• Title/Summary/Keyword: High $K^{+}$-induced contraction

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Studies on the Efficacy of Combined Preparation of Crude Drugs(XXXI) -The Effect of Taeksa-tang on Diuresis, Serum Lipid, Isolated Ileum, Heart, Blood Vessel, Blood Pressure and Respiration- (생약(生藥) 복합제제(複合製劑)의 약효(藥效) 연구(硏究)(제31보)(第31報) -택사탕(澤瀉湯)이 이뇨(利尿), 고지혈증(高脂血症), 적출장관(摘出腸管), 적출심장(摘出心臟), 혈관(血管), 혈압(血壓) 및 호흡(呼吸)에 미치는 영향(影響)-)

  • Nam, Sang-Kyung;Lee, Dong-Suk;Kim, Nam-Jae;Lee, Kyung-Sup;Hong, Nam-Doo
    • Korean Journal of Pharmacognosy
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    • v.17 no.4
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    • pp.263-271
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    • 1986
  • In order to investigate experimentally the clinical effects of Taeksa-Tang that was prescribed to cure the severe dizziness, the water extract of Taeksa-Tang was experimented about the effects on the diuretic action, the serum lipid, the isolated ileum and heart, the blood vessel, the blood pressure and respiration. The results of this study were obtained as follows: The diuretic action was significantly shown in rabbits. The level of total cholesterol, triglyceride and phopholipid in serum of rabbits given high cholesterol diet were significantly decreased. The contraction of the isolated ileum of mice induced by acetylcholine chloride and barium chloride was remarkably inhibited. The vasodilating and hypotensive actions were noted in rabbits. Negative inotropic action on the isolated frog heart was recognized.

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Mechanisms Underlying the Inhibitory Effect of GS 283 in Various Smooth Muscles (GS 283의 평활근 억제 작용기전)

  • Kim, Si-Hwan;Lee, Young-Soo;Chong, Won-Seog;Chang, Ki-Churl
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.101-109
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    • 1994
  • Pharmacological characterization of GS 283, a tetrahydroisoquinoline derivative has been elucidated using rat thoracic aorta, guinea pig tenea coli and rabbit mesentery artery in vitro. GS 283 showed calcium antagonistic action in vascular smooth muscle, since high $K^+-induced$ contraction was concentration dependently inhibited. GS 283 also inhibited the contraction induced by ${\alpha}_1$ receptor activation. Vasodilating action of GS 283 was not modified by the propranolol, indicating that GS 283 has no ${\beta}$ receptor stimulatory action. Simultaneous measurement of intracellular calcium change and muscle tension indicated that the inhibitory effect of GS 283 was accompanied by the increase in tissue fluorescence. This increment was not due to fura 2 fluorescence but to endogenous pyridine nucleotide, suggesting that GS 283 has an effect to inhibit mitochondrial function. GS 283 had an inhibitory action on cyclic AMP and GMP-dependent phosphodiesterases from rat brain with Ki values of 2.5 and 6.7 mM. From these findings we concluded that GS 283 has multiple action such as the inhibition of cyclic nucleotide-dependent phosphodiesterases, blocking of calcium channel as well as inhibition of mitochondrial function which are responsible for vasodilatation.

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Poly(N-isopropylacrylamide-co-N-vinylpyrrolidone) as a Novel Implant Materials : Preparation and Thermo-Gelling Behavior

  • Nam, Irina;Bae, Jin-Woo;Jee, Kyoung-Soo;Lee, Joon-Woo;Park, Ki-Dong
    • Macromolecular Research
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    • v.10 no.2
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    • pp.115-121
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    • 2002
  • Synthesis of polymers with controlled thermosensitive properties was carried out by conventional radical copolymerization of N-isopropylacrylamide (NIPAAm) with N-vinylpyrrolidone (NVP) taken as a hydrophilic comonomer. Lower activity of NVP rather than NIPAAm was revealed by gravimetric and $^1$H NMR analysis. Thermosensitive properties of the copolymers were investigated. It was found that aqueous solutions of the copolymers undergo thermo-induced phase transition and become opaque, precipitate or gel with heating. After formation of the gels their significant contraction was observed at storage. Swelling degree and amount of expelled water were measured in dependence on the copolymer composition, temperature and ionic strength of environment medium and concentration of the solution. It was determined that in collapsed state gels exhibit quite high water content. According to physico-chemical properties of the copolymers observed they could be suitable for biomedical application as an injectable implant material.

