• Title/Summary/Keyword: Tension Force

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Paleogene dyke swarms in the eastern Geoje Island, Korea: their absolute ages and tectonic implications (거제도 동부에 분포하는 고제3기 암맥군: 절대연대와 지구조적 의미)

  • Son, Moon;Kim, Jong-Sun;Hwang, Byoung-Hoon;Lee, In-Hyun;Kim, Jeong-Min;Song, Cheol-Woo;Kim, In-Soo
    • The Journal of the Petrological Society of Korea
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    • v.16 no.2 s.48
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    • pp.82-99
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    • 2007
  • The Paleogene dikes intruding into the late Cretaceous granodiorite are pervasively observed in the Irun-myeon, eastern Geoje Island. They are classified into three groups: NW-trending acidic dike swarm and WNW- (A-Group) and $NS{\sim}NNE-trending$ (B-Group) basic dike swarms. Based on their cross-cutting relationships, the earliest is the acidic dike group and fellowed by A- and B-Groups in succession. The acidic dikes seem to have intruded into tension gashes induced by the sinistral strike-slip faulting of the Yangsan fault system during the late $Cretaceous{\sim}early$ Paleogene. In terms of rock-type, orientation, age, and geochemistry, A-Group and B-Group are intimately correlated with the intermediate and basic dike swarms in the Gyeongju-Gampo area, respectively. These results significantly suggest that the corresponding dike swarms are genetically related. Based on the K-Ar and Ar-Ar age data, A- and B- Groups were intruded during $64{\sim}52\;Ma$ and $51{\sim}44\;Ma$, respectively. The result means that the direction of tensional stress in and around the SE Korean peninsula was changed abruptly from NNE-SSW to $EW{\sim}WNW-ESE$ at about 51 Ma. Considering the tectonic environments during the Paleogene, it is interpreted that A-Group was injected along the WNW-trending tensional fractures developed under an regional sinistral simple shear regime which was caused by the north-northwestward oblique subduction of the Pacific plate beneath the Eurasian plate. Meanwhile, the regional stress caused by the collision of India and Eurasia continents at about 55 Ma was likely propagated to the East Asia at about 51 Ma, and then the East Asia including the Korean peninsula was extruded eastwards as a trench-rollback and the dip of downgoing slab of the Pacific plate was abruptly steepened. As a result, the strong suction-force along the plate boundary produced a tensional stress field trending EW or WNW-ESE in and around the Korean peninsula, which resultantly induced B-Group to intrude passively into the study area.

Reactivity of Human Isolated Gastroepiploic Artery to Constrictor and Relaxant Agents (위대망동맥의 혈관 수축제 및 이완제에 대한 반응)

  • 이종태;이응배;박창률;김인겸;유완식;유영선
    • Journal of Chest Surgery
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    • v.31 no.9
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    • pp.884-892
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    • 1998
  • Background: The gastroepiploic artery is not only an alternative graft but also may be considered an important primary graft for coronary revascularization. However, the long-term patency of the gastroepiploic arterial graft is yet to be determined and the incidence of perioperative spasm and long-term patency of a coronary graft may be affected by the properties of the graft response to certain vasoactive substances. The reactivity of the gastroepiploic artery to vasoactive substances has not been studied extensively and the results of the studies are contradictory. Material and Method: This study was designed to test the reactivity of human gastroepiploic artery to four constrictors and four relaxants. The middle sections of the human gastroepiploic arteries were collected from the patients undergoing gastrectomy and the arterial rings with intact endothelium were suspended in organ baths for isometric tension recording. Result: Epinephrine, norepinephrine, and potassium chloride induced the maximum constriction to higher forces (7.0$\pm$1.1g, 6.6$\pm$0.9g, and 6.5$\pm$1.1g) than 5-hydroxytryptamine did (3.8$\pm$1.7g, p<0.05). Nitroprusside and histamine induced almost full relaxation in the gastroepiploic arteries preconstricted with norepinephrine. There was no significant difference between two relaxants regarding maximum relaxation force. Acetylcholine induced the maximum relaxation to weaker force when compared with nitroprusside and histamine (p<0.05), and isoproterenol was the weakest of the relaxants (p<0.05 compared with acetylcholine). Conclusion: The gastroepiploic artery has a strong capacity of endothelium-dependent relaxation which could have an important influence on long-term patency. The gastroepiploic artery exhibits a potent contractility to catecholamines and the enhanced contractility may facilitate vasospasm in the presence of high circulating levels of catecholamines. Nitroprusside, a potent relaxant in gastroepiploic artery, might be beneficial for the treatment of gastroepiploic arterial graft spasm. The gastroepiploic arterial graft with intact endothelium may respond weakly to beta-adrenoceptor agonist and 5-hydroxytryptamine.

