Estudo Morfofuncional do Átrio Esquerdo Isolado de um Modelo Experimental de Hipertensão Pulmonar em Ratos / Isolated Left Atrium Morphofunctional Study of an Experimental Pulmonary Hypertension Model in Rats

Resumo Fundamento A alta incidência de arritmias atriais na hipertensão pulmonar (HP) pode estar associada a um prognóstico ruim, e o átrio esquerdo (AE) pode desempenhar um papel neste quadro. Um achado importante nos estudos de HP é que a remodelação do AE é subestimada. Objetivo Este estudo investigou a morfologia e a função mecânica do AE, bem como a suscetibilidade ao desenvolvimento de arritmias em um modelo de HP induzida por monocrotalina (HP-MCT). Métodos Ratos Wistar com 4 semanas de idade receberam 50 mg/kg de MCT. Foram realizadas análises eletrocardiográficas e histológicas para avaliar o estabelecimento do modelo de HP-MCT. O tecido foi montado em banho de órgão isolado para caracterizar a função mecânica do AE. Resultados Em comparação com o grupo controle, o modelo de HP-MCT apresentou hipertrofia do AE e alterações da atividade elétrica cardíaca, conforme evidenciadas pelo aumento da duração da onda P, PR e intervalo QT. Não foi observada alteração no inotropismo do AE isolado de ratos com HP-MCT; no entanto, o tempo para atingir a contração máxima foi atrasado. Finalmente, não observamos diferença na suscetibilidade à arritmia no AE dos ratos com HP-MCT após o protocolo de estimulação intermitente. Conclusão A remodelação morfofuncional do AE não levou ao aumento da suscetibilidade à arritmia ex vivo após a aplicação do protocolo de estimulação intermitente.

Abstract Background The high incidence of atrial arrhythmias in pulmonary hypertension (PH) might be associated with poor prognosis, and the left atrium (LA) may play a role in this. An important finding in PH studies is that LA remodeling is underestimated. Objective This study investigated LA morphology and mechanical function, as well as the susceptibility to develop arrhythmias in a monocrotaline-induced PH (MCT-PH) model. Methods Wistar rats aged 4 weeks received 50 mg/kg of MCT. Electrocardiography and histology analysis were performed to evaluate the establishment of the MCT-PH model. The tissue was mounted in an isolated organ bath to characterize the LA mechanical function Results Compared with the control group (CTRL), the MCT-PH model presented LA hypertrophy and changes in cardiac electrical activity, as evidenced by increased P wave duration, PR and QT interval in MCT-PH rats. In LA isolated from MCT-PH rats, no alteration in inotropism was observed; however, the time to peak contraction was delayed in the experimental MCT-PH group. Finally, there was no difference in arrhythmia susceptibility of LA from MCT-PH animals after the burst pacing protocol. Conclusion The morphofunctional remodeling of the LA did not lead to increased susceptibility to ex vivo arrhythmia after application of the burst pacing protocol.

Tanshinone IIA alleviates monocrotaline-induced pulmonary hypertension in rats through the PI3K/Akt-eNOS signaling pathway / 南方医科大学学报

OBJECTIVE@#To explore the therapeutic mechanism of tanshinone IIA in the treatment of pulmonary arterial hypertension (PAH) in rats.@*METHODS@#A total of 100 male SD rats were randomized into 5 groups (n=20), and except for those in the control group with saline injection, all the rats were injected with monocrotaline (MCT) on the back of the neck to establish models of pulmonary hypertension. Two weeks after the injection, the rat models received intraperitoneal injections of tanshinone IIA (10 mg/kg), phosphatidylinositol 3 kinase (PI3K) inhibitor (1 mg/kg), both tanshinone IIA and PI3K inhibitor, or saline (model group) on a daily basis. After 2 weeks of treatment, HE staining and α-SMA immunofluorescence staining were used to evaluate the morphology of the pulmonary vessels of the rats. The phosphorylation levels of PI3K, protein kinase B (PKB/Akt) and endothelial nitric oxide synthase (eNOS) in the lung tissue were determined with Western blotting; the levels of eNOS and NO were measured using enzyme-linked immunosorbent assay (ELISA).@*RESULTS@#The results of HE staining and α-SMA immunofluorescence staining showed that tanshinone IIA effectively inhibited MCT-induced pulmonary artery intimamedia thickening and muscularization of the pulmonary arterioles (P < 0.01). The results of Western blotting showed that treatment with tanshinone IIA significantly increased the phosphorylation levels of PI3K, Akt and eNOS proteins in the lung tissue of PAH rats; ELISA results showed that the levels of eNOS and NO were significantly decreased in the rat models after tanshinone IIA treatment (P < 0.01).@*CONCLUSION@#Treatment with tanshinone IIA can improve MCT-induced pulmonary hypertension in rats through the PI3K/Akt-eNOS signaling pathway.

