• Title/Summary/Keyword: blocking agent

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Influence of Some Sympathetic Blocking Agents on Pressor Actions of Norepinephrine and Angiotensin in Rabbits. (Norepinephrine 및 Angiotensin의 승압효과(昇壓效果)에 대(對)한 교감신경단제(交感神經斷濟) 의 영향(影響))

  • Eun, Chong-Young
    • Journal of Pharmaceutical Investigation
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    • v.15 no.1
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    • pp.22-31
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    • 1985
  • The influence of some sympathetic blocking agents on pressor actions of norepinephrine and angiotensin was investigated in rabbits. 1. Phentolamine, sympathetic ${\alpha}-blocking$ agent, blocked the pressor action of norepinephrine, but did not affect the pressor action of angiotensin 2. Chlorisondamine, autonomic ganglionic blocking agent, potentiated the both actions of norepinephrine and angiotensin. 3. Guanethidine, bethanidine and debrisoquine, sympathetic neuronal blocking agents, potentiated the action of norepinephrine, while diminished that of angiotensin. 4. Reserpine, norepinephrine depleting agent, increased the pressor response of norepinephrine, but did not influence the pressor action of angiotensin.

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Taraxacum mongolieum Hand-Mass Aqua-acupuncture Solution as the Blocking Agent of Carcinogenesis (포공영약침액의 발암과정 blocking agent로서의 활성)

  • 손윤희;김소연;임종국;남경수
    • Journal of Life Science
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    • v.12 no.5
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    • pp.549-554
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    • 2002
  • Taraxacunf mongofieum Hand-Mass aqua-acupuncture solution (TMAS) was prepared and investigated og, the effect on initiation of carcinogenesis. The following effe.Is as a blocking agent were measured. .(a) Indu.ction of quinone reductase, (b) Induction of glutathione S-transferase activity (c) Increase of reduced glutathione. TMAS was potent inducer of quinone reductase in Hepa Iclc7 murine hepatoma cells. Clutathione S-transferase activity was increased with TMAS. In addition glutathione levels were increased about 1.6-fold with TMAS in cultured murine hepatoma Hepa Iclc7 cells.

An Agent System for Searching of Host Computer and Blocking Network Access in IPv6 Environment (IPv6 환경에서 호스트 탐색 및 네트워크 접속 차단 에이전트 시스템)

  • Chung, Youn-Ky;Moon, Hae-Eun
    • Journal of Korea Multimedia Society
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    • v.14 no.1
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    • pp.144-152
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    • 2011
  • As IPv4 addresses are exhausting, the use of IPv6 addresses is increasing. IPv6 environment provides address auto-configuration function. If addresses are allocated to each host automatically, network management system has difficulty in inspecting every IP of all devices and keeping the relevant informations. Also, as IP addresses are configured automatically, problems such as malicious users accessing network devices with no restriction can occur. To solve these problems, managing and blocking of malicious user is necessary. In this paper, we suggest agent system for searching of host computer and blocking network access which manages and protects the major network resources efficiently by searching host and blocking unauthorized host access to network in IPv6 environment. According to the test results of function of this agent system in IPv6 environment, we have checked that this system performs searching and blocking function normally.

Influence of Debrisoquine Pressor Actions of Norepinephrine and Tyramine in Rabbits (Debrisoquine이 노르에피네프린 및 티라민의 승압효과에 미치는 영향)

  • 고석태;김해석;이상현
    • YAKHAK HOEJI
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    • v.30 no.3
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    • pp.111-120
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    • 1986
  • The influence of debrisoquine on pressor actions of norepinephrine (NE) and tyramine (TR) was investigated in rabbits. Debrisquine(D), in the doses of 1.0, 3.0 and 6.0.mu.g/kg, i.v. potentiated significantly the pressor actions of NE and TR, except the action of TR in the dose of 1.0mg/kg of debrisoquine. NE response potentiated by debrisoquine was not affected by tranylcypromine, a MAO inhabiter, or desipramine, a NE uptake blocking agent, but augmented by reserpine, a NE depleting agent, or bethanidine, a sympathetic neuronal blocking agent. NE response potentiated by tranylcypromine or desipramine was augmented by debrisoquine, while NE response potentiated by reserine or bethanidine was not affected by debrisoquine. TR response potentiated by debrisoquine was weakened by tranylcypromine, desipramine or reserpine, and not affected by bethanidine. TR response in rabbit pretreated with tranylcypromine, desipramine or reserpine was augmented by debrisoquine, but in rabbit pretreated with bethanidine was not affected by debrisoquine.

