2-Methoxyestradiol mediates the protective effects of estradiol in monocrotaline-induced pulmonary hypertension

When exposed to chronic hypoxia or toxin monocrotaline (MCT), female animals develop less severe pulmonary arterial hypertension (PH) compared to males; ovariectomy (OVX) exacerbates PH, and OVX animals treated with estradiol (E2) develop less severe disease. There is a line of evidence suggesting that cardiovascular protective effects of E2 are mediated by its major metabolite, 2-methoxyestradiol (2ME). Recently, we have shown that 2ME attenuates the development and retards the progression of MCT-induced pulmonary hypertension in male rats. We hypothesized that the protective effects of E2 in experimental PH are mediated by 2ME. Subsets of intact and OVX female rats were injected saline (Cont and OXV groups) or MCT (60 mg/kg; MCT and OVX-MCT groups) and some of OVX-MCT animals were treated with 2ME (10 microg/kg/h via osmotic minipumps; OVX-MCT+2ME). After 28 days, MCT caused PH, i.e., increased right ventricular peak systolic pressure (RVPSP) and right ventricle/left ventricle+septum (RV/LV+S) ratio, induced inflammatory response in the lungs and caused media hypertrophy (media thickness and % media index) and adventitia widening of small size pulmonary arteries. Ovariectomy exacerbated the disease, i.e., further increased RVPSP, and RV/LV+S ratio, and augmented vascular remodeling and inflammatory response. In diseased OVX rats, treatment with 2ME prevented the worsening of PH and attenuated the inflammatory response and vascular remodeling. No mortality was recorded in the OVX-MCT+2ME group vs. 10% and 36% mortality in the MCT and OVX-MCT group, respectively. This study suggests that 2-methoxyestradiol (a major non-estrogenic metabolite of E2) may mediate the protective effects of estradiol in MCT-induced PH, and warrants further evaluation of 2ME for treatment of PH.     

2-methoxyestradiol attenuates bleomycin-induced pulmonary hypertension and fibrosis in estrogen-deficient rats

Pulmonary hypertension (PH) is a common and life-threatening complication of pulmonary fibrosis. Estradiol (E2) is protective in experimental PH, and its non-estrogenic metabolite 2-methoxyestradiol (2ME) prevents the development and retards the progression of monocrotaline-induced PH in male and female rats. However, the effects of E2 and 2ME on pulmonary fibrosis and associated PH have not been examined. Therefore, we compared the growth inhibitory effects of E2 and 2ME in human lung fibroblasts (hLFs) and pulmonary vascular smooth muscle cells (hPASMCs), and we investigated the effects of estrogen deficiency and 2ME on bleomycin-induced pulmonary fibrosis and PH. Intact and ovariectomized (OVX) female Sprague–Dawley rats were administered intratracheally either saline or bleomycin (15 IU/kg), and a subset of OVX bleomycin-treated rats received 2ME (10 μg/kg/h) for 21 days. Estradiol had only limited inhibitory effects on growth in hPASMCs and no effect in hLFs, whereas 2ME exhibited strong and concentration-dependent (1–10 μM) antimitogenic effects in both cell types. Bleomycin caused lung injury/PH (significantly increased lung and right ventricle (RV) weights, RV peak systolic pressure (RVPSP), and RV/left ventricle + septum ratio (RV/LV + S); caused medial hypertrophy and adventitial widening of pulmonary arteries; induced marked focal/diffuse fibrosis with diffuse infiltration of inflammatory (ED1+) cells; and resulted in 30% mortality). OVX exacerbated the disease and increased mortality (to 75%); whereas 2ME tended to reduce mortality (55.5%) and in surviving animals reduced RVPSP and RV/LV + S ratio, and attenuated vascular remodeling, pulmonary inflammation and fibrosis. This study suggests that 2ME may have protective effects in bleomycin-induced PH and fibrosis. Further investigation of 2ME in pulmonary fibrosis and PH is warranted.     