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Experimental Studies on the Effects of Chunggeumtang (청금탕(淸金湯)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Kim, Eung-Sik;Lee, Si-Hyeong
    • The Journal of Internal Korean Medicine
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    • v.18 no.2
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    • pp.1-26
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    • 1997
  • Chunggeumtang has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Chunggeumtang on tracheal smooth muscle is not konwn. The purpose of the present study is to determine the effect of Chunggeumtang on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats (250g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from each rat and guinea pig was cut into equal swegments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force diplacement transducers under 0.5g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine and acetylcholine($10^{-7}{\sim}10^{-4}M$). Contractions evoked by His ($ED_{50}$) and Ach ($ED_{50}$) were inhibited significantly by Chunggeumtang. In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.1%after\;30{\mu}l/ml$ Chunggeumtang, and 49.4% (p<0.01) after $100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.7%\;after\;30{\mu}l/ml$ Chunggeumtang, and $54.2%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $30.6%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $53.0%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $24.1%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $55.3%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Propranolol and indomethacin($10^{-7}M$) slightly but significantly attenuated the inhibitory effects of Chunggeumtang. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 27.6% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.2% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by histamine contraction. Indomethacin, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 20.0% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 16.9% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.4% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 23.1% (p<0.05) in rat induced by histamine contraction. Methylene blue($10^{-7}M$) did not significantly alter the inhibitory effect of Chunggeumtang. Also, I could find the effects of Chunggeumtang and Chunggeumtanggamorphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Chunggeumtang can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects and the release of cyclooxygenase products.

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A Study on Sexual Function of Women with Coronary Artery Disease (관상동맥질환 여성의 성기능에 관한 연구)

  • Kim, Choon Shim;So, Hyang Sook
    • Korean Journal of Adult Nursing
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    • v.12 no.1
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    • pp.99-111
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    • 2000
  • The purpose of this study was to identify risk factors related to sexual function of women with coronary artery disease, and to determine the predictors of sexual function. The study design, a descriptive correlational study, was done through structural questionnaire and interview. A total of 50 subjects from C University Hospital at Kwang-ju city who have undergone coronary angiography at department of cardiology were observed and interviewed from Feb. 22, 1999 to March. 23, 1999. The number of affected vessels, the level of total serum cholesterol, and the ejection fraction of 2-D echo cardiography were analyzed to evaluate the severity of coronary artery disease. And also type A behavior pattern, health behavior, Brief Index of Sexual Functioning for Women (BISF-W) were measured. The data obtained were analyzed using percentage, mean and standard deviation, t-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression analysis via SPSS PC+. The results of this study were as follows: 1. The mean age of the subjects were 58.1 and 72.0% of those have been married over 30 years. Seventy two percentage were unemployed and monthly family income of 56.6% was less than 1,000,000 won (approximately $ 840). Eighty percent were in their postmenopausal state, and the frequency of sexual intercourse of 84.0% were two to three times per month. 2. The scores of type A behavior pattern were from 16 to 38(mean 24.94) and health behavior ranged from 21 to 43(mean 31.2). Abstinence from smoking, alcohol, and caffeine were best compliant factors and weight control and exercise were least abided ones. The result of 2D-ECHO EF showed that the half of the subjects were abnormal, and 24% had more than 240mg/dl of total serum cholesterol. The coronary angiography showed that 64% of the subjects had more than one affected vessels. 3. The predictors to explain the factor score of 'orgasm' were number of health examination, the pre- or post-menopausal state, protestant, number of coronary vessel affected, level of serum total cholesterol, and comorbid group of hypertension and diabetes, and it's total variance accounted for 52.4%. The predictors to explain the factor score of 'sexual activity' were comorbid group of hypertension and diabetes and type A behavior pattern, which accounted for 22.4% of total variance. The predictors to explain the factor score of 'sexual satisfaction' were type A behavior pattern, no religion, exercise, level of serum total cholesterol, and pre or post menopausal state, which accounted for 52.1%. The predictors to explain the factor score of 'sexual desire' were the period of marriage, type A behavior, employment or unemployment, and weight control, which accounted for 43.2%. The predictors to explain the factor score of 'external force of sexual functioning' were physical overload and exercise, which accounted for 41.1%. The predictors to explain the factor score of 'sexual activity' were family monthly income, catholics, and exercise, and which accounted for 35.4%. Above results lead us to some consensus that sexual function of women with coronary artery disease is related to various factors including vasogenic factors such as total serum cholesterol level, number of coronary vessel affected, an endocrinal factor such as menopausal state, and type A behavior pattern as a sociopshychological factor. And also health behaviors such as fitness care, overwork, weight control, and emotional tension are contributed to sexual function.

