Animals ; Hypertension, Pulmonary ; chemically induced ; physiopathology ; Monocrotaline ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Thrombomodulin ; metabolism

OBJECTIVETo observe the changes in pulmonary artery protein kinase C (PKC) activity in rats with chronic inflammatory pulmonary hypertension (PHT).

METHODSChronic inflammatory PHT was induced in rats with monocrotaline. The PKC activities in the rat pulmonary arteries were measured by radioactive assay during the development of PHT.

RESULTSWith the development of chronic inflammatory PHT, the total and cytosolic fractions of PKC activity in PHT rat pulmonary arteries increased initially with subsequent decrease (Plt;0.05), but the membranous fraction of PKC activity and the membrane-to-cytosol PKC activity ratio increased continuously (P<0.05).

CONCLUSIONThe up-regulation of PKC activity and the translocation of PKC might be associated with the development of chronic inflammatory PHT in rats.

Animals ; Chronic Disease ; Hypertension, Pulmonary ; chemically induced ; enzymology ; Inflammation ; chemically induced ; enzymology ; Male ; Monocrotaline ; Protein Kinase C ; metabolism ; Pulmonary Artery ; enzymology ; Rats ; Rats, Wistar

OBJECTIVETo explore the mechanism of pulmonary hypertension and Cor Pulmonale rat models induced by monocrotaline (MCT).

METHODSTwenty Wistar male rats were randomly divided into normal control group and model group (n= 10), which received a single intraperitoneal injection of MCT solution (50 mg/kg , the first day) or dissolvant, respectively. On day 28 after MCT administration, the hemodynamic parameters were assessed; levels of tumour necrosis factor-alpha (TNF-alpha), nitric oxide (NO), endothelin-1 (ET-1), B-type natriuretic peptide(BNP) in pulmonary tissue or blood were measured using radio immunoassay or nitrate reductase method.

RESULTS28 days after MCT injection, compared with control group, right ventricle systolic pressure (RVSP) increased and heart rate(HR), mean arterial pressure (MAP) decreased; Levels of TNF-alpha, NO, ET-1 in pulmonary tissue or blood increased significantly in MCT group.

CONCLUSIONThe potential mechanism of MCI- induced pulmonary hypertension and Cor Pulmonale rat models associates with increasing TNF-alpha, NO, ET-1 levels in vivo, which results from inflammatory injury of lung tissue and blood vessels induced by MCT.

Animals ; Disease Models, Animal ; Endothelin-1 ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; physiopathology ; Lung ; metabolism ; Male ; Monocrotaline ; adverse effects ; Nitric Oxide ; metabolism ; Pulmonary Heart Disease ; chemically induced ; metabolism ; physiopathology ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; metabolism

The purpose of the present study was to explore the role of endogenous hydrogen sulfide (H2S) in pulmonary arterial hypertension induced by endotoxin. Adult male Sprague-Dawley (SD) rats were randomly divided into four groups: Control group (0.5 mL/kg body weight of normal saline, i.v.), lipopolysaccharide (LPS)-treated group (5 mg/kg body weight of LPS, i.v.), LPS + NaHS (5 mg/kg body weight of LPS, i.v., and 28 μmol/kg body weight of NaHS, i.p.) and LPS + PPG group (5 mg/kg body weight of LPS, i.v., and 30 μmol/kg body weight of PPG, i.p.). Rats were anesthetized with 20% urethane (1 g/kg body weight, i.p.). A polyethylene catheter was inserted into the pulmonary artery through the right external jugular vein to measure the mean pulmonary arterial pressure (mPAP) for 7 h, and then the pulmonary artery was isolated rapidly by the method described previously. Pulmonary arterial activity was detected. H2S concentration and cystathionine γ-lyase (CSE) activity in pulmonary artery tissues were determined by biochemical method. CSE mRNA expression was detected by competitive reverse transcriptase-polymerase chain reaction (RT-PCR). Compared with control, LPS significantly increased mPAP [(1.82±0.29) kPa vs (1.43±0.26) kPa, P<0.01], decreased H2S production [(26.33±7.84) vs (42.92±8.73) pmol/g wet tissue per minute, P<0.01), and reduced endothelium-dependent relaxation response [(75.72±7.22)% vs (86.40±4.40) %, P<0.01) induced by ACh (1×10(-6) mol/L). These effects were partly reversed by co-administration of NaHS and enhanced by co-administration of PPG. Both CSE activity and CSE mRNA expression were consistent with H2S production. It is suggested that the inhibitory effect of LPS on endothelium-dependent relaxation results in pulmonary hypertension, which might be mediated through H(2)S.
Animals ; Arterial Pressure ; Cystathionine gamma-Lyase ; metabolism ; Hydrogen Sulfide ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Lipopolysaccharides ; adverse effects ; Male ; Rats ; Rats, Sprague-Dawley ; Sulfides ; pharmacology

