The relationship between splenic, renal, gastric and cardiac sonographic and post-mortem measurements in horses

2012 ◽  
Vol 8 (1) ◽  
pp. 27-31
Author(s):  
C. Navas de Solis ◽  
J.H. Foreman ◽  
C.R. Byron ◽  
R.E. Carpenter
Keyword(s):  
Root Diameter ◽  
Left Ventricular ◽  
Heart Weight ◽  
Strongly Correlated ◽  
Spleen Size ◽  
Post Mortem ◽  
Internal Reference ◽  
Athletic Ability ◽  
Interesting Corollary ◽  
Splenic Size

The relationships between spleen size and the size of kidney, stomach, and heart were studied ultrasonographically. Kidney was studied as a non-mobile internal reference standard. Stomach has been reported to alter spleen size with changing stomach diameter. Heart would logically be hypothesized to correlate with spleen size as measure of athleticism. Standard echocardiograms, sonographic and post-mortem splenic, renal and gastric measurements were obtained from 8 donated horses. Splenic measurements were obtained at baseline and after administration of epinephrine and detomidine (separately) to mimic maximal and resting sympathetic tone and obtain minimal and maximal splenic size, respectively. No significant correlations (r<0.5, P≯0.05) were observed between the sonographic or post-mortem splenic measurements and sonographic or post-mortem renal measurements. Sonographically-estimated and post-mortem spleen volume were correlated with the sonographic (r=0.89, P=0.003) and post-mortem stomach length (r=0.77, P=0.02). Sonographic and post-mortem gastric measurements were not strongly correlated. Baseline (before administration of drugs) sonographically-estimated volume of the spleen was not strongly correlated with echocardiographic or post-mortem cardiac measurements. Sonographically-estimated splenic volume after detomidine administration was correlated with left ventricular weight (r=0.82, P=0.01). The post-mortem volume of the spleen was moderately correlated with aortic root diameter (r=0.75, P=0.03) and the correlation approached significance for heart weight (r=0.7, P=0.055). The spleen-to-kidney ratio is unlikely to be useful in assessing splenomegaly in horses. Further studies are needed to assess the accuracy of the sonographic method to measure the kidneys, stomach and the effect of gastric filling on splenic size. Assessment of the interactions between cardiac size, splenic size, and athletic ability would be an interesting corollary to this experiment.

The aging-induced hyperexcretion of glucose-dependent insulinotropic peptide is essential for the healthy cardiac remodeling by prevention of cardiac ceramide accumulation

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Kureishi Bando ◽  
Y.R Remina ◽  
T.K Kamihara ◽  
K.N Nishimura ◽  
T.M Murohara
Keyword(s):  
Oxidative Stress ◽  
Ketone Bodies ◽  
Left Ventricular ◽  
Heart Weight ◽  
Lv Function ◽  
Cardiac Aging ◽  
Normal Left Ventricular ◽  
Insulinotropic Peptide ◽  
Ceramide Accumulation ◽  
And Oxidative Stress

Abstract Background Glucose-dependent insulinotropic peptide (GIP) is incretin hormone that is emerged as an important regulator of lipid metabolism. Fat intake induces hypersecretion of GIP that is involved in obesity and ectopic fat accumulation. Aging is another stimulant of GIP hypersecretion, which is suggested as a cause of “sarcopenic obesity in elderly”. In heart, aging is the known risk factor of HFpEF, of which typical characteristics is pathological cardiac hypertrophy induced by unknown cause(s). It remained uncertain whether any ectopic fat accumulation, such as cardiac steatosis may cause the aging-induced cardiac hypertrophy. Ceramide is one of the lipid metabolites that involves in apoptosis, inflammation, and stress responses, which are among the pathogenic components of heart failure. However, it remained unclear whether the ceramide may play any pathophysiological role in cardiac aging. Purpose We thus hypothesized whether cardiac aging may alter cardiac lipid metabolism and the GIP may play a regulatory role in the cardiac aging via modulating cardiac steatosis, particularly ceramide. Methods Mouse model of GIPR deficiency (GIPR-KO) was employed and cardiac evaluation of GIPR-KO and the age-matched wild type mice were performed. Results Aging (50w/o) induced GIP hypersecretion in control mice and their body and heart weight were 50% increased as compared to younger counterpart (10w/o). In contrast, the aging-induced increase rate in body and heart weight of GIPR-KO was significantly lower (22%). Aging also increased the circulating ketone bodies with increase in FGF21 expression in heart and, notably, there was no pathological increase in cardiac ceremide and oxidative stress with normal left-ventricular (LV) function (LVEF=82.2±1.8). In contrast, GIPR-KO exhibited pathological increase in cardiac ceramide without the elevation of the circulating ketone bodies. The younger GIPR-KO (10 w/o) exhibited normal left-ventricular (LV) function, however, the older mice (50 w/o) exhibited systolic LV dysfunction (LVEF=55.8±8.5) with increase in cardiac apoptosis and oxidative stress. Cardiac ceramide accumulation was increased in the aged normal mice, which was significantly higher in the aged GIPR-KO. Furthermore, GIPR-KO exhibited increase in cardiac fibrosis and oxidative stress, which were absent in the aged normal counterpart. Conclusion Aging increased circulating GIP level the leads to compensatory rise in the circulating ketone bodies without pathological increase in cardiac ceremide and related oxidative stress in heart. Loss of GIP signaling caused pathological increase in cardiac ceramide, leading to the aging-induced progression of systolic left-ventricular dysfunction. Collectively, we conclude that the aging-induced GIP hyperexcretion is essential for the aging-induced healthy cardiac remodeling by augmenting compensatory ketone body elevation. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): KAKEN-HI