Pathological Mechanism of HSOS in Rats Induced by Different Doses of Monocrotaline / 中国实验方剂学杂志

ObjectiveTo observe the pathological changes of hepatic sinusoidal obstruction syndrome （HSOS） induced by different doses of monocrotaline （MCT） in rats， investigate the dose and duration of modeling， and elucidate the mechanism. MethodA total of 72 male SD rats were randomized into normal group （n=12）， and low-， medium-， and high-dose MCT groups （n=20 per group， 80，120，160 mg·kg-1， respecctively）. In the model groups， different doses of MCT were intragastrically administered to induce the HSOS in rats. After 48 h and 120 h separately， rats in each group were sacrificed and sampling was performed. The survival rate of rats in each group was calculated， and the body weight， liver weight， and and serum liver function indexes of the rats were examined. The histopathological changes of the liver were observed based on scanning electron microscopy， hematoxylin and eosin （HE） staining， and Sirius red （SR） staining. Glutathione S-transferase （GST） activity， total superoxide dismutase （T-SOD） activity， and malondialdehyde （MDA） content of liver tissue homogenate were measured with microplate method. The expression of liver tissue-related indexes was detected by real-time polymerase chain reaction （PCR）， Western blot， and immunohistochemistry. ResultThe activity of serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） in MCT groups rose with the increase in MCT dose （P<0.05， P<0.01） compared with that in the normal group. With the extension of modeling time， the activity of serum ALT and AST in the low-dose group decreased （P<0.01）， while the activity of them in the medium-dose and high-dose groups increased （P<0.01）. HE staining showed that hepatocyte necrosis， inflammatory cell infiltration， and erythrocyte accumulation in MCT groups. Electron microscopy demonstrated that fenestrae of liver sinusoidal endothelial cells widened and the sieve plates disappeared. Morever， the injury was worsened with the increase in MCT dose. In addition， the expression of CD44 in MCT groups was significantly reduced compared with that in the normal group （P<0.05， P<0.01）. SR staining showed that no positive staining was found in model groups after 48 h， while collagen deposition in portal areas and liver sinusoids could be seen in model groups after 120 h. MCT groups showed increase in MDA content and GST activity and decrease in T-SOD activity compared with the normal group， particularly the medium-dose and high-dose groups （P<0.01）， and the changes were dose-dependent after 120 h （P<0.01）. The protein expression of CD68 （pro-inflammatory macrophage marker） was raised with the increase in dosage， which was consistent with the results of immunohistochemistry （P<0.01）， while CD163 （anti-inflammatory macrophage marker） protein and mRNA expression was significantly decreased with the increase in dosage （P<0.01）. Western blot results showed that the expression of phosphorylated nuclear factor-κB/nuclear factor-κB （p-NF-κB/NF-κB） and phosphorylated protein kinase B/protein kinase B （p-Akt/t-Akt） was significantly increased in medium-dose and high-dose MCT groups （P<0.05，P<0.01）. The protein expression of α-smooth muscle actin （α-SMA） in liver tissues in MCT groups was significantly increased over time and with the increase in dose， and the mRNA expression of α-SMA， collagen type I α1 （Col1a1）， and collagen type Ⅳ α1 （Col4a1） showed the same trend （P<0.05， P<0.01）. The results of TUNEL staining showed that apoptotic cells were increased with the rise of MCT dose， while B-cell lymphoma-2（Bcl-2） /Bcl-2 associated X protein （Bax） was remarkably decreased （P<0.01）. ConclusionHSOS in rats induced by intragastric administration of different doses of MCT was aggravated with the increase of dosage. In the low-dose （80 mg·kg-1） MCT group， the liver healed spontaneously over time. However， liver damage caused by MCT of 120 mg·kg-1 and 160 mg·kg-1 aggravated over time， and even fibrosis and death occurred. The pathological mechanism of MCT-induced HSOS in rats may be that MCT triggered intense oxidative stress in liver tissue， thus activated pro-inflammatory macrophages to secrete large amounts of inflammatory factors， and further activated the NF-κB/Akt signalling pathway， leading to severe cell damage and death.

Efeitos do Óleo de Copaíba em Marcadores Periféricos de Estresse Oxidativo em um Modelo de Cor Pulmonale em Ratos / Effects of Copaiba Oil in Peripheral Markers of Oxidative Stress in a Model of Cor Pulmonale in Rats

