• Archives of Pharmacal Research
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• 제26권8호
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• pp.612-619
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• 2003

In this study, we evaluated the effects of oral administration of DA-8159, a selective phosphodiesterase-5 inhibitor, on the development of pulmonary hypertension (PH) induced by monocrotaline (MCT). Rats were administered either MCT (60 mg/kg) or saline. MCT-treated rats were divided into three groups and received orally administered vehicle, or 1 mg/kg or 5 mg/kg of DA-8159, twice a day for twenty-one days. The MCT group demonstrated increased right ventricular weights, medial wall thickening in the pulmonary arteries, myocardial fibrosis and the level of plasma cyclic guanosine monophosphate (cGMP), along with decreased body weight gains. However, DA-8159 markedly and dose-dependently reduced the development of right ventricular hypertrophy and medial wall thickening. DA-8159 also amplified the increase in plasma cGMP level and significantly increased the level of lung cGMP, compared with the MCT group. Although the body weight gain was still lower from the saline-treated control group, DA-8159 demonstrated a significant increase in body weight gains, in both 1 mg/kg and 5 mg/kg groups, when compared with the MCT group. In myocardial morphology, MCT-induced myocardial fibrosis was markedly prevented by DA-8159. These results suggest that DA-8159 may be a useful oral treatment option for PH.

• Clinical and Experimental Pediatrics
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• 제52권6호
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• pp.689-695
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• 2009

목 적 : 폐동맥 고혈압은 지속적인 폐혈관 저항의 증가로 우심실 부전에 이르게 되는 질병 상태를 일컫는다. 폐동맥 고혈압의 기전으로 폐혈관의 내피세포로부터 endothelin 분비가 증가되어 세포 증식 촉진, 세포 자멸 억제, 혈관 수축, 염증 반응을 통해 폐혈관의 재형성에 관여함이 제시되었다. Bosentan은 endothelin 수용체에 결합하여 효과를 차단시키는 약물로 개발되었다. 이에 monocrotaline으로 폐고혈압을 유발시킨 동물에서 non-selective endothelin receptor blocker인 bosentan을 투여하였을 때 폐동맥 고혈압 발생에 미치는 효과를 알아보고자 본 연구를 시행하였다. 방 법 : 체중 250 g 내외의 4주령 가량 된 자성 Sprague-Dawley 백서를 대조군, monocrotaline군, bosentan군으로 나누었다. Monocrotaline군과 bosentan군에는 monocrotaline 수용액 60 mg/kg를 배부에 1회 피하 주사하고 대조군에는 동량의 생리식염수를 주사하였다. Bosentan군에는 bosentan ($20mg{\cdot}kg^{-1}{\cdot}day^{-1}$)을 monocrotaline 투여 직후부터 매일 1일 2회 위관 영양법으로 투여하였다. 7일, 14일, 28일에 각각 동물을 희생시켜 심장의 무게를 우심실벽, 좌심실벽, 심실간벽으로 나누어 기관의 무게를 측정하고 조직 검사를 위해 양측 폐를 포르말린 수용액에 고정하였다. 결 과 : 7일, 14일, 28일째 평균 체중은 대조군에 비해 monocrotaline군과 bosentan군이 유의하게 적었다. 우심실/(좌심실＋심실간벽)의 무게 비율은 28일째 monocrotaline군($0.71{\pm}0.10mg/g$)에 비해 bosentan군($0.49{\pm}0.09mg/g$)이 유의하게 적었다(P<0.05). 폐세동맥의 조직형태학적 분석 결과 실험 28일째 monocrotaline투여에 의해 유발된 중막 비후 소견이 bosentan 투여에 의해 현저하게 저하된 것으로 나타났다(monocrotaline군 $49.94{\pm}10.06$ vs bosentan군 $47.09{\pm}10.48$, P<0.05). 또한 호흡성 세기관지 이하의 폐포에 분포하는 근육성 폐세동맥의 숫자도 monocrotaline 투여에 의해 증가되었으나 14, 28일째 bosentan군에서는 현저하게 적은 것으로 나타났다. 결 론 : Monocrotaline으로 유도한 백서의 폐고혈압에서 bosentan을 투여하고 초기 경과를 관찰한 결과, 2주째부터 우심실 비대가 억제되었고 4주 이내 사망률도 낮아 endothelin receptor에 대한 길항 작용의 효과로 해석될 수 있겠다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.641-647
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• 2016