Pulmonary arterial hypertension is associated with profound vascular remodeling and alterations in Ca2+ homeostasis in pulmonary arterial smooth muscle cells (PASMCs). Recent studies show that canonical transient receptor potential channel 6 (TRPC6) genes, which encode receptor-operated cation channels (ROCC) in PASMCs, play an important role in Ca2+ regulation and cell proliferation. The aim of the present study was to investigate the role of TRPC6 in monocrotaline (MCT)-induced pulmonary artery hypertension. Sprague-Dawley rats were randomly divided into normal control group and MCT group. In MCT group, pulmonary arterial hypertension was induced by a single intraperitoneal injection of MCT at a dose of 60 mg/kg. After 3 weeks, the right ventricular systolic pressure (RVSP) and the right ventricular mass index (RVMI) were measured. The lung sections were stained by HE and observed under light microscope. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot were performed to detect the expression of TRPC6 in rat pulmonary arteries. The 1-oleoyl-2-acetyl-sn-glycerol (OAG)-induced contractile tension of pulmonary arteries were measured by vascular ring tension analysis and the intracellular Ca2+ concentration ([Ca2+](i))of PASMCs was monitored using Fluo3-AM assay. The results showed that RVSP and RVMI markedly elevated in MCT group (P<0.01) in comparison to CON group. The thickness of pulmonary vascular smooth muscles was increased and the inner diameter of pulmonary arteries was diminished in MCT group. Though there was no significant difference in the levels of mRNA and protein of TRPC6 between CON and MCT groups, the application of OAG, which can directly activate ROCC, induced greater contraction tension of pulmonary arteries (P<0.01) and more Ca2+ entries in PASMCs (P<0.05) in MCT group compared to those in control group. These results indicate that MCT induces pulmonary artery hypertension and thus remodeling of the right ventricle and pulmonary arteries in rats. The expression of mRNA and protein of TRPC6 is not potentiated by MCT, but the TRPC6/ROCC-mediated Ca2+ entry in PASMCs and vascular tone of pulmonary arteries are significantly increased with MCT treatment.
Animals ; Calcium ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; physiopathology ; Male ; Monocrotaline ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Myocytes, Smooth Muscle ; cytology ; metabolism ; Pulmonary Artery ; cytology ; metabolism ; physiopathology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; TRPC Cation Channels ; genetics ; metabolism

OBJECTIVETo evaluate the contribution of platelet and leukocyte activation in pathogenesis primary pulmonary hypertension (PPH).

METHODSPulmonary hypertension was induced by subcutaneous injection of 2% monocrotaline (MCT) in male Prague-Dawley (SD) rats. Blood samples were collected at the third week after MCT injection, and flow cytometry was used to determine the fibrinogen-binding platelet, CD11b expression on leukocyte and platelet-leukocyte aggregation.

RESULTThree weeks after MCT injection, rats exhibited higher right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure(mPAP), as compared with controls. MCT induced vascular remodeling characterized by vascular medial wall thickening in pulmonary muscular arteries. The ratio of platelets fibrinogen binding was increased in rats 3 weeks after MCT injection than that of control group[(4.08 +/-1.59)% compared with (1.45 +/- 0.61)%, P<0.01]. CD11b expression in monocytes and neutrophils, but not in lymphocytes was increased significantly 3 weeks after MCT injection (P <0.01). Platelet-neutrophil aggregations increased in MCT injected rats as compared with controls (P <0.01).

CONCLUSIONRats of PPH model demonstrate enhanced circulating platelet and leukocyte activation, which may contribute to the pathogenesis of PPH.

Animals ; Blood Platelets ; metabolism ; Fibrinogen ; metabolism ; Hypertension, Pulmonary ; blood ; chemically induced ; Leukocytes ; physiology ; Male ; Monocrotaline ; Platelet Aggregation ; Platelet Count ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the effects and related mechanisms of fasudil on monocrotaline-induced pulmonary arterial hypertension (PAH) in rats.