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Role of p-38 MAP Kinase in apoptosis of hypoxia-induced osteoblasts (저산소 상태로 인한 조골세포 고사사기전에서 p-38 MAP kinase의 역할에 관한 연구)

  • Yoon, Jeong-Hyeon;Jeong, Ae-Jin;Kang, Kyung-Hwa;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.33 no.3 s.98
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    • pp.169-183
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    • 2003
  • Tooth movement by orthodontic force effects great tissue changes within the periodontium, especially by shifting the blood flow in the pressure side and resulting in a hypoxic state of low oxygen tension. The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3El osteoblasts, the main cells in bone remodeling during orthodontic tooth movement. MC3T3El osteoblasts under hypoxic conditions ($2\%$ orygen) resulted in apoptosis in a time-dependent manner as estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, Western blot analysis was performed using anti-caspase-3 or -6 antibodies. The 10-kDa protein, corresponding to the active products of caspase-3, and the 10-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which the processing of the full length form of caspase-3 and -6 was evident. While a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, which was typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we observed that pre-treatment with SB203580, a selective p38 mitogen activated protein kinase inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203S80 suppressed caspase-3 and -6-like protease activity by hypoxia up to $50\%$. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAPK -JNK/SAPK or ERK- was either only modestly activated or not at all. These results suggest that p38 MAPK is involved in hypoxia-induced apoptosis in MC3T3El osteoblasts.

The Effect of Surface Defects on the Cyclic Fatigue Fracture of HEROShaper Ni-Ti rotary files in a Dynamic Model: A Fractographic Analysis (Fractographic 분석을 통한 HEROShaper 니켈티타늄 전동 파일의 피로파절에 미치는 표면결함의 역할)

  • Lee, Jung-Kyu;Kim, Eui-Sung;Kang, Myoung-Whai;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.32 no.2
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    • pp.130-137
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    • 2007
  • This in vitro study examined the effect of surface defects on cutting blades on the extent of the cyclic fatigue fracture of HEROShaper Ni-Ti rotary files using fractographic analysis of the fractured surfaces. A total of 45 HEROShaper (MicroMega) Ni-Ti rotary flies with a #30/.04 taper were divided into three groups of 15 each. Group 1 contained new HEROShapers without any surface defects. Group 2 contained HEROShapers with manufacturing defects such as metal rollover and machining marks. Croup 3 contained HEROShapers that had been clinically used for the canal preparation of 4-6 molars A fatigue-testing device was designed to allow cyclic tension and compressive stress on the tip of the instrument whilst maintaining similar conditions to those experienced in a clinic. The level of fatigue fracture time was measured using a computer connected the system. Statistical analysis was performed using a Tukey's test. Scanning electron microscopy (SEM) was used for fractographic analysis of the fractured surfaces. The fatigue fracture time between groups 1 and 2, and between groups 1 and 3 was significantly different (p<0.05) but there was no significant difference between groups 2 and 3 (p>0.05). A low magnification SEM views show brittle fracture as the main initial failure mode At higher magnification, the brittle fracture region showed clusters of fatigue striations and a large number of secondary cracks. These fractures typically led to a central region of catastrophic ductile failure. Qualitatively, the ductile fracture region was characterized by the formation of microvoids and dimpling. The fractured surfaces of the HEROShapers in groups 2 and 3 were always associated with pre-existing surface defects. Typically, the fractured surface in the brittle fracture region showed evidence of cleavage (transgranular) facets across the grains, as well as intergranular facets along the grain boundaries. These results show that surface defects on cutting blades of Ni-Ti rotary files might be the preferred sites for the origin of fatigue fracture under experimental conditions. Furthermore this work demonstrates the utility of fractography in evaluating the failure of Ni-Ti rotary flies.