2-Ethoxyestradiol is antimitogenic and attenuates monocrotaline-induced pulmonary hypertension and vascular remodeling

Our previous studies show that 2-methoxyestradiol, a non-estrogenic metabolite of estradiol (E2), attenuates the development and retards the progression of pulmonary hypertension (PH) in male rats, and in female rats prevents the exacerbation of PH and eliminates mortality due to ovariectomy. Recent studies suggest that 2-ethoxyestradiol (2-EE), a synthetic analog of 2-ME, is an even more potent antimitogen than 2-ME. The goals of this study were: 1) to compare the effects of E2, 2-ME and 2-EE on proliferation of human pulmonary artery endothelial (hPAEC) and smooth muscle cells (hPASMC) and lung fibroblasts (hLF); 2) to examine the effects of 2-ME, its metabolic precursor 2-hydroxyestradiol (2-HE) and 2-EE on isoproterenol (ISO)-induced cardiac hypertrophy in male rats; and 3) to investigate in male rats the effects of 2-EE (10 mug/kg/h via osmotic pump) on the development of monocrotaline (MCT; 60 mg/kg i.p.)-induced PH. E2 had biphasic effects on growth (stimulation at low and inhibition at high concentrations) in hPAEC and mild growth inhibitory effects in hPASMC and hLF (1-10 muM). In contrast, in all three pulmonary cell lines, 2-ME and 2-EE inhibited cell growth with 2-EE being ten times more potent than 2-ME. In ISO-induced cardiac hypertrophy, 2-ME, 2-HE and 2-EE similarly reduced (~-50%) left (LV) and right (RV) ventricular hypertrophy and fibrosis (hydroxyproline content). In animals with MCT-induced PH, treatment with 2-EE for 28 days significantly decreased the elevated RV peak systolic pressure and reduced RV/LV+septum weight ratio, strongly inhibited vascular remodeling (media hypertrophy and adventitia widening), markedly reduced inflammatory responses, and eliminated MCT-induced (63%) mortality. This study provides the first evidence that 2-ethoxyestradiol strongly inhibits vascular remodeling in PH and suggests that anti-proliferative agents, including synthetic analogs of estradiol metabolites may be protective in PH.     

Synergistic therapeutic effects of 2-methoxyestradiol with either sildenafil or bosentan on amelioration of monocrotaline-induced pulmonary hypertension and vascular remodeling

2-Methoxyestradiol (2ME) is a major nonestrogenic metabolite of estradiol. Our previous studies suggest that 2ME, in several models of cardiac and/or vascular injury, strongly inhibits cardiac and vascular remodeling. Furthermore, our most recent study shows that in male rats, 2ME attenuates the development and retards the progression of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH), and in female rats, 2ME eliminates the exacerbation of PAH and the increased mortality due to ovariectomy. The current standard of care of patients with PAH includes treatment with an endothelin receptor antagonist (eg, bosentan) or a phosphodiesterase5 inhibitor (eg, sildenafil). Moreover, combination therapy is often prescribed. Therefore, in the present study, we compared the efficacy of 2ME (10 μg · kg(-1) · h(-1), 2ME-10) to the effects of bosentan (200 mg/kg; BOS), sildenafil (50 mg/kg; SIL), and their respective combinations with 2ME-10 (2ME + BOS and 2ME + SIL groups, respectively). Treatments were initiated 12 days after administration of MCT (60 mg/kg). Twenty-eight days after MCT administration, right ventricular peak systolic pressure was measured and morphometric analysis was conducted. 2ME exhibited beneficial effects in pulmonary hypertensive animals and had efficacy comparable to that of BOS and SIL. Importantly, combination treatments had favorable effects on survival, vascular remodeling, and inflammatory response, and the 2ME + SIL combination was significantly more efficacious than any other treatment. These results indicate that 2ME is effective in experimental PAH and suggests that 2ME may provide additional therapeutic benefit over existing drugs used for the treatment of pulmonary hypertension.     

