• YAKHAK HOEJI
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• v.43 no.5
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• pp.659-664
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• 1999

To investigate the difference of contractile mechanism between KCI and phenylephrine-induced contraction, we observed effects of $Ca^{2+}$ antagonists and protein kinase inhibitors on aorta contraction of rats. Verapamil dose-dependently inhibited the contraction induced by KCI and phenylephrine, the inhibitory effect of verapamil was more potent in KCI-induced contraction than phenylephrine-induced contraction. Econazole and TMB-8 significantly inhibited CKI-induced contraction but did not inhibit phenylephrine-induced contraction. Staurosporine dose-dependently inhibited both KCI and phenylephrine-induced contraction. Genistein and calmodulin antagonists (W-7 and trifluoperazine) also inhibited both contraction in a dose dependent manner. However, the inhibitory effects of genistein and calmodulin antagonists were more potent in phenylephrine-induced contraction than KCI-induced contraction. These results suggest that involvements of $Ca^{2+}$ channel and protein kinase in rat aorta contraction were dependent on agonist causing aorta smooth muscle contraction.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.91-102
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• 1990

The effects of extracellular $Ca^{2+}$ and various $Ca^{2+}$ antagonists on endothelium-dependent relaxation to acetylcholine were studied in the isolated rabbit thoracic aorta in order to elucidate the control mechanism of endothelium derived relaxing factor (EDRF) release. Endothelium was removed from aortic strips by gentle rubbing with cotton ball. The effect of hemoglobin on basal tension was also observed with hemolysate. The results obtained were as follows: 1) Endothelium-dependent relaxation (EDR) to acetylcholine (ACh) showed biphasic pattern; the initial rapid relaxation phase and the late slow relaxation phase. 2) With the depletion of the extracellular $Ca^{2+}$, EDR was gradually suppressed, especially the late slow relaxation. 3) Verapamil, nifedipine, $Mn^{2+}$ and $Cd^{2+}$ had not any effect on EDR, while $La^{3+}$ and $Co^{2+}$ suppressed EDR completely. 4) The resting tension of the strips with rubbed endothelium was not altered by the addition of hemoglobin. That of the strips with intact endothelium, however, was enhanced and EDR to ACh was completely blocked From these results, we suggest that extracellular $Ca^{2+}$ is necessary for ACh-induced slow relaxation while $Ca^{2+}$ antagonists have not any effect on EDR.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.28-53
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• 1975

Experiments on the physiological root activity and its related characteristics of rice varieties were carried out in order to obtain some basic informations for the application of the results obtained to a rice breeding program. A significant positive correlation was found not only among the various characteristics related to conducting and ventilating systems which connects top and root of rice plant, but also between these characteristics and root activity. On the other hand, a significant difference in physiological root activity was recognized among different varieties and also between different groups of recognized 7 rice varieties differing in the their origin. It was also found that varieties with higher root activity (root activity indices) after ear formation stage tended to have more number of lower green leaves and consequently resulted in higher grain yield. Therefore, it may be possible to diagnose indirectly the root activity by examining the number of green leaves of the rice plant at later growth stage when breeders make selections of parent material for crossing or of hybrid lines in pedigree nurseries.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.246-259
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• 1995

