OBJECTIVES: To study the association between hepatocyte growth factor (HGF) and treatment response in mice with hypoxic pulmonary arterial hypertension (HPAH) and the possibility of HGF as a new targeted drug for HPAH. METHODS: After successful modeling, the HPAH model mice were randomly divided into two groups: HPAH group and HGF treatment group (tail vein injection of recombinant mouse HGF 1 mg/kg), with 10 mice in each group. Ten normal mice were used as the control group. After 5 weeks, echocardiography was used to measure tricuspid peak velocity, right ventricular systolic pressure, right ventricular hypertrophy index, and right ventricular/body weight ratio; the Griess method was used to measure the content of nitric oxide in serum; ELISA was used to measure the serum level of endothelin-1; transmission electron microscopy was used to observe changes in the ultrastructure of pulmonary artery. RESULTS: Compared with the HGF treatment and normal control groups, the HPAH group had significantly higher tricuspid peak velocity, right ventricular systolic pressure, right ventricular hypertrophy index, and right ventricular/body weight ratio (P<0.05). The transmission electron microscopy showed that the HPAH group had massive destruction of vascular endothelial cells and disordered arrangement of the elastic membrane of arteriolar intima with rupture and loss. The structure of vascular endothelial cells was almost complete and the structure of arterial intima elastic membrane was almost normal in the HGF treatment group. Compared with the normal control and HGF treatment groups, the HPAH group had significantly higher serum levels of nitric oxide and endothelin-1 (P<0.05). CONCLUSIONS Increasing serum HGF level can alleviate the impact of HPAH on the cardiovascular system of mice, possibly by repairing endothelial cell injury, improving vascular remodeling, and restoring the normal vasomotor function of pulmonary vessels.
Animals ; Body Weight ; Endothelial Cells ; Endothelin-1 ; Hepatocyte Growth Factor/therapeutic use* ; Hypertrophy, Right Ventricular ; Hypoxia ; Mice ; Nitric Oxide ; Pulmonary Arterial Hypertension/drug therapy*

In vascular smooth muscle, K⁺ channels, such as voltage-gated K⁺ channels (Kv), inward-rectifier K⁺ channels (Kir), and big-conductance Ca²⁺-activated K⁺ channels (BK(Ca)), establish a hyperpolarized membrane potential and counterbalance the depolarizing vasoactive stimuli. Additionally, Kir mediates endothelium-dependent hyperpolarization and the active hyperemia response in various vessels, including the coronary artery. Pulmonary arterial hypertension (PAH) induces right ventricular hypertrophy (RVH), thereby elevating the risk of ischemia and right heart failure. Here, using the whole-cell patch-clamp technique, we compared Kv and Kir current densities (I(Kv) and I(Kir)) in the left (LCSMCs), right (RCSMCs), and septal branches of coronary smooth muscle cells (SCSMCs) from control and monocrotaline (MCT)-induced PAH rats exhibiting RVH. In control rats, (1) I(Kv) was larger in RCSMCs than that in SCSMCs and LCSMCs, (2) I(Kv) inactivation occurred at more negative voltages in SCSMCs than those in RCSMCs and LCSMCs, (3) I(Kir) was smaller in SCSMCs than that in RCSMCs and LCSMCs, and (4) I(BKCa) did not differ between branches. Moreover, in PAH rats, I(Kir) and I(Kv) decreased in SCSMCs, but not in RCSMCs or LCSMCs, and I(BKCa) did not change in any of the branches. These results demonstrated that SCSMC-specific decreases in I(Kv) and I(Kir) occur in an MCT-induced PAH model, thereby offering insights into the potential pathophysiological implications of coronary blood flow regulation in right heart disease. Furthermore, the relatively smaller I(Kir) in SCSMCs suggested a less effective vasodilatory response in the septal region to the moderate increase in extracellular K⁺ concentration under increased activity of the myocardium.
Animals ; Coronary Vessels ; Heart Diseases ; Heart Failure ; Hyperemia ; Hypertension ; Hypertrophy, Right Ventricular ; Ischemia ; Membrane Potentials ; Monocrotaline ; Muscle, Smooth ; Muscle, Smooth, Vascular ; Myocardium ; Myocytes, Smooth Muscle ; Patch-Clamp Techniques ; Potassium Channels ; Rats ; Septum of Brain

