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AIM: To explore the regulatory effect of adrenomedullin (ADM) on pulmonary oxidative stress in the rats with pulmonary hypertension induced by high blood flow.METHODS: Healthy male SD rats (n=22) were randomly divided into control group, shunt group and shunt with ADM group.Abdominal aorta and inferior vena cava shunting was produced in the rats in shunt group and shunt with ADM group.After 8 weeks, ADM (1.5 μg·kg-1·h-1) was administered into the rats in shunt with ADM group subcutaneously by mini-osmotic pump for 2 weeks.Mean pulmonary artery pressure (mPAP) was evaluated by a right cardiac catheterization procedure.The ratio of right ventricular mass to left ventricular plus interventricular septal mass [RV/(LV+SP)] and relative medial thickness (RMT) in pulmonary muscularized arteries were calculated.The content of malonaldehyde (MDA), total antioxidative capacity (T-AOC), and activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in lung tissues were detected by colorimetry.The expression of NADPH oxidase 4 (NOX4) in the lung tissue was analyzed by Western blot.RESULTS: Compared with control group, the mPAP, RV/(LV+SP) and RMT in pulmonary muscularized arteries in shunt group were all significantly increased.The content of MDA and the expression of NOX4 in the lung tissues were significantly increased.The T-AOC, and activity of SOD and GSH-Px in the lung tissues were significantly decreased.However, mPAP, RV/(LV+SP) and RMT in pulmonary muscularized arteries in shunt with ADM group were significantly decreased as compared with shunt group.Meanwhile, ADM decreased the content of MDA and the expression of NOX4 in the lung tissues, but increased the T-AOC, and activity of SOD and GSH-Px in the lung tissue of shunt rats.CONCLUSION: ADM inhibits oxidative stress response in the development of pulmonary hypertension and pulmonary vascular structural remodeling induced by high pulmonary blood flow in the rats by down-regulating the NOX4 expression and strengthening the anti-oxidation response.
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Objective To investigate the effects of calcium - dependent and calcium - independent in myosin light chain(MLC)dephosphorylation on pulmonary hemodynamics and right ventricular remodeling,and to observe whether there is a superimposition effect while intervention is conducted in two ways at the same time. Methods Ac-cording to random number table,50 rats were divided into 5 groups:sham operation group,model group,3 mg/(kg·d) ML - 7[MLC kinase(MLCK)inhibitor]treating group(M group),20 mg/(kg·d)Fasudil(Rho kinase inhibitor) treating group(F group)and 3 mg/(kg·d)ML - 7 plus 20 mg/(kg·d)Fasudil treating group(M + F group). The shunt between the abdominal aorta and inferior vena cava was used to establish rat models of pulmonary hypertension in-duced by high pulmonary flow in group of C and the experimental groups. The sham operation group was given a sham operation. MLCK and Rho kinase inhibitor were administrated intraperitoneally to rats with the shunt. After 8 weeks of shunting,mean right ventricular pressure(MRVP),mean pulmonary arterial pressure(MPAP),right ventricular hyper-trophy index(RVHI)and width of inferior venacava were evaluated by the right cardiac catheterization procedure. Results Compared with the sham operation group,MRVP,MPAP,and RVHI were obviously elevated in the model group [(2. 65 ±0. 57)kPa vs(4. 19 ±0. 67)kPa;(2. 42 ± 0. 48)kPa vs(4. 04 ± 0. 61)kPa,F = 295. 368,263. 912,all P ﹤0. 01;(0. 21 ±0. 01)g/ g vs(0. 41 ±0. 03)g/ g,F =247. 024,P ﹤0. 01]. Compared with model group,the MRVP,MPAP and RVHI in M group and F group were decreased significantly[(3. 51 ± 0. 47)kPa vs(4. 19 ± 0. 67)kPa;(3. 68 ± 0. 55)kPa vs(4. 19 ±0. 67)kPa,all P ﹤0. 01;M group:(0. 29 ±0. 02)g/ g,model group:(0. 41 ± 0. 03)g/ g,F group (0. 30 ±0. 03)g/ g,F =247. 024,P ﹤0. 05]. But the MRVP,MPAP and RVHI in M group and F group were higher than those of rats in the sham operation group. The MRVP,MPAP and RVHI of M + F group were elevated much obviously compared with those of the M or F group(P ﹤0. 05). Conclusions The calcium - dependent and calcium - independent in MLC dephosphorylation can respectively restrain the development of pulmonary hypertension and right ventricular re-modeling,and the obvious additive effect can be observed when the 2 drugs are used jointly.
