• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.441-447
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• 2016

Despite the complex vascular effects of dexmedetomidine (DEX), its actions on human pulmonary resistance arteries remain unknown. The present study tested the hypothesis that DEX inhibits vascular tension in human pulmonary arteries through the endothelial nitric oxide synthase (eNOS) mediated production of nitric oxide (NO). Pulmonary artery segments were obtained from 62 patients who underwent lung resection. The direct effects of DEX on human pulmonary artery tension and changes in vascular tension were determined by isometric force measurements recorded on a myograph. Arterial contractions caused by increasing concentrations of serotonin with DEX in the presence or absence of L-NAME (endothelial nitric oxide synthase inhibitor), yohimbine (${\alpha}_2$-adrenoceptor antagonist) and indomethacin (cyclooxygenase inhibitor) as antagonists were also measured. DEX had no effect on endothelium-intact pulmonary arteries, whereas at concentrations of $10^{-8}{\sim}10^{-6}mol/L$, it elicited contractions in endothelium-denuded pulmonary arteries. DEX (0.3, 1, or $3{\times}10^{-9}mmol/L$) inhibited serotonin-induced contraction in arteries with intact endothelium in a dose-dependent manner. L-NAME and yohimbine abolished DEX-induced inhibition, whereas indomethacin had no effect. No inhibitory effect was observed in endothelium-denuded pulmonary arteries. DEX-induced inhibition of vasoconstriction in human pulmonary arteries is mediated by NO production induced by the activation of endothelial ${\alpha}_2$-adrenoceptor and nitric oxide synthase.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.591-598
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• 2017

Propofol is known to cause vasorelaxation of several systemic vascular beds. However, its effect on the pulmonary vasculature remains controversial. In the present study, we investigated the effects of propofol on human pulmonary arteries obtained from patients who had undergone surgery. Arterial rings were mounted in a Multi-Myograph system for measurement of isometric forces. U46619 was used to induce sustained contraction of the intrapulmonary arteries, and propofol was then applied (in increments from $10-300{\mu}m$). Arteries denuded of endothelium, preincubated or not with indomethacin, were used to investigate the effects of propofol on isolated arteries. Propofol exhibited a bifunctional effect on isolated human pulmonary arteries contracted by U46619, evoking constriction at low concentrations ($10-100{\mu}m$) followed by secondary relaxation (at $100-300{\mu}m$). The extent of constriction induced by propofol was higher in an endothelium-denuded group than in an endothelium-intact group. Preincubation with indomethacin abolished constriction and potentiated relaxation. The maximal relaxation was greater in the endothelium-intact than the endothelium-denuded group. Propofol also suppressed $CaCl_2$-induced constriction in the 60 mM $K^+$-containing $Ca^{2+}$-free solution in a dose-dependent manner. Fluorescent imaging of $Ca^{2+}$ using fluo-4 showed that a 10 min incubation with propofol ($10-300{\mu}m$) inhibited the $Ca^{2+}$ influx into human pulmonary arterial smooth muscle cells induced by a 60 mM $K^+$-containing $Ca^{2+}$-free solution. In conclusion, propofol-induced arterial constriction appears to involve prostaglandin production by cyclooxygenase in pulmonary artery smooth muscle cells and the relaxation depends in part on endothelial function, principally on the inhibition of calcium influx through L-type voltage-operated calcium channels.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.57-75
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• 1966

This study was conducted to observe the condition of the ramifications of the bronchus and pulmonary blood vascular system by injecting the vinylite into the bronchial tree and pulmonary blood vessels in 100 normal adult dogs. The results obtained were summarized as follows: 1. Lungs of dog were composed of the same pulmonary territories as in lungs of human. 2. Cardiac lobe corresponding to R.medio-bassalis of human lungs was well developed and situated as a independent cardiac lobe, in ventral side of right lung. 3. Bronchial tree were in the patterns of axial divergency and blood vascular systems were (in general) branched along the bronchial tree, arteries lying near the bronchial tree but veins apart from it. 4. Among the branching patterns of bronchus pulmonary artery and pulmonary vein in each lobe, the type presented most frequently were noted, which were designated basic type by the author. 5. Pulmonary blood vessels were not always branched in accordance with bronchial tree, diverged inmore complex patterns, especially in venous vascular system. 6. Ramus anterior (lobe apicalis) was always observed in all casting specimen. 7. There was a case of peculiar variation patterns of the ramification in the bronchi directing into the left apical and cardiac lobe, arose respectivelly, at independent origin of bifurcation in the left bronchial stem, and a case of peculiar variation pattern of the artery entering left apical lobe and cardiac lobe, had a same origin of the bifurcation at rami pulmonary artery, and then divided respectivelly into the rami medi artery and rami left apical lobe artery. 8. In the classification based on the patterns of bronchial and blood vasculor divergencys, there were a lot of significant combination cases in their patterns.