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Thermal Decomposition Behavior of Blocked Diisocyanates Derived from Mixture of Blocking Agents

  • Lee Jung Min;Subramani Sankaraiah;Lee Young Soo;Kim Jung Hyun
    • Macromolecular Research
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    • v.13 no.5
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    • pp.427-434
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    • 2005
  • To improve the performance and reduce raw material costs, blocked isocyanates were prepared with mixture of blocking agents in many industries. Three blocked isocyanates (adducts) namely $\varepsilon$-caprolactam/benzotriazole-blocked 4,4'-diphenylmethane diisocyanate (MDI), toluene-2,4-diisocyanate (TDI) and 4,4'-dicyclohexyl-methane diisocyanate ($H_{12}$MDI) were synthesized. Six reference adducts were also prepared by blocking MDI, TDI, and $H_{12}$MDI with $\varepsilon$-caprolactam ($\varepsilon$-CL) or benzotriazole. The reactions were carried out in acetone medium and dibutyltin dilaurate (DBTDL) was used as a catalyst. The progress of the blocking reaction was monitored by IR spectroscopy. De-blocking temperatures (dissociation temperatures) of these adducts were studied using DSC and TGA and the results were correlated. As expected, the thermal analysis data showed that de-blocking temperature of blocked aromatic isocyanates was lower than that of the blocked aliphatic isocyanates. The low de-blocking temperature of blocked aromatic isocyanate could be due to electron withdrawing benzene ring present in the blocked isocyanates. It was also found that benzotriazole-blocked adducts de-blocked at higher temperature compared with $\varepsilon$-CL-blocked adducts.

Study on Synthesis and Properties of Water-born Polyurethane (수분산성 폴리우레탄의 합성 및 물성에 관한 연구)

  • Cho, Ur-Ryong;Choi, Seo-Yoon
    • Elastomers and Composites
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    • v.40 no.4
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    • pp.249-257
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    • 2005
  • Polyurethane(PU) prepolymers were prepared from polyol and diisocyanate. Unionized PU prepolymers were synthesized from poly(propylene glycol)(PPG, MW: 1000), 2,2-bis (hydroxymethyl) propionic acid(DMPA), and isophorone diisocyanate(IPDI) by prepolymer syhthesizing process. After PU prepolymers were dispersed into water, the physical properties were investigated by changing the molar ratio of polyol and diisocyanate. The results showed a stable state with the best physical properties when the prepolymer was composed of PPG/DMPA with hard segment=40%, NCO%=3.43%, [NCO]: [OH]=1.5: 1.0 in molar ratio, and was dispersed into water with 30% solid content. PU prepolymers also were synthesized with various molar ratio of PPG and DMPA. Upon higher molar ratio of DMPA, particle size of polyurethane dispersion(PUD) gradually decreased. PU-prepolymers prepared from the various blocking agents represented characteristic initial deblocking temperatures that depended on the blocking agents, and the beginning of deblocking occured within 30 mins on all the blocking agents used.

Influence of Bethanidine on the Renal Function of the Dog (개의 신장 기능에 미치는 Bethanidine의 영향)

  • 고석태
    • YAKHAK HOEJI
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    • v.22 no.3
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    • pp.138-147
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    • 1978
  • Bethanidine, which is known as a sympathetic blocking agent, was injected into the vein of a dog in an attempt to investigate the influence on renal funciton. Bethanidine resulted in an increased urine flow and glomerular filtration rate, and it produced an increase of urinary sodium and potassium excretion and a decrease of reabsorption rate of sodium and potassium in renal tubules, whereas renal plasma flow showed no significant changes. After pretreatment of phentolamine, a specific alpha adrenergic blocking agent, bethanidine did not significantly increase glomerular filtration rate and diuresis, significantly increased urinary sodium and potassium excretion although the magnitudes were reduced when compared with that of bethanidine alone. In conclusion, bethanidine-induced diuresis appears to be the result of an inhibited tubuler reabsorpting of electrolytes within the kidney through its sympathetic blockade of renal nerves and of an increased glomerular filtration rate, which was caused by the constriction of vas efferense in the glomeruli.