Resumo Fundamento Até o presente momento, os efeitos sistêmicos do óleo de copaíba jamais foram documentados no Cor pulmonale induzido por monocrotalina. Objetivos Investigar os efeitos do óleo de copaíba nos marcadores periféricos de stress oxidativo em ratos com Cor pulmonale. Métodos Ratos Wistar machos (170±20g, n=7/grupo) foram divididos em quatro grupos: controle (CO), monocrotalina (MCT), óleo de copaíba (O), e monocrotalina + óleo de copaíba (MCT-O). Foi administrada a MCT (60 mg/kg i.p.) e, depois de uma semana, foi iniciado o tratamento com óleo de copaíba (400 mg/kg/day-gavagem-14 dias). Foi realizado o ecocardiograma e, depois disso, foi coletado sangue do tronco para a realização de avaliações de stress oxidativo. Análise estatística: ANOVA de duas vias com teste Student-Newman-Keuls post hoc. P-valores <0,05 foram considerados significativos. Resultados O óleo de copaíba reduziu a resistência vascular pulmonar e a hipertrofia do ventrículo direito (VD) hipertrofia (Índice de Fulton (mg/mg)): MCT-O= 0,39±0,03; MCT= 0,49±0,01), e função sistólica melhorada (fração de encurtamento do VD, %) no grupo MCT-O (17,8±8,2) em comparação com o grupo de MCT (9,4±3,1; p<0,05). Além disso, no grupo MCT-O, espécies reativas do oxigênio e os níveis de carbonila foram reduzidos, e os parâmetros antioxidantes aumentaram no sangue periférico (p <0,05). Conclusões Os resultados deste estudo sugerem que o óleo de copaíba tem um efeito antioxidante sistêmico interessante, que se reflete na melhoria da função e na morfometria do VD nesse modelo de Cor pulmonale . A atenuação do Cor pulmonale promovida pelo óleo de copaíba coincidiu com uma redução no stress oxidativo sistêmico.

Abstract Background To date, copaiba oil's systemic effects have never documented in Cor pulmonale induced by monocrotaline. Objectives To investigate copaiba oil's effects in peripheral markers of oxidative stress in rats with Cor pulmonale. Methods Male Wistar rats (170±20g, n=7/group) were divided into four groups: control (CO), monocrotaline (MCT), copaiba oil (O), and monocrotaline+copaiba oil (MCT-O). MCT (60 mg/kg i.p.) was administered, and after one week, treatment with copaiba oil (400 mg/kg/day-gavage-14 days) was begun. Echocardiography was performed and, later, trunk blood collection was performed for oxidative stress evaluations. Statistical analysis: two-way ANOVA with Student-Newman-Keuls post-hoc test. P values<0.05 were considered significant. Results Copaiba oil reduced pulmonary vascular resistance and right ventricle (RV) hypertrophy (Fulton index (mg/mg): MCT-O=0.39±0.03; MCT=0.49±0.01), and improved RV systolic function (RV shortening fraction, %) in the MCT-O group (17.8±8.2) as compared to the MCT group (9.4±3.1; p<0.05). Moreover, in the MCT-O group, reactive oxygen species and carbonyl levels were reduced, and antioxidant parameters were increased in the peripheral blood (p<0.05). Conclusions: Our results suggest that copaiba oil has an interesting systemic antioxidant effect, which is reflected in the improvements in function and RV morphometry in this Cor pulmonale model. Cor pulmonale attenuation promoted by copaiba oil coincided with a reduction in systemic oxidative stress.

Lesões Plexiformes em Modelo Experimental de Hipertensão Arterial Pulmonar Induzida por Monocrotalina / Plexiform Lesions in an Experimental Model of Monocrotalin-Induced Pulmonary Arterial Hypertension

Resumo Fundamento O modelo de hipertensão arterial pulmonar induzida por monocrotalina (MCT) é um dos mais reproduzidos atualmente, apresentando como limitação a ausência de lesões plexiformes, manifestações típicas da doença grave em humanos. Objetivo Avaliar a gravidade da arteriopatia pulmonar induzida por MCT por meio dos achados anatomopatológicos pulmonares e cardíacos, evolução clínica e sobrevida em 37 dias. Métodos Foram utilizados 50 ratos machos Wistar divididos em quatro grupos, sendo um controle (n = 10). Os três grupos restantes foram submetidos à inoculação de MCT (60 mg/kg i.p.) e ficaram sob o seu efeito por 15 (n = 10), 30 (n = 10) e 37 dias (n = 20). Ao final de cada período, os animais foram sacrificados, obtendo-se tecidos pulmonar e cardíaco para análise anatomopatológica e morfométrica. Empregou-se o teste Kruskal-Wallis, considerando nível de significância de 5%. Resultados Nos pulmões dos animais MCT foram constatadas lesões referentes à arteriopatia pulmonar, incluindo muscularização das arteríolas, hipertrofia da camada média e lesões neointimais concêntricas. Lesões complexas foram observadas nos grupos MCT, descritas como plexiforme e do "tipo" plexiforme (plexiform-like). A hipertrofia do ventrículo direito foi constatada pelo aumento da espessura e diâmetro dos cardiomiócitos e pelo aumento significativo da espessura da parede do ventrículo direito (p<0,0000). Conclusão O modelo foi capaz de gerar arteriopatia pulmonar moderada-grave associada à hipertrofia do ventrículo direito secundária, com sobrevida de 50% em 37 dias. De nosso conhecimento, este estudo foi o primeiro a constatar a presença de lesões vasculares complexas, semelhantes às observadas em pacientes com hipertensão arterial pulmonar grave, em modelo isolado de MCT. (Arq Bras Cardiol. 2020; 115(3):480-490)

