• 제목/요약/키워드: $S_N1$ mechanism

검색결과 717건 처리시간 0.031초

청공고(淸空膏)의 내피세포 의존성 혈관이완효과 (Endothelium Dependent Vasorelaxant Action of ChungGongGo Extract on Arterial Contraction in Rabbit)

  • 오철;김호현;고흥
    • 동의생리병리학회지
    • /
    • 제22권3호
    • /
    • pp.666-671
    • /
    • 2008
  • This study was undertaken to define the effect of ChungGongGo extract on norepinephrine-induced arterial contraction in rabbit. In order to investigate the effect of ChungGongGo extract on rabbit's contracted vascular ring detached from common carotid artery, vascular ring with intact or damaged endothelium was used for the experiment using organ bath. To analyze the mechanism of ChungGongGo extract-induced relaxation, ChungGongGo extract was infused into contracted vascular ring which had been pretreated by $N{\omega}$-nitro-L-arginine(L-NNA), Methylene blue(MB), and $Ca^{2+}$ was infused into contracted vascular ring induced by NE or KCl after treatment of ChungGongGo in $Ca^{2+}$-free solution. The results were as follows: ChungGongGo extract had an effective relaxation to the contracted vascular ring by NE in 1.0mg/ml and 0mg/ml level. ChungGongGo extract had an effective relaxation to the intact endothelium vascular ring, but when endothelium was removed, vascular ring did not relax. ChungGongGo extract-induced relaxation was inhibited by the pretreatment of L-NNA and MB. Pretreatment of ChungGongGo extract inhibit the contraction by influx of extra-$Ca^{2+}$ in contracted vascular ring induced by NE in $Ca^{2+}$-free solution. As mentioned above, we suggest that ChungGongGo relaxes vascular ring through suppress influx of extra-cellular $Ca^{2+}$ by the action of nitric oxide from endothelium.

Involvement of nitric oxide-induced NADPH oxidase in adventitious root growth and antioxidant defense in Panax ginseng

  • Tewari, Rajesh Kumar;Kim, Soohyun;Hahn, Eun-Joo;Paek, Kee-Yoeup
    • Plant Biotechnology Reports
    • /
    • 제2권2호
    • /
    • pp.113-122
    • /
    • 2008
  • Nitric oxide (NO) affects the growth and development of plants and also affects plant responses to various stresses. Because NO induces root differentiation, we examined whether or not it is involved in increased ROS generation. Treatments with sodium nitroprusside (SNP), an NO donor, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), a specific NO scavenger, and $N{\omega}-nitro-{\text\tiny{L}}-arginine$ methyl ester hydrochloride (${\text\tiny{L}}-NAME$), an NO synthase (NOS) inhibitor, revealed that NO is involved in the adventitious root growth of mountain ginseng. Supply of an NO donor, SNP, activates NADPH oxidase activity, resulting in increased generation of $O_2{^{{\cdot}-}}$, which subsequently induces growth of adventitious roots. Moreover, treatment with diphenyliodonium chloride (DPI), an NADPH oxidase inhibitor, individually or with SNP, inhibited root growth, NADPH oxidase activity, and $O_2{^{{\cdot}-}}$ anion generation. Supply of the NO donor, SNP, did not induce any notable isoforms of enzymes; it did, however, increase the activity of pre-existing bands of NADPH oxidase, superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, and glutathione reductase. Enhanced activity of antioxidant enzymes induced by SNP supply seems to be responsible for a low level of $H_2O_2$ in the adventitious roots of mountain ginseng. It was therefore concluded that NO-induced generation of $O_2{^{{\cdot}-}}$ by NADPH oxidase seems to have a role in adventitious root growth of mountain ginseng. The possible mechanism of NO involvement in $O_2{^{{\cdot}-}}$ generation through NADPH oxidase and subsequent root growth is discussed.

차전자 메탄올 엑기스의 혈압강하작용에 관한 연구 (A Study on the Hypotensive Action of Methanol Extract of Plantaginis Seed in the Rabbit)

  • 고석태;임동윤
    • 약학회지
    • /
    • 제22권3호
    • /
    • pp.163-174
    • /
    • 1978
  • 차전자(Plantaginis Semen)은 우리나라 전국 각지의 원야와 노방의 자생하는 다년생 초목으로 Plantaginaceae(질경이과)에 속하는 Plantago major L. var. asiatica Decaisne 질경이의 종자를 말하며 그의 성분으로는 다량의 점액, 지방유, pentosan 및 galactan, succinic acid, plantanolic acid, adenine, choline. K-염등이 알려져 있다. 이 차전자는 한방과 민간에서 소염, 이뇨, 진해, 지사제로서 널리 사용되어 왔으며 그의 약리작용에 관해서는 이미 저자들이 가토를 이용한 실험에서 이의 methanol extract가 자궁수축작용, 호흡흥분작용, 혈압강하작용, 장관수축작용, 심장박동의 완제작용, 항이뇨작용이 있음을 보고한 바 있다. 그러나 그의 기전에 관해서는 거의 알려진 바가 없다. 따라서 저자들은 위의 여러가지 작용중 특히 혈압강하작용에 관한 본태를 파악하여 그의 실용성 여부를 구명코자 이 실험을 착수하였다.