Association of the time course of pulmonary arterial hypertension with changes in oxidative stress in the left ventricle

1. This study investigates the time course of pulmonary arterial hypertension (PAH) due to monocrotaline (MCT) and its association with cardiac function and oxidative stress markers in the left ventricle (LV). 2. Male Wistar rats were divided into six groups: 7 days, 21 days, and 31 days for both control and MCT groups. Following echocardiographic analysis, the heart was removed. The LV was separated and homogenized to analyze oxidized-to-total glutathione ratio and thioredoxin reductase (TrxR) activity as well as hydrogen peroxide (H(2) O(2) ) and ascorbic acid levels. 3. There was significant (P < 0.01) cardiac and right ventricle (RV) hypertrophy and pulmonary congestion in the MCT 21 day and 31 day groups. Echocardiography showed a change in the flow wave of the pulmonary artery at 21 days after MCT treatment. There was an increase in the LV ejection time (P < 0.05) at 31 days after MCT. The LV H(2)O(2) concentration was increased (P < 0.05) in the MCT 21 day and MCT 31 day groups compared with controls. There was a reduction (P < 0.05) in the LV ascorbic acid concentration and an increase (P < 0.05) in TrxR activity in the MCT 31 day rats. 4. Our findings showed RV changes due to pulmonary hypertension at 21 days after MCT injection. There was a correlation between the degree of dysfunction and the morphometry of the heart chambers, along with impairment of the antioxidant/pro-oxidant balance in the LV 31 days after the beginning of the protocol. This study suggests that LV changes follow RV dysfunction subsequent to pulmonary hypertension.     

Protection by oestradiol against the development of cardiovascular changes associated with monocrotaline pulmonary hypertension in rats.

1. We studied the effects of oestradiol 17 beta on the development of pulmonary vascular changes and right ventricular (RV) hypertrophy in response to monocrotaline in male Sprague-Dawley rats. 2. Rats were treated with either placebo or oestradiol 17 beta (10 mg) in the form of slow release pellets implanted subcutaneously 48 h before monocrotaline administration. Rats were injected with either saline or a single dose of monocrotaline (60 mg kg-1, i.m.). Pulmonary vascular changes and RV hypertrophy were studied at 4 weeks following monocrotaline administration. 3. Monocrotaline induced a significant increase in the ratio of right ventricle (RV) to left ventricle-plus-septum (LV + S) weights. Monocrotaline-treated rats also showed significant myointimal proliferation in small pulmonary arteries, decrease of arterial numbers and increase in the number of abnormal alveolar macrophages. 4. Oestradiol 17 beta attenuated myointimal hyperplasia in pulmonary vessels, decreased the RV/(LV + S) ratio in monocrotaline-treated rats. Oestradiol 17 beta had no significant effect on control animals. 5. Oestradiol treatment prevented the increase in lung wet to dry weight ratio, observed 7 days post monocrotaline administration. 6. These results suggest that oestradiol 17 beta protects against the pulmonary vascular remodelling and RV hypertrophy associated with monocrotaline-induced pulmonary hypertension in the rat. Oestradiol also protects against microvascular leak observed in the early days of lesion.     

Neuregulin‐1 attenuates right ventricular diastolic stiffness in experimental pulmonary hypertension