Hypertrophic cardiomyopathy (HCM) has diverse pathophysiological and clinical features, according to the extent and severity of the hypertrophy development. Hypertrophy mostly involves the left ventricle and sometimes causes a left ventricular outflow tract obstruction. Right ventricular involvement is less frequent, and even the severe form of a right ventricular outflow tract (RVOT) obstruction by concurrent right ventricular hypertrophy in a patient with HCM is rare. We report a case of biventricular HCM with a clinically, morphologically, and hemodynamically significant RVOT obstruction, which had been treated successfully with surgical myectomy.
Cardiomyopathy, Hypertrophic ; Heart Ventricles ; Humans ; Hypertrophy ; Hypertrophy, Right Ventricular

OBJECTIVE: To study the protective effects of ginkgo biloba extract on the right ventricular hypertrophy. METHODS: Seventy-two SD male rats were randomly divided into 3 groups: control group(CON), monocrotaline-induced right ventricular hypertrophy group (MCT) and ginkgo biloba extract treated group (EGB) (n=24 in each group). Group MCT and group EGB were intraperitoneally injected with 2%MCT at the dose of 60 mg /kg on the first day. From the second day, group MCT was injected with 2 ml 0.9% sodium chloride, and 60 mg/kg ginkgo leaf extract was administered to the stomach in group EGB. The control group was injected with 2 ml 0.9% sodium chloride on the first day. After 3 weeks, in each group,cardiac hemodynamic changes were measured, heart weight index was calculated, and myocardial pathological changes were observed by HE staining. The expression of TRPC6 was detected by real-time polymerase chain reaction (real-time -PCR) and Western blot. RESULTS: Compared with the control group, the right ventricular systolic pressure (RVSP) was increased significantly in the MCT group(P＜0.01), the maximum or decline rate of descent (RV ±dp/dt) of the right ventricle pressure was increased significantly(P＜0.01), while the EGB group had the same trend as all the indexes in the group MCT, but the amplitude of all indicators in group EGB were decreased significantly than those of group MCT(P＜0.01), and the right ventricular hypertrophy index (RVMI) in group EGB was significantly lower than that in group MCT(P＜0.01).Group MCT showed typical myocardial hypertrophy performance by HE staining, and the right ventricular myocytes in group EGB were significantly improved than that in group MCT, and the mRNA and protein expression levels of TRPC6 in the right ventricle of group MCT and group EGB were increased(P＜0.01), while the EGB group was significantly lower than that of the MCT group(P＜0.01). CONCLUSION Ginkgo biloba extract may inhibit the signal pathway of CaN / NFAT in cardiac myocytes by reducing the expression of TRPC6 protein, and then play an early protective effect on myocardial hypertrophy.
Animals ; Hypertrophy, Right Ventricular ; chemically induced ; drug therapy ; Male ; Monocrotaline ; Plant Extracts ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley

PURPOSE: Adenotonsillar hypertrophy (ATH) that causes upper airway obstruction might lead to chronic hypoxemic pulmonary vasoconstriction and right ventricular (RV) dysfunction. We aimed to evaluate whether adenotonsillectomy (T&A) in children suffering from obstructive sleep apnea (OSA) due to severe ATH could improve RV function. METHODS: Thirty-seven children (boy:girl=21:16; mean age, 9.52±2.20 years), who underwent T&A forsleep apnea due to ATH, were included. We analyzedthe mean pulmonary artery pressure (mPAP), the presence and the maximal velocity of tricuspid regurgitation (TR), the tricuspid annular plane systolic excursion (TAPSE), and the right ventricular myocardial performance index (RVMPI) with tissue Doppler echocardiography (TDE) by transthoracic echocardiography pre- and post-T&A. The follow-up period was 1.78±0.27 years. RESULTS: Only the RVMPI using TDE improved after T&A (42.18±2.03 vs. 40±1.86, P=0.001). The absolute value of TAPSE increased (21.45±0.90 mm vs. 22.30±1.10 mm, P=0.001) but there was no change in the z score of TAPSE pre- and post-T&A (1.19±0.34 vs. 1.24±0.30, P=0.194). The mPAP was within normal range in children with ATH, and there was no significant difference between pre- and post-T&A (19.6±3.40 vs. 18.7±2.68, P=0.052). There was no difference in the presence and the maximal velocity of TR (P=0.058). CONCLUSION: RVMPI using TDE could be an early parameter of RV function in children with OSA due to ATH.
Airway Obstruction ; Apnea ; Child* ; Dichlorodiphenyldichloroethane ; Echocardiography ; Echocardiography, Doppler ; Follow-Up Studies ; Humans ; Hypertrophy ; Pulmonary Artery ; Reference Values ; Sleep Apnea, Obstructive* ; Tricuspid Valve Insufficiency ; Vasoconstriction ; Ventricular Function, Right*