  • PDF

A New Functional Model of Catechol Dioxygenases: Properties and Reactivity of [Fe(BLPA)DBC]$BPh_4$

  • Lim, Ji H.;Lee, Ho J.;이강봉;Jang, Ho G.
    • Bulletin of the Korean Chemical Society
    • /
    • 제18권11호
    • /
    • pp.1166-1172
    • /
    • 1997
  • [FeⅢ(BLPA)DBC]BPh4, a new functional model for the catechol dioxygenases, has been synthesized, where BLPA is bis((6-methyl-2-pyridyl)methyl)(2-pyridylmethyl)amine and DBC is 3,5-di-tert-butylcatecholate dianion. The BLPA complex has a structural feature that iron center has a six-coordinate geometry with N4O2 donor set. It exhibits EPR signals at g=5.5 and 8.0 which are typical values for the high-spin FeⅢ (S=5/2) complex with axial symmetry. The BLPA complex reacts with O2 within a few hours to afford intradiol cleavage (75%) and extradiol cleavage (15%) products which is very unique result of all [Fe(L)DBC] complexes studied. The iron-catecholate interaction of BLPA complex is significantly stronger, resulting in the enhanced covalency of the metal-catecholate bonds and low energy catecholate to FeⅢ charge transfer bands at 583 and 962 nm in CH3CN. The enhanced covalency is also reflected by the isotropic shifts exhibited by the DBC protons, which indicate increased semiquinone character. The greater semiquinone character in the BLPA complex correlates well with its high reactivity towards O2. Kinetic studies of the reaction of the BLPA complex with 1 atm O2 in CH3OH and CH2Cl2 under pseudo-first order conditions show that the BLPA complex reacts with O2 much slower than the TPA complex, where TPA is tris(2-pyridylmethyl)amine. It is presumably due to the steric effect of the methyl substituent on the pyridine ring. Nevertheless, both the high specificity and the fast kinetics can be rationalized on the basis of its low energy catecholate to FeⅢ charge transfer bands and large isotropic NMR shifts for the BLPA protons. These results provide insight into the nature of the oxygenation mechanism of the catechol dioxygenases.

Does Strategy of Downward Stepping Stair Due to Load of Additional Weight Affect Lower Limb's Kinetic Mechanism?

  • Ryew, Checheong;Yoo, Taeseok;Hyun, Seunghyun
    • International journal of advanced smart convergence
    • /
    • 제9권4호
    • /
    • pp.26-33
    • /
    • 2020
  • This study measured the downward stepping movement relative to weight change (no load, and 10%, 20%, 30% of body weight respectively of adult male (n=10) from standardized stair (rise of 0.3 m, tread of 0.29 m, width of 1 m). The 3-dimensional cinematography and ground reaction force were also utilized for analysis of leg stiffness: Peak vertical force, change in stance phase leg length, Torque of whole body, kinematic variables. The strategy heightened the leg stiffness and standardized vertical ground reaction force relative to the added weights (p<.01). Torque showed rather larger rotational force in case of no load, but less in 10% of body weight (p<.05). Similarly angle of hip joint showed most extended in no-load, but most flexed in 10% of body weight (p<.05). Inclined angle of body trunk showed largest range in posterior direction in no-load, but in vertical line nearly relative to added weights (p<.001). Thus the result of the study proved that downward stepping strategy altered from height of 30 cm, regardless of added weight, did not affect velocity and length of lower leg. But added weight contributed to more vertical impulse force and increase of rigidity of whole body than forward rotational torque under condition of altered stepping strategy. In future study, the experimental on effect of weight change and alteration of downward stepping strategy using ankle joint may provide helpful information for development of enhanced program of prevention and rehabilitation on motor performance and injury.