Periodontal Tissue Response Following Different Types of Fixed Retainers in Young Adult Dogs (수종의 고정성 보정장치에 따른 유성견의 치주조직 반응)

  • Jo, Myung-Hun;Yoon, Young-Jooh;Kim, Kwang-Won
    • The korean journal of orthodontics
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    • v.31 no.1 s.84
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    • pp.85-95
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    • 2001
  • The purpose of this study was to evaluate the material for fixed type retainer, allowing physiologic tooth movement. and proper remodeling or periodontal tissue during retention period. The Present study was Performed to observe the histologic changes of periodontal tissue after application of different types of fixed type retainer after orthodontic tooth movement in young adult dogs. For this study, 4 young adult dogs were used as a experimental animal and experimental group was divided into three groups : experimental group 1 contained right side maxillayy third incisors and canines, experimental group 2 contained contralateral teeth of same animals, and control group contained mandibular premolars. And each dogs were applied the 4 different types of fixed type retainer to experimental group 1. The experimental teeth were ligated on the Sentalloy closed coil $spring^{\circledR}$(Tomy Co., Japan) from maxillary third incisors and canines and applied orthodontic force at initial 200gm-forced during 1 week. All the experimental animals were sacrificed on the 3rd week after the orthodontic teeth movement and then the specimens were taken, fixed in formalin, embeded in parafin, sectioned $6-8{\mu}m$ in thickness and stained with Hematoxylin-Eosin staining, and Masson's trichrome staining method. Examined under the light microscopy The following results were observed. 1. There were observed that decreased infiltration of giant tells in pressure side and increased the new bone forming in tension side on the specimen of 6-stranded 0.0195' $Respond^{\circledR}$(G&H Co., U.S.A.) group. Periodontal ligament fibers were much compressed or elongated in 3-stranded 0.018', 0.020' $Dentaflex^{\circledR}$(Dentarum Co., Germany), and Superbond $C&B^{\circledR}$(Sun Medical Co., Japan) groups. 2. In experimental group 1, necrotic bone inside the alveolar bone of pressure side, forming of the sharpey's fiber in osteoid tissue, and remodeling of the periodontal ligament were observed in all animals. 3. In experimental group 2, it was observed that the amount of bone resorption was equal or decreased in pressure side, and increased new bone forming and significantly decreased infiltration of giant cell than the experimental group 1. By this results, it considered that 6-stranded $Respond^{\circledR}$(G&H Co., U.S.A.) wire was the most useful material allowing early periodontal tissue remodeling.

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Identification of Compound Heterozygous Alleles in a Patient with Autosomal Recessive Limb-Girdle Muscular Dystrophy (상염색체 열성 지대형 근이영양증 환자로부터 TTN 유전자의 복합 이형접합성 대립유전자의 분리)