We have previously shown that treatment with recombinant human neuregulin‐1 (rhNRG‐1) improves pulmonary arterial hypertension (PAH) in a monocrotaline (MCT)‐induced animal model, by decreasing pulmonary arterial remodelling and endothelial dysfunction, as well as by restoring right ventricular (RV) function. Additionally, rhNRG‐1 treatment showed direct myocardial anti‐remodelling effects in a model of pressure loading of the RV without PAH. This work aimed to study the intrinsic cardiac effects of rhNRG‐1 on experimental PAH and RV pressure overload, and more specifically on diastolic stiffness, at both the ventricular and cardiomyocyte level. We studied the effects of chronic rhNRG‐1 treatment on ventricular passive stiffness in RV and LV samples from MCT‐induced PAH animals and in the RV from animals with compensated and decompensated RV hypertrophy, through a mild and severe pulmonary artery banding (PAB). We also measured passive tension in isolated cardiomyocytes and quantified the expression of myocardial remodelling‐associated genes and calcium handling proteins. Chronic rhNRG‐1 treatment decreased passive tension development in RV and LV isolated from animals with MCT‐induced PAH. This decrease was associated with increased phospholamban phosphorylation, and with attenuation of the expression of cardiac maladaptive remodelling markers. Finally, we showed that rhNRG‐1 therapy decreased RV remodelling and cardiomyocyte passive tension development in PAB‐induced RV hypertrophy animals, without compromising cardiac function, pointing to cardiac‐specific effects in both hypertrophy stages. In conclusion, we demonstrated that rhNRG‐1 treatment decreased RV intrinsic diastolic stiffness, through the improvement of calcium handling and cardiac remodelling signalling.     

Reactive oxygen species and substance P in monocrotaline-induced pulmonary hypertension

We attempted to evaluate whether the antioxidants 1,3-dimethyl-2-thiourea (DMTU) and hexa(sulfobutyl)fullerenes (FC(4)S) attenuate monocrotaline (MCT)-induced pulmonary hypertension (PH) by lowering lung substance P (SP) in Wistar rats. Sixty-three rats weighing 297 +/- 8 g were divided into six groups: control; MCT; capsaicin + MCT; MCT + DMTU-1; MCT + DMTU-2; and MCT + FC(4)S. Three weeks before the functional study, saline was injected into each control rat, whereas each MCT rat received 60 mg/kg sc MCT. Rats in the third group received capsaicin pretreatment followed by MCT. A 3-day injection of DMTU was performed during the early (DMTU-1) or the late (DMTU-2) post-MCT period. For the last group, each MCT-treated rat received a daily FC(4)S injection until the commencement of the functional study. Compared to the control group, MCT caused significant increases in pulmonary arterial pressure (Ppa), right ventricular hypertropy, pulmonary arterial medial thickness, lung SP level, and luminol-enhanced chemiluminescence counts in bronchoalveolar lavage. Both capsaicin and antioxidants significantly attenuated the above MCT-induced alterations. SP-induced acute increase in Ppa was exaggerated in MCT-treated rats. These results suggest that oxygen radicals play an important role in MCT-induced PH via elevating lung SP level.     

Downregulation of Kυ4.2 and Kυ4.3 channel gene expression in right ventricular hypertrophy induced by monocrotaline in rat

INTRODUCTION The calcium-independent transient outward potas-sium current (Ito) is activated by depolarization and playsa key role in controlling the amplitudes and cardiac ac-tion potential duration (APD). Ito contributesto the phase1 repolarization of action potential in myocytes, theprolongation of APD is the result of decrease in Ito den-sity[1]. Ito which is encoded by genes of Kv1.4, Kv4.2,and Kv4.3[2], based on differences in kinetics, as wellas recovery from inactivation…     

Isoquercitrin protects against pulmonary hypertension via inhibiting PASMCs proliferation