Abstract Background The monocrotaline (MCT)-induced pulmonary arterial hypertension model is one of the most reproduced today, presenting as a limitation the absence of plexiform lesions, typical manifestations of the severe disease in humans. Objective To evaluate the severity of MCT-induced pulmonary arteriopathy by pathological findings of lung and heart tissue samples, clinical course and 37-day survival. Methods Fifty male Wistar rats were divided into one of the four groups - control (CG) (n = 10) and three intervention (MCT) groups. The MCT groups received intraperitoneal injection (60 mg/kg) of MCT and remained exposed to the substance for 15 days (G15, n = 10), 30 days (G30, n = 10) and 37 days (G37, n = 20). At the end of each period, the animals were sacrificed, and pulmonary and cardiac tissues were collected for anatomopathological and morphometric analysis. The Kruskal-Wallis test was used, considering a level of significance of 5%. Results In the lungs of MCT animals, lesions related to pulmonary arteriopathy were found, including muscularization of the arterioles, hypertrophy of the middle layer and concentric neointimal lesions. Complex lesions were observed in MCT groups, described as plexiform and plexiform-like lesions. Right ventricular hypertrophy was evidenced by increased thickness and diameter of the cardiomyocytes and a significant increase in the right ventricular wall thickness (p <0.0000). Conclusion The MCT model was able to generate moderate-severe pulmonary arteriopathy associated with secondary right ventricular hypertrophy. The 37-day survival rate was 50%. To our knowledge, this study was the first to note the presence of complex vascular lesions, similar to those observed in patients with severe pulmonary arterial hypertension, in an isolated MCT model. (Arq Bras Cardiol. 2020; 115(3):480-490)

An in vitro study on interaction of anisodine and monocrotaline with organic cation transporters of the SLC22 and SLC47 families / 中国天然药物

Current study systematically investigated the interaction of two alkaloids, anisodine and monocrotaline, with organic cation transporter OCT1, 2, 3, MATE1 and MATE2-K by using in vitro stably transfected HEK293 cells. Both anisodine and monocrotaline inhibited the OCTs and MATE transporters. The lowest IC was 12.9 µmol·L of anisodine on OCT1 and the highest was 1.8 mmol·L of monocrotaline on OCT2. Anisodine was a substrate of OCT2 (K = 13.3 ± 2.6 µmol·L and V = 286.8 ± 53.6 pmol/mg protein/min). Monocrotaline was determined to be a substrate of both OCT1 (K = 109.1 ± 17.8 µmol·L, V = 576.5 ± 87.5 pmol/mg protein/min) and OCT2 (K = 64.7 ± 14.8 µmol·L, V = 180.7 ± 22.0 pmol/mg protein/min), other than OCT3 and MATE transporters. The results indicated that OCT2 may be important for renal elimination of anisodine and OCT1 was responsible for monocrotaline uptake into liver. However neither MATE1 nor MATE2-K could facilitate transcellular transport of anisodine and monocrotaline. Accumulation of these drugs in the organs with high OCT1 expression (liver) and OCT2 expression (kidney) may be expected.

Effect of Ambrisentan Therapy on the Expression of Endothelin Receptor, Endothelial Nitric Oxide Synthase and NADPH Oxidase 4 in Monocrotaline-induced Pulmonary Arterial Hypertension Rat Model

BACKGROUND AND OBJECTIVES: Elevated endothelin (ET)-1 level is strongly correlated with the pathogenesis of pulmonary arterial hypertension (PAH). Expression level of nicotinamide adenine dinucleotide phosphate oxidase (NOX) 4 is increased in the PAH patients. Ambrisentan, a selective endothelin receptor A (ERA) antagonist, is widely used in PAH therapy. The current study was undertaken to evaluate the effects of ambrisentan treatment in the monocrotaline (MCT)-induced PAH rat model. METHODS: Rats were categorized into control group (C), monocrotaline group (M) and ambrisentan group (Am). The M and Am were subcutaneously injected 60 mg/kg MCT at day 0, and in Am, ambrisentan was orally administered the day after MCT injection for 4 weeks. The right ventricle (RV) pressure was measured and pathological changes of the lung tissues were observed by Victoria blue staining. Protein expressions of ET-1, ERA, endothelial nitric oxide synthase (eNOS) and NOX4 were confirmed by western blot analysis. RESULTS: Ambrisentan treatment resulted in a recovery of the body weight and RV/left ventricle+septum at week 4. The RV pressure was lowered at weeks 2 and 4 after ambrisentan administration. Medial wall thickening of pulmonary arterioles and the number of intra-acinar arteries were also attenuated by ambrisentan at week 4. Protein expression levels of ET-1 and eNOS were recovered at weeks 2 and 4, and ERA levels recovered at week 4. CONCLUSIONS: Ambrisentan administration resulted in the recovery of ET-1, ERA and eNOS protein expression levels in the PAH model. However, the expression level of NOX4 remained unaffected after ambrisentan treatment.