Elastic Behavior of Zeolite Mesolite under Hydrostatic Pressure (제올라이트 메소라이트의 수압 하 탄성특성)

  • Lee, Yong-Jae;Lee, Yong-Moon;Seoung, Dong-Hoon;Jang, Young-Nam
    • Economic and Environmental Geology
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    • v.42 no.5
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    • pp.509-512
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    • 2009
  • Powder diffraction patterns of the zeolite mesolite ($Na_{5.33}Ca_{5.33}Al_{16}Si_{24}O_{80}{\cdot}21.33H_2O$), with a natrolite framework topology were measured as a function of pressure up to 5.0 GPa using a diamond-anvil cell and a $200{\mu}m$-focused monochromatic synchrotron X-ray. Under the hydrostatic conditions mediated by pore-penetrating alcohol and water mixture, the elastic behavior of mesolite is characterized by continuous volume expansion between ca. 0.5 and 1.5 GPa, which results from expansion in the ab-plane and contraction along the c-axis. Subsequent to this anomalous behavior, changes in the powder diffraction patterns suggest possible reentrant order-disorder transition. The ordered layers of sodium- and calcium-containing channels in a 1:2 ratio along the b-axis attribute to the $3b_{natrolite}$ cell below 1.5 GPa. When the volume expansion is completed above 1.5 GPa, such characteristic ordering reflections disappear and the $b_{natrolite}$ cell persists with marginal volume contraction up to ca. 2.5 GPa. Further increase in pressure leads to progressive volume contraction and appears to generate another set of superlattice reflections in the $3c_{natrolite}$ cell. This suggests that mesolite in the pressure-induced hydration state experiences order-disorder-order transition involving the motions of sodium and calcium cations either through cross-channel diffusion or within the respective channels.

Wind induced internal pressure overshoot in buildings with opening

  • Guha, T.K.;Sharma, R.N.;Richards, P.J.
    • Wind and Structures
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    • v.16 no.1
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    • pp.1-23
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    • 2013
  • The wind-induced transient response of internal pressure following the creation of a sudden dominant opening during the occurrence of high external pressure, in low-rise residential and industrial buildings was numerically investigated. The values of the ill-defined parameters namely the flow contraction coefficient, loss coefficient and the effective slug length were calibrated by matching the analytical response with the computational fluid dynamics predictions. The effect of a sudden i.e., "instantaneously created" windward opening in the Texas Technical University (TTU) test building envelope was studied for two different envelope flexibility-leakage combinations namely: (1) a quasi-statically flexible and non-porous envelope and (2) a quasi-statically flexible and porous envelope. The responses forced by creating the openings at different time leads/lags with respect to the occurrence of the peak external pressure showed that for cases where the openings are created in close temporal proximity to the peak pressure, the transient overshoot values of internal pressure could be higher than the peak values of internal pressure in the pre-sequent or subsequent resonant response. In addition, the influence of time taken for opening creation on the level of overshoot was also investigated for the TTU building for the two different envelope characteristics. Non-dimensional overshoot factors are presented for a variety of cavity volume-opening area combinations for (1) buildings with rigid/quasi-statically flexible non-porous envelope, and (2) buildings with rigid/quasi-statically flexible and porous envelope (representing most low rise residential and industrial buildings). While the factors appear slightly on the high side due to conservative assumptions made in the analysis, a careful consideration regarding the implication of the timing and magnitude of such overshoots during strong gusts, in relation to the steady state internal pressure response in cyclonic regions, is warranted.

