Impact of acute and enduring volume overload on mechanotransduction and cytoskeletal integrity of canine left ventricular myocardium

2007 ◽  
Vol 292 (5) ◽  
pp. H2324-H2332 ◽  
Author(s):  
Dirk W. Donker ◽  
Jos G. Maessen ◽  
Fons Verheyen ◽  
Frans C. Ramaekers ◽  
Roel L. H. M. G. Spätjens ◽  
...  
Keyword(s):  
Protein Expression ◽  
Volume Overload ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Mechanical Stimuli ◽  
Hypertrophic Growth ◽  
Lim Protein ◽  
Ventricular Mechanics

It is poorly understood how mechanical stimuli influence in vivo myocardial remodeling during chronic hemodynamic overload. Combined quantitation of ventricular mechanics and expression of key proteins involved in mechanotransduction can improve fundamental understanding. Adult anesthetized dogs ( n = 20) were studied at sinus rhythm (SR) and 0, 3, 10, and 35 days of complete atrioventricular block (AVB). Serial left ventricular (LV) myofiber mechanics were measured. Repeated LV biopsies were analyzed for mRNA and/or protein expression of β1D-integrin, melusin, Akt, GSK3β, muscle LIM protein (MLP), four-and-a-half LIM protein 2 (fhl2), desmin, and calpain. Upon AVB, increased ejection strain (0.29 ± 0.01 vs. 0.13 ± 0.02, SR) and end-diastolic stress (4.8 ± 1.1 vs. 2.7 ± 0.4 kPa) dominated mechanical changes. Brain natriuretic peptide plasma levels were correspondingly high (33 ± 4 vs. 19 ± 1 pg/ml, SR). β1D-Integrin protein expression increased chronically after AVB. Melusin was temporarily overexpressed (+33 ± 9%, 3 days AVB vs. SR), followed by elevated ratios of phosphorylated (P)-Akt to Akt and P-GSK3β to GSK3β (+26 ± 6% and +30 ± 8% at 10 days AVB vs. SR). These changes corresponded to peak hypertrophic growth at 3 to 10 days. MLP increased gradually to maxima at chronic AVB (+36 ± 7%). In contrast, fhl2 (−22 ± 3%, 3 days) and desmin (−30 ± 9%, 10 days AVB) transiently declined but recovered at chronic AVB. Calpain protein expression remained unaltered. In conclusion, volume overload after AVB causes a transient compromise of cytoskeletal integrity based, at least partly, on transcriptional downregulation. Subsequent cytoskeletal reorganization coincides with the upregulation of melusin, P-Akt, P-GSK3β, and MLP, indicating a strong drive to compensated hypertrophy.

β-blockade abolishes the augmented cardiac tPA release induced by transactivation of heterodimerised bradykinin receptor-2 and β2-adrenergic receptor in vivo

2014 ◽  
Vol 112 (11) ◽  
pp. 951-959 ◽  
Author(s):  
Morten Eriksen ◽  
Arnfinn Ilebekk ◽  
Alessandro Cataliotti ◽  
Cathrine Rein Carlson ◽  
Torstein Lyberg ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Sympathetic Nerves ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Adrenergic Stimulation ◽  
Β2 Adrenergic Receptor ◽  
Β Blocker

SummaryBradykinin (BK) receptor-2 (B2R) and β2-adrenergic receptor (β2AR) have been shown to form heterodimers in vitro. However, in vivo proofs of the functional effects of B2R-β2AR heterodimerisation are missing. Both BK and adrenergic stimulation are known inducers of tPA release. Our goal was to demonstrate the existence of B2R-β2AR heterodimerisation in myocardium and to define its functional effect on cardiac release of tPA in vivo. We further investigated the effects of a non-selective β-blocker on this receptor interplay. To investigate functional effects of B2R-β2AR heterodimerisation (i. e. BK transactivation of β2AR) in vivo, we induced serial electrical stimulation of cardiac sympathetic nerves (SS) in normal pigs that underwent concomitant BK infusion. Both SS and BK alone induced increases in cardiac tPA release. Importantly, despite B2R desensitisation, simultaneous BK infusion and SS (BK+SS) was characterised by 2.3 ± 0.3-fold enhanced tPA release compared to SS alone. When β-blockade (propranolol) was introduced prior to BK+SS, tPA release was inhibited. A persistent B2R-β2AR heterodimer was confirmed in BK-stimulated and nonstimulated left ventricular myocardium by immunoprecipitation studies and under non-reducing gel conditions. All together, these results strongly suggest BK transactivation of β2AR leading to enhanced β2AR-mediated release of tPA. Importantly, non-selective β-blockade inhibits both SS-induced release of tPA and the functional effects of B2R-β2AR heterodimerisation in vivo, which may have important clinical implications.

