the application of A23187 (Ca2+ ionophore). The inhibitory effect of EGTA in the ethylene producton was magnified in the presence of A23187. From these results, we suggest that the external Ca2+ influx to the cytosol resulted in the stimulatin of ACC oxidase activity after ACC-uptake resulting from a H+-gradient across the plasma membrane.

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Formulation Design for Skin Permeation of Lincomycin Cream (린코마이신 크림의 피부투과를 위한 처방설계)

  • 김미정;김영일;양재헌
    • YAKHAK HOEJI
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    • v.47 no.3
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    • pp.154-158
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    • 2003
  • Lincomycin, a selective tyrosinase blocker, has been thought to be effective in the treatment of melanogenesis, ephelis, post inflammatory pigmentation, and facial discoloration. In an attempt to develop a transdermal perparation for lincomycin, this study was designed to examine the appropriate contents of various surfactants and ethanol in the cream preparation. Frans type diffusion cell was used to investigate permeation efficiency of the preparation, and lincomycin in the receptor phase was measured by HPLC. After having a 1.5 hrs of leg time, the permeability of lincomycin was rapidly increased by adding surfactants, and varied with different types of surfactants after 10 hrs, the permeability of Brij 56$^{(R)}$ preparation (501.4$\pm$45 $\mu\textrm{g}$/mι) was greater than that either of Labrasol$^{(R)}$ (263.9$\pm$33.7 $\mu\textrm{g}$/mι) or Tween$^{(R)}$20(386.2$\pm$26.7 $\mu\textrm{g}$/mι). Ethanol also increased the permeability of lincomycin.mycin.

Identification of Inhibitors Against BAK Pore Formation using an Improved in vitro Assay System

  • Song, Seong-Soo;Lee, Won-Kyu;Aluvila, Sreevidya;Oh, Kyoung Joon;Yu, Yeon Gyu
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.419-424
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    • 2014
  • The pro-apoptotic BCL-2 family protein BID activates BAK and/or BAX, which form oligomeric pores in the mitochondrial outer membrane. This results in the release of cytochrome c into the cytoplasm, initiating the apoptotic cascade. Here, we utilized liposomes encapsulating sulfo-rhodamine at a controlled temperature to improve upon a previously reported assay system with enhanced sensitivity and specificity for measuring membrane permeabilization by BID-dependent BAK activation. BAK activation was inhibited by BCL-$X_L$ protein but not by a mutant protein with impaired anti-apoptotic activity. With the assay system, we screened a chemical library and identified several compounds including trifluoperazine, a mitochondrial apoptosis-induced channel blocker. It inhibited BAK activation by direct binding to BAK and blocking the oligomerization of BAK.

Performance Evaluation of Content Blocker in Web Browser (웹 브라우저에서의 콘텐츠 차단기능에 대한 성능평가)

  • You, Ho-Sung;Lee, Yong-Ha
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.11a
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    • pp.986-987
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    • 2017
  • 사용자의 온라인 활동을 추적하는 트래커나 무분별한 광고 등 웹 브라우저의 사용성을 해치는 콘텐츠를 차단하는 웹 브라우저의 기능에 대한 요구는 크게 증가하고 있다. 일부 데스크탑 브라우저 및 모바일 브라우저에서 확장 기능으로 컨텐츠 차단 및 광고 차단 기능을 제공하고 있으며, 삼성 모바일 브라우저인 삼성 인터넷에서도 EasyList의 규칙을 따르는 확장 기능으로 콘텐츠 차단 기능을 구현 적용하였다. 이에 웹 브라우저의 중요 사용성 항목인 페이지 로딩 시간, 전류 소모량의 성능평가를 진행하였다. Alexa top 30 사이트를 기준으로 성능평가를 진행한 결과 페이지 로딩속도는 11.5%, 전류소모량은 16%가 개선되는 것을 확인하였다.