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[ ABSTRACT] AIM:To explore the regulatory effect of intermedin ( IMD) on pulmonary collagen synthesis and ac-cumulation in rats with pulmonary hypertension induced by high pulmonary blood flow.METHODS: Healthy male SD rats (n=20) were randomly divided into control group (n=7), shunt group (n=7) and shunt with IMD group (n=6).The shunting of abdominal aorta and inferior vena cava was produced in rats of shunt group and shunt with IMD group.After 8 weeks, IMD was administered into the rats of shunt with IMD group subcutaneously by mini-osmotic pump for 2 weeks.Mean pulmonary artery pressure (mPAP), relative medial thickness (RMT) of pulmonary arteries, contents of hydroxyproline, collagen type I and III, bone morphogenetic protein-2 (BMP-2), and the mRNA expression of procollagen I and III in lung tissues were measured and compared.RESULTS:Compared with control group, mPAP and RMT of medium and small pul-monary arteries in the rats of shunt group were significantly increased.Meanwhile, the lung hydroxyproline, collagens I and III and BMP-2 contents, and the mRNA expression of lung procollagen I and III were all significantly increased compared with control group.However, IMD significantly decreased mPAP, alleviated the changes of pulmonary vascular micro-struc-ture, decreased the collagen accumulation and pulmonary tissue homogenate BMP-2 contents, and inhibited the mRNA ex-pression of procollagen I and III in the lung tissue of shunting rats.CONCLUSION:IMD plays a protective role in the de-velopment of pulmonary hypertension and pulmonary vascular structural remodeling induced by high blood flow by inhibiting pulmonary collagen synthesis and accumulation, possibly in association with the BMP-2 pathway.
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Objective To study the pulmonary interstitial changes in pulmonary hypertension induced by high pulmonary blood flow.Methods Sixty-five male or female Sprague-Dawley rats (180-230 g) were used and randomly divided into 3 groups:normal group (n =20) ; sham group (n =20),only exposing the abdominal aorta and inferior vena cava about 10-20 minutes;model group(n =25),rats in this group were subjected to an abdominal aorta-inferior vena cava shunt to create animal models of high pulmonary.After operation,all the rats were reared under the same conditions for 11 weeks.Then,the systolic pulmonary artery pressure (sPAP) and mean pulmonary artery pressure (mPAP) of every rat were determined by means of homemade right heart catheterization.After that,the right ventricle (RV) was separated from the left ventricle (LV) and septum (S),then weighed.And right ventricular hypertrophy index (RVHI) was measured by the ratio of RV to LV + S [RV/(LV + S)].In addition,the morphological changes of pulmonary interstitial of rats were observed under optical microscope by means of hematoxylin-eosin (HE) staining.In the end,single pulmonary artery smooth muscle cell (PASMC) was isolated through acute enzyme separation.Then membrane capacitance (Cm) was recorded through in the method of patch clamp technique.Results 1.Compared with sham group and normal group,the sPAP,mPAP and RVHI of model group increased significantly(F =17.293,16.259,12.878,all P ＜ 0.01).2.In contrast to sham group and normal group,arterial wall area/vessel area(W/V) and arterial wall thickness/vessel external diameter(T/D) in model group increased significantly(F =85.717,22.795,all P ＜0.01).3.The membrane capacitance of model group was bigger than that of sham group and normal group(F =8.704,P ＜ 0.01).4.mPAP was positively correlated with W/V,T/D and Cm (r =0.669,0.662,0.663,all P ＜ 0.01).Conclusions Shunts from abdominal aorta-inferior vena cava in SD rats caused high pulmonary blood flow-induced pulmonary hypertension,and these rats appeared with pulmonary smooth muscle cells hypertrophy,pulmonary vascular wall thickening and inflammatory cells infiltration.