scholarly journals NT pro- B-type Natriuretic Peptide in the Small Ventricular Septal Defect in Children

2021 ◽  
Vol 9 (B) ◽  
pp. 1677-1680
Author(s):  
Rahmat Budi Kuswiyanto ◽  
Putria Apandi ◽  
Dany Hilmanto ◽  
Muhammad Hasan Bashari ◽  
Sri Endah Rahayuningsih
Keyword(s):  
Natriuretic Peptide ◽  
Transcatheter Closure ◽  
Volume Overload ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Natriuretic Peptide Level ◽  
Peptide Level ◽  
Before And After ◽  
Male Patients

Background: Brain natriuretic peptide is a cardiac hormone secreted from the left ventricular myocardium due to ventricular expansion and volume overload. A recent study shows that small VSD will have risk of ventricular dysfunction in adulthood. Another complications such as endocarditis, congestive heart failure, aortic regurgitation, arrhythmia also we should be aware. Evaluations of the plasma B-type natriuretic peptide level (NT pro BNP) are currently being considered as methods to identify the possible presence of ventricular dilation in small VSD. Objective: To evaluate the change in plasma B-type natriuretic peptide after transcatheter closure of VSD. Methods: A pretest-posttest design was conducted on VSD patients before and after transcatheter closure. Plasma B-type natriuretic peptide level were measured before and 30 days after the transcatheter closure of VSD. Result: A total of 32 peri membranous VSD patients were included in this study with 62.5 % female patients (n=20) and 37.5 % male patients (n=12). A significant decrease was observed in the median NT pro BNP level when the level before closure of 1.08 (0.74 – 3.47) ng/ml was compared to the level after closure of 0.91 (0.68 – 2.07) ng/ml (p<0.05). Conclusion: Significant decreases in NT pro BNP level are seen in small VSD patients 30 days after transcatheter closure. Patients with small peri membranous VSD are generally considered to need occlusion for their childhood defect.  

Laminar fiber architecture and three-dimensional systolic mechanics in canine ventricular myocardium

1999 ◽  
Vol 276 (2) ◽  
pp. H595-H607 ◽  
Author(s):  
Kevin D. Costa ◽  
Yasuo Takayama ◽  
Andrew D. McCulloch ◽  
James W. Covell
Keyword(s):  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Wall Thickening ◽  
Left Ventricular Myocardium ◽  
Fiber Architecture ◽  
Left Ventricular Free Wall ◽  
Ventricular Mechanics ◽  
Interlaminar Shear ◽  
Canine Ventricular Myocardium

Previous studies suggest that the laminar architecture of left ventricular myocardium may be critical for normal ventricular mechanics. However, systolic three-dimensional deformation of the laminae has never been measured. Therefore, end-systolic finite strains relative to end diastole, from biplane radiography of transmural markers near the apex and base of the anesthetized open-chest canine anterior left ventricular free wall ( n = 6), were referred to three-dimensional laminar microstructural axes reconstructed from histology. Whereas fiber shortening was uniform [−0.07 ± 0.04 (SD)], radial wall thickening increased from base (0.10 ± 0.09) to apex (0.14 ± 0.13). Extension of the laminae transverse to the muscle fibers also increased from base (0.08 ± 0.07) to apex (0.11 ± 0.08), and interlaminar shear changed sign [0.05 ± 0.07 (base) and −0.07 ± 0.09 (apex)], reflecting variations in laminar architecture. Nevertheless, the apex and base were similar in that at each site laminar extension and shear contributed ∼60 and 40%, respectively, of mean transmural thickening. Kinematic considerations suggest that these dual wall-thickening mechanisms may have distinct ultrastructural origins.