scholarly journals Association between Neonatal Intakes and Hyperglycemia, and Left Heart and Aortic Dimensions at 6.5 Years of Age in Children Born Extremely Preterm

2021 ◽  
Vol 10 (12) ◽  
pp. 2554
Author(s):  
Jawwad Hamayun ◽  
Lilly-Ann Mohlkert ◽  
Elisabeth Stoltz Sjöström ◽  
Magnus Domellöf ◽  
Mikael Norman ◽  
...  
Keyword(s):  
Interventricular Septum ◽  
Posterior Wall ◽  
Root Diameter ◽  
Left Ventricular ◽  
Left Heart ◽  
Extremely Preterm ◽  
Extremely Preterm Infants ◽  
Nutritional Data ◽  
Aortic Dimensions

Survivors of extremely preterm birth (gestational age < 27 weeks) have been reported to exhibit an altered cardiovascular phenotype in childhood. The mechanisms are unknown. We investigated associations between postnatal nutritional intakes and hyperglycemia, and left heart and aortic dimensions in children born extremely preterm. Postnatal nutritional data and echocardiographic dimensions at 6.5 years of age were extracted from a sub-cohort of the Extremely Preterm Infants in Sweden Study (EXPRESS; children born extremely preterm between 2004–2007, n = 171, mean (SD) birth weight = 784 (165) grams). Associations between macronutrient intakes or number of days with hyperglycemia (blood glucose > 8 mmol/L) in the neonatal period (exposure) and left heart and aortic dimensions at follow-up (outcome) were investigated. Neonatal protein intake was not associated with the outcomes, whereas higher lipid intake was significantly associated with larger aortic root diameter (B = 0.040, p = 0.009). Higher neonatal carbohydrate intake was associated with smaller aorta annulus diameter (B = −0.016, p = 0.008). Longer exposure to neonatal hyperglycemia was associated with increased thickness of the left ventricular posterior wall (B = 0.004, p = 0.008) and interventricular septum (B = 0.004, p = 0.010). The findings in this study indicate that postnatal nutrition and hyperglycemia may play a role in some but not all long-lasting developmental adaptations of the cardiovascular system in children born extremely preterm.

scholarly journals Associations of the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay diet with cardiac remodelling in the community: the Framingham Heart Study

2021 ◽  
pp. 1-9
Author(s):  
Maura E. Walker ◽  
Adrienne A. O’Donnell ◽  
Jayandra J. Himali ◽  
Iniya Rajendran ◽  
Debora Melo van Lent ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systolic Function ◽  
Global Longitudinal Strain ◽  
Root Diameter ◽  
Left Ventricular ◽  
Cardiac Remodelling ◽  
Lv Function ◽  
The Mediterranean ◽  
Diet Score ◽  
Mind Diet