Assessment of Right Ventricular Function by Tissue Doppler Imaging in Pulmonary Arterial Hypertensive Rat / 이화의대지

OBJECTIVES: Elevated pulmonary pressure and right ventricular (RV) dysfunction are the hallmarks of pulmonary vascular disease in animal models and human patients with pulmonary arterial hypertension (PAH). Monocrotaline models of PAH are widely used to study the pathophysiology of PAH. The purpose of this study was to evaluate the severity of PAH rat model by tissue Doppler imaging (TDI). METHODS: PAH was induced in Sprague-Dawley rats by monocrotaline (M) group. The peak systolic (s'), early diastolic (e'), and late diastolic myocardial velocities (a') were measured using TDI at basal segments. Tricuspid annular plane systolic excursion (TAPSE) was measured in the 4-chamber view. Velocity of a tricuspid regurgitation (TR) jet was measured to estimate the pulmonary artery pressure to assess the severity of PAH. RESULTS: Decrease in the RV shortening fraction and ejection fraction were observed in the M group compared with the control (C) group. RV e' velocity and s' velocity were significantly lower in the M group compared with the C group. The TAPSE was significantly lower in the M group compared with the C group (1.26±0.22 mm vs. 2.83±0.34 mm). The TR velocity was significantly higher in the M group compared with the C group (4.48±0.34 m/sec vs. 1.23±0.02 m/sec). CONCLUSION: TAPSE is an easily obtainable, widely recognized and clinically useful echocardiographic parameter of global RV function in the PAH rat model. We recommend that TDI would be a helpful diagnostic tool to evaluate the RV function in PAH rat model.

Introduction to animal models of pulmonary hypertension / 国际儿科学杂志

Pulmonary arterial hypertension (PAH) is a multifactorial pulmonary vascular disease accompanied by abnormal increase of pulmonary artery pressure with complicated pathogenesis,which leads to progressive right heart failure and death.It is necessary to establish an animal model that can simulate the pathophysiological characteristics of PAH in order to study the pathogenesis of PAH further.Animal models of PAH act as effective methods to study the pathogenesis,pathophysiology,development,prognosis and treatment of PAH.Classic PAH models include chronically hypoxia,drug injection,and so forth.Although animal models of PAH differ from each other,there is still no widely accepted animal model which can totally imitate human PAH.This review summarizes animal models of PAH in order to provide reference for choosing experimental animals of PAH and to establish a better animal model similar to human PAH.

Echocardiographic evaluation of monocrotaline induced pulmonary arterial hypertension in rats / 中华超声影像学杂志

Objective To analyze the correlation between the direct measurement of pulmonary artery pressure and the related echocardiographic parameters in rats with pulmonary arterial hypertension ( PA H ) , and establish a predictable equation for pulmonary artery pressure using non‐invasive ultrasonic parameters . Methods Fifteen male Wistar rats were randomly divided into normal control ( NC ) group with five rats and PA H model group with 10 rats .PA H model was established by intraperitoneal injection of 1% MCT solution in the dose of 60 mg/kg . All the rats were examined by ultrasonic apparatus to record cardiac parameters including right ventricle anterior wall thickness ( RVAWT ) ,pulmonary artery diameter ( PAD) , aorta diameter ( AOD ) , pulmonary artery acceleration time ( PAAT ) , pulmonary artery ejection time ( PAET ) ,right ventricle end‐diastolic diameter ( RVEDD ) ,right ventricle end‐diastolic length ( RVEDL ) , tricuspid annular plane systolic excursion ( T APSE) and left ventricular ejection fraction ( LVEF ) before experiments as well as 2 and 4 weeks after modeling . At the fifth week of modeling ,all the rats were administrated with thoracotomy and right ventricular catheter to obtain pulmonary artery systolic ,diastolic and mean pressures ( PASP ,PADP and PAM P) . Results As time went on ,measures of RVAWT ,PAD , PAD/AOD ,RVEDD ,RVEDL ,RVEDD/RVEDL increased ,while measurements of PAA T ,PAA T/PAET , T APSE decreased in the model group .T he changes of RVAWT ,PAD ,PAA T/PAET ,RVEDD in the model group appeared early in the second week in contrast to data before molding ( P ＜0 .05) . When comparing model group with NC group ,there were statistic differences of RVAWT ,PAAT/PAET as early as 2 weeks after modeling measuring (all P ＜0 .05) and the dramatic variance in the parameters of PAD/AOD ,PAAT , RVEDD ,RVEDD/RVEDL ,T APSE appeared in 4‐week observation . Correlation analysis suggested there were high‐degree correlations between PAA T ,PAA T/PAET and PASP ,PAM P ( for PASP : r ＝ －0 .829 ,－0 .865 ,P＜ 0 .05 ; for PAM P : r ＝ －0 .831 , －0 .842 , P ＜ 0 .05 ) ,and moderate‐degree correlations between RVAWT ,PAD/AOD ,RVEDD ,RVEDD/RVEDL ,T APSE and PASP ,PAM P ( for PASP :|r|＝0 .615－0 .786 , P ＜0 .05 ; for PAM P : r ＝0 .683－0 .799 , P ＜0 .05) .T he linear dependent equations were established as PASP ＝ －169 .392 PAAT/PAET + 105 .092 ( r2 ＝ 0 .748 , P ＝ 0 .000 ) ,PASP ＝ 49 .576 RVAWT+67 .314RVEDD/RVEDL －45 .198 ( r2 ＝0 .731 , P ＝0 .003) ,PAM P＝ －150 .664PAAT/PAET+88 .156 ( r2 ＝0 .709 , P ＝ 0 .001 ) ,PAM P＝37 .988RVAWT +82 .072RVEDD/RVEDL －50 .517 ( r2 ＝0 .794 , P ＝ 0 .001 ) to represent the relationships between PASP or PAM P and PAAT/PAET or RVAWTcombined RVEDD/RVEDL . Conclusions Echocardiography can monitor changes in heart structure and hemodynamics .Ultrasonic parameters especially PAAT/PAET or RVAWT ,RVEDD/RVEDL could be used to estimate PASP or PAM P measured by catheterization .