Pulmonary vascular remodelling is a common feature among the heterogeneous disorders that cause pulmonary arterial hypertension (PAH), and pulmonary arterial smooth muscle cells (PASMCs) proliferation impact the long‐term prognosis of the patient. Isoquercitrin (IQC) is a flavonoid with anti‐oxidative, anti‐inflammatory and anti‐proliferative activations. This study aimed to investigate whether IQC could prevent PASMCs proliferation and vascular remodelling in monocrotaline (MCT) induced PAH. Male Wistar rats were administered with Vehicle or 0.1% IQC maintain feed after MCT (40 mg/kg) injection. Haemodynamic changes, right ventricular hypertrophy and lung morphological features were assessed 3 weeks later. MCT‐induced PAH, pulmonary vascular remodelling and PASMCs proliferation in Vehicle‐treated rats. IQC reduced the right ventricle systolic pressure (RVSP), the ratio of RV/LV+S and the RV hypertrophy. IQC significantly alleviated the expression of proliferating cell nuclear antigen (PCNA), smooth muscle α‐actin (α‐SMA), and the percentage of fully muscularized small arterioles. In vitro studies, PASMCs were pretreated with IQC and stimulated with platelet‐derived growth factor (PDGF)‐BB (20 ng/mL). IQC suppressed PDGF‐BB‐induced PASMCs proliferation and caused G0/G1 phase cell cycle arrest. IQC downregulated the expression of Cyclin D1 and CDK4 as well as inhibited p27Kip1 degradation. Meanwhile, IQC negatively modulated PDGF‐BB‐induced phosphorylation of PDGF‐Rβ, Akt/GSK3β and ERK1/2. IQC ameliorated MCT‐induced pulmonary vascular remodelling via suppressing PASMCs proliferation and blocking PDGF‐Rβ signalling pathway.     

Downregulation of Kv4.2 and Kv4.3 channel gene expression in right ventricular hypertrophy induced by monocrotaline in rat

AIM: To investigate the differences in gene expression of transient outward potassium ion channel between the free wall of right ventricle, free wall of left ventricle, and the septum in monocrotaline (MCT)-induced right ventricular hypertrophy of rat. METHODS: Twenty rats were randomly divided into two groups: a single injection of monocrotaline (MCT) 60 mg/kg (model) or saline (control). Four weeks later, hemodynamic parameters were measured and the gene expression of Ito channels were detected by semi-quantitative RT-PCR. RESULTS: After 28 d, the right ventricular systolic pressure and central venous pressure were remarkably elevated by 128% and 533% in the MCT-treated group, accompanied by an overt right ventricle (RV) remodeling. The difference of mRNA expression of Kv1.4 was not significant in free wall of RV, left ventricle (LV), and septum in MCT group compared with control group. In contrast, mRNA of Kv4.2 and Kv4.3 in the free wall of RV in MCT-induced rat was dramatically decreased by 45.2% and 51.1% vs control, however, in free wall of LV and septum, no difference was found. In addition, mRNA expression level of Kv4.2 in control rat was significantly lower in septum than that in free wall of RV and LV. CONCLUSION: Expression of Kv1.4, Kv4.2, and Kv4.3 differs between regions in normal rat hearts. The down-regulation of Kv4 family gene expression of Ito contributed to the pathophysiological changes in ventricular hypertrophy and pulmonary hypertension induced by MCT.     

Effects of purple grape juice in the redox-sensitive modulation of right ventricular remodeling in a pulmonary arterial hypertension model

The effects of purple grape juice (PGJ) pretreatment in signaling proteins involved in cardiac remodeling in rats with pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT) were investigated. Male Wistar rats (control, MCT, PGJ, and MCT + PGJ groups) were treated for 6 weeks with water or PGJ (10 mL·kg(-1)·d(-1)) by gavage. In the third week, they were administered a single dose of MCT (60 mg/kg i.p.). Pulmonary vascular resistance was determined by echocardiography, and hemodynamic analysis was performed in the right ventricle (RV). Hydrogen peroxide (H2O2) concentration and lipid peroxidation were quantified and thioredoxin-1 (Trx-1), p-ERK1/2/ERK1/2, p-Akt/Akt, p-JNK/JNK, and cleaved caspase-3 were detected at RV by Western blot. Pretreatment with PGJ attenuated pulmonary vascular resistance and improved hemodynamic parameters in MCT-induced PAH. PGJ and MCT groups exhibited increased H2O2 levels, which were reduced to baseline in MCT + PGJ. ERK1/2 phosphorylation showed the same profile of H2O2 changes. No changes in p-JNK/JNK and p-Akt/Akt expressions were found. An enhanced cleaved caspase-3 immunodetection was induced by the model, which was reversed in the MCT + PGJ group and associated with increased Trx-1 and reduced lipid peroxidation. Improvement in functional parameters mediated by PGJ pretreatment may be associated with the induction of Trx-1, influencing the expression of proteins involved in RV remodeling.     