Immuno-Enzyme Histochemistry of Creatine Phosphokinase

1977 ◽  
Vol 35 ◽  
pp. 446-447
Author(s):  
N. Baba ◽  
E.T. Poe ◽  
J. Scillian ◽  
T. Myser
Keyword(s):  
Creatine Phosphokinase ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Rabbit Muscle ◽  
Cytoplasmic Staining ◽  
Heart Muscle Cells ◽  
Diffuse Cytoplasmic Staining ◽  
Strong Staining

With a commercially available rabbit muscle (MM) type isoenzyme of the creatine phosphokinase (CPK) (Worthington Biochemical), anti-CPK antibody was produced in chicken and goat (Figure 1). Fab' fragments of the chicken and goat IgG were isolated and conjugated with a commercially available horseradish peroxidase (HRP) according to the Nakane method (J. Histochem. Cytochem,, 22:1084, 1974).Rabbit hearts were perfused in vivo with freshly prepared 2% paraformaldehyde solution, and the left ventricular myocardium was fixed for 30 minutes. Forty-micrometer-thick frozen sections of the myocardium were incubated with the Fab'-HRP conjugate overnight at 4°C. After a thorough rinse, the sections were stained for the peroxidase reaction.In an electron microscope, diffuse cytoplasmic staining of the heart muscle cells was noted, indicating the diffuse cytosol distribution of CPK (Figure 2). In addition, there was strong staining of the intermembranous and intracristal space of the mitochondria as well as the M-lines of the myofibrils (Figures 3 and 4).

Abstract 13391: Cardiomyocyte Cell Cycling, Maturation, and Growth by Multinucleation in Postnatal Swine

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Nivedhitha Velayutham ◽  
Christina M Alfieri ◽  
Emma J Agnew ◽  
Kyle W Riggs ◽  
Richard S Baker ◽  
...  
Keyword(s):  
Ventricular Myocardium ◽  
Postnatal Period ◽  
Left Ventricular ◽  
Cell Junctions ◽  
Left Ventricular Myocardium ◽  
Cross Sectional ◽  
Hypertrophic Growth ◽  
Species Response ◽  
Neuronal Remodeling ◽  
Cell Cycling

Background: Rodent cardiomyocytes (CM) undergo mitotic arrest and decline of mononucleated-diploid population post-birth, which are implicated in neonatal loss of heart regenerative potential. However, the dynamics of postnatal CM maturation are largely unknown in swine, despite a similar neonatal cardiac regenerative capacity as rodents. Here, we provide a comprehensive analysis of postnatal cardiac maturation in swine, including CM cell cycling, multinucleation and hypertrophic growth, as well as non-CM cardiac factors such as extracellular matrix (ECM), immune cells, capillaries, and neurons. Our study reveals discordance in postnatal pig heart maturational events compared to rodents. Methods and Results: Left-ventricular myocardium from White Yorkshire-Landrace pigs at postnatal day (P)0 to 6 months (6mo) was analyzed. Mature cardiac sarcomeric characteristics, such as fetal TNNI1 repression and CX43 co-localization to cell junctions, were not evident until P30 in pigs. In CMs, appreciable binucleation is observed by P7, with extensive multinucleation (4-16 nuclei per CM) beyond P15. Individual CM nuclei remain predominantly diploid at all ages. CM mononucleation at ~50% incidence is observed at P7-P15, and CM mitotic activity is measurable up to 2mo. CM cross-sectional area does not increase until 2mo-6mo in pigs, though longitudinal CM growth proportional to multinucleation occurs after P15. RNAseq analysis of neonatal pig left ventricles showed increased expression of ECM maturation, immune signaling, neuronal remodeling, and reactive oxygen species response genes, highlighting significance of the non-CM milieu in postnatal mammalian heart maturation. Conclusions: CM maturational events such as decline of mononucleation and cell cycle arrest occur over a 2-month postnatal period in pigs, despite reported loss of heart regenerative potential by P3. Moreover, CMs grow primarily by multinucleation and longitudinal hypertrophy in older pigs, distinct from mice and humans. These differences are important to consider for preclinical testing of cardiovascular therapies using swine, and may offer opportunities to study aspects of heart regeneration unavailable in other models.

