• Title/Summary/Keyword: inhibition effect

검색결과 6,835건 처리시간 0.031초

삼화산(三和散)이 대뇌피질(大腦皮質) microsome분획(分劃)에서 Na-K-ATPase활성(活性)에 미치는 영향(影響) (Effect of Sam Hwa San on Na-K-ATPase Activity in Microsomal Fraction of Rabbit Cerebral Cortex)

  • 김길섭;정지천
    • 대한한의학회지
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    • 제16권1호통권29호
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    • pp.281-294
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    • 1995
  • The effect of Sam Hwa San on the Na-K-ATPase activity was evaluated in microsomal fraction prepared from rabbit cerebral cortex to determine whether Sam Hwa San affects Na-K-ATPase activity of nervous system. Sam Hwa San markedly inhibited the Na-K-ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.12%. Optimal pH for the Na-K-ATPase activity was at 7.5 in the presence or absence of Sam Hwa San. The degree of inhibition by the drug more increased at acidic and alkalic pHs than neutral pH. Kinetic studies of substrate and cationic activation of the enzyme indicate classic noncompetitive inhibition fashion for ATP, Na and K, showing significant reduction in Vmax without a change in Km. Dithiothreitol, a sulfhydryl reducing reagent, partially protects the inhibition of Na-K-ATPase activity by Sam Hwa San. Combination of Sam Hwa San and ouabain showed higher inhibition than cumulative inhibition. These results suggest that Sam Hwa San inhibits Na-K-ATPase activity in central nervous system by reacting with, at least a part, sulfhydryl group and ouabain binding site of the enzyme protein, but with different binding site from those of ATP, Na and K.

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만성 뇌졸중 시 반복경두개자기자극에 의한 경직성 발목관절의 관절가동 범위 향상 및 H-반사 억제 효과 (The Effect of Repetitive Transcranial Magnetic Stimulation on H-Reflex Inhibition and Fascilitation of Range of Motion of Spastic Ankle Joint in Chronic Stroke Patients)

  • 조미숙
    • 대한물리의학회지
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    • 제6권1호
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    • pp.71-79
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    • 2011
  • Purpose : The purpose of this study was carried out to investigate the effect of repetitive transcranial magnetic stimulation on increase of H-reflex inhibition and fascilitation of range of motion of spastic ankle joint in chronic stroke patients. Methods : 30 chronic stroke patients were randomly divided into three groups, a control group(placebo rTMS group), 5 Hz rTMS group and manual therapy group. The MAS and ROM of ankle joint and H-reflex inhibition of soleus muscle were evaluated on each group. Results : The rTMS group decreased MAS of ankle joint and increased H-reflex inhibition of soleus muscle, and ROM of ankle joint than manual therapy group. The placebo rTMS group did not affected the change of MAS, ROM of ankle joint and H-reflex inhibition of soleus muscle. Conclusion : The rTMS was a good therapeutic tool to improve the foot drop in the chronic stroke patients.

한국산 녹차로부터 분리한 Flavan-3-ol 화합물의 Angiotensin Converting Enzyme 저해 효과 (Inhibition Effect of Against Angiotensin Converting Enzyme of Flavan-3-ols isolated Korean Green Tea)

  • 조영제;안봉전;최청
    • 한국식품과학회지
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    • 제25권3호
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    • pp.238-242
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    • 1993
  • 기능성 식품과 생약재로의 이용을 위한 연구의 일환으로 한국산 녹차로부터 탄닌을 분리하여 angiotensin converting enzyme 저해효과를 측정하였다. 녹차의 acetone 추출물에서 angiotensin converting enzyme 저해효과가 있음이 확인되었고 정제된 탄닌의 효소저해효과를 검토한 결과 angiotensin converting enzyme 저해는 galloyl tannin류가 nongalloyl tannin류 보다 활성이 더 우수하였고 구조적 이성체에서도 (+)-catechin류 보다 (-)-epicatechin류가 효소저해효과가 더 좋았으며, 각 물질 간 상승효과가 인정되었다. 녹차에서의 탄닌류는 angiotensin converting enzyme에 대해 비경쟁적 저해를 하는 것을 알 수 있다.

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Characterization of the Galvanizing Behavior Depending on Annealing Dew Point and Chemical Composition in Dual-Phase Steels

  • Shin, K.S.;Park, S.H.;Jeon, S.H.;Bae, D.C.;Choi, Y.M.
    • Corrosion Science and Technology
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    • 제9권6호
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    • pp.247-253
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    • 2010
  • The characteristics of selective oxidation prior to hot-dip galvanizing with the annealing atmosphere dew point and chemical composition in dual-phase steels and their effect on the inhibition layer formation relevant to coating adhesion have been studied using a combination of electron microscopic and surface analytical techniques. The annealed and also galvanized samples of 3 kinds of Si/Mn ratios with varied amounts of Si addition were prepared by galvanizing simulator. The dew point was controlled at soaking temperature $800^{\circ}C$ in 15%$H_2$ -85%$N_2$ atmosphere. It was shown that good adhesion factors were mainly uniformity of oxide particle distribution of low number density and low Si/Mn ratio prior to hot-dip galvanizing. Their effect was the greatly reduced coating bare spots and the formation of uniform inhibition layer leading to good adhesion of Zn overlay. The mechanism of good adhesion is suggested by two processes: the formation of inhibition layer on the oxide free surface uncovered with no $SiO_2$-containing particles in particular, and the inhibition layer bridging of oxide particles. The growth of inhibition layer was enhanced markedly by the delayed reaction of Fe and Al with the increase of Si/Mn ratio.