This study aimed to investigate the mechanism of action of baclofen on the detrusor muscle isolated from rat. Rats (Sprague-Dawley) were sacrificed by decapitation and exsanguination. Horizontal muscle strips of $2mm{\times}15mm$ were prepared for isometric myography in isolated muscle chamber bubbled with 95% / 5%-$O_2$ / $CO_2$ at $37^{\circ}C$, and the pH was maintained at 7.4. Detrusor strips contracted responding to the electrical field stimulation (EFS) by 2 Hz, 20 msec, monophasic square wave of 60 VDC. The initial peak of EFS-Induced contraction was tended to be suppresed by ${\alpha},{\beta}$-methylene-adenosine 5'-triphosphate (mATP), a partial agonist of purinergic receptor, and baclofen, a $GABA_B$ receptor agonist (statistically nonsignificant). The late sustained contraction by EFS was suppressed significantly (p < 0.05) by additions of atropione, a cholinergic muscarinic receptor antagonist and baclofen. The adenosine 5'-triphosphate-induced contraction was completely abolished by mA TP but not by baclofen. In the presence of atropine, the subsequent addition of acetylcholine could not contract the muscle strips: but the addition of acetylcholine in the presence of baclofen evoked a contraction to a remarkable extent. These results suggest that in the condition of present study, the cholinergic innervation may play a more important role than the purinergic one, and baclofen suppresses the contractility of rat detrusor by the stimulation of the $GABA_B$ receptors to inhibit the release of neurotransmitter from the cholinergic nerve ending.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.16.1-16
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• 1982

The lips play an important role of passage of food as well as articulation and production of intelligible speech. So, the orbicularis oris muscle which composes the lip must act as a sphincter for the right structure. Also, the muscle conforms to the shape of the lips to make words. The surrounding cheek muscles antagonize and synergize to position the orbicularis oris sphincter. It is highly significant from the standpoint of reconstruction that the surrounding muscle can be separated from the orbicularis oris muscle without loss of sphincteric competence as long as the facial nerves and vessels remain intact. The authors performed the reconstruction of a lower lip defect due to human bite and achieved an excellent result from a functional and cosmetic aspect. This report with the literature is herewith submitted.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.115-120
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• 1989

Universal characteristics of ginseng replanting problems appeared to be decrease in root yields due to root rot and inhibition of root growth. Incitants of ginseng replanting problems have not been clearly elucidated, however, it appeared to be a complex phenomenon with several pathogenic soil microorganisms and environmental changes in the soil due to decomposition of ginseng debris such as rootlets and shoots. Decomposition of ginseng debris may cause direct or indirect damage to the root. The effect of conventional fungicide on the control of the problems has not been recognized. However, it has been suggested that treatment with soil fumigants may solve the problems. Meanwhile paddy-rice and ginseng rotation system appeared to be the best way of solving the problems so far.

• Journal of Life Science
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• v.20 no.4
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• pp.549-554
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• 2010

Increased external rotation and decreased internal rotation have been noted to occur progressively in the throwing shoulders of baseball pitchers. The purpose of this study was to provide descriptive data for terminal range eccentric antagonist/concentric agonist shoulder muscle strength in collegiate baseball pitchers with humeral head retroversion diagnosed through MRI. The dominant and non-dominant shoulders of 9 asymptomatic baseball pitchers were tested through a range of 20 degrees of external rotation to 90 degrees of internal rotation using the Biodex system 3 isokinetic dynamometer at speeds of $90^{\circ}/s$ and $180^{\circ}/s$. Differences between the dominant and non-dominant shoulders were assessed using the paired samples t-test. Total range of motion, measured at $90^{\circ}$ of glenohumeral abduction, was $180.1^{\circ}$ for dominant shoulders and $183.7^{\circ}$ for non-dominant shoulders. Humeral head retroversion measured $47.6{\pm}6.1^{\circ}$ in dominant and $37.8{\pm}5.3^{\circ}$ in non-dominant extremities. The mean internal rotator concentric contraction (IR-Con) showed a significant difference compared to $31.5{\pm}5.1$ (Nm) in dominant and $38.7{\pm}5.2$ (Nm) in non-dominant shoulders at $180^{\circ}/s$ (p<0.05). The mean external rotator eccentric contraction (ER-Ecc) showed a significant difference compared to $20.3{\pm}4.7$ (Nm) in dominant and $25.1{\pm}3.7$ (Nm) in non-dominant shoulders at $90^{\circ}/s$ (p<0.05). There is a pattern of increased external rotation and decreased internal rotation in the dominant extremity that significantly correlates with an increase in humeral retroversion.