Abstract Normal cardiac function is directly associated with the maintenance of cerebrovascular health. Whether the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet, designed for the maintenance of neurocognitive health, is associated with cardiac remodelling is unknown. We evaluated 2512 Framingham Offspring Cohort participants who attended the eighth examination cycle and had available dietary and echocardiographic data (mean age 66 years; 55 % women). Using multivariable regression, we related the cumulative MIND diet score (independent variable) to left ventricular (LV) ejection fraction, left atrial emptying fraction, LV mass (LVM), E/e’ ratio (dependent variables; primary), global longitudinal strain, global circumferential strain (GCS), mitral annular plane systolic excursion, longitudinal segmental synchrony, LV hypertrophy and aortic root diameter (secondary). Adjusting for age, sex and energy intake, higher cumulative MIND diet scores were associated with lower values of indices of LV diastolic (E/e’ ratio: logβ = −0·03) and systolic function (GCS: β = −0·04) and with higher values of LVM (logβ = 0·02), all P ≤ 0·01. We observed effect modification by age in the association between the cumulative MIND diet score and GCS. When we further adjusted for clinical risk factors, the associations of the cumulative MIND diet score with GCS in participants ≥66 years (β = −0·06, P = 0·005) and LVM remained significant. In our community-based sample, relations between the cumulative MIND diet score and cardiac remodelling differ among indices of LV structure and function. Our results suggest that favourable associations between a higher cumulative MIND diet score and indices of LV function may be influenced by cardiometabolic and lifestyle risk factors.

scholarly journals Losing Regulation of the Extracellular Matrix is Strongly Predictive of Unfavorable Prognostic Outcome after Acute Myocardial Infarction

2020 ◽  
Vol 21 (17) ◽  
pp. 6219
Author(s):  
Pei-Hsun Sung ◽  
Kun-Chen Lin ◽  
Han-Tan Chai ◽  
John Y. Chiang ◽  
Pei-Lin Shao ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Left Ventricular ◽  
Heart Weight ◽  
Lung Injury Score ◽  
Opposite Pattern ◽  
Knock Out ◽  
Group 4 ◽  
Prognostic Outcome ◽  
Group 3

This study tested the hypothesis that MMP-9−/−tPA−/− double knock out (i.e., MTDKO) plays a crucial role in the prognostic outcome after acute myocardial infarction (AMI by ligation of left-coronary-artery) in MTDKO mouse. Animals were categorized into sham-operated controls in MTDKO animals (group 1) and in wild type (B6: group 2), AMI-MTDKO (group 3) and AMI-B6 (group 4) animals. They were euthanized, and the ischemic myocardium was harvested, by day 60 post AMI. The mortality rate was significantly higher in group 3 than in other groups and significantly higher in group 4 than in groups 1/2, but it showed no difference in the latter two groups (all p < 0.01). By day 28, the left-ventricular (LV) ejection fraction displayed an opposite pattern, whereas by day 60, the gross anatomic infarct size displayed an identical pattern of mortality among the four groups (all p < 0.001). The ratio of heart weight to tibial length and the lung injury score exhibited an identical pattern of mortality (p < 0.01). The protein expressions of apoptosis (mitochondrial-Bax/cleaved-caspase3/cleaved-PARP), fibrosis (Smad3/T-GF-ß), oxidative stress (NOX-1/NOX-2/oxidized-protein), inflammation (MMPs2,9/TNF-α/p-NF-κB), heart failure/pressure overload (BNP/ß-MHC) and mitochondrial/DNA damage (cytosolic-cytochrome-C/γ-H2AX) biomarkers displayed identical patterns, whereas the angiogenesis markers (small vessel number/CD31+cells in LV myocardium) displayed opposite patterns of mortality among the groups (all p < 0.0001). The microscopic findings of fibrotic/collagen deposition/infarct areas and inflammatory cell infiltration of LV myocardium were similar to the mortality among the four groups (all p < 0.0001). MTDKO strongly predicted unfavorable prognostic outcome after AMI.

Abstract 16165: Inorganic Arsenic Induces Sex-Dependent Pathological Cardiac Hypertrophy

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Raihan Kabir ◽  
Prithvi Sinha ◽  
Sumita Mishra ◽  
Obialunanma V Ebenebe ◽  
Nicole Taube ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Cardiac Hypertrophy ◽  
Inorganic Arsenic ◽  
Left Ventricular ◽  
Luciferase Assay ◽  
Heart Weight ◽  
Left Ventricular Geometry ◽  
Wall Thickening ◽  
Pathological Cardiac Hypertrophy ◽  
Relevant Dose