丹参酮-ⅡA磺酸钠对慢性低氧性肺动脉高压大鼠的治疗作用

目的探讨丹参酮-ⅡA磺酸钠(STS)对大鼠慢性低氧性肺动脉高压(HPH)的治疗作用。方法采用间断性低压低氧法建立SD大鼠慢性HPH模型。将大鼠随机分成:常氧组、常氧+STS组、低氧组和低氧+STS组。造模后测定平均左颈总动脉压(mean carotid arterial pressure,mCAP)、右心室收缩压峰值(right ventricular peak systolic pressure,RVP-SP)、右心室肥厚指数〔RV/(LV+S)%〕、肺小动脉管壁厚度占外径的百分比(WT%)及管壁面积占血管总面积的百分比(WA%)和肺组织匀浆中SOD与MDA含量。结果低氧+STS组大鼠的RVPSP与低氧组相比明显降低(P<0.01),而各组大鼠的mCAP无差别。HE染色结果显示常氧组与常氧+STS组肺组织结构均正常,而低氧组可见肺泡腔水肿,点、片状渗出、出血,肺小动脉管壁和平滑肌层明显增厚,管腔狭窄;低氧+STS组较低氧组明显减轻,平滑肌层呈不规则间断性肥厚,管腔部分狭窄。低氧+STS组大鼠右心室肥厚指数〔RV/(LV+S)%〕、肺小动脉WA%和WT%值、肺组织MDA含量也明显低于低氧组(P<0.01),SOD含量高于低氧组(P<0.01);常氧组与常氧+STS组则无差别。结论STS能够抑制大鼠慢性HPH及其所引起的心、肺血管的病理变化,这种作用可能与其降低氧化应激有关。     

Resveratrol inhibits right ventricular hypertrophy induced by monocrotaline in rats

1. Resveratrol (RSV), a polyphenol in red wine, exhibits cardioprotective effects in vitro, such as inhibition of angiotensin II‐ or phenylephrine‐induced cardiomyocyte hypertrophy in rat neonatal myocyte cultures and suppression of cardiac fibroblast proliferation. The aim of the present study was to investigate the protective effects of RSV against monocrotaline (MCT)‐induced right ventricular (RV) hypertrophy in rats. 2. Male Sprague‐Dawley rats were given a single injection of MCT (50 mg/kg, s.c.) and were then treated with either vehicle (normal saline) or RSV (10 and 30 mg/kg, i.g., twice daily) for 21 days. A separate group of control rats were not injected with MCT and were treated with normal saline for 21 days. At the end of the treatment period, all rats were subjected to echocardiography and haemodynamic measurements. In addition, after rats had been killed, the hearts were subjected to histopathological, untrastructural and immunohistochemical analyses. 3. In vehicle‐treated rats, MCT injection resulted in 33% mortality, whereas mortality in RSV‐treated MCT‐injected rats was 0%. In vehicle‐treated rats, MCT increased RV free wall thickness and RV systolic pressure and decreased pulmonary arterial acceleration time at the end of the experimental period. These dynamic changes were ameliorated by RSV in a dose‐dependent manner. Histologically, MCT injection resulted in RV hypertrophy, swollen mitochrondria and cardiomyocyte apoptosis; all these morphological changes were dose‐dependently improved in rats treated with RSV. 4. In conclusion, RSV inhibits the RV hypertrophy induced by MCT in rats and this effect is mediated by both a direct effect of RSV on cardiomyocytes and an indirect effect mediated via a reduction in pulmonary hypertension.     

