• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.184-184
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• 1994

개와 흰쥐의 장간막동맥 절편의 긴장도와 $^{86}$Rb$^{+}$ 유출에 대한 cromakalim의 효과를 관찰하고 이를 ATP를 고갈시킨 조직에서 얻어지는 결과와 비교하였다. Cromakalim은 개와 흰쥐의 장간막 동맥을 이완시켰으며, 이러한 이완은 glibenclamide에 의하여 상경적으로 억제되었다. Glibenclamide는 phenylephriue에 의한 개와 흰쥐의 장간막 동맥 수축을 증가시킨다든지 혹은 cromakalim에 의한 억제성 반응을 역전시켰다. 개와 흰쥐 장간막 등맥의 $^{55}$Rb$^{+}$ 유출 실험에서 tromakalim (10 $\mu$M) 투여시 ATP를 고갈시킨 흰쥐의 장간막 동맥에서 현저히 증가하였다. HPLC를 이용하여 adenine nucleotide를 분석하였다. Adenine nucleotide의 HPLC 분석시에 혈관의 내피세포를 제거하였고 0.2 M ammonium phosphate (pH 5.5)를 용출용매로 이용하여 분석하였다.

• 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.

• The Korean Journal of Pharmacology
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• v.26 no.2
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• pp.145-152
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• 1990

We recently reported a development of an experimental system which can identify the release of a superoxide-dependent vasorelaxant factor from endothelial cells using a two-bath system. In the present work, we further exploited the above system and observed whether the superoxide-dependent relaxing factor(s), released from the porcine coronary artery (PCA) endothelium, was similar in relaxation to those obtained from cat thoracic aortic endothelium and cultured endothelial cells of bovine aorta. However, there was observed a novel difference among the former one and the latter two relaxing factors; the release of relaxing factor from PCA endothelium can be inhibited either by catalase or by superoxide dismutase (SOD), whereas the latter two can be inhibited only by SOD. It was further attempted to characterize the synthetic mechanisms of the relaxing factors: (1) They were readily inhibited by various lipoxygenase inhibitors (gossypol, nordihydroguaiaretic acid, AA 861, and eicosatetraynoic acid). (2) They were not inhibited by cyclooxygenase inhibitor (indomethacin) and by cytochrome P-450 monooxygenease inhibitors (proadifen and cimetidine). Thus, it is likely that these relaxing factors, although obtained from different species, show common functional roles of arteriolar relaxation. It is suggested that they are related to pathophysiological involvement of various tissue ischemia-reperfusion injuries.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.125-133
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• 1991

In the isolated rabbit mesenteric artery denuded of endothelium, we characterized the identity of the A23187-induced endothelium-dependent relaxing factor (EDRF) released from the endothelium of rabbit aorta, which is distinct from that of acetylcholine-induced relaxing factor. In the normal physiological salt solution (PSS), the dose-response curves to A23187 and acetylcholine were overlapped together. Their effects were also inhibited by methylene blue. Upon application of hypoxanthine and xanthine oxidase into the bath, the phenylephrine-induced precontraction was transiently increased followed by the sustained relaxation. During the burst of hypoxanthine-xanthine oxidase reaction, the $Ca^{++}$ ionophore, A23187 but not acetylcholine was able to cause an immediate relaxation. However, A23187-induced relaxation was not manifested when precontracted by 50 mM $K^+-PSS$. Nevertheless, in the presence of superoxide dismutase, A23187 could produce an immediate relaxation without accompanying the transient contraction as acetylcholine did during the hypoxanthine-xanthine oxidase reaction. On the other hand, acetylcholine-induced relaxation was more sensitively inhibited by phorbol 12-myristate 13-acetate (PMA) than A23187-induced relaxation. Endothelium-independent relaxation to sodium nitroprusside was not affected by PMA. Based on these results it is suggested that both A23187 and acetylcholine cause the methylene blue-inhibitable endothelium-dependent relaxation, and in addition, A23187 may release a stable EDRF which is resistant to superoxide anion and PMA.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.411-417
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• 2000