천연식물성분이 N-Nitrosodimethylamine 생성억제에 미치는 영향 (Effect of Natural Foods on the Inhibition of N-Nitrosodimethylamine Formation)

  • 이수정;신정혜;정미자;성낙주
    • 한국식품위생안전성학회지
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    • 제15권2호
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    • pp.95-100
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    • 2000
  • 천연식물류인 차류(녹차, 두충), 약용식물(어성초, 백화사설초, 삼백초) 및 해조류(미역, 청각, 김) 추출물, 채소류(피망, 케일,오이, 양파) 및 과실류(토마토, 매실,자두,포도)쥬스 등을 이용하여 NDMA생성억제작용을 pH 1.2, 4.2 및 6.0의 반응용액을 이용하여 in vitro에서 확인하였다 차류 및 약용식물류에서는 NDMA생성을 촉진시키는 경향을 보였으나, 해조류 추출물은 차류 및 약용식물류 추출물과는 달리 NDMA의 생성을 다소간 억제시켰으며, 반응용액의 pH가 산성일수록, 추출물의 농도를 높일수록 NDMA생성에 대한 억제효과가 컸다. pH 1.2에서 채소류쥬스는 57.6∼99.7%, 과실류쥬스는 35.9∼99.7%, pH 4.2에서 채소류쥬스는 55.0∼97.5%, 과실류쥬스는 21.3∼96.8%의 억제효과를 보였다.

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건칠(乾漆)이 혈관신생관련 단백질 발현에 미치는 영향 (The Effect of Lacca Sinica Exsiccata on The Manifestation of Angiogenic Proteins)

  • 김성학;김경준
    • 한방안이비인후피부과학회지
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    • 제19권3호통권31호
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    • pp.1-12
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    • 2006
  • Objective : Angiogenesis is an essential process for metastasis of solid tumors and Psoriasis. Lots of Researches for anti-angiogenic effect to angiogenic factors have been carried out in the world. So this experiment was carried out for whether Lacca Sinica Exsiccata(LSE) extracts have an anti-angiogenic effect for angiogenic factors. Methods: To investigate the roles of the LSE extracts, we performed MIS assay, western blots using HaCaT cells and HepG2 cells. And then, HaCaT cells were treated with 10, 50, 100, 250, $500{\mu}g/ml$ LSE extracts. After 4hrs, HaCaT cells were theated with IGF-II protein for 1hr. HepG2 cells were treated with 1, 10, 25, 50, 100, 200 ${\mu}g/ml$ LSE extracts. After 4hrs, HepG2 cells were theated with $CoCl_2$ for 24hrs Results: 1. In $50{\mu}g/ml$ and $100{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by IGF-II in HaCaT cells. 2. In $50{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to $HIF-1{\alpha}$ activation which was induced by $CoCl_2$ in HepG2 cells. 3. In $25{\mu}g/ml$ density we confirmed the inhibition effect of LSE extracts to VEGF activation which was induced by $CoCl_2$ in HepG2 cells. Conclusion: The above-mentioned results proved that LSE extracts reduced $HIF-1{\alpha}$ protein level in the HaCaT cells and HepG2 cells. These results suggest that inhibition of HaCaT cell and HepG2 cell proliferation by LSE extracts contributes to the anti-angiogenic activities on the keratinocytes and hepatocellular carcinoma.

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Phenylmercuric 8-oxyquinolinate 및 phenylmercuric acetate가 호마엽고병균의 호흡작용에 미치는 영향 (Effect of phenylmercuric 8-oxyquinolinate and phenylmercuric acetate on respiration of Cochliobolus miyabeanus)

  • 김기청;서용택
    • 한국응용곤충학회지
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    • 제5_6권
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    • pp.65-69
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    • 1968
  • 본 실험에 있어서는 phenylmercuric acetate에 못지 않은 살균력을 나타낸다고 보고된 phenylemercuric 8-oxyquinolinate를 phenylmercuric acetate 와 대비시켜 벼 고마엽고병균 에 대하여 먼저 균체의 건물량에 의한 균사발육 효과를 확인하고 포자 및 균사의 호흡 저해효과를 검토한 바 그 결과를 보고하는 바이다. (1) 균사발육 억제효과를 보면 phenylmercuric 8-oxyquinolinate는 phenylmercuric acetate보다 약간 떨어지나 현저한 차이는 없으며, 양자 모두 0.01ppm부터 1.0ppm까지의 사이에서 급격히 발육 억제효과가 증가한다. (2) 포자효흡 저해작용은 0.1ppm을 제외하고는 phenylmercuric acetate가 phenylmercuric 8-oxyquinolinate보다 약간 강하나 뚜렷한 차이는 인정할 수 없으며 0.01ppm에서는 거의 저해효과가 없는 듯하다. (3) 균사호흡 저해작용은 포자호흡과는 반대로 phenylmercuric 8-oxyquinolinate 가 phenylmercuric acctate 보다 강하며, 또한 그 차도 커서 약 $10\%$쯤 된다. (4) 이상의 결과로 미루어 보아 phenylmercuric 8-oxyquinolinate의 포자발아 억제효과는 phenylmercuric acetate와 동정도이거나 약간 높으며, 균사발육 억제효과는 phenylmercuric acetate보다 낮음이 명백하다.