Involvement of miR-200b–PKCα signalling in pulmonary hypertension in cor pulmonale model

The right ventricle (RV) enlargement and pulmonary fibrosis are involved in cor pulmonale. The role of miR-200b in cor pulmonale is less well understood. This study was designed to evaluate the regulatory roles of miR-200b in cor pulmonale. Cor pulmonary mouse model was built via monocrotaline injection of monocrotaline (MCT). The expression of miR-200b in the lungs, RV and left ventricle (LV) are using real-time polymerase chain reaction. The transthoracic echocardiography was employed to determine the effects of miR-200b mimics and Gö6976 injection on MCT mice. The protein levels of protein kinase C α (PKCα), collagen, and fibronectin in the lung, RV, and LV in the mice with and without miR-200b mimics and Gö6976 injection were evaluated using western blot. The expression of miR-200b decreased in MCT mice, while there was no difference in LV. Both the miR-200b mimics and Gö6976 injection reversed the muscularization in the pulmonary artery, reversed RV hypertrophy, reduced RV systolic pressure, wall thickness and pulmonary fibrosis. The injection of miR-200b can reduce the PKCα expression in the lung, RV, and LV. This study confirmed the down-regulation of miR-200b in cor pulmonale. The reverse effects of miR-200b in the present study may provide a potential tool for cor pulmonary treatment.     

Evaluation of olmesartan medoxomil in the rat monocrotaline model of pulmonary hypertension

It is suggested that angiotensin II is involved in the pathogenesis of pulmonary hypertension and subsequent right ventricular hypertrophy; therefore, an angiotensin AT1 receptor antagonist could be beneficial for the treatment of this disease. We tested the effect of the new AT1 receptor antagonist olmesartan medoxomil on monocrotaline-induced pulmonary hypertension in rats. At 3 weeks after a single subcutaneous injection of monocrotaline (50 mg/kg), the lung/body weight ratio, the right ventricle/(left ventricle plus septum) weight ratio [RV/(LV+S)], and right ventricular systolic pressure were increased, indicating establishment of pulmonary hypertension and right ventricular hypertrophy. Oral administration of olmesartan medoxomil (2 or 5 mg/kg/day for 3 weeks) restored RV/(LV+S) and right ventricular systolic pressure, and a higher dose (5 mg/kg/day) improved the lung/body weight ratio. Pulmonary arteries isolated from monocrotaline-treated rats exhibited an increase in basal tone in the resting state, indicating that they had intrinsic tone. Three weeks of treatment with olmesartan decreased this intrinsic tone. These data suggest that long-term treatment with olmesartan has beneficial effects on monocrotaline-induced pulmonary hypertension and subsequent right ventricular hypertrophy.     

松龄血脉康抑制肺动脉高压的实验研究

为观察松龄血脉康胶囊对肺动脉高压大鼠肺动脉压的影响，取１００只健康Ｗｉｓｔａｒ大鼠，其中６０只背部注射野百合碱ｍｏｎｏｃｒｏｔａｌｉｎｅ，ＭＣＴ８０ｍｇ／ｋｇ复制出肺动脉高压模型。再将其分为两组，各３０只，其中一组以标准饲料喂养，另一组加用松龄血脉康胶囊１．５ｇ·ｋｇ－１·ｄ－１。其余４０只健康大鼠做为正常对照组，在实验当天、７天、１４天、２１天、２８天、３５天从各组中随机抽取５只行右心导管测肺动脉压。结果：注射ＭＣＴ后肺高压组２８天时达高峰，但加用松龄血脉康组上升幅度明显小于未用药组。结论：松龄血脉康有显著抑制大鼠肺动脉高压发展的作用     