METHODSA total of 56 healthy male Sprague-Dawley rats were randomly divided into 5 groups: 4 weeks control group (N4), 4 weeks PAH group (M4), 8 weeks control group (N8), 8 weeks PAH group (M8), 8 weeks PAH and fasudil group (F8). PAH was induced by subcutaneous injection of monocrotaline (50 mg/kg). Animals in F8 group received intraperitoneal injection of fasudil hydrochloride (15 mg×kg(-1)×d(-1)) from the end of the 4th week to the end of the 8th week. Rats in control groups and PAH groups received equal volume saline injection. Polyethylene catheters were inserted into the RV through the jugular vein for right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) measurements after various treatment protocols. RV hypertrophy index [RV/(LV+S)] was also measured. Arteries of 50 to 150 µm were evaluated for the median wall thickness and wall area by HE staining as follows: percent wall thickness (WT%) = [(medial thickness×2/external diameter)]×100 and percent wall area (WA%) = (wall area/total area)×100%. The mRNA expression of ROCK-1 in lung tissue was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The protein expressions of ROCK-1 and MYPT-1 in lung tissue were analyzed by Western blot and MYPT-1 phosphorylation, respectively.

RESULTSForty-one rats survived and mortality rate was zero in N4, N8 and M4 groups. Survival rate was significantly higher in F8 group compared to M8 group (75.00% vs. 31.25%, P < 0.05). At the end of the 4th week, RVSP [(62.25 ± 3.24) vs. (31.33 ± 2.35) mm Hg(1 mm Hg = 0.133 kPa)], mPAP [(36.38 ± 2.31) vs.(20.32 ± 1.81) mm Hg], [RV/(LV+S)] (0.5648 ± 0.0580 vs. 0.3458 ± 0.0455), WT% [(25.63 ± 5.35)% vs.(13.38 ± 3.45)%], WA% [(60.36 ± 2.51)% vs. (38.42 ± 2.84)%] were all significantly higher in M4 group than in N4 group (all P < 0.01). RVSP [(54.64 ± 4.11) vs. (67.37 ± 4.68) mm Hg], mPAP [(26.25 ± 2.32) vs. (39.83 ± 1.83) mm Hg], and markedly relieve [RV/(LV+S)] (0.3985 ± 0.0210 vs. 0.7600 ± 0.0341), WT% [(15.64 ± 2.81)% vs. (28.26 ± 4.38)%], WA% [(40.35 ± 2.82)% vs. (68.83 ± 1.63)%] were all significantly lower in F8 group than in M8 group (all P < 0.05) while the expression of ROCK-1 mRNA (1.2139 ± 0.1778 vs. 1.6839 ± 0.3251, P < 0.01), and the protein expression of ROCK-1 and MYPT-1 as well as the extent of MYPT-1 phosphorylation were all downregualted in F8 group compared to M8 group (all P < 0.01).

CONCLUSIONSFasudil can effectively reverse the MCT-induced PAH in rats via downregulating ROCK-1 and MYPT-1.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine ; analogs & derivatives ; therapeutic use ; Animals ; Disease Models, Animal ; Familial Primary Pulmonary Hypertension ; Hypertension, Pulmonary ; chemically induced ; drug therapy ; Male ; Monocrotaline ; toxicity ; Protein Phosphatase 1 ; metabolism ; Rats ; Rats, Sprague-Dawley ; Treatment Outcome ; rho-Associated Kinases ; metabolism

Pulmonary artery hypertension (PAH) causes right ventricular failure and possibly even death by a progressive increase in pulmonary vascular resistance. Bone marrow-derived mesenchymal stem cell therapy has provided an alternative treatment for ailments of various organs by promoting cell regeneration at the site of pathology. The purpose of this study was to investigate changes of pulmonary haemodynamics, pathology and expressions of various genes, including ET (endothelin)-1, ET receptor A (ERA), endothelial nitric oxide synthase (NOS) 3, matrix metalloproteinase (MMP) 2, tissue inhibitor of matrix metalloproteinase (TIMP), interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha in monocrotaline (MCT)-induced PAH rat models after bone marrow cell (BMC) transfusion. The rats were grouped as the control (C) group, monocrotaline (M) group, and BMC transfusion (B) group. M and B groups received subcutaneous (sc) injection of MCT (60 mg/kg). BMCs were transfused by intravenous injection at the tail 1 week after MCT injection in B group. Results showed that the average RV pressure significantly decreased in the B group compared with the M group. RV weight and the ratio of RH/LH+septum significantly decreased in the B group compared to the M group. Gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha significantly decreased in week 4 in the B group compared with the M group. In conclusion, BMC transfusion appears to improve survival rate, RVH, and mean RV pressure, and decreases gene expressions of ET-1, ERA, NOS 3, MMP 2, TIMP, IL-6, and TNF-alpha.
Animals ; Bone Marrow Cells/*cytology ; *Bone Marrow Transplantation ; Cytokines/genetics/metabolism ; Enzymes/genetics/metabolism ; Gene Expression Regulation ; Hypertension, Pulmonary/chemically induced/*metabolism/pathology ; Lung/metabolism ; Male ; Monocrotaline/toxicity ; Pulmonary Artery/physiology ; Rats ; Rats, Sprague-Dawley ; Survival Rate ; Ventricular Function/physiology

OBJECTIVETo investigate the effect of vascular endothelial growth factor (VEGF) gene transfer on the bleomycin(BLM)-induced pulmonary hypertension in immature rabbits.

