• Title/Summary/Keyword: selective action

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Inhibition by Pinusolide of Platelet-Activating Factor (PAF-acether)-Induced Hypotension and Bronchoconstriction.

  • Kim, Kyung-A;Kim, Yeon-Su;Lee, Moo-Tak;Lee, Shin-Woong
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.203-203
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    • 1996
  • It has been known that pinusolide isolated from Biota orientalis inhibits specifically [$^3$H] PAF binding to and PAF-induced aggregation of rabbit platelets in vitro. The present study was undertaken to evaluate the effects of pinusolide on hypotension and bronchoconstriction due to PAF. PAF(i.v.) in doses of 0.01 to 0.3 $\mu\textrm{g}$/kg induced a dose-dependent hypotension without tachyphylaxis in rat. Pinusolide(5~20 mg/kg, i.v.) inhibited PAF(0.03 $\mu\textrm{g}$/kg, i.v.)-induced hypotension dose-dependently, while it failed to block the hypotensive action of histamine, serotonin and acetylcholine. It inhibited bronchoconstriction and cutaneous vascular permeability induced by PAF in anesthetized guinea-pigs and rats, respectively, but it showed no inhibitory effect on the increase in bronchial resistance by histamine and acetylcholine. These results strongly suggest that in vivo pinusolide acts as a selective antagonist of PAF.

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INFLUENCE OF GLUCOCORTICOIDS ON NICOTINIC AND MUSCARINIC STIMULATION-INDUCED CATECHOL-AMINE SECRETION FROM THE RAT ADRENAL GLAND

  • Lim, Dong-Yoon;Lee, Jae-Joon;Park, Cheol-Hee;Ko, Suk-Tai
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.242-242
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    • 1996
  • The influence of glucocorticoids on the secretory responses of catecholamines (CA) evoked by acetylcholine (ACh), DMPP, McN-A-343, excess K$\^$+/ and Bay-K-8644 from the isolated perfused rat adrenal gland and to clarify the mechanism of its action. The perfusion of the synthetic glucocorticoid dexamethasone (10-100 uM) into an adrenal vein for 20min produced relatively a dose-dependent inhibition in CA secretion evoked by ACh (5.32mM), excess K$\^$+/ (56mM), DMPP (a selective nicotinic receptor agonist, 100uM for 2min), McN-A-343 (a muscarinic receptor agonist, 100uM for 4min), Bay-K-8644 (a calcium channel activator, 10 uM for 4min) and cyclopiazonic acid (a releaser of intracellular Ca$\^$2+/, 10uM for 4min).

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N-Acetylglycine Side Chain is Critical for the Antimicrobial Activity of Xanthostatin

  • Kim, Si-Kwan;Ubukata, Makoto;Isono, Kiyoshi
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.998-1000
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    • 2003
  • This study was carried out to elucidate the mode of bacteriostatic property of xanthostatin (XS), a novel depsipeptide antibiotic with an N-acetylglycine side chain and selective antimicrobial activity against Xanthomonas spp. Two biotransformed XSs were isolated by the treatment of XS with the cell lysate of Xanthomonas campestris pv. citri, a solvent partition, preparative TLC, and HPLC. Structure determination of those two biotransformed XSs demonstrated deletion of the N-acetylglycine side chain. Noteworthily, they showed no antimicrobial activity against Xanthomonas spp. This result suggests that the N-acetylglycine side chain plays a critical role in the antimicrobial activity of XS, and that the bacteriostatic property of XS is due to susceptibility of the ester bond between the hexadepsipeptide nucleus and the N-acetylglycine side chain to hydrolytic enzyme(s) produced by Xanthomonas spp.

PREPARATION OF CHITO-OLIGOSACCHARIDE AS AN ANTIMICROBIAL AGENT AND ITS EFFECT ON COTTON FABRICS

  • Seong, Ha-Soo;Kim, Jae-Pil;Ko, Sohk-Won
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.04a
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    • pp.329-333
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    • 1998
  • The major classes of antimicrobial agents for textiles include organo-metallics, phenols, quaternary ammonium salts, and organo-silicones. These finishes should be durable, have selective activity towards undesirable organisms, be compatible with other finishes and dyes, and be nontoxic to man [1]. Chitosan, as a deacetylated derivative of chitin, is a natural, non-toxic and biodegradable polymer. Chitosan is also known as an antimicrobial polysaccharide due to antimicrobial action of the amino group at the C-2 position of the glucosamine residue.(omitted)

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Photocleavage of DNA by 4′-Bromoacetophenone- Pyrrole Carboxamides

  • Jeon, Raok
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.79-79
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    • 2001
  • Genotoxic chemotherapeutics are irreversible DNA targeting agents, which can act as anticancer and antiviral drugs. Natural antibacterial and anticancer enediynes function through the formation of free radicals formed by Bergman-type cycloaromatization and being capable of cleavage of DNA strand. They have been focused primarily on the design and syntheses of simple enediyne structures, which can be mimic their mechanistic feature. Recently. I have been reported the possible application of 4'-bromoacetophenone as a simple photoactivatable DNA cleaving agent, which could be readily prepared and exhibit potent and selective DNA cleaving activity. Herein, we further investigated the activity of 4'-bromoacetophenone-pyrrolecarboxamides, which consist of both DNA cleaving element and recognition unit under various conditions in order to get more understanding of the mechanism of the action and find a broad spectrum of application.