Expression change of NBL1 in rats with pulmonary arterial hypertension / 中国药理学通报

Aim To study the expression pattern of neuroblastoma, suppression of tumorigenicity 1 (NBL1) in pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). Methods Forty rats were randomly allocated into control group (n = 10) and MCT group (n= 30). Intraperitoneal injection of 60mg 'kg"1 MCT for MCT group or equal volume normal saline for control group was performed. The changes of NBL1 in lungs and plasma of the 3 rd, 4 th and 5 th week after MCT injection were detected respectively. NBL1 levels in rat plasma were detected by enzyme linked immunosorbent assay. Results At the 3 rd, 4 th, and 5 th week after MCT injection, the mRNA level of NBL1 decreased by 70%, 81% and 89% , the protein level decreased by 36% , 78% and 99% , and the plasma concentration of NBL1 decreased from (2. 82 ± 0. 58) xg L"1 (control rats) to (1. 90±0.55) fig L-1, (1.51 ±0.43) jxg L'1, (0.64 ±0. 34)ug L-l and presented a negative correlation with pulmonary hemodynamic indices and right ventricular hypertrophy. Immunohistochernical staining demonstrated that NBL1 was mainly expressed in small pulmonary arteries in normal lungs from control group but seldom detected in severely remodeled pulmonary arteries from MCT group. Furthermore, NBL1 significantly inhibited the activation of BMP signal in pulmonary artery endothelial cells induced by BMP2/4. Conclusions NBL1 level demonstrates a stepwise decrease in MCT induced PAH, implying its vital roles in the pulmonary vascular remodeling process and the possibility of NBL1 to be a potential biomarker for PAH.

Microarray Analysis in Pulmonary Hypertensive Rat Heart after Simvastatin Treatment / 이화의대지

OBJECTIVES: Simvastatin has been reported to attenuate the development of pulmonary hypertension through increased apoptosis as well as reduced proliferation of smooth muscle cells in obstructive vascular lesions. Microarray experiment can accomplish many genetic tests in parallel. The purpose of this study is to evaluate altered expressions of gene in rat hearts with monocrotaline (MCT)-induced pulmonary arterial hypertension after simvastatin treatment. METHODS: Six-week-old male rats were grouped as follows: control group (C group, saline injection), M group (MCT 60 mg/kg), and S group (MCT 60 mg/kg plus 10 mg/kg/day simvastatin by gavage during 28 days). Body weight, right ventricular pressure and right ventricular/left ventricle+septum ratio in each group were measured. The rats were sacrificed after 28 days. Total RNA was extracted from the rat heart tissue and microarray analysis was performed. RESULTS: Administration of simvastatin significantly inhibited the progression of right ventricular hypertrophy at day 28 in the S group than in the M group. Compared with the C group, MCT was associated with a significant difference in expression of genes related to biosynthesis and with the regulation of heart contraction rate. Simvastatin treatment resulted in a significantly changed expression of genes about the regulation of progression through cell cycle and system development compared to the M group. The expressions of nitric oxide synthase and brain natriuretic peptide were significantly decreased after simvastatin treatment. CONCLUSION: Administration of simvastatin exerted inhibitory effects on right ventricular hypertrophy during the development of MCT-induced pulmonary arterial hypertension in rats. Simvastatin changes the expression of genes associated with various functions.

Expression and significance of serum leptin and lung tissue leptin receptor in rats with pulmonary arterial hypertension induced by monocrotaline / 重庆医学

Objective To study the significance of leptin and its receptor(OB-R) in the occurrence and development of pulmonary arterial hypertension(PAH) induced by monocrotaline(MCT).Methods Fifteen SD rats were divided into the control group(n=5) and two experimental groups(n=10).The experimental groups were intraperitoneally injected by MCT for constructing the PAH model and the control group was injected by the same dose of solvent groups.The venous blood was extracted at 2,4 weeks after MCT injection in the two experimental groups.The mean pulmonary artery pressure(mPAP) and right ventricular hypertrophy index(RVHI) were measured and then the lung tissue was removed.The pathological change of lung blood vessels was observed.The expression of serum leptin was detected by ELISA.The expression of OB-R in lung tissue was tested by Western blot.Results Compared with the control group,mPAP and RVHI in the experimental groups were significantly increased(P＜0.05);the expression levels of serum leptin and lung tissue OB-R were increased significantly(P＜0.05),moreover,which were positively correlated with mPAP(r=0.912,P＜0.05;r=0.861,P＜0.05).Conclusion Leptin and OB-R may play an important role in the occurrence and development of PAH induced by MCT.