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Effect of Nifedipine on the Action of Drug Participating in Blood Pressure in Rabbits (가토에서 혈압에 관여하는 약물의 작용에 대한 니페디핀의 영향)

  • Ko, Suk-Tai;Jung, Chang-Ju;Kim, Hai-Suk
    • YAKHAK HOEJI
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    • v.36 no.4
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    • pp.379-389
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    • 1992
  • In order to investigate the effect of nifedipine, $Ca^{+2}$ channel antagoninst, on the action of some drugs participating in blood pressure, this experiment was peformed in rabbits. Nifedipine decreased the pressor actions of norepinephrine, angiotensin and carotid artery clamping, but did not affect the pressor actions of tyramine and depressor actions of acetylcholine and pilocarpine. Nifedipine inhibited the potentiated pressor action of norepinephrine and angiotensin, but did not influence the potentiated pressor action of tyramine in rabbits pretreated with chlorisondamine, ganglionic blocking agent. Nifedipine weakened the potentiated pressor action of norepinephrine, did not affect the pressor action of angiotensin and the potentiated pressor action of tyramine in rabbits pretreated with debrisoquine, sympathetic neuronal blocking agent.

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Differential Vasorelaxant Effects of KR-30075, a New Cyclic AMP-phosphodiesterase Inhibitor, on Guinea-pig Pulmonary, Bovine Coronary and Renal Arteries

  • Jung, Yee-Suk;Kwon, Kwang-Il;Zee, Ok-Pyo
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.136-141
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    • 1990
  • The vasorelaxant effects of KR-30075 in guinea-pig pulmonary, bovine coronary and renal arterial strips contracted by either$K^+$depolarization, phenylephrine, or prostaglandin $F_{2a}$($PGF_{2a}$) were evaluated. KR-30075 was more potent than imazodan as a vasorelaxant against $PGF_{2a}$-induced contractions in bovine coronary and renal arteries, whereas against$K^+$induced contractions KR-30075 was less potent than imazodan in guieapig pulmonary arteries and more potent in bovine coronary arteries. KR-30075 was more potent against contractions induced by phenylephrine or $PGF_{2a}$ than the contractions induced by $K^+$ This profile of activity for KR-30075 was similar to that of imazodan and dissimilar from the calcium entry blocking agent nifedipine. There was no vascular selectivity of KR-30075 between bovine coronary and renal arterial strip preparations. In conclusion, this study shows that KR-30075 represents the vasorelaxant effects on guinea-pig pulmonary, bovine coronary and renal arteries without specific vascular selectivity. The vasorelaxant profile of KR-30075, with different sources of vascular smooth muscle, is unlike that of calcium entry blocking agent and more similar to the profile of the agent that inhibit cyclic nucleotide phosphodiesterase.

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A Case of Neonatal Tetanus Cured with Neuromuscular Blocking Agent and Ventilatory Support (근이완제 및 인공 환기요법으로 치료한 신생아 파상풍 1례)

  • Lee, Hyeon Joo;Jeong, Ji Young;Jung, Sa Jun;Choi, Yong Mook;Bae, Chong Woo
    • Clinical and Experimental Pediatrics
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    • v.46 no.2
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    • pp.192-194
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    • 2003
  • A neonate born at 38 gestational weeks was admitted due to generalized tonic-clonic seizure and cyanosis. The neonate was born six days previously at home through normal delivery and the umbilical cord was cut using scissors sterilized in boiling water. The neonate weighed 3,180 g at admission. Physical examination revealed cyanosis, opisthotonus, trismus and reactive muscle spasms. Laboratory exam, brain sonogram and EEG showed no significant abnormal findings. Based on her history and physical examination, the neonate was diagnosed with tetanus and put in an incubator isolated in a quiet, dark room. Treatment with tetanus human immunoglobulin along with antibiotics (penicillin G) were started immediately, and mechanical ventilation, administration of neuromuscular blocking agent and muscle relaxant were also started off. The frequency of seizure episode decreased gradually, and on the 32nd hospital day, mechanical ventilatory support was stopped along with extubation two days later. Thereafter, the neonate was in continuous generalized hypertonic state and showed feeding difficulty, but there was gradual improvement. She was dismissed on the 49th hospital day and is currently under OPD follow-up, doing well with no special problems. Respiratory management is critical to neonatal tetanus. We report here a case of tetanus treated with inhibition of self-respiration, neuromuscular blocker and application of ventilator, and present this method as a useful direction for future treatment of neonatal tetanus.