葛根素干预肺动脉高压大鼠时钙网蛋白前体变化的研究

目的：观察正常组与野百合碱致肺动脉高压组及葛根素干预组大鼠肺组织差异蛋白质组学的变化,在蛋白质组学水平探讨葛根素抑制肺动脉高压、肺血管重建的机制。方法：制备各组模型大鼠后分别测定平均肺动脉压力（mPAP）、平均颈动脉压力（mCAP）、右心室重量比[Rv／（LV＋S）]％,制作光镜标本、测量肺血管重建指标（PAMT））及统计学分析,明确模型制备成功。对各组肺组织提出的总蛋白质进行双向电泳、串联质谱鉴定有差异的蛋白质并用NCBInr数据库进行检索。对鉴定的蛋白质进行分析。结果：野百合碱组与正常组比较,mPAP、[RV／（LV＋S）]％、PAMT显著增高（P〈0．05）,提示肺动脉高压模型制备成功。葛根素干预组与野百合碱组比较,mPAP、IRV／（LV＋S）]％、PAMT显著下降（P〈0．05）,表明葛根素可抑制野百合碱引起的肺动脉高压、肺血管重建与右心室肥大。通过双向凝胶电泳、串联质谱鉴定及数据库检索发现钙网蛋白前体在正常组表达几乎为0,在野百合碱组大量表达,而在葛根素干预组迅速下调至0水平。结论：钙网蛋白前体可能与葛根素抑制肺动脉高压形成相关,值得深入研究。     

G蛋白抑制肽抑制野百合碱所诱导的右室重构

目的探讨G蛋白抑制肽(GCIP-27)对野百合碱(monocrotaline,MCT)所诱导右室重构的作用及相关机制。方法SD大鼠随机分为正常组、MCT模型组、GCIP-27低剂量组(30μg·kg-1)和GCIP-27高剂量组(90μg·kg-1)。MCT造模后1d～21d给GCIP-27(ip,bid)。造模d22右心导管术测肺动脉压;称右心室自由壁重(RV)及左心室加室间隔重(LV+S),计算右心肥大指数[RVHI=RV/(LV+S)];HE染色光镜观察右室形态学改变;电镜观察右室超微结构变化;免疫组化观察右室心肌细胞核增殖抗原(PCNA)的表达。结果GCIP-27能明显抑制MCT所引起RVHI的升高、右室心肌细胞肥大及线粒体肿胀、变性和右室心肌细胞PCNA的过表达。高剂量GCIP-27降低MCT所诱导的肺动脉收缩压,平均肺动脉压的升高(P<0.05或P<0.01),但低剂量GCIP-27(30μg·kg-1)仅降低肺动脉收缩压的升高(P<0.05)。结论GCIP-27能明显抑制MCT诱导的右室重构。     

Effects and mechanisms of Artemisia argyi essential oil on monocrotaline-induced pulmonary hypertension in rats

In the present study, we aimed to investigate the effects of Artemisia argyi essential oil (AO) on pulmonary hypertension (PH)inducedbymonocrotaline(MCT)andtoexploretheunderlying mechanism.A total of 80 Sprague-Dawley ratswererandomlydividedintofourgroups as follows:controlgroup, modelgroup,bosentan(0.1g/kg)groupandAO(0.1g/kg)group.After30dofexperiment, hemodynamicparameters,lungandrightventricle hypertrophy indexweredetermined. HEand Immunohistochemistrystainingoflungs were performedto detectthe injuriesandprotein expressions. Theresultsshowedthatlevels of mPAP,mRVP,maxRVP,wW,LI,RV and RVHI as well asthe expressionsofNF-κBp65andα-SMA were increased,smallpulmonaryarterythickened, the cavity of the arteriole narrowed, and there was marked infiltration of inflammatory cells in lungs of rats receiving MCT compared with the normal group. After the administration of AO, the levels of mPAP and mRVP were significantly decreased,and the wW, LI, LV+S and pulmonary arterial remodeling were markedly improved. The expression levels of NF-κB p65 and α-SMAwerereduced by AOcomparedwiththe modelgroup.Ourresultssuggestedthat AOreduced the progressionof PH induced byMCTthroughinhibiting the expressions of NF-κB p65 and α-SMA.