  • Choi, Hee Ji;Lee, Soo Bin;Kwon, Hye Mi;Choi, Byung-Ok;Chung, Ki Wha
    • Journal of Life Science
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    • v.31 no.10
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    • pp.913-921
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    • 2021
  • Limb-girdle muscular dystrophy (LGMD) which is characterized by progressive muscle weakening of the hip and shoulder shows both dominant and recessive inheritances with many pathogenic genes including TTN. This study performed to identify genetic causes of a male patient with late onset (45 years old) autosomal recessive LGMD and atrial flutter. By application of the whole exome sequencing, we identified bi-allelic variants of TTN gene in the patient. One allele had a single missense variant of [c.24124G>T (p.V8042F)], while the other allele consisted of three missense variants of [c.29222G>C (p.R9741P) + c.67490A>G (p.H22497R) + c.75376C>T (p.R25126C)]. The p.V8042F allele was transmitted from his mother, while the other haplotype allele was putatively transmitted from his father. His two unaffected sons had only the p.R9741P. These variants have been not reported or rarely reported in the public human genome databases (1,000 Genome, gnomAD, and KRGDB). Most variants were located in the highly conserved immunoglobulin or fibronectin domains and were predicted to be pathogenic by the in silico analyses. The TTN giant protein plays a key role in muscle assembly, force transmission at the Z-line, and maintenance of resting tension in the I-band. In conclusion, we think that these bi-allelic compound heterozygous mutations may play a role as the genetic causes of the LGMD phenotype.

A Study of Endothelium-dependent Pulmonary Arterial Relaxation and the Role of Nitric oxide on Acute Hypoxic Pulmonary Vasoconstriction in Rats (흰쥐 폐동맥의 내피세포의존성 혈관이완과 급성 저산소성 폐동맥수축에서 산화질소의 역할)

  • In, Kwang-Ho;Lee, Jin-Goo;Cho, Jae-Youn;Shim, Jae-Jung;Kang, Kyung-Ho;Yoo, Se-Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.3
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    • pp.231-238
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    • 1994
  • Backgroud: Since the demonstration of the fact that vascular relaxation by acetylcholine(Ach) results from the release of relaxing factor from the endothelium, the identity and physiology of this endothelium-derived relaxing factor(EDRF) has been the target for many researches. EDRF has been identified as nitric oxide(NO). With the recent evidences that EDRF is an important mediator of vascular tone, there have been increasing interests in defining the role of the EDRF as a potential mediator of hypoxic pulmonary vasoconstriction. But the role of EDRF in modulating the pulmonary circulation is not compeletely clarified. To investigate the endothelium-dependent pulmonary vasodilation and the role of EDRF during hypoxic pulmonary vasoconstriction, we studied the effects of $N^G$-monomethyl-L-arginine(L-NMMA) and L-arginine on the precontracted pulmonary arterial rings of the rat in normoxia and hypoxia. Mothods: The pulmonary arteries of male Sprague Dawley(300~350g) were dissected free of surrounding tissue, and cut into rings. Rings were mounted over fine rigid wires, in organ chambers filled with 20ml of Krebs solution bubbled with 95 percent oxygen and 5 percent carbon dioxide and maintained at $37^{\circ}C$. Changes in isometric tension were recorded with a force transducer(FT.03 Grass, Quincy, USA) Results: 1) Precontraction of rat pulmonry artery with intact endothelium by phenylephrine(PE, $10^{-6}M$) was relaxed completely by acetylcholine(Ach, $10^{-9}-10^{-5}M$) and sodium nitroprusside(SN, $10^{-9}-10^{-5}M$), but relaxing response by Ach in rat pulmonary artery with denuded endothelium was significantly decreased. 2) L-NMMA($10^{-4}M$) pretreatment inhibited Ach($10^{-9}-10^{-5}M$)-induced relaxation, but L-NMMA ($10^{-4}M$) had no effect on relaxation induced by SN($10^{-9}-10^{-5}M$). 3) Pretreatment of the L-arginine($10^{-4}M$) significantly reversed the inhibition of the Ach ($10^{-9}-10^{-5}M$)-induced relaxation caused by L-NMMA($10^{-4}M$) 4) Pulmonary arterial contraction by PE($10^{-6}M$) was stronger in hypoxia than normoxia but relaxing response by Ach($10^{-9}-10^{-5}M$) was decreased, 5) With pretreatment of L-arginine($10^{-4}M$), pulmonary arterial relaxation by Ach($10^{-9}-10^{-5}M$) in hypoxia was reversed to the level of relaxation in normoxia. Conclusion: It is concluded that rat pulmonary arterial relaxation by Ach is dependent on the intact endothelium and is largely mediated by NO. Acute hypoxic pulmonary vasoconstriction is related to the suppression on NO formation in the vascular endothelium.

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