Studies on the Mechanism of Contraction by Substance P in Rabbit Ileum (Substance P에 의한 가토 회장평활근의 수축기전에 대한 연구)

  • Jo, Se-Hun;Jung, Jin-Sup;Lee, Sang-Ho
    • The Korean Journal of Physiology
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    • v.18 no.2
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    • pp.151-162
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    • 1984
  • The mechanism of the contractile response of longitudial muscle of rabbit ileum to substance P (SP) has been investigated. The contractions in rabbit ileum under various conditions were recorded isometrically The following results were obtained. 1) The contractions by SP increased according to concentrations. SP·induced contraction was not sustained but faded rapidly at $10^{-7}M$. The response to the commutative addition of SP was decreased in comparison to the response to separate administration of each concentration . 2) The response to $10^{-8}M$ SP after 5 min application cf $10^{-7}M$ SP was increased with increasing the time interval between the administration of $10^{-7}$ and $10^{-8}M$ SP. 3) The treatment of rabbit ileum by $10^{-7}M$ SP for 5 min didn't decrease the response to $10^{-6}M$ acetylcholine. 4) $10^{-6}M$ atropine had no effect of the contractile response to $10^{-7}M$ SP. The response to $10^{-7}M$ SP was normal or subnormal in the presence of 3 mM tetraethylammonium(TEA). 5) 100k solution, $10^{-4}M$ ouabain, and Na-free solution inhibited the response to $10^{-8}M$ SP and 3 mM TEA completely, and to $10^{-7}M$ SP incompletely. 3 mM TEA induced a considerable contraction in K-free solution, but $10^{-8}M$ SP didn't induce the contraction. $10^{-6}M$ norepinephrine decreased the contractile responses to SP and TEA. 6) The contractile response to $10^{-7}M$ SP was dependent on the extracellular $Ca^{2+}$ concentrations to 1.8 mM. 7) The contractile response to $10^{-7}M$ SP remained 15% of the maximal response after bathing the ileum in a Ca-free solution for 2.5 min. 8) The responsiveness to SP was completely lost within 10 min of bathing in Ca-free solution, but was restored by the exposure to $Ca^{2+}$. The restorative effect of $Ca^{2+}$ depended on the concentration of $Ca^{2+}$, and on time for which the tissue exposed to this $Ca^{2+}$ concentration. These results suggest that there are two mechanisms of the action by which the low concentrations of substance P causes the contraction of intestinal smooth muscle: the reduction of K conductance and a mechanism dependent on the extracellular $Ca^{2+}$, and that high concentration of SP may elicit a contraction by releasing $Ca^{2+}$ from an intracellular store, which is not as sensitive to removal of extracellular $Ca^{2+}$ or as easily accessible to EGTA as the extracellular space of the muscle. The location of this store is not known; it may be associated with the internal side of the cell membrane.

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$Na^{+}/Ca^{2+}$ Exchange System in Atrial Trabeculae and Vascular Smooth Muscle of the Rabbit (토끼 심방근 및 혈관 평활근에서의 $Na^{+}/Ca^{2+}$ 교환기전에 관한 연구)

  • Kim, Hee-Ju;Moon, Hyung-Ro;Earm, Yung-E;Ho, Won-Kyung
    • The Korean Journal of Physiology
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    • v.22 no.1
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    • pp.13-29
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    • 1988
  • In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.

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Involvement of Peripheral Benzodiazepine Receptor on the Contractility of Canine Trachealis Muscle (기관근의 수축성에 대한 말초성 Benzodiazepine 수용체의 역할)

  • Rhyu, Han-Young;Choi, Hyung-Cheol;Choi, Eun-Mee;Sohn, Uy-Dong;Lee, Kwang-Youn;Kim, Won-Joon;Ha, Jeoung-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.6
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    • pp.769-774
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    • 1997
  • Non-neuronal high affinity binding sites for benzodiazepines have been found in many peripheral tissues including cardiac muscle and vascular smooth muscle, and have been designated as 'peripheral benzodiazepine receptor'. Benzodiazepines have been shown to induce relaxation of the ileal, vesical, and uterine smooth muscles. However, it is still unclear about possible involvement of peripheral benzodiazepine receptor on the contractility of trachealis muscle. This study was performed to investigate the role of the peripheral benzodiazepine receptor on the contractility of canine trachealis muscle. Canine trachealis muscle strips of 15 mm long were suspended in an isolated organ bath containing 1 ml of physiological salt solution maintained at $37^{\circ}C$, and aerated with $95%\;O_2/5%\;CO_2$. Isometric myography was performed, and the results of the experiments were as follows: Ro5-4684, FGIN-1-27 and clonazepam reduced a basal tone of isolated canine trachealis muscle strip concentration dependently, relaxant actions of RoS-4684 and FGIN-1-27 were antagonized by PK11195, a peripheral benzodiazepine receptor antagonist. Flumazenil, a central type antagonist, did not antagonize the relaxant action of Peripheral type agonists. Saturation binding assay of [3H]Ro5-4864 showed a high affinity$(Kd=5.33{\pm}1.27nM,\;Bmax=\;867.3{\pm}147.2\;fmol/mg\;protein)$ binding site on the canine trachealis muscle. Ro 5-4684 suppressed the bethanechol-, 5-hydroxyoyptamine- and histamine- induced contractions. Platelet activating factor (PAF) exerted strong and prolonged contraction in trachealis muscle strip. Strong tonic contraction by PAE was attenuated by Ro 5-4684, but not by WEB 2086, a PAF antagonist. Based on these results, it is concluded that the peripheral benzodiazepine receptor mediates the inhibitory regulation of contractilty of canine trachealis muscle.