Exposure to inorganic arsenic (iAS) through drinking water is well-associated with adverse cardiovascular outcomes, yet the mechanisms through which it induces these effects are not fully understood. Recent epidemiological findings highlight an association between iAS exposure and altered left ventricular geometry in both the presence and absence of hypertension. We therefore tested the hypothesis that iAS exposure has a bimodal impact on cardiac-intrinsic and hemodynamic mechanisms that together induce pathological remodeling of the myocardium. Adult male and female mice were exposed to an environmentally relevant dose of 615 μg/L NaAsO 2 for eight weeks. Males (n=9-10 mice/group) exhibited increased systolic blood pressure (115.1±3.0 vs. 106.0±2.3 mmHg, p=0.0350) via tail cuff photoplethysmography, left ventricular wall thickening (0.98±0.01 vs. 0.88±0.01 mm, p<0.0001) via transthoracic echocardiography, increased heart weight to tibia length (8.56±0.21 vs. 7.15±0.24 mg/mm; n=24 mice/group), and increased plasma atrial natriuretic peptide (47.85±12.0 vs. 15.14±3.73 pg/mL, p=0.0379) via enzyme immunoassay. Myocardial mRNA transcript levels (n=10 hearts/group) of Acta1 (1.36±0.18 vs. 0.73±0.11, p=0.0037), Myh7 (1.53±0.15 vs. 1.04±0.10, p=0.0138), and Nppa (2.40±0.29 vs. 1.02±0.07, p=0.0001) were increased, and Myh6 (0.92±0.17 vs. 1.14±0.23, p=0.0001) was decreased, evidencing pathological hypertrophy in the male heart. Female hearts, however, were largely protected at this eight-week timepoint as similar changes were not detected. Further investigation found that Rcan1 was upregulated (1.47±0.19 vs. 0.97±0.04, p=0.0161; n=10 hearts/group) in male hearts, suggesting that calcineurin-NFAT was activated. Interestingly, iAS was sufficient to activate NFAT (0.82±0.11 vs. 0.46±0.05, p=0.0214; n=8 wells/group) independent of blood pressure via luciferase assay. In conclusion, these results demonstrate for the first time that iAS may cause pathological cardiac hypertrophy not only by increasing hemodynamic load, but also by activating calcineurin-NFAT and inducing fetal gene expression in the male heart, thus providing novel mechanistic insight into the threat of iAS exposure to the cardiovascular system.

Abstract 280: Deficiency of FKBP12 in the Heart Leads to Impaired Contractility and Pregnancy Induced Cardiomyopathy

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Joshua Oakes ◽  
Susan Hamilton
Keyword(s):  
Ejection Fraction ◽  
Ryanodine Receptors ◽  
Left Ventricular ◽  
Heart Weight ◽  
Mild Phenotype ◽  
Adult Mice ◽  
Significant Difference ◽  
Fk506 Binding Proteins ◽  
Deficient Mice ◽  
Fractional Shortening

FK506 Binding Proteins (FKBPs) are a family of cis-trans prolyl isomerases that bind rapamycin and FK506. FKBP12 and 12.6 interact with ryanodine receptors (RyR), homotetrameric transmembrane ion channels that regulate Ca2+ release from the sarcoplasmic reticulum (SR). FKBP12 interacts with RyR1 in skeletal muscle and FKBP12.6 interacts with RyR2 in cardiac muscle to regulate the Ca2+ leak properties of these channels. Recently it has been suggested that FKBP12 also plays a role in regulating RyR2 activity. Using mice with a cardiac specific deficiency in FKBP12, we analyzed the role of FKBP12 in cardiac function. We found that both male and female mice with a α-MyHC Cre/Lox mediated deficiency in FKBP12 in the heart (FKBP12 KD) developed a mild dilated cardiomyopathy, with enlarged left ventricular diameter both during systole and diastole, decreased ejection fraction and decreased fractional shortening. To elucidate the mechanism for these effects we assessed Ca2+ sparks in isolated cardiomyocytes. We found an increase in both Ca2+ spark frequency and spark amplitude in FKBP12 cardiac deficient mice without a change in spark duration. Despite a mild phenotype in adult mice, we found that approximately 25% of all pregnancies (26/106) in the FKBP12 deficient mice resulted in the mothers dying following the birth. Autopsies show that these cardiac specific FKBP12 deficient mice had increased heart weight and significantly dilated ventricles compared to female Cre mice. Our data suggest that a cardiac specific deficiency in FKBP12 leads to the development of pregnancy induced cardiomyopathy. Echocardiography on FKBP12 deficient mice one day after giving birth found that there was no significant difference in ejection fraction or fractional shortening compared to α-MyHC Cre control mice. FKBP12 deficient females, however, had larger hearts and 50% (2/4) displayed heart failure and died. In conclusion, we show that FKBP12 does indeed alter Ca2+ handling in the heart and that a loss of FKBP12 leads to the development of pregnancy induced cardiomyopathies in females.