CCR5-mediated Recruitment of NK Cells to the Kidney Is a Critical Step for Host Defense to Systemic Candida albicans Infection

  • Nu Z. N. Nguyen;Vuvi G. Tran;Saerom Lee;Minji Kim;Sang W. Kang;Juyang Kim;Hye J. Kim;Jong S. Lee;Hong R. Cho;Byungsuk Kwon
    • IMMUNE NETWORK
    • /
    • 제20권6호
    • /
    • pp.49.1-49.15
    • /
    • 2020
  • C-C chemokine receptor type 5 (CCR5) regulates the trafficking of various immune cells to sites of infection. In this study, we showed that expression of CCR5 and its ligands was rapidly increased in the kidney after systemic Candida albicans infection, and infected CCR5-/- mice exhibited increased mortality and morbidity, indicating that CCR5 contributes to an effective defense mechanism against systemic C. albicans infection. The susceptibility of CCR5-/- mice to C. albicans infection was due to impaired fungal clearance, which in turn resulted in exacerbated renal inflammation and damage. CCR5-mediated recruitment of NK cells to the kidney in response to C. albicans infection was necessary for the anti-microbial activity of neutrophils, the main fungicidal effector cells. Mechanistically, C. albicans induced expression of IL-23 by CD11c+ dendritic cells (DCs). IL-23 in turn augmented the fungicidal activity of neutrophils through GM-CSF production by NK cells. As GM-CSF potentiated production of IL-23 in response to C. albicans, a positive feedback loop formed between NK cells and DCs seemed to function as an amplification point for host defense. Taken together, our results suggest that CCR5-mediated recruitment of NK cells to the site of fungal infection is an important step that underlies innate resistance to systemic C. albicans infection.

Dasatinib Inhibits Lyn and Fyn Src-Family Kinases in Mast Cells to Suppress Type I Hypersensitivity in Mice

  • Lee, Dajeong;Park, Young Hwan;Lee, Ji Eon;Kim, Hyuk Soon;Min, Keun Young;Jo, Min Geun;Kim, Hyung Sik;Choi, Wahn Soo;Kim, Young Mi
    • Biomolecules & Therapeutics
    • /
    • 제28권5호
    • /
    • pp.456-464
    • /
    • 2020
  • Mast cells (MCs) are systemically distributed and secrete several allergic mediators such as histamine and leukotrienes to cause type I hypersensitivity. Dasatinib is a type of anti-cancer agent and it has also been reported to inhibit human basophils. However, dasatinib has not been reported for its inhibitory effects on MCs or type I hypersensitivity in mice. In this study, we examined the inhibitory effect of dasatinib on MCs and MC-mediated allergic response in vitro and in vivo. In vitro, dasatinib inhibited the degranulation of MCs by antigen stimulation in a dose-dependent manner (IC50, ~34 nM for RBL-2H3 cells; ~52 nM for BMMCs) without any cytotoxicity. It also suppressed the secretion of inflammatory cytokines IL-4 and TNF-α by antigen stimulation. Furthermore, dasatinib inhibited MC-mediated passive cutaneous anaphylaxis (PCA) in mice (ED50, ~29 mg/kg). Notably, dasatinib significantly suppressed the degranulation of MCs in the ear tissue. As the mechanism of its effect, dasatinib inhibited the activation of Syk and Syk-mediated downstream signaling proteins, LAT, PLCγ1, and three typical MAP kinases (Erk1/2, JNK, and p38), which are essential for the activation of MCs. Interestingly, in vitro tyrosine kinase assay, dasatinib directly inhibited the activities of Lyn and Fyn, the upstream tyrosine kinases of Syk in MCs. Taken together, dasatinib suppresses MCs and PCA in vitro and in vivo through the inhibition of Lyn and Fyn Src-family kinases. Therefore, we suggest the possibility of repositioning the anti-cancer drug dasatinib as a treatment for various MC-mediated type I hypersensitive diseases.

위성원격탐사를 이용한 동해 원산연안의 재발생 와동류 연구 (Study of a Recurring Anticyclonic Eddy off Wonsan Coast in Northern Korea Using Satellite Tracking Drifter, Satellite Ocean Color and Sea Surface Temperature Imagery)