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General Pharmacological Study of CJ-11828, an Amlodipine adipate

  • Choi, Jae-Mook;Lee, Sung-Hak;Kim, Il-Hwan;Park, Jie-Eun;Park, Choong-Sil;Youn, Yong-Sik;Lim, Dong-Kwon;Cho, Sung-Hwan;Chang, Jun-Hwan;Do, Sun-Hee;Kim, Eun-Joo;Kim, Young-Hoon
    • Biomolecules & Therapeutics
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    • v.12 no.2
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    • pp.114-121
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    • 2004
  • This study was undertaken to evaluate the general pharmacological properties of CJ-11828, an amlodipine adipate, in experimental animals and in vitro system. CJ-11828 had no effects on general behavior, motor coordination, writhing syndromes, pentetrazol-induced chemoshock and electric shock in mice at dose levels of 3,10, anti 30 mg/kg, po. But there were decrease of body temperature, prolongation of sleeping time, and inhibition of intestinal activity in mice treated with CJ-11828 at doses of 10 and 30 mg/kg, po. CJ-11828 decreased the blood pressure in coscuous fog at the dose level of 2mg/kg, po, but it was expected as a result of pharmacological activity of CJ-11828. Any effect on respiratory system was not observed in conscious rat at doses of 3,10, and 30 mg/kg, po. The slight decrease in spontaneous motor activity was observed in mice treated with CJ-11828 at high dose, 30 mg/kg. In vitro experiments, CJ-11828 had no effect on agonists-induced contraction of isolated guinea pig ileum at 0.1, 1, and 10 ${\mu}$M. Based on these results, it was concluded that CJ-11828 had no pharmacological effect ill these studies even up to the 36-fold anticipated clinical dose, 3 mg/kg.

A case of Tocolytics Induced Pulmonary Edema (Tocolytics에 의해 유발된 폐부종 1예)

  • Lee, Dae Jun;Kim, Chang In;Jee, Young Goo;Lee, Kye Young;Kim, Keun Yeol;Choi, Young Hi;Seo, Pil Weon
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.1
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    • pp.183-190
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    • 1997
  • Tocolytics are agents widely used in the treatment of premature labor to inhibit uterine contractions. Ritodrine is most commonly used tocolytic agent and acts by increasing intracellular cyclic adenosine monophosphate, which decreases the activity of myosin light-chain kinase, the rate-limiting enzyme in the signal network leading to contraction. Physiologic effects associated with the use of ritodrine are due to their effect on bera-l as well as beta-2 receptors. Some of maternal complications of therapy are rachycardia, hyperglycemia, hypokalemia, lactic acidosis, myocardial ischemia, and pulmonary edema. Tocolytics induced pulmonary edema is a serious complication that can lead to marternal death, although infrequent, The incidence varies from 0.5% to 5% of those receiving these agents. Predisposing factors include the concommitant use of corticosteroid, twin gestation, fluid overload (particularly with saline), and anemia. Several mechanisms have been postulated, but the pathogenesis is uncertain. It is suggested that both types of mechanism, hydrostatic and permeability induced, might be involved. The association of tocolytic therapy with pulmonary edema appears to be unique to the pregnant state, because this complication has never been reported in asthmatic patients exposed to high dosages. We report a case of tocolytic induced pulmonary edema developed in 24 hours after delivery.

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