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.67-74
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• 1996

Cholecystokinin octapeptide (CCK-8), acetylcholine (ACh) and KCl caused a dose dependent contraction in muscle cells enzymatically digested from cat gallbladder. Maximal contraction was obtained at concentration of $10^{-9}M$ for CCK-8, $10^{-5}M$ for ACh and 20mM for KCl. CCK-8 induced contraction was unaffected in calcium free physiological salt solution (PSS) and was completely blocked by strontium substitution for calcium (p<0.001). In contrast, KCl evoked contraction was blocked in calcium free PSS (p<0.01) but was unaffected by strontium replacement of calcium. The contraction elicited by ACh was only slightly reduced in calcium free PSS (p<0.05) and was unaltered by strontium. Muscle cells permeabilized with saponin contracted in response to inositol 1,4.5-trisphosphate $(IP_3)$ and CCK-8. The contraction was blocked by the calmodulin antagonist CGS 9343B (p<0.001), whereas heparin completely blocked the effect of $IP_3$ (p<0.001). The protein kinase C (PKC) antagonist H7 had no effect on either agonist. We conclude that CCK-8 induced gallbladder muscle contraction is mediated by $IP_3$ dependent intracellular calcium release from intracellular stores and a calmodulin dependent pathway; ACh may utilize both extracellular and intracellular calcium. KCl causes muscle contracrion through influx of extracellular calcium and a calmodulin independent machanism.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.318-325
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• 1999

Background: Anticholinesterase drug inhibits acetylcholinesterase(AChE), induce accumulation of acetylcholine(ACh) near cholinergic receptors and cholinergic stimulation. This experiment was performed to study the effects of anticholinesterase drugs on gastric motility and the effect of ethanol on anticholinesterase drug-induced motility change. Materials and Methods: After excision of stomach, $2{\times}10mm$ circular muscle strips were made, which were then fixed to the isolated muscle chamber. An isometric tension transducer was used to measure the contraction change of the gastric smooth muscle strips after drug addition. Results: Fenthion, an irreversible anticholinesterase drug, increased ACh induced contraction of gastric smooth muscle strips and PAM, a cholinesterase activator, antagonized this action. Physostigmine, a reversible anticholinesterase drug, also increased the ACh induced contraction. The gastric motility was decreased by PAM. Ethanol, which is known to induce smooth muscle relaxation, inhibited the increase of contraction by fenthion. Conclusion: These results indicate that irreversible and reversible anticholinesterase drugs increase gastric motility and antagonized by cholinesterase activating drugs. And when exposed to both ethanol and anticholinesterase drug, gastric motility was decreased by the smooth muscle relaxation effect by ethanol.

• The Korean Journal of Physiology
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• v.18 no.2
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• pp.139-150
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• 1984

Vanadate is a potent inhibitor of Na-K-ATPase. Ouabain, the another specific inhibitor of Na-K-ATPase, induces the contraction in cardiac muscle and smooth muscle. But, some investigators observed the discrepancies between vanadate and ouabain-induced contraction in cardiac muscle. The difference of vanadate and ouabain-induced contraction was investigated in the cat ileal smooth muscle. The following results were obtained. 1) Ouabain-induced contraction was biphasic, but vanadate-induced contraction had one peak. 2) Atropine inhibited ouabain·induced contraction, but did not inhibit vanadate-induced contraction. 3) Changes in external $Ca^{++}$concentration or $Ca^{++}$ antagonists had a greater influence on the contraction induced hy vanadate than by ouabain. 4) Removal of $Na^+$ from incubation medium and high $K^+$ abolished ouabain-induced contraction, but had no effect on vanadate-induced contraction. 5) Vanadate-induced contraction was potentiated in the presence of ouabain. 6) After 3 hrs incubation with vanadate, there was no change in intracellular $Na^+$ concentrations in contrast with ouabain. These results suggest that vanadate contracts ileal smooth muscle through the mechanism different from ouabain, and this is independent of the inhibition of Na-K-ATPase activity.