Inhibition and reversal of myocardial infarction-induced hypertrophy and heart failure by NHE-1 inhibition

2004 ◽  
Vol 286 (1) ◽  
pp. H381-H387 ◽  
Author(s):  
Ling Chen ◽  
Chang Xun Chen ◽  
Xiaohong Tracey Gan ◽  
Norbert Beier ◽  
Wolfgang Scholz ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Infarct Size ◽  
Treatment Delay ◽  
Left Ventricular ◽  
Heart Weight ◽  
Coronary Artery Ligation ◽  
Treatment Protocols ◽  
Beneficial Effects ◽  
All Treatment

Sodium/hydrogen exchange (NHE) inhibitors show promise as potential therapeutic agents for the treatment of heart failure, but it is not known whether they can reverse the maladaptive remodeling that results in heart failure. We sought to determine the effect of the NHE-1-specific inhibitor EMD-87580 (EMD) on heart failure produced by myocardial infarction in the rat and to assess whether up to 4 wk of treatment delay results in beneficial effects. Male Sprague-Dawley rats were subjected to coronary artery ligation (or a sham procedure) and followed for up to 3 mo, at which time hypertrophy and hemodynamics were determined. EMD was provided in the diet, and treatment commenced immediately or 2–4 wk after ligation. EMD significantly reduced hemodynamic abnormalities, including the elevation in left ventricular end-diastolic pressure, and diminished the loss of systolic function with all treatment protocols. Left ventricular dilatation and hypertrophy, as assessed by heart weight, cell size, and atrial natriuretic peptide (ANP) expression, were similarly reversed to sham or near-sham levels. In addition, the increased plasma ANP and pro-ANP values were reversed to levels not significantly different from sham. Surprisingly, virtually all beneficial effects were identical with all treatment protocols. These effects were observed in the absence of infarct size reduction or blood pressure-lowering effects. Our results suggest that NHE-1 inhibition attenuates and reverses postinfarction remodeling and heart failure with a treatment delay of up to 4 wk after infarction. The effect is independent of infarct size or afterload reduction, indicating a direct effect on the myocardium.

Effect of endurance training on cardiac morphology in Alaskan sled dogs

1998 ◽  
Vol 85 (4) ◽  
pp. 1368-1375 ◽  
Author(s):  
R. L. Stepien ◽  
K. W. Hinchcliff ◽  
P. D. Constable ◽  
J. Olson
Keyword(s):  
Endurance Training ◽  
Morphological Changes ◽  
Left Ventricular ◽  
Volume Index ◽  
Heart Weight ◽  
Wall Thickening ◽  
Cardiac Morphology ◽  
End Diastolic Volume ◽  
Sled Dogs ◽  
Lv Mass

The cardiac morphology of 77 conscious Alaskan sled dogs before and after 5 mo of endurance training (20 km/day team pulling a sled and musher) was studied using two-dimensional and M-mode echocardiography. Subgroups included dogs with at least one season of previous training (“veterans”) and dogs undergoing their first season of training (“rookies”). Training resulted in a significant ( P< 0.05) decrease in resting heart rate (−15%) and significant increases in interventricular septal thickness (systole, 15%; diastole, 13%), left ventricular (LV) internal dimension in diastole (LVIDd, 4%), LV free wall thickness in systole (9%) and diastole (LVWd, 9%), and left atrial diameter (5%) in all dogs, but the increase in LVWd was greater in rookies (16%) than in veterans (7%). Training increased end-diastolic volume index (8%), LV mass index (24%), and heart weight index (24%) and decreased the LVIDd-to-LVWd ratio (−6%) but did not alter cardiac index. We conclude that increased LV mass attributable to LV dilation and hypertrophy is associated with endurance training in Alaskan sled dogs. Disproportionate LV wall thickening accompanying LV dilation suggests that cardiac morphological changes are due to volume and pressure loading. These training-induced changes are similar to those documented in human athletes undergoing combined isometric and isotonic training and differ from studies of dogs trained on treadmills.