Abstract 382: Kidney-Heart Connection: One Kidney Nephrectomy Results in Cardiac Fibrosis and Differential Ventricular Gene Profiles in the Absence of Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Fernando L Martin ◽  
Brenda K Huntley ◽  
Gerald E Harders ◽  
John C Burnett
Keyword(s):  
Renal Insufficiency ◽  
Renal Dysfunction ◽  
Microarray Analysis ◽  
Volume Overload ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Unilateral Nephrectomy ◽  
Left Ventricular Myocardium ◽  
Cardiovascular Morbidity And Mortality ◽  
Mild Renal Insufficiency

Background: Decreased renal function is associated with increased cardiovascular morbidity and mortality by mechanisms that remain unclear. We hypothesized that even mild renal insufficiency produced by unilateral nephrectomy results in changes in ventricular structure and gene expression in the absence of hypertension or volume overload underscoring a kidney-heart connection in the control of myocardial structure. Methods: Cardiorenal function and structure were assessed in Wistar rats [sham (S; n=10) and unilateral nephrectomized (UNX; n=9)] 4 weeks after UNX. GFR was determined by inulin clearance and renal blood flow (RBF) by PAH. Blood was obtained for BNP, PRA, and aldosterone. Hearts and kidneys were harvested for histological analysis. Cardiac function was assessed by echo. Genome-wide microarray analysis was performed on left ventricular myocardium (Affymetrix GeneChip® Rat Genome 230 2.0). Results: Glomerular hypertrophy was observed in UNX (S:1±0.04, Nx:1.6±0.1 u3x106, p<0.001). GFR tended to decrease with a reduction in RBF (S:8±1, Nx:5±1 ml/min, p<0.005). Sodium and water excretions were not different between groups with no activation of PRA, aldosterone or BNP. LVEF and LV end-systolic and end-diastolic diameters were normal. Blood pressure (BP) was not different between groups. Importantly, Picrosirius Red staining in the ventricular myocardium of UNX compared to S revealed greater fibrosis (S:2.4±0.1, Nx:4.2±0.4 %, p<0.001). Further, microarray analysis of ventricular myocardium revealed that 278 genes significantly changed with UNX (1.5 fold, P<0.05) compared to S in genes related to cell growth, bone remodeling and muscle contraction (Z value>2). Conclusion: We conclude that even mild renal insufficiency produced by unilateral nephrectomy initiates myocardial gene responses and fibrosis independent of alterations in the circulating RAAS, BNP, BP, volume overload or systolic dysfunction. These studies support a kidney - heart connection in early renal dysfunction resulting in molecular ventricular remodeling and fibrosis. These studies in experimental mild renal dysfunction produced by removal of one kidney reveal a renal mediated mechanism for myocardial remodeling.

In vivo detection of endogenous acetylcholine release in cat ventricles

1994 ◽  
Vol 266 (3) ◽  
pp. H854-H860 ◽  
Author(s):  
T. Akiyama ◽  
T. Yamazaki ◽  
I. Ninomiya
Keyword(s):  
Nerve Stimulation ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Vagal Nerve ◽  
Vagal Nerve Stimulation ◽  
Left Ventricular Myocardium ◽  
Ach Release ◽  
Vagal Nerves ◽  
Dialysis Technique

To detect and monitor endogenous acetylcholine (ACh) release in the in vivo heart, we applied a dialysis technique to the hearts of anesthetized cats. Dialysis probes were implanted in the left ventricular myocardium and were perfused with Krebs-Henseleit solution containing Eserine (10(-4) M) at 3 microliters/min. Dialysate ACh concentration was measured with high-performance liquid chromatography. In four cats, the response to vagal stimulation was studied. Electrical stimulation of efferent vagal nerves (10 Hz) significantly increased dialysate ACh concentration from 596 +/- 118 (control) to 12,210 +/- 1,661 pM. After stimulation, dialysate ACh concentration significantly decreased to 382 +/- 80 pM below control. The influence of ganglionic blocker was determined in six cats. Control vagal nerve stimulation (10 Hz) increased dialysate ACh concentration from 582 +/- 136 to 9,102 +/- 754 pM. Local perfusion of hexamethonium (10(-4) M) did not affect this nerve stimulation-induced ACh increase (8,611 +/- 1,189 pM), and intravenous administration of hexamethonium (20 mg/kg) prevented this increase (340 +/- 88 pM). We examined the response to vagal nerve stimulation at different frequencies in three cats. Vagal nerve stimulation increased dialysate ACh concentration from a control of 588 +/- 211 to 1,227 +/- 195 pM at 2 Hz, 3,946 +/- 1,059 pM at 5 Hz, and 9,366 +/- 1,873 pM at 10 Hz. Dialysate ACh concentration reflects ACh release from postganglionic vagal nerves innervating the left ventricular myocardium; the dialysis technique permits estimation of relative changes in efferent cardiac vagal nerve activity.