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Objective To study the effect of chloride channel blocker(niflumic acid,NFA) on pulmonary hypertension induced by high pulmonary blood flow in rats.Methods Fifty male or female Sprague-Dawley rats were randomly divided into 5 groups:normal group,sham group,model group,drug 1 group,and drug 2 group,with 10 rats in each group.After subjected to an abdominal aorta-inferior vena cava shunt,all the rats were reared under the same condition for 11 weeks.Then,mean pulmonary artery pressure(mPAP) and right ventricular hypertrophy index(RVHI) of each rat were measured.In addition,arterial wall area/vessel area (W/V) and arterial wall thickness/vessel external diameter(T/D) of each rat were also measured.Results 1.The mPAP of model group [(25.79 ± 4.03) mmHg,1 mmHg =0.133 kPa] was significantly higher than those of normal group [(16.48 ± 1.70) mmHg],sham group [(17.03 ± 2.01) mmHg],drug 1 group [(21.78 ± 2.77) mmHg] and drug 2 group [(20.31 ± 2.15) mmHg] (F =18.983,P ＜0.01).Although the mPAP of drug 1 group was a little higher than drug 2 group,there was no significant difference (P ＞ 0.05).Compared with normal group and sham group,the mPAP of drug 1 group and drug 2 group increased(P ＜0.01,respectively).2.The W/V and T/D of model group were significantly higher than those of normal group,sham group,drug 1 group and drug 2 group (F =26.135,15.527,all P ＜ 0.001).The W/V and T/D of two drug groups showed no significant difference,but they were higher than those of normal group and sham group (P ＜ 0.01,respectively).Conclusions Chloride channel blocker NFA partly decrease mPAP of pulmonary hypertension indnced by high pulmonary blood flow in rats,and inhibit proliferation of vascular smooth muscle cells.These results suggest that NFA had part of therapeutic effect to pulmonary hypertension induced by high pulmonary blood flow.
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Objective To study the influence of hydrogen sulfide (H2 S)on the mitochondrial function of pulmonary artery smooth muscle cells of the rats with high pulmonary blood flow pulmonary hypertension, and to clarify the function and its mechanism in the occurrence of high pulmonary blood flow pulmonary hypertension.Methods A total of 27 rats were randomly divided sham operation group,operation group,and operation+sodium hydrosulfide (NaHS)group (n=9).The pulmonary hypertension rat model was built by left lung resection.After fed for 35 d, the mean pulmonary artery pressure (mPAP),ratio of right ventricle/body weight (RV/BW),and ratio of right ventricle/(left ventricle+septum)[RV/(LV + S)]of the rats in three groups were measured.The plasma H2 S levels and the CSE activities in pulmonary artery tissue of the rats were detected;the activities of total mitochondrial ATP enzyme,superoxide dismutase (SOD),glutathione peroxidase (GSH-Px)and malondialdehyde (MDA)levels were determined;the ultrastructure of pulmonary artery smooth muscle mitochondria was observed through transmission electron microscope.Results Compared with sham operation group,the plasma H2 S level and the CSE activity in pulmonary artery tissue of the rats in operation group were decreased(P<0.01);the mitochondrial membrane of pulmonary tissue was swelling, and the mitochondrial activity was decreased (P<0.01);the mitochondrial ATP enzyme,SOD and GSH-Px activities were significantly decreased,and the MDA level was significantly increased (P<0.01).Compared with operation group,the H2S level in plasma and the activity of CSE in pulmonary tissue of the rats in operation + NaHS group were increased (P<0.01 );the mitochondrial membrane swelling was reduced, and the vitality was restored;the ATP enzyme, GSH-Px, and SOD level in pulmonary tissue were significantly increased (P<0.01),and the MDA level was significantly reduced (P<0.01).Conclusion H2 S can enhance the activities of mitochondrial ATP enzyme,GSH-Px,and SOD,and decrease the mitochondrial lipid peroxidation level,thus it plays a protective effect on rat pulmonary artery smooth muscle.