BACKGROUND AND OBJECTIVES: Mitochondria play a key role in the pathophysiology of heart failure and mitochondrial permeability transition pore (MPTP) play a critical role in cell death and a critical target for cardioprotection. The aim of this study was to evaluate the protective effects of cyclosporine A (CsA), one of MPTP blockers, and morphological changes of mitochondria and MPTP related proteins in monocrotaline (MCT) induced pulmonary arterial hypertension (PAH). METHODS: Eight weeks old Sprague-Dawley rats were randomized to control, MCT (60 mg/kg) and MCT plus CsA (10 mg/kg/day) treatment groups. Four weeks later, right ventricular hypertrophy (RVH) and morphological changes of right ventricle (RV) were done. Western blot and reverse transcription polymerase chain reaction (RT-PCR) for MPTP related protein were performed. RESULTS: In electron microscopy, CsA treatment prevented MCT-induced mitochondrial disruption of RV. RVH was significantly increased in MCT group compared to that of the controls but RVH was more increased with CsA treatment. Thickened medial wall thickness of pulmonary arteriole in PAH was not changed after CsA treatment. In western blot, caspase-3 was significantly increased in MCT group, and was attenuated in CsA treatment. There were no significant differences in voltage-dependent anion channel, adenine nucleotide translocator 1 and cyclophilin D expression in western blot and RT-PCR between the 3 groups. CONCLUSIONS: CsA reduces MCT induced RV mitochondrial damage. Although, MPTP blocking does not reverse pulmonary pathology, it may reduce RV dysfunction in PAH. The results suggest that it could serve as an adjunctive therapy to PAH treatment.
1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine ; Adenine Nucleotide Translocator 1 ; Arterioles ; Blotting, Western ; Caspase 3 ; Cell Death ; Cyclophilins ; Cyclosporine ; Heart Failure ; Heart Ventricles ; Hypertension ; Hypertension, Pulmonary ; Hypertrophy, Right Ventricular ; Microscopy, Electron ; Mitochondria ; Monocrotaline ; Pathology ; Permeability ; Polymerase Chain Reaction ; Pulmonary Circulation ; Rats, Sprague-Dawley ; Reverse Transcription

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.
Animals ; Apoptosis ; Body Weight ; Cell Cycle ; Gene Expression ; Heart* ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Hypertension ; Hypertension, Pulmonary ; Hypertrophy, Right Ventricular ; Male ; Microarray Analysis* ; Monocrotaline ; Myocytes, Smooth Muscle ; Natriuretic Peptide, Brain ; Nitric Oxide Synthase ; Rats* ; RNA ; Simvastatin* ; Ventricular Pressure

An abnormal myocardial perfusion is not uncommon in congenital heart defects (CHD). Many case reports and prospective studies were done describing myocardial peOision scintigraphy (MPS)findings after an arterial switch operation (ASO) among transposition of the great arteries (TCA), but to the best of the authors' knowledge, none have cited MPS findings in the immediate post-operative petiod. This paper aims to show two ckfferent clinicalthuatiomts in which (MPS) was used in the assessment of myocarchalfiinction in TCA immediatelyfollowing an arterial switch operation. Two male infants; aged 2 months and 4 months; both diagnosed with transposition of the great arteries presenting with past-operative morbidities after an arterial switch operation were referred to the Department of Nuclear Medicine/or evaluation. The younger infant was ditty discharged improved with an earlier magical intervention in contrast to the other who expired Bothpatients revealed a scintigraphic picture of myocarcbal ischemia and left ventricular a54ifiniction with concomitant right ventricular hypertrophy MPS .findings and reflective clinical pictures of patients with corrected congenital disease are yet to be/illy elticidated,.from the expected natural course after the stag/Cal intervention and long term complications ofsuch cases. The two cases present an invaluable avenue of non-invasive diagnostic modality using-MPS to assess probable pathologic mechanisms that occur after an arterial switch operation, and perhaps suggest incremental value not only in the post-operative period but in the preoperative scenario in the prognostication of these patients.