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The Effects on the Family Relations Caused by AIDS (후천성면역결핍증이 가족관계에 미치는 영향)

  • 전형미
    • Journal of the Korean Home Economics Association
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    • v.32 no.4
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    • pp.85-95
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    • 1994
  • Today the occurrence and world-wide transfusion of the AIDS has brought about new problems related to family relations. The AIDS is more threatening than any other disease because of the special processes of infection trough sex and intravenous injections high care cost and terminal death. The AIDS causes conflicts among family members economic destitution and family dissolution. In the U.S Marriage without noticing of the AIDS may lead to divorce like injuries abandonment and misfeasance during marriage. But the AIDS victims should not be rejected from the rights of parental decision divorce beneficiaries and visiting rights. More discussion is needed about such issues as the pregnancy rights rongful birth action and selective nontreatment by doctors. The AIDS may influence the every party involved and interdisplinary studies should be required to solve the problem including family science laws psychology sociology and medical research as well.

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Neuropeptidomics: Mass Spectrometry-Based Identification and Quantitation of Neuropeptides

  • Lee, Ji Eun
    • Genomics & Informatics
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    • v.14 no.1
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    • pp.12-19
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    • 2016
  • Neuropeptides produced from prohormones by selective action of endopeptidases are vital signaling molecules, playing a critical role in a variety of physiological processes, such as addiction, depression, pain, and circadian rhythms. Neuropeptides bind to post-synaptic receptors and elicit cellular effects like classical neurotransmitters. While each neuropeptide could have its own biological function, mass spectrometry (MS) allows for the identification of the precise molecular forms of each peptide without a priori knowledge of the peptide identity and for the quantitation of neuropeptides in different conditions of the samples. MS-based neuropeptidomics approaches have been applied to various animal models and conditions to characterize and quantify novel neuropeptides, as well as known neuropeptides, advancing our understanding of nervous system function over the past decade. Here, we will present an overview of neuropeptides and MS-based neuropeptidomic strategies for the identification and quantitation of neuropeptides.

Crosstalk and Interplay between the Ubiquitin-Proteasome System and Autophagy

  • Ji, Chang Hoon;Kwon, Yong Tae
    • Molecules and Cells
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    • v.40 no.7
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    • pp.441-449
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    • 2017
  • Proteolysis in eukaryotic cells is mainly mediated by the ubiquitin (Ub)-proteasome system (UPS) and the autophagy-lysosome system (hereafter autophagy). The UPS is a selective proteolytic system in which substrates are recognized and tagged with ubiquitin for processive degradation by the proteasome. Autophagy is a bulk degradative system that uses lysosomal hydrolases to degrade proteins as well as various other cellular constituents. Since the inception of their discoveries, the UPS and autophagy were thought to be independent of each other in components, action mechanisms, and substrate selectivity. Recent studies suggest that cells operate a single proteolytic network comprising of the UPS and autophagy that share notable similarity in many aspects and functionally cooperate with each other to maintain proteostasis. In this review, we discuss the mechanisms underlying the crosstalk and interplay between the UPS and autophagy, with an emphasis on substrate selectivity and compensatory regulation under cellular stresses.

Effects of the water soluble fraction of the musk on the activities of murine peritoneal macrophages (사향(麝香)의 수용성분(水容性分)이 생쥐 복강내(腹腔內) 거식세포(巨食細胞)의 활성(活性)에 미치는 영향(影響))

  • Lim Seok-Rhin
    • Journal of Society of Preventive Korean Medicine
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    • v.6 no.2
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    • pp.147-155
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    • 2002
  • The musk has been reported to have significant anti-inflammatory activities in clinical use and several animal models and we examined the effects of water soluble fraction(WSF) of the musk on murine peritoneal macrophages. WSF decreased the production of nitric oxide from the lipopolysaccharide(LPS)-treated murine peritoneal macrophages and also reduced the phagocytic activity of macrophages on the opsonized sheep red blood cells(SRBC). Transcriptional expression level of the inducible nitric oxide synthase(iNOS) was also decreased and the viability of the treated macrophages was not affected by WSF, suggesting that the effects could be partly explained by transcriptional regulation. Contrary to down-regulating iNOS expression, WSF slightly increased the release of tumor necrosis factor-alpha$(TNF-{\alpha})$, which implied its selective action on cellular pathways activated by LPS. Our results showed that anti-inflammatory activities of the musk could be partly explained by the inhibitory effects of the water soluble fraction on the macrophageal activation.

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PKC-Independent Stimulation of Cardiac $Na^+/Ca^{2+}$ Exchanger by Staurosporine

  • Kang, Tong-Mook
    • The Korean Journal of Physiology and Pharmacology
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    • v.12 no.5
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    • pp.259-265
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    • 2008
  • $[Ca^{2+}]_i$ transients by reverse mode of cardiac $Na^+/Ca^{2+}$ exchanger (NCX1) were recorded in fura-2 loaded BHK cells with stable expression of NCX1. Repeated stimulation of reverse NCX1 produced a long-lasting decrease of $Ca^{2+}$ transients ('rundown'). Rundown of NCX1 was independent of membrane $PIP_2$ depletion. Although the activation of protein kinase C (PKC) was observed during the $Ca^{2+}$ transients, neither a selective PKC inhibitor (calphostin C) nor a PKC activator (PMA) changed the degrees of rundown. By comparison, a non-specific PKC inhibitor, staurosporine (STS), reversed rundown in a dose-dependent and reversible manner. The action of STS was unaffected by pretreatment of the cells with calphostin C, PMA, or forskolin. Taken together, the results suggest that the stimulation of reverse NCX1 by STS is independent of PKC and/or PKA inhibition.