Basal and Ethanol-Induced Cardiac Contractile Response in Lean and Obese Zucker Rat Hearts

Ren, Jun; Walsh, Mary F.; Jefferson, LeQuishia; Natavio, Melissa; Ilg, Karl J.; Sowers, James R.; Brown, Ronald C.

doi:10.1159/000025474

Cited by 4 publications

(6 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 60s maneuver reduced DT, +dT/dt and -dT/dt values in myocardium of obese rats, as in Figure 3. The results agree with previous studies showing lower contractile response in obese Zucker rats after 60s of PPP 35 . As -dT/dt is influenced by the frequency of calcium ions absorption into the sarcoplasmic reticulum, 7 the lower Ca 2+ recapture shown by -dT/dt in obese rats suggests that SERCA2 protein activity was reduced.…”

Section: Discussionsupporting

confidence: 93%

“…A previous study showed decreased contractile strength and other functional disorders in basal conditions of obese papillary muscles. 35 Lima-Leopoldo et al 7 showed that increased Ca 2+ extracellular concentration resulted in lower values of myocardial parameters of contraction (DT) and relaxation (-dT/dt) in obesity. These divergences may regard differences in dietary compositions, including added sugar 7 and/or lipid profile from formulations.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

Oliveira¹,

Muzili²,

Carvalho³

et al. 2020

Arquivos Brasileiros De Cardiologia

View full text Add to dashboard Cite

Background: Obesity has been associated with chronic activation of the renin-angiotensin-aldosterone system and with significant changes in cardiac performance. Objective: To assess the impact of a blockade of angiotensin-II receptor type 1 (AT 1 receptor) on morphology and on myocardial functional performance in rats with high-fat diet-induced obesity. Methods: Wistar rats (n=48) were submitted to control (2.9 kcal/g) or high-fat (3.6 kcal/g) diet for 20 weeks. After the 16 th week they were divided into four groups: Control (CO), Obese (OB), Control Losartan (CL) and Obese Losartan (OL). CL and OL received losartan (30 mg/kg/day) in drinking water for four weeks. Subsequently, body composition, systolic blood pressure (SBP) and echocardiographic variables were analyzed. Papillary muscle function was assessed at baseline with 2.50 mM calcium concentration ([Ca 2+ ] o) and after inotropic maneuvers: post-pause potentiation (PPP), [Ca 2+ ] o elevation, and during beta-adrenergic stimulation with isoproterenol. Analysis of the results was performed by the Two-Way ANOVA and by the appropriate comparison test. The level of significance was set at 5%. Results: Although SBP change had been not maintained at the end of the experiment, obesity was associated with cardiac hypertrophy and with increased left ventricle posterior wall shortening velocity. In the study of papillary muscles in basal condition, CL showed lower developed tension maximum negative variation velocity (-dT/dt) than CO. The 60s PPP promoted lower-dT/dt and maximum developed tension (DT) in OB and CL compared with CO, and higher relative DT variation and maximum positive variation velocity (+dT/dt) in OL compared with CL and OB. Under 1.5, 2.0, and 2.5mM [Ca 2+ ] o , the OL group showed higher-dT/dt than CL. Conclusion: Losartan improves myocardial function in high-fat diet-induced obesity.

show abstract

Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

Oliveira¹,

Muzili²,

Carvalho³

et al. 2020

Arquivos Brasileiros De Cardiologia

View full text Add to dashboard Cite

show abstract

“…Reduced contractile function of cardiac myocytes has been demonstrated in models of genetic obesity with concomitant hypertension (46)(47)(48) and diabetes (49). In the present study, untreated OZR exhibited significant decrease in their FS % , which represents a substantial reduction in the LV systolic function.…”

Section: Discussionmentioning

confidence: 99%

Angiotensin‐Converting Enzyme Inhibition Reduces Lipid Deposits in Myocardium and Improves Left Ventricular Function of Obese Zucker Rats

Toblli

Cao

Rivas

et al. 2006

Obesity

View full text Add to dashboard Cite

show abstract

“…Uncorrected obesity, a worldwide epidemic problem, is commonly associated with high cardiovascular morbidity and mortality (1)(2)(3)(4). Compromised ventricular function occurs in severely obese humans and genetically obese rodents in whole hearts (5)(6) and individual cardiomyocytes (7)(8)(9). However, the direct impact of obesity on cardiomyocyte function remains poorly defined in the presence of other confounding factors including hypertension, insulin resistance, diabetes, and dyslipidemia (4)(7)(9)(10)(11).…”

Section: Introductionmentioning

confidence: 99%

“…However, the direct impact of obesity on cardiomyocyte function remains poorly defined in the presence of other confounding factors including hypertension, insulin resistance, diabetes, and dyslipidemia (4)(7)(9)(10)(11). Depressed contractile function of cardiomyocytes has been shown in models of genetic obesity with concomitant hypertension (8)(9) and diabetes (12)(13). Recently, cardiomyocyte contractile dysfunction has also been reported in high‐fat diet–induced obesity (14).…”

Section: Introductionmentioning

confidence: 99%

Dietary Interaction of High Fat and Marginal Copper Deficiency on Cardiac Contractile Function

Relling

Esberg

Johnson

et al. 2007

Obesity

Self Cite

View full text Add to dashboard Cite

Objective: High‐fat and marginally copper‐deficient diets impair heart function, leading to cardiac hypertrophy, increased lipid droplet volume, and compromised contractile function, resembling lipotoxic cardiac dysfunction. However, the combined effect of the two on cardiac function is unknown. This study was designed to examine the interaction between high‐fat and marginally copper‐deficient diets on cardiomyocyte contractile function. Research Methods and Procedures: Weanling male rats were fed diets incorporating a low