Abstract 36: Cardiac Progenitor Cell Lineage Tracing During Embryonic Cardiomyogenesis

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Bingyan J Wang ◽  
Alvin Muliono ◽  
Roberto Alvarez ◽  
Mark A Sussman
Keyword(s):  
Adoptive Transfer ◽  
Connexin 43 ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Lineage Tracing ◽  
Left Ventricular Myocardium ◽  
Post Injection ◽  
Term Survival

Introduction: Stem cell therapy represents great promises to myocardium regeneration. Multipotent c-Kit pos cardiac progenitor cells (CPCs) are able to differentiate into endothelial cells, smooth muscle cells, and cardiomyocytes. However, fundamental knowledge of CPC biology remains incomplete. Studies in rodent myocardial infarction model revealed that CPCs have poor long-term survival and engraftment after adoptive transfer, perhaps due to the severely damaged host environment. Therefore, it is critical to understand how CPCs interface with the recipient environment following transfer in order to enhance their true regenerative potentials. Hypothesis: Adoptively transferred stem cells are thought to survive and engraft best in an environment closely resembling their original habitat. Thus, we hypothesized that the embryonic environment provides the optimal spatiotemporal conditions to promote CPCs engraftment and commitment to cardiac fate. Methods: CPCs isolated from adult mouse hearts were expanded, fluorescence-tagged, and injected into blastocysts at E3.75 and in utero at E15.5. Embryos were analyzed following cardiogenesis by immunofluorescence for presence of CPC-derived tissues. Additionally, CPCs were injected intramyocardially at various stages from P0 to P7, to follow long-term adoptive transfer and assess CPCs lineage commitment. Results and Conclusions: At 48 hours post injection, donor CPCs were found anchoring in blastocoel and trophoblasts at E5.5, and were detected within the host myocardium at E17.5 predominantly at perivascular regions (n=4). Interestingly, CPCs also integrated into aminochorionic sac, indicating a novel non-cardiogenic fate of CPCs (n=5). CPCs injected at P3 stably engrafted into left ventricular myocardium by 14 days post injection (n=4), sharing gap junction proteins (ZO-1, Connexin-43) with neighboring cells. In conclusion, this study provides vivid evidence for the first time of CPC engraftment and survival in vivo under homeostasis during cardiogenesis. Future studies will assess the permissive environmental conditions, which may optimize their use in therapeutic applications, and the cardiogenic potential of CPCs in order to provide fundamental insights on CPCs biology.

scholarly journals Noninvasive measurements of transmural myocardial metabolites using 3-D 31P NMR spectroscopy

2001 ◽  
Vol 280 (1) ◽  
pp. H489-H497 ◽  
Author(s):  
Yong K. Cho ◽  
Hellmut Merkle ◽  
Jianyi Zhang ◽  
Nikolaos V. Tsekos ◽  
Robert J. Bache ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
31P Nmr Spectroscopy ◽  
Phase Encoding ◽  
Noninvasive Measurements ◽  
Magnetic Field Magnitude

A completely noninvasive three-dimensional (3-D) static magnetic field magnitude spatially localized 31P spectroscopy technique has been developed and applied to study the in vivo canine myocardium at 9.4 T. The technique incorporates both Fourier series windows and selective Fourier transform methods utilizing all three orthogonal gradients for 3-D phase encoding. The number of data acquisitions for each phase-encoding step was weighted according to the Fourier coefficients to define cylindrical voxels. Spatially localized 31P spectra can be generated for voxels of desired location within the field of view as a postprocessing step. The quality of localization was first demonstrated by using a three-compartment phantom. The technique was then applied to in vivo canine models and yielded 31P cardiac spectra with an excellent signal-to-noise ratio. The in vivo validation experiments, using an implanted 2-phosphoenolpyruvate-containing marker, demonstrated that the technique is capable of measuring at least two transmural layers of left ventricular myocardium representing the subepicardium and subendocardium.

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