  • 서영상;장이현;김정희
    • 대한원격탐사학회지
    • /
    • 제16권3호
    • /
    • pp.211-220
    • /
    • 2000
  • 위성자료를 이용하여 동해북부 원산 연근해역의 재발생 와동류에 대한 형태변동, 유속, 발생기작 등을 연구하였다. 1999년 1월 4일부터 3월 18일까지의 기간에 대한 ARGOS의 표류부이 자료(위치정보 및 수온), NOAA 위성의 AVHRR 자료(표면수온) 그리고 Orbview-2 위성의 SeaWiFS 자료(클로로필 a)를 이용하여 재발생 와동류의 수평공간 규모를 파악하였다. 또한 재발생 와동류의 기작과 변동원인을 규명하고자 속초와 울릉도에서의 풍향, 풍속자료, 묵호-울릉도간 해수면 차 값 및 해저지형과 와동류에 포획되어 있는 표류부이의 시.공간적 위치변동간의 상관정도를 파악하였다. 원산 연안해역에서의 와동류의 72일간 평균유속은 153 km/h (42 cm/sec)로 분석되었다. 이 와동류는 cold core, 시계방향의 회전, 직경 110 km의 수평공간을 가진 재발생 와동류로서 와동류의 중심은 위도 $39^{\circ}N$, 경도 $129^{\circ}E$로 분석되었다.

전침에 의한 CFA유발 통증모델의 NMDA 수용체 의존적 ERK MAPK 발현 변화 (Effects of Electroacupucture on NMDA Receptor-dependent Spinal ERK MAPK Expression in CFA-induced Pain Model)

  • 김하늬;김유리;장지연;최영현;이용태;최병태
    • 동의생리병리학회지
    • /
    • 제24권6호
    • /
    • pp.983-988
    • /
    • 2010
  • The present study aims to investigate a possible mechanism of electroacupuncture (EA) in the spinal dorsal horn that may underlie N-methyl-D-aspartate (NMDA) receptor-associated extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathways. The hot plate latency of the ipsilateral hindpaw of EA-treated rats was significantly decreased compared with complete Freund's adjuvant (CFA)-injected ones. The expressions of NR1 and NR2B subuint mRNA of NMDA receptor in the whole L4-5 segments are decreased by CFA treatment, but NR2B subunit was significantly recovered by EA treatment. When we detected the expression of ERK, there were no significant difference between normal and CFA-treated rats with EA or NMDA receptor antagonist MK801. But phosphorylated ERK expressions were markedly induced by CFA, but these inductions were significantly modulated by EA treatment. Although hosphorylation of ERK was also arrested by MK801, these inductions of CFA-injected rats was markedly inhibited only by co-treatment with EA and MK801. Phosphorylated cAMP response element-binding protein (CREB), ERK-related transcriptional factor, showed a significant increase in CFA-treated rats and this increase was slightly inhibited by EA and MK801 treatments. But immunoreaction for phosphorylated CREB were significantly increased by CFA treatment in the superficial laminae of the dorsal horn and these inductions were significantly arrested by co-treatment of EA and MK801. Consequently, the hyperalgesia induced by CFA are associated NMDA receptor and EA and MK801 may showed anti-hyperalgesia via same mechanism for inhibition of ERK and CREB phosphorylation in the dorsal horn.

소교세포에서 heme oxygenase-1 발현 유도를 통한 치자(Gardenia jasminoides)의 항염증 효과 (Gardenia jasminoides Exerts Anti-inflammatory Activity via Akt and p38-dependent Heme Oxygenase-1 Upregulation in Microglial Cells)

  • 송지수;신지은;김지희;김영희
    • 생명과학회지
    • /
    • 제27권1호
    • /
    • pp.8-14
    • /
    • 2017
  • 치자 열매는 아시아에서 음식과 옷의 염료로 사용되어 왔다. 본 연구에서는 BV-2 소교세포에서 치자열매 열수추출물(GJ)의 항염증 효과를 관찰하고 그 작용 기전을 연구하였다. GJ는 세포에 독성을 유도하지 않으면서 lipopolysaccharide로 인한 nitric oxide (NO) 분비와 inducible nitric oxide synthase (iNOS) 생성 및 활성산소 생성을 억제하였다. 또한 GJ는 농도의존적으로 heme oxygenase-1 (HO-1)의 발현을 유도하였다. 더군다나 HO-1 siRNA를 처리했을 때는 GJ가 iNOS의 발현을 억제하지 못하였다. GJ는 HO-1의 발현에 관여하는 전사인자인 nuclear factor E2-related factor 2를 핵으로 이동시켰다. 또한 GJ에 의한 HO-1의 발현은 phosphatidylinositol 3-kinase(PI-3K) 및 p38 kinase 억제제에 의해 감소되었으며, GJ가 Akt와 p38 kinase의 인산화를 유도하였다. 이상의 결과를 종합해보면, GJ는 PI3K/Akt 및 p38 신호전달과정을 통해 HO-1의 발현을 유도함으로써 NO와 같은 염증매개물질의 생성을 억제한다는 것을 알 수 있다. 이러한 연구결과는 치자열매가 신경염증을 억제하는 새로운 기전을 밝힌 것이다.