Salvianolic acid A attenuates vascular remodeling in pulmonary arterial hypertension rats induced by monocrotaline / 中国药理学与毒理学杂志

OBJECTIVE Salvianolic acid A (SAA) is one of the most bioactive compounds from a traditional Chinese medicine called Dan Shen(Salvia Miltiorrhiza Bunge)and exhibits many pharmaco-logical activities.Previous studies have indicated that SAA may inhibit endothelial dysfunction and vascular remodeling in spontaneously hypertensive rats. However, whether SAA improves vascular remodeling induced by pulmonary arterial hypertension (PAH) remains unknown. In this study we examined whether SAA attenuated vascular remodeling in a PAH rat induced by monocrotaline(MCT),and elucidated the underlying mechanisms.METHODS PAH was induced in rats by injecting a single dose of monocrotaline (MCT 60 mg·kg-1).The rats were orally treated with either SAA(0.3,1,3 mg·kg-1·d-1)or a positive con-trol Bosentan(30 mg·kg-1·d-1)for 4 weeks.Echocardiography and hemodynamic measurements were performed on d 28.Then the hearts and lungs were harvested,the organ indices and pulmonary artery wall thickness were calculated,and biochemical and histochemical analysis were conducted.The levels of apoptotic and signaling proteins in the lungs were measured using immunoblotting.RESULTS Treatment with SAA effectively ameliorated MCT-induced pulmonary artery remodeling,pulmonary hemodynamic ab-normalities and the subsequent increases of right ventricular systolic pressure (RVSP). Furthermore, the treatments significantly attenuated MCT-induced hypertrophic damage of myocardium,parenchymal in-jury and collagen deposition in the lungs.Moreover,the treatments attenuated MCT-induced apoptosis and fibrosis in the lungs.The treatments partially restored MCT-induced reductions of bone morphoge-netic protein typeⅡ receptor (BMPRⅡ) and phosphorylated Smad1/5 in the lungs. CONCLUSION SAA ameliorates the pulmonary arterial remodeling in MCT-induced PAH rats most likely via activating the BMPRII-Smad pathway and inhibiting apoptosis.Thus,SAA may have therapeutic potential for the pa-tients at high risk of PAH.

Alteration of tetraethylammonium-sensitive potassium current in pulmonary artery smooth muscle cells of pulmonary hypertension rats / 中国药理学通报

Aim To investigate the alteration of volt-age-depending potassium channel(KV) current in pul-monary arterial smooth muscle cells(PASMCs) of pul-monary hypertension (PH) rats, and the effect of tet-raethylammonium (TEA,a blocker of KV) on potassi-um channel current in different PH models. Methods The whole-cell patch clamp techniques were applied to record the KVcurrents from PASMCs cultured with Ham's F-12 (1% FBS). Furthermore, the effects of TEA on the KVcurrents were examined in different PH models. Results The whole-cell KVcurrents were ob-viously inhibited in PASMCs of chronic hypoxia (CH)and monocrotaline (MCT)-treated rats. TEA signifi-cantly decreased the whole-cell KVcurrents in PASMCs of control and PH rats,and the inhibitory effect of TEA was dramatically reduced in PH group. Conclusions The degree of the voltage-dependent potassium chan-nels opening is significantly inhibited in PASMCs of CH and MCT-treated rats,accordingly,the TEA-sen-sitive KVcurrents obviously decrease.

Baicalein inhibits monocrotaline-induced vascular wall thickening in rats with pulmonary hypertension / 中国病理生理杂志