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Kinetic Evidence for the Interactive Inhibition of Laccase from Trametes versicolor by pH and Chloride

  • Raseda, Nasrin;Hong, Soonho;Kwon, O Yul;Ryu, Keungarp
    • Journal of Microbiology and Biotechnology
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    • 제24권12호
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    • pp.1673-1678
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    • 2014
  • The interactive inhibitory effects of pH and chloride on the catalysis of laccase from Trametes versicolor were investigated by studying the alteration of inhibition characteristics of sodium chloride at different pHs for the oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). At pH 3.0, the addition of sodium chloride (50 mM) brought about a 40-fold increase in $K{_m}^{app}$ and a 4-fold decrease in $V_{max}{^{app}}$. As the pH increased to 7.0, the inhibitory effects of sodium chloride became significantly weakened. The mixed-inhibition mechanism was successfully used to quantitatively estimate the competitive and uncompetitive inhibition strengths by chloride at two different pHs (pH 3.0 and 6.0). At pH 3.0, the competitive inhibition constant, $K_i$, was 0.35 mM, whereas the uncompetitive inhibition constant, $K{_i}^{\prime}$, was 18.1 mM, indicating that the major cause of the laccase inhibition by chloride is due to the competitive inhibition step. At a higher pH of 6.0, where the inhibition of the laccase by hydroxide ions takes effect, the inhibition of the laccase by chloride diminished to a great extent, showing increased values of both the competitive inhibition constant ($K_i=23.7mM$) and uncompetitive inhibition constant ($K{_i}^{\prime}=324mM$). These kinetic results evidenced that the hydroxide anion and chloride share a common mechanism to inhibit the laccase activity.

Differential Inhibition of $MPP^+$- or 6-Hydroxydopamine-induced Cell Viability Loss in PC12 Cells by Trifluoperazine and W-7

  • Lee, Chung-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권4호
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    • pp.247-253
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    • 2005
  • The present study assessed the effect of calmodulin antagonists trifluoperazine and W-7 against the cytotoxicity of $MPP^+$ and 6-bydroxydoparnine (6-OHDA) in relation to the mitochondrial dysfunction and cell death in PC12 cells. Trifluoperazine (an inhibitor of the mitochondrial permeability transition and calmodulin antagonist) and W-7 (a specific calmodulin antagonist) significantly attenuated the $MPP^+-induced$ cell viability loss in PC12 cells with a maximum inhibition at $0.5{\sim}1{\mu}M$; beyond these concentrations the inhibitory effect declined. Both compounds at this concentration range did not cause cell death significantly. In contrast to $MPP^+$, the trifluoperazine and W-7 did not depress the cytotoxic effect of 6-OHDA. Addition of trifluoperazine and W-7 inhibited the cytosolic accumulation of cytochrome c and caspase-3 activation in PC12 cells treated with $MPP^+$ and attenuated the formation of reactive oxygen species and the depletion of GSH, whereas both compounds did not reduce the effect of 6-OHDA. The results show that trifluoperazine and W-7 may attenuate the cytotoxicity of $MPP^+$ by inhibition of the mitochondrial permeability transition and calmodulin. Meanwhile, the cytotoxic effect of 6-OHDA seems to be mediated by the actions, which are different from $MPP^+$.

Oxidant에 의한 신장세뇨관 물질이동계의 장애에 대한 단삼(丹參)의 효과 (Effect of Salviae-radix on oxidant-induced impairment of membrane transport function in renal tubules)

  • 김상범;정지천
    • 대한한방내과학회지
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    • 제18권1호
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    • pp.147-155
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    • 1997
  • This study was undertaken to determine whether Salviae-radix (SVR) exraction exerts benefical effect against oxidant-induced inhibition of tetraethylammonium (TEA) uptake which is actively secreted by renal proximal tubules. TEA uptake increased as function of incubation time to 60 min. When renal cortical slices were exposed to 50 mM $H_2O_2$, TEA uptake was significantly inhibited. The inhibition was significantly protected by addition of 0.5% SVR extraction. The benefical effect of SVR was dose-dependent over the concentration range of 0.1-1%; $H_2O_2$ (50 mM)-induced inhibition of TEA uptake was completely protected by 0.5-1% SVR extraction. $H_2O_2$ increased LDH release which was accompanied by an increase in lipid peroxidation in renal cortical slices. These changes were prevented by 0.5% SVR. These results suggest that SVR exerts benefical effect against oxidant-induced impairment of membrane transport function, this effect may be due to by an antioxidant action.

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