scholarly journals Teratogenic effect of alcohol on the myocardium of laboratory animals at the stages of prenatal ontogenesis (literature review)

Morphologia ◽  
2021 ◽  
Vol 15 (3) ◽  
pp. 30-38
Author(s):  
O.A. Cherkas
Keyword(s):  
Alcohol Consumption ◽  
Adverse Effects ◽  
Retrospective Analysis ◽  
Structural Organization ◽  
Alcohol Intoxication ◽  
Left Ventricular ◽  
Laboratory Animals ◽  
Heart Weight ◽  
Heart Cells ◽  
Time Frequency

Background. To date, close attention is paid to the problems of formation and development of the myocardium in general and in particular its structural components. This phenomenon is associated with an increase in cardiovascular malformations in both adults and infants. These defects can be caused by genetic factors, as well as various teratogenic substances. One such substance is alcohol. Despite the risks, many women still drink alcohol during pregnancy. The main problem is that almost half of pregnancies are unplanned, so a woman may continue to consume alcohol for several weeks before learning about her condition. Especially in young women, fertilization can occur in a state of intoxication. In addition, under the influence of ethanol, cardiac function may be impaired in the absence of structural abnormalities. Chronic alcohol intoxication causes changes in the myocardium at all levels of its structural organization. First of all, teratogenic changes caused by the action of ethanol affect the development of cardiomyocytes in the process of embryogenesis, which contributes to the underdevelopment of the structure or function of heart cells. Although the effect of maternal alcohol consumption on the fetus has been studied for decades, there are still conflicting conclusions about the severity of myocardial morphological changes depending on the time, frequency and duration of alcohol consumption. Objective: to conduct a retrospective analysis of literature sources devoted to the study of adverse effects on the fetus caused by alcohol. Methods. The paper conducted a retrospective analysis of literature references and formed an understanding of the changes in the structure of the myocardium caused by teratogenic effects of alcohol. Results and conclusion. Analysis of literature sources showed a high level of adverse effects observed in offspring born to alcoholic mothers. Detrimental effects of alcohol cause changes in the myocardium at all levels of structural organization, including its ultrastructure. It was studied that prenatal exposure to ethanol induces significant changes in relative heart weight, left ventricular wall thickness and cardiomyocyte size. Exposure to high concentrations of alcohol in experimental animals during gestation can lead to congenital heart defects, such as atrial, ventricular, and septal defects. The main manifestation of the prenatal effect of alcohol after birth is the fetal alcohol syndrome, which combines various degrees of deviation in the development of the child.

Minimally invasive aortic banding in mice: effects of altered cardiomyocyte insulin signaling during pressure overload

2003 ◽  
Vol 285 (3) ◽  
pp. H1261-H1269 ◽  
Author(s):  
Ping Hu ◽  
Dongfang Zhang ◽  
LeAnne Swenson ◽  
Gopa Chakrabarti ◽  
E. Dale Abel ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Insulin Signaling ◽  
Systolic Pressure ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Tissue Growth ◽  
Cardiac Response ◽  
Heart Weight ◽  
Surgical Morbidity ◽  
Aortic Banding

We developed a minimally invasive method for producing left ventricular (LV) pressure overload in mice. With the use of this technique, we quickly and reproducibly banded the transverse aorta with low surgical morbidity and mortality. Minimally invasive transverse aortic banding (MTAB) acutely and chronically increased LV systolic pressure, increased heart weight-to-body weight ratio, and induced myocardial fibrosis. We used this technique to determine whether reduced insulin signaling in the heart altered the cardiac response to pressure overload. Mice with cardiac myocyte-restricted knockout of the insulin receptor (CIRKO) have smaller hearts than wild-type (WT) controls. Four weeks after MTAB, WT and CIRKO mice had comparably increased LV systolic pressure, increased cardiac mass, and induction of mRNA for β-myosin heavy chain and atrial natriuretic factor. However, CIRKO hearts were more dilated, had depressed LV systolic function by echocardiography, and had greater interstitial fibrosis than WT mice. Expression of connective tissue growth factor was increased in banded CIRKO hearts compared with WT hearts. Thus lack of insulin signaling in the heart accelerates the transition to a more decompensated state during cardiac pressure overload. The use of the MTAB approach should facilitate the study of the pathophysiology and treatment of pressure-overload hypertrophy.

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