AIM:To investigate the effects of baicalein on pulmonary arterial hypertension(PAH)induced by monocrotaline(MCT)in rats,and its molecular mechanism was further explored.METHODS: Male SD rats(n=28) were randomly divided into 4 groups: control group, MCT group, MCT+baicalein 50 mg/kg group and MCT +baicalein 100 mg/kg group.The PAH model was established by subcutaneous injection of MCT.After 2 weeks of modeling,the rats in baicalein treatment groups were gavaged baicalein 50 and 100 mg· kg -1· d-1for 14 d,the rats in control group were administered with saline.After 4 weeks of modeling,right ventricular systolic pressure(RVSP),right ventricular hypertro-phy index(RVHI)and right ventricular mass index(RVMI)were detected.Masson staining was used to detect the degree of lung fibrosis.The pathomorphological changes of the pulmonary vessels were observed by HE staining.Western blot was used to detect the expression of α-smooth muscle actin(α-SMA)in the lung tissue and the phosphorylation p 38,ERK and JNK in the artery.RESULTS:Compared with the control group,RVSP, RVHI and RVMI increased significantly in the MCT group(P<0.01).Pulmonary fibrosis and the thickening of pulmonary artery wall were observed.α-SMA was up-regulated and p38,ERK and JNK was activated significantly(P<0.01).Compared with the MCT group,baicalein(50 and 100 mg/kg)significantly decreased the RVSP,RVHI and RVMI(P<0.01).Lung fibrosis was reduced and the vas-cular wall thickening was decreased in baicalein-treated groups.Baicalein(50 and 100 mg/kg)inhibited the phosphoryla-tion of p38,ERK and JNK compared with the MCT group(P<0.01).CONCLUSION:Baicalein ameliorates MCT-in-duced PAH by the inhibition of pulmonary artery wall thickening at least partially via MAPK signaling pathway.

The Progress in the Animal Modeling of Pulmonary Arterial Hypertension / 现代生物医学进展

Animal models of pulmonary artery hypertension (PAH),aiming to simulate human characteristics of the disease,have contributed extensively to understanding the pathophysiology of PAH and the investigation of experimental treatments.The classical models include monocrotaline models,chronic hypoxia model and so on,more new models were investigated in recent years.These animal models were not able to perfectly mimic human pathological characteristics of PAH because of the defect in different aspects.In this review,both typical and novel methods of PAH modeling were summarized and evaluated to provide a suitable guidance for the settlement of animal models which can meet human characteristics comprehensively.

Preventive and therapeutic effect of diminazene in the rat model of pulmonary arterial hypertension / 中国比较医学杂志

Objective To explore the preventive and therapeutic effects of diminazene (DIZE) on pulmonary arterial hypertension (PAH) in rats.Methods Left pulmonary lobectomy combined with injection of monocrotaline was used to establish a rat model of pulmonary arterial hypertension.One hundred adult male Wistar rats were randomly divided into blank control group (group A,n=20),DIZE control group (group B,n=20),PAH model group (group C,n=20),PAH model plus DIZE group (group D,n=20) and PAH model plus DIZE and C-16 group (group E,n=20).Angiotensin-converting enzyme 2 (ACE2),IL-6 and IL-8 levels were determined by fluorescence resonance energy transfer (FRET) and enzyme linked immunosorbent assay (ELISA),and the mean pulmonary arterial pressure (mPAP) and right ventricular hypertrophy index (RVHI) were measured.The wall thickness (WT) and intimal hyperplasia score were calculated,and the pulmonary vascular lesions were analyzed using elastic fiber staining.Results RVHI,ACE2 enzyme activity and WT in the group A were significantly different from those of the groups C,D and E (P<0.05).Those of the group D and E were significantly different (P<0.05).The five groups showed significant differences in the overall analysis of each index (P<0.05).Conclusions Diminazene can increase the ACE2 enzyme activity,and decrease the mPAP,RVHI and WT,while reducing the pulmonary arterial medial hypertrophy,and inhibit intimal hyperplasia of pulmonary arterioles.The results of this study provide an experimental basis for the use of diminazene in the treatment of human pulmonary hypertension.

MRI analysis of right ventricular function in rat model of pulmonary artery hypertension induced by monocrotaline / 中国实验动物学报

Objective The aim of this study was to establish a rat models of pulmonary artery hypertention with monocrotaline, and to study the relationship between the evolution of right ventricular function and the evolution of pulmo-nary artery pressure ( PAP) by magnetic resonance ( MR) imaging of the right ventricular function. Methods Rat models of pulmonary artery hypertension were established by monocrotaline (MCT). The model rats were divided into 4 groups:the 1-week-PAH group, 2-week-PAH group, 3-week-PAH group, and 4-week-PAH group, and pulmonary artery pressure in the rats was measured by right heart catheterization. After injection of MCT, we used MRI to evaluate the ventricular function of the rats every week. All the measurement data of right ventricular function in the model group were compared with the average pulmonary pressure using Pearson' s correlation test. Results There were strong correlations between the parameters of RV function in model group with the average pulmonary pressure ( r= -0. 823 for RV EF, r=0. 732 and 0. 803 for RV EDV and RV ESV) . At 2 weeks after injection of monocrotaline, the mean pulmonary pressure, right ven-tricular eject fraction ( RVEF) , the end-diastolic volume ( EDV) and the end-systolic volume ( ESV) of right ventricle be-tween rats in PAH and the control group showed no significant difference (P>0. 05). But three-four weeks after MCT in-jection, all these parameters were significantly different in the PAH rats than in control rats (P<0. 05). Conclusions As the pulmonary arterial pressure is increased in the rats, the right ventricular function is gradually impaired. For the monito-ring of chronic pulmonary artery hypertension in rats, MRI can be used to accurately measure the changes of parameters. The PAH can be indicated by looking at the changes of parameter such as RV EF, RV EDV and RV ESV.