Human ; Male ; Female ; Adult ; Infant ; Hypertrophy, Right Ventricular ; Transposition Of Great Vessels ; Arterial Switch Operation ; Myocardial Perfusion Imaging ; Heart Defects, Congenital ; Heart Ventricles

An abnormal myocardial perfusion is not uncommon in congenital heart defects (CHD). Many case reports and prospective studies were done describing myocardial peOision scintigraphy (MPS)findings after an arterial switch operation (ASO) among transposition of the great arteries (TCA), but to the best of the authors' knowledge, none have cited MPS findings in the immediate post-operative petiod. This paper aims to show two ckfferent clinicalthuatiomts in which (MPS) was used in the assessment of myocarchalfiinction in TCA immediatelyfollowing an arterial switch operation. Two male infants; aged 2 months and 4 months; both diagnosed with transposition of the great arteries presenting with past-operative morbidities after an arterial switch operation were referred to the Department of Nuclear Medicine/or evaluation. The younger infant was ditty discharged improved with an earlier magical intervention in contrast to the other who expired Bothpatients revealed a scintigraphic picture of myocarcbal ischemia and left ventricular a54ifiniction with concomitant right ventricular hypertrophy MPS .findings and reflective clinical pictures of patients with corrected congenital disease are yet to be/illy elticidated,.from the expected natural course after the stag/Cal intervention and long term complications ofsuch cases. The two cases present an invaluable avenue of non-invasive diagnostic modality using-MPS to assess probable pathologic mechanisms that occur after an arterial switch operation, and perhaps suggest incremental value not only in the post-operative period but in the preoperative scenario in the prognostication of these patients.

Human ; Male ; Female ; Adult ; Infant ; Hypertrophy, Right Ventricular ; Transposition Of Great Vessels ; Arterial Switch Operation ; Myocardial Perfusion Imaging ; Heart Defects, Congenital ; Heart Ventricles

OBJECTIVE: To explore the role of calpain in pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension and the underlying mechanisms.
 METHODS: Sprague-Dawley rats were randomly divided into the hypoxia group and the normoxia control group. Right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored by a method with right external jugular vein cannula. Right ventricular hypertrophy index was presented as the ratio of right ventricular weight to left ventricular weight (left ventricle plus septum weight). Levels of calpain-1, -2 and -4 mRNA in pulmonary artery were determined by real-time PCR. Levels of calpain-1, -2 and -4 protein were determined by Western blot. Primary rat pulmonary arterial smooth muscle cells (PASMCs) were divided into 4 groups: a normoxia control group, a normoxia+MDL28170 group, a hypoxia group and a hypoxia+MDL28170 group. Cell proliferation was detected by MTS and flow cytometry. Levels of Ki-67 and proliferating cell nuclear antigen (PCNA) mRNA were determined by real-time PCR.
 RESULTS: RVSP, mPAP and right ventricular remodeling index were significantly elevated in the hypoxia group compared to those in the normoxia group. In the hypoxia group, pulmonary vascular remodeling was significantly developed, accompanied by up-regulation of calpain-1, -2 and -4. MDL28170 significantly inhibited hypoxia-induced proliferation of PASMCs concomitant with the suppression of Ki-67 and PCNA mRNA expression.
 CONCLUSION Calpain mediates vascular remodeling via promoting proliferation of PASMCs in hypoxia-induced pulmonary hypertension.
Animals ; Calpain ; genetics ; physiology ; Cell Proliferation ; Dipeptides ; physiology ; Hypertension, Pulmonary ; chemically induced ; genetics ; physiopathology ; Hypertrophy, Right Ventricular ; Hypoxia ; Ki-67 Antigen ; drug effects ; Myocytes, Smooth Muscle ; physiology ; Proliferating Cell Nuclear Antigen ; drug effects ; Pulmonary Artery ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Up-Regulation ; Vascular Remodeling ; genetics ; physiology