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Objective To comprehend the action mechanism of simvastatin in pulmonary hypertension(PH)when it induced by high pulmonary blood flow.Methods Abdominal aorta-inferior vena cava shunting was made in rats to establish animal model of PH induced by high pulmonary blood flow,simvastatin with dose of 2 mg/(kg?d)was used to interfere for 11 weeks.And then,pulmonary arterial pressure,apoptosis rate and proliferation rate of pulmonary vascular smooth muscle cell were determined.Results were compared with other groups.Results Simvastatin could cut down the pulmonary arterial pressure well,pulmonary arterial pressures of simvastatin group rats were lower than those of spliting groups obviously(Pa
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Objective To explore impact of high pulmonary blood flow on the content and metabolism of collagen in rats.Methods Thirty-two male SD rats were randomly divided into shunt group and control group.Rats in shunt group were subjected to an abdominal aorta-inferior vena cava shunt to create an animal model of high pulmonary blood flow.In control group,rats experienced the same expe-rimental processes except the shunting procedure.After 4 and 11 weeks of experiment,these changes of pulmonaryartery collagen Ⅰ,collagen Ⅲ,matrix metalloproteinase(MMP-13)and tissue inhibitor of metalloproteinase(TIMP-1) protein expression of rat were investigated by immunohistochemistry.Results After 4 weeks and 11 weeks of shunt,the collagen Ⅰ,collagen Ⅲ,MMP-13 and TIMP-1 of pulmonary artery in rats of shunt group increased significantly compared with those of control group,respectively(all P
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Objective To explore possible impact of endogenous hydrogen sulfide(H2S) on connective tissue growth factor(CTGF) expression in rat pulmonary artery with high pulmonary blood flow.Methods Thirty-two male SD rats,weighing 120～140 g,were randomly divided into 4 groups:shunt group,shunt+PPG group,sham group and sham+PPG group.After 4 weeks of experiment,Rat lung tissue H2S content was determined by a modified sulfide electrode method.Plasma ET-1 concentration was detected by radioimmunoactivity,and lung tissue ET-1 mRNA expression of rat was determined by quantitative competitive reverse transcriptional polymerase chain reaction(RT-PCR).Pulmonary artery connective tissue growth factor(CTGF) protein expression of rats was investigated by immunohistochemistry.Results After 4 weeks of experiment,lung tissue H2S content plasma ET-1,lung tissue ET-1 mRNA and CTGF expression increased significantly in rats of shunt group as compared with that of sham group(P
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Aim The study was designed to explore the possible impact of sodium hydrosulfide NaHS on the content and metabolism of collagen in rats with pulmonary hypertension induced by high pulmonary blood flow. Methods Thirty-two male SD rats, weighing 140~160 g, were randomly divided into 4 groups, shunt group (n=8), shunt+NaHS group (n=8), sham group (n=8) and sham+NaHS group (n=8). Rats in shunt group and shunt+NaHS group were subjected to an abdominal aorta-inferior vena cava shunt to create an animal model of high pulmonary flow. In the sham group and sham+NaHS group, rats experienced the same experimental processes except the shunting procedure. After 11 weeks of experiment, systolic pulmonary artery pressure (SPAP) of rats was detected using a right cardiac catheterization procedure. Lung tissue hydrogen sulfide(H2S) content of rats was determined by a modified sulfide electrode method. Pulmonary artery collagen Ⅰ,collagen Ⅲ,MMP-13 and TIMP-1 protein expression of rats was investigated by immunohistochemistry.Results After 11 weeks of experiment, SPAP increased significantly, whereas lung tissue hydrogen sulfide(H2S) content decreased significantly in rats of shunt group as compared with those of sham group (P