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by vascular remodeling of pulmonary arteries (PAs) and increased vascular resistance in the lung. Monocrotaline (MCT), a toxic alkaloid, is widely used for developing rat models of PAH caused by injury to pulmonary endothelial cells; however, characteristics of vascular functions in MCT-induced PAH vary and are not fully understood. Here, we investigated hypoxic pulmonary vasoconstriction (HPV) responses and effects of various vasoconstrictors with isolated/perfused lungs of MCT-induced PAH (PAH-MCT) rats. Using hematoxylin and eosin staining, we confirmed vascular remodeling (i.e., medial thickening of PA) and right ventricle hypertrophy in PAH-MCT rats. The basal pulmonary arterial pressure (PAP) and PAP increase by a raised flow rate (40 mL/min) were higher in the PAH-MCT than in the control rats. In addition, both high $K^+$ (40 mM KCl)- and angiotensin II-induced PAP increases were higher in the PAH-MCT than in the control rats. Surprisingly, application of a nitric oxide synthase inhibitor, L-$N^G$-Nitroarginine methyl ester (L-NAME), induced a marked PAP increase in the PAH-MCT rats, suggesting that endothelial functions were recovered in the three-week PAH-MCT rats. In addition, the medial thickening of the PA was similar to that in chronic hypoxia-induced PAH (PAH-CH) rats. However, the HPV response (i.e., PAP increased by acute hypoxia) was not affected in the MCT rats, whereas HPV disappeared in the PAH-CH rats. These results showed that vascular contractility and HPV remain robust in the MCT-induced PAH rat model with vascular remodeling.

• Korean Circulation Journal
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• 제48권12호
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• pp.1135-1144
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• 2018

Background and Objectives: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). Methods: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. Results: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. Conclusions: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.249.1-249.1
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• 2002

This study was carried out to demonstrate the effects of oral administration of DA-8159. a selective phosphodiesterase 5 inhibitor. on development of pulmonary hypertension induced by monocrotaline (MCT). MCT-treated rats(60mg/kg) were divided into three groups and orally administered vehicle, 1 mg/kg or 5 mg/kgg of DA-8159 twice a day for 3 weeks. Increased right ventricular weights, medial wall thickening in pulmonary arteries. myocardial fibrosis, decrease of plasma cyclic guanosine monophosphate (cGMP) level and body weight gains were shown in MCT group. (omitted)

• Applied Microscopy
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• 제37권1호
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• pp.1-10
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• 2007

MCT 유발 간독성 흰쥐에 해독정기탕의 투여가 시간경과에 따른 간세포의 항산화효소 활성변화, 세포사멸 억제와 간의 조직병리학적 변화에 미치는 영향을 조사하였다. 대조군은 생리식염수를 투여하였으며, 실험군은 해독정기탕 0.9 mL을 6시간, 24시간 간격으로 경구투여 하였다. 간기능의 지표가 되는 GPT 효소 활성은 해독정기탕 투여한 6시간 군에서 대조군에 비해 감소하였다. 항산화 효소인 SOD, catalase 활성도의 변화에 있어서도 6시간 실험군에서 변화를 보여주었고 24시간 경과 후에는 대조군과 실험군의 통계적인 유의성은 없었다. 간의 조직병리학적 관찰 결과 대조군은 심한 출혈, 간세포의 팽창과 중심정맥 내피세포의 파괴 현상이 뚜렷이 나타났으며, 24시간 경과 후에는 핵질의 응축과 사립체의 팽대현상이 현저하였다. 반면 해독정기탕 투여후 6시간 실험군은 일부 세포괴사와 세포사멸 보호 및 회복효과를 관찰하였다. 이상의 연구 결과로 보아 해독정기탕은 투여시간에 따라 간 기능회복 및 해독, 간세포의 항산화 활성변화, 세포사멸의 보호효과 약물로서 작용함이 사료된다.

• Clinical and Experimental Pediatrics
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• 제59권6호
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• pp.262-270
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• 2016

Purpose: Pulmonary arterial hypertension (PAH) leads to right ventricular failure (RVF) as well as an increase in pulmonary vascular resistance. Our purpose was to study the effect of sildenafil on right ventricular remodeling in a rat model of monocrotaline (MCT)-induced RVF. Methods: The rats were distributed randomly into 3 groups. The control (C) group, the monocrotaline (M) group (MCT 60 mg/kg) and the sildenafil (S) group (MCT 60 mg/kg+ sildenafil 30 mg/kg/day for 28 days). Masson Trichrome staining was used for heart tissues. Western blot analysis and immunohistochemical staining were performed. Results: The mean right ventricular pressure (RVP) was significantly lower in the S group at weeks 1, 2, and 4. The number of intra-acinar arteries and the medial wall thickness of the pulmonary arterioles significantly lessened in the S group at week 4. The collagen content also decreased in heart tissues in the S group at week 4. Protein expression levels of B-cell lymphoma-2 (Bcl-2)-associated X, caspase-3, Bcl-2, interleukin (IL)-6, matrix metalloproteinase (MMP)-2, endothelial nitric oxide synthase (eNOS), endothelin (ET)-1 and ET receptor A (ERA) in lung tissues greatly decreased in the S group at week 4 according to immunohistochemical staining. According to Western blotting, protein expression levels of troponin I, brain natriuretic peptide, caspase-3, Bcl-2, tumor necrosis factor-${\alpha}$, IL-6, MMP-2, eNOS, ET-1, and ERA in heart tissues greatly diminished in the S group at week 4. Conclusion: Sildenafil alleviated right ventricular hypertrophy and mean RVP. These data suggest that sildenafil improves right ventricular function.