• Journal of Chest Surgery
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• v.20 no.1
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• pp.1-12
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• 1987

Respiratory care with oxygen inhalation is often a necessity to maintain life, and it is one of the important therapeutic adjuncts in respiratory disease and in intensive care after surgery. However, it has been reported that oxygen toxicity occurs after prolonged exposure to 100% 0, [Smith, 1899; Kistler et al. 1967; Schaffner et al. 1967; Rowland and Newman, 1969. Subjective symptoms of oxygen toxicity include tracheal irritation, frequent cough, some burning sensation in the trachea, tachypnea, severe dyspnea, etc. [Welch, 1963; Fisher et al, 1968; Milier et al, 1970; Clark and Lambertsen, 1971; Sackner, 1975]. Pathologic findings are atelectasis, injuries to the pulmonary capillaries and hemorrhage in the alveoli in gross specimens. There can be inflammation, proliferation of fibrin, thickening of alveolar membranes, degeneration of collagen fibers and interstitial edema in the microscopic findings. [Penrod, 1956; Cedergren, 1959; Bean, 1965; Schaffner, 1967]. Dubois and colleagues [1961] found that the amount of pulmonary surfactant was decreased in oxygen toxicity and atelectasis followed by the decreased pulmonary surfactant. Many authors reported that vital capacity, inspiratory force, pulmonary compliance, pulmonary capillary blood flow and pulmonary elasticity were deceased and arteriovenous shunting increased. [Comroe et al, 1945; Fuson et al, 1965; Kistler et al, 1966; Knowles and Blenner-hassett, 1967; Barber et al, 1978]. Many human volunteers were examined after prolonged exposure in a high oxygenated chamber and there were a few reports on animals with oxygen toxicity, subjects including rabbits. Gas partial pressures of alveoli and arteries were measured in rabbits exposed to 100% $O_2$ and the alveolar-arterial gas gradients were analyzed, which is the basis for the study of oxygen toxicity. These rabbits were divided into two groups; rabbits under natural respiration, and second group under artificial respiration with a respirator. The alveolar $PO_2$ [$P]AO_2$] and $PCO_2$ [$PACO_2$], and the arterial $PO_2$ [$PaO_2$] were measured under varying $O_2$ pressures; 15% $O_2$, 21% $O_2$ and 100% $O_2$.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.822-827
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• 1996

Ross procedure is an ideal operative modality for diseased aortic valve especially in children, but homogrart for right ventricular outflow tract(RVOT) reconstruction is not easily available in Korea. We tried to perform REV procedure for RVOT reconstruction in 10 young piglets(15.3 $\pm$ 1.3 kg) In an attempt to e clude the use of homograft in Ross operation. 3 of them survived after operation and raised till adult pig(about 70 kg), then examined their pulmonary arteries and hearts. Without any stenotic residues in the great arteries, we only found the deformed monocusp patch with severe calcification, which deprived the adequate valve function, but kept the pig growing normally We are sure that this operative modality (REV + Ross procedure) could be extendedly applied to the diseased human aortic valve, but we need to develope the anti-calcification method for the heterograft patch.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.79-83
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• 2001

Dirofilaria immitis parasitizes mainly in the pulmonary arteries and in the heart of dogs and cats. The parasite is also of public health importance, because it often elicits nodules in the pulmonary parenchyma and in the subcutaneous tissues, or sometimes parasitize itself in the eyes of human. In this study, we investigated the prevalence of heartworm infection among 165 dogs on three breeding farms in the vicinity of Seoul, Korea. Of 165 dogs, 83 dogs (50.3%) were infected with the parasite, as revealed by an antigen-detecting test using the peripheral blood. Of these, 23 dogs (20.2%) contained microfilaria using the peripheral blood, which are potential source of transmission to uninfected animals and to humans in the endemic area. None of infected dogs showed any clinical signs associated with the disease. Since the three farms were located in the vicinity of Seoul, the unexpectedly high infection rate could imply that the possibility of exposure of both animals and humans living in the metropolitan Seoul area to the parasite is higher than in the other area of Korea.