METHODSImmature rabbits were divided into 4 groups; control, BLM, liposome and trans-gene groups. The systolic, diastolic and mean pulmonary artery pressure (PASP, PADP, MPAP) were measured by micro-catheter, the pathological changes and the expression of VEGFmRNA and eNOSmRNA of endothelial cells in pulmonary arteries were evaluated by HE stain and in situ hybridization.

RESULT(1) The PAP of BLM and liposome groups was higher than that of control and trans-gene groups. The PASP was 16.5+/-2.9, 25.2+/-7.0, 24.4+/-6.0 and 18.3+/-2.7 mmHg; the PADP was 8.8+/-4.2, 13.1+/-3.8, 13.7+/-4.6 and 10.2+/-2.6 mmHg; the MPAP was 12.1+/-4.0, 18.4+/-4.7, 18.4+/-5.1 and 14.1+/-2.5 mmHg in control, BLM, liposome and trans-gene groups respectively. (2) The thickness of wall increased and the cavity became narrow, and the thickness index (TI) and area index (AI) increased in middle and small pulmonary arteries of BLM and liposome groups. The TI was 0.52+/-0.16, 0.65+/-0.16, 0.63+/-0.11 and 0.55+/-0.13; and the AI was 0.74+/-0.17, 0.84+/-0.14, 0.85+/-0.08 and 0.79+/-0.12 in control, BLM, liposome and trans-gene groups,respectively. (3) The level of VEGFmRNA and eNOSmRNA expression in pulmonary arterial endothelial cells decreased in BLM and liposome groups. The level of VEGFmRNA and eNOSmRNA expression in trans-gene group was higher than that in BLM and liposome groups, but lower than that in control group. VEGFmRNA was 0.83+/-0.09, 0.45+/-0.11, 0.45+/-0.13 and 0.65+/-0.18; eNOSmRNA was 0.79+/-0.12, 0.45+/-0.12, 0.50+/-0.14 and 0.56+/-0.08 in control, BLM, liposome and trans-gene groups, respectively.

CONCLUSIONVEGF gene transfer in immature rabbits with BLM-induced pulmonary hypertension could attenuate the increasing of PAP and wall thickness in middle and small pulmonary arteries, and increase the level of VEGFmRNA and eNOSmRNA expression in pulmonary arterial endothelial cells.

Animals ; Animals, Newborn ; Bleomycin ; Endothelium ; metabolism ; Gene Transfer Techniques ; Genetic Therapy ; Hypertension, Pulmonary ; chemically induced ; metabolism ; therapy ; Nitric Oxide Synthase Type III ; biosynthesis ; genetics ; Pulmonary Artery ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rabbits ; Vascular Endothelial Growth Factor A ; biosynthesis ; genetics

The aim of the present study is to investigate the protective effect of chrysin (5,7-dihydroxyflavone) on right ventricular remodeling in a rat model of monocrotaline-induced pulmonary arterial hypertension (PAH). PAH rats were induced by a single injection of monocrotaline (60 mg x kg(-1), sc) and were administered with chrysin (50 or 100 mg x kg(-1) x d(-1)) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. Right ventricle (RV) to left ventricle (LV) + septum (S) and RV to tibial length were calculated. Right ventricular morphological change was observed by HE staining. Masson's trichrome stain was used to demonstrate collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. The expressions of collagen I, collagen III, NADPH oxidase 4 (NOX4) and nuclear factor-kappa B (NF-κB) were analyzed by immunohistochemisty, qPCR and (or) Western blot. The results showed that chrysin treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV+S and RV/Tibial length) of PAH rats induced by monocrotaline. Furthermore, monocrotaline-induced right ventricular collagen accumulation and collagen I and collagen III expression were both significantly suppressed by chrysin. The expressions of NOX4, NF-κB and MDA contents were obviously decreased, while the T-AOC was significantly increased in right ventricule from PAH rats with chrysin treatment. These results suggest that chrysin ameliorates right ventricular remodeling of PAH induced by monocrotaline in rats through its down-regulating of NOX4 expression and antioxidant activity, and inhibiting NF-κB expression and collagen accumulation.
Animals ; Blotting, Western ; Collagen ; metabolism ; Disease Models, Animal ; Flavonoids ; pharmacology ; Heart Ventricles ; drug effects ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Monocrotaline ; toxicity ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NF-kappa B ; metabolism ; Rats ; Ventricular Remodeling ; drug effects