• Clinical and Experimental Pediatrics
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• 제61권9호
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• pp.271-278
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• 2018

Purpose: Abnormal potassium channels expression affects vessel function, including vascular tone and proliferation rate. Diverse potassium channels, including voltage-gated potassium (Kv) channels, are involved in pathological changes of pulmonary arterial hypertension (PAH). Since the role of the Kv1.7 channel in PAH has not been previously studied, we investigated whether Kv1.7 channel expression changes in the lung tissue of a monocrotaline (MCT)-induced PAH rat model and whether this change is influenced by the endothelin (ET)-1 and reactive oxygen species (ROS) pathways. Methods: Rats were separated into 2 groups: the control (C) group and the MCT (M) group (60 mg/kg MCT). A hemodynamic study was performed by catheterization into the external jugular vein to estimate the right ventricular pressure (RVP), and pathological changes in the lung tissue were investigated. Changes in protein and mRNA levels were confirmed by western blot and polymerase chain reaction analysis, respectively. Results: MCT caused increased RVP, medial wall thickening of the pulmonary arterioles, and increased expression level of ET-1, ET receptor A, and NADPH oxidase (NOX) 4 proteins. Decreased Kv1.7 channel expression was detected in the lung tissue. Inward-rectifier channel 6.1 expression in the lung tissue also increased. We confirmed that ET-1 increased NOX4 level and decreased glutathione peroxidase-1 level in pulmonary artery smooth muscle cells (PASMCs). ET-1 increased ROS level in PASMCs. Conclusion: Decreased Kv1.7 channel expression might be caused by the ET-1 and ROS pathways and contributes to MCT-induced PAH.

• Journal of Ginseng Research
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• 제40권3호
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• pp.285-291
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• 2016

Background: Ginsenosides have been shown to exert beneficial pharmacological effects on the central nervous, cardiovascular, and endocrine systems. We sought to determine whether total ginsenosides (TG) inhibit monocrotaline (MCT)-induced pulmonary hypertension and to elucidate the underlying mechanism. Methods: MCT-intoxicated rats were treated with gradient doses of TG, with or without $N^G$-nitro-$\small{L}$-arginine methyl ester. The levels of molecules involving the regulation of nitric oxide and mitogen-activated protein kinase pathways were determined. Results: TG ameliorated MCT-induced pulmonary hypertension in a dose-dependent manner, as assessed by the right ventricular systolic pressure, the right ventricular hypertrophy index, and pulmonary arterial remodeling. Furthermore, TG increased the levels of pulmonary nitric oxide, endothelial nitric oxide synthase, and cyclic guanosine monophosphate. Lastly, TG increased mitogen-activated protein kinase phosphatase-1 expression and promoted the dephosphorylation of extracellular signal-regulated protein kinases 1/2, p38 mitogen-activated protein kinase, and c-Jun NH2-terminal kinase 1/2. Conclusion: TG attenuates MCT-induced pulmonary hypertension, which may involve in part the regulation of nitric oxide and mitogen-activated protein kinase pathways.

• The Korean Journal of Physiology and Pharmacology
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• 제22권4호
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• pp.447-456
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• 2018

Angiotensin-(1-9) [Ang-(1-9)], generated from Ang I by Ang II converting enzyme 2, has been reported to have protective effects on cardiac and vascular remodeling. However, there is no report about the effect of Ang-(1-9) on pulmonary hypertension. The aim of the present study is to investigate whether Ang-(1-9) improves pulmonary vascular remodeling in monocrotaline (MCT)-induced pulmonary hypertensive rats. Sprague-Dawley rats received Ang-(1-9) ($576{\mu}g/kg/day$) or saline via osmotic mini-pumps for 3 weeks. Three days after implantation of osmotic mini-pumps, 50 mg/kg MCT or vehicle were subcutaneously injected. MCT caused increases in right ventricular weight and systolic pressure, which were reduced by co-administration of Ang-(1-9). Ang-(1-9) also attenuated endothelial damage and medial hypertrophy of pulmonary arterioles as well as pulmonary fibrosis induced by MCT. The protective effects of Ang-(1-9) against pulmonary hypertension were inhibited by Ang type 2 receptor ($AT_2R$) blocker, but not by Mas receptor blocker. Additionally, the levels of LDH and inflammatory cytokines, such as $TNF-{\alpha}$, MCP-1, $IL-1{\beta}$, and IL-6, in plasma were lower in Ang-(1-9) co-treated MCT group than in vehicle-treated MCT group. Changes in expressions of apoptosis-related proteins such as Bax, Bcl2, Caspase-3 and -9 in the lung tissue of MCT rats were attenuated by the treatment with Ang-(1-9). These results indicate that Ang-(1-9) improves MCT-induced pulmonary hypertension by decreasing apoptosis and inflammatory reaction via $AT_2R$.