Economic Value of Platelet Glycoprotein IIb/IIIA Receptor Blocker (Abciximab) for Percutaneous Coronary Intervention (PCI시술시 혈소판 당단백 GP IIb/IIIA 억제제(Abciximab) 투여의 경제적 가치)

  • Kim, Jin-hyun;Shin, Sang-Jin;Kim, Eun-Ju;Lee, Young-Hee
    • YAKHAK HOEJI
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    • v.51 no.3
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    • pp.186-193
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    • 2007
  • This study was performed to analyse the economic value of abciximab which is used in PCI to prevent high-risk patients with ischemic complications. The effectiveness of abciximab was extracted from published clinical trials by search-ing CCIS, and the direct medical costs relevant to using abciximab were estimated from the NHI claims database. The results in terms of cost per life-year gained (LYG) and cost per QALY gained showed that abciximab was cost-effective enough to deserve its cost. Social net benefit resulting from abciximab in PCI was estimated to be 60-70 billion Won per year.

A Case of Electrocardiographic Change Associated with Anaphylaxis (아나필락시스에 의한 심전도 변화 1례)

  • Lee Dong Hoon;Jang Hye Young;Eo Eun Kyung;Jung Koo Young
    • Journal of The Korean Society of Clinical Toxicology
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    • v.2 no.1
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    • pp.12-14
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    • 2004
  • Anaphylaxis is a systemic allergic reaction which can bring fatal results. The common symptoms are erythema, angioedema, urticaria, hypertension and dyspnea. However, in very few cases, ST segment changes in the electrocardiogram can be seen. This is a case of a 51 year old female with normal heart function who showed reversible ST segment depression during anaphylaxis caused by a $H_2$-blocker agent. The cause of ST segment changes during anaphylaxis is thought to be the result of coronary vasospasm mediated by various factors.

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Renal Action of Domperidone in Dog (돔페이돈의 신장작용)

  • 고석태;최홍석
    • YAKHAK HOEJI
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    • v.37 no.6
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    • pp.561-570
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    • 1993
  • Renal action of domperidone known as dopamine receptor blocker and effect of domperidone on renal function of dopamine were investigated in dog. Domperidone, when administered into vein, produced diuretic action by the improvement of renal hemodynamic state, when given into a renal artery, elicited diuretic action accompanied with natriuresis in only experimental kidney, whereas domperidone given into carotid artery exhibited antidiuretic action by the decrease of Na$^{+}$ excretion in urine. Diuretic action of dopamine was not influenced by domperidone given into vein or into a renal artery, was blocked by domperidone given into carotid artery. Above results suggest that domperidone produced both peripheral diuretic and central antidiuretic action, and domperidone do not block diuretic action by renal hemodynamic improvement of dopamine in kidney.

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Involvement of Adenosine in The Spinal Antinociception by Capsaicinoids (캅사이신 유사체들의 척수 진통작용을 매개하는 아데노신)

  • 유은숙;김옥희;손여원;정인경;이상섭
    • YAKHAK HOEJI
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    • v.43 no.1
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    • pp.55-60
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    • 1999
  • To investigate analgesic mechanism of capsaicin and its analogues (capaicinoids) adenosine release was measured by high performance liquid chromatography from rat spinal cord synaptosomes. Exposure of synaptosomes to $K^+$ and morphine produced a dose dependent release of adenosine in the presence of $Ca^{++}$. Capsaicin (0.1, 1, $10{\;}{\mu}M$), and its analogues: NE-19550 (1, 10, $100{\;}{\mu}M$), DMNE (1, 10, $100{\;}{\mu}M$) and KR 25018 (0.1, 1, $10{\;}{\mu}M$) produced a concentration dependent release of adenosine in the presence of $Ca^{++}$. Nifedifine, L-type voltage sensitive calcium channel blocker, inhibited $K^+$ (6, 12 mM)-and morphine ($10{\;}{\mu}M$)-evoked release of adenosine partially. Capsazepine, a novel capsaicin selective antagonist, blocked only capsaicin and capsaicinoids induced release of adenoside. Therefore, it is suggested that the adenosine release by capsaicin and capsaicinoids having antinociceptive effects involves actvation of capsaicin specific receptor and capsaicin sensitive $Ca^{++}$. channel.

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