This paper describes the analysis of the oscillometric method based on the shape of arterial pressure and proposal of a new algorithm for estimating the blood pressure by computer simulation. In the first step, the arterial pressure model which is able to control the shape of arterial pressure was designed and then we simulated the oscillometric model using both the existing exponential model showing the static arterial pressure-volume relation and the designed arterial pressure model. By analyzing the correlation of characteristic ratio based on the shape of arterial pressure, we could find that the characteristic ratio was not the only standard parameter for estimating systolic and diastolic pressure. We were able to estimate the shape of arterial pressure by computing the correlation of arterial pressure shape with oscillation shape. Finally, we proposed an algorithm which is able to estimate systolic and diastolic pressure according to pressure(Pp) table constructed from the relation of maximum amplitude of oscillation and arterial pressure shape. We tested 60 arterial pressure waveforms having various arterial pressure shape and pulse. As a results, the absolute deviation average values of the estimation of systolic, diastolic and mean pressure were 1.62%, 2.40% and 2.20%, respectively. In conclusions, the proposed algorithm showed the possibility of usefullness in estimating the blood pressure.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.85-85
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• 1993

뇌동맥계는 일과성 저혈압에 반응하여 혈관확장이 야기되고, 혈압 상승시에는 혈관수축이 일어남으로서 뇌혈류가 일정하게 조절된다. 이러한 자가조절은 뇌손상 등의 병적 상태에서 야기된다. 연구의 목적은 \circled1 Cromakalim, CGRP(calcitonin-gene related peptide), 및 substance P에 의하여 뇌연막동맥의 직경이 어떻게 변동하는가를 관찰하고 \circled2 이들 신경성 peptide의 작용에 대하여 $K^{＋}$ 통로 개방 봉쇄제인 glibenclamide의 전처치 효과를 검색하고 \circled3 Capsaicin 전처치가 뇌혈류 자가조절에 어떻게 영향을 미치는가를 검색하였다. 그 결과는 다음과 같다. 1. 뇌혈류 자가조절은 대퇴동맥을 통한 사혈에 의하여 혈압하강을 일으킬 때 뇌연막 동맥은 이완하였고, reservoir내의 혈액을 체내로 주입함로서 혈압반전을 일으켰을 때는 혈관 수축이 일어났다. 2. 연막동맥은 glibenclamide (1~3$\mu$M)의 관류에 의하여는 영향을 받아니하였다. 3. 혈압변동에 따른 혈관직경의 변화를 회기직선으로 분석하였다. Glibenclamide 1과 3$\mu$M의 전처치 관류에 의하여 혈압하강에 따른 혈관 이완경사도와 혈압반전에 따른 혈관수축 경사도가 대조군에 비하여 현저히 약화되었다. 4. Cromakalim (0.1-30$\mu$M)의 각 농도를 대뇌표면에 관류시 연막동맥의 기초직경은 약물농도에 의존하여 증가되었고, 이는 glibenclamide (1$\mu$M) 전처치 관류에 의하여 억제되었다. 5. CGRP (0.1~100 nM)와 substance P (0.1~10nM)도 용량에 의존하여 혈관이완을 일으켰다. 전자는 glibenclamide (1$\mu$M) 전처치 관류에 의하여 억제되었으나 후자는 영향을 받지 아니하였다. 6. Capsaicin(50 nmol: intracisternally) 주사에 의하여 뇌혈류자가조절의 변동이 초래되었다. 이상의 결과들을 종합하면 CGRP가 혈압변동에 의하여 반사적으로 유리되고, 이는 glibenclamide-sensitive $K^{＋}$ 통로에 작용하는 것으로 시사된다.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.27-37
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• 1995

In anesthetized rats, we examined the possibility that endothelium-derived relaxing factor (EDRF) or nitric oxide (NO) released in response to cholinergic mechanism may contribute to the reflex autoregulation of cerebral blood flow. Suffusion with mock cerebrospinal fluid (CSF), containing acetylcholine (ACh, $10^{-9}{\sim}10^{-6}M$) evoked concentration-dependent vasodilatation of the resting pial artery (mean, $19.3{\pm}1.7{\mu}m$, n=36), which was significantly inhibited not only by $N{\omega}$-nitro-L-arginine (L-NNA, $10^{-5}M$) but also by methylene blue ($10^{-6}M$) and oxyhemoglobin ($10^{-6}M$). The muscarinic receptors in the endothelium of pial artery implicated in the release of EDRF were considered to be $M_1\;and\;M_3$ subtypes. When suffused with mock CSF containing L-arginine it caused a transient vasodilatation, which was strongly inhibited by LY 83583 ($10^{-5}M$), but not by L-NNA ($10^{-5}M$). Additionally, both ACh- and L-arginine-induced vasodilation were significantly inhibited by glibenclamide, a specific ATP-sensitive $K^+$ channel blocker. On the other hand, changes in pial arterial diameter were plotted as a function of changes in systemic arterial blood pressure. The slopes of regression lines for vasodilation and vasoconstriction were not affected by pretreatment with $10^{-5}M$ L-NNA, but significantly reduced by $3{\times}10^{-6}M$ glibenclamide. Thus it is suggested that the reflex vasodilation of rat pial arteries in response to a transient hypotension is not mediated by EDRF (NO).

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.745-752
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• 2005

Purpose : Adolescent obesity is known to be associated with complications such as hypertension, coronary artery disease and insulin resistance. We measured the common carotid artery by ultrasound as a predictor of atherosclerosis, and investigated the relationship between carotid artery parameters and serum cytokines in obese adolescents. Methods : Twenty-nine obese adolescents(16-17 years old, obesity index>130 percent) and twentyseven normal controls were included. Obesity index and body mass index were calculated from their height and weight. Skin fold thickness was measured at the triceps, and fat mass and fat distribution by bioelectrical impedence analysis. Blood pressure was measured at resting state and serum lipid, insulin, and homocysteine levels after a 12-hour fasting period. Intimal wall thickness, systolic and diastolic diameters of the common carotid artery were measured by ultrasound, and compliance and distensibility calculated by equation. Results : Systolic and diastolic diameters of the carotid artery significantly correlated with arm circumference, body mass index, fat distribution and fat mass. The higher systolic blood pressure was, the larger systolic and diastolic diameter. The higher diastolic blood pressure was, the larger carotid intimal thickness. Insulin levels had positive correlations with systolic, diastolic diameters and serum homocysteine level with intimal thickness. Conclusion : The carotid artery diameter significantly increased with the degree of obesity and blood pressure. The carotid intimal wall thickness significantly correlated with diastolic blood pressure. Measurement of carotid artery thickness, insulin and homocysteine levels might be useful to predict the development of coronary artery disease.

• The Korean Journal of Pharmacology
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• v.28 no.1
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• pp.75-79
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• 1992

Higenamine, which is one of active component of Aconiti tuber, has been known to have positive inotropic effect through adrenergic beta-receptor. The effect of higenamine on norepinepharine or potassium induced contraction of pulmonary aorta in rabbit were studies. 1. The contraction of aortic strips induced by norepinephrine was suppressec by pre-or post-treatment of higenamine dose dependently and those effects of higenamine were prevented by propranolol. The $pA_2$ value of higenamine against propranolol calculated as 8.25. 2. The effect of higenamine was not affected by phentolamine. 3. Isoprotrenol has shown 10 times stronger vasodiatory effect on norepinephrine induced cntracture than that of higenamine but high concentration $(3.3{\times}10^{-6}\;M)$ of isoproterenol produce intrinsic activity. 4. Vasodilatory effect of higenamine or isoproterenol was not observed in potassium induced contacture of pulmonary aortic strips. These results strongly suggest that higenamine dilated the pulmonary vascular smooth muscle through stimulation of adrenergic beta-receptor.

• The Korean Journal of Pharmacology
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• v.31 no.3
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• pp.285-290
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• 1995

This study was undertaken to define the varying responses of vascular smooth muscle to different wavelengths of ultraviolet radiation and to relate them to the changes in cyclic GMP contents. The ring preparations of rat thoracic aorta with intact or removed endothelium were irradiated with the ultraviolet or visible light (UVR) of wavelengths in step of 10 nm between 250 and 500 nm from xenon lamp of a spectrofluorometer, and the changes in vascular tension were recorded. For cyclic GMP assay, the preparations, pretreated with phenylephrine as in the tension experinents, were frozen after irradiation and homogenated in trichloroacetic acid. The supernatant was extracted with ether and the cyclic GMP contents were measured with radioimmunoassay. In the endothelium-intact preparations, biphasic responses, vasoconstriction (UVR-contraction) followed by vasodilatation (UVR-dilatation), were observed. The maximal UVR-contraction was observed at 320 nm, while the maximal vasodilatation was elicited at 420 nm. In the endothelium-removed rings, however, only vasodilatation was observed, with the maximal vasodilatation taking place at 370 nm. The cyclic GMP contents were not affected by the Irradiation with 320 nm for 30 sec or 1 min in the endothelium-intact preparations, while it was significantly increased by 380 and 420 nm. In the endothelium-removed preparations, UVR of 370 nm markedly increased the cyclic GMP contents. The present study indicates that the increase in cyclic GMP is closely related to vasodilatation induced by UVR of 420 nm in the endothelium-intact or 370 nm in the denuded preparations, whereas it is not involved in the vasoconstriction induced by UVR of 320 nm in the intact rings, and the mechanism leading to UVR-contraction remains to be clarified. These observations suggest that nitric oxide-cyclic GMP system is closely related to the UVR-dilatation in rat aortic preparation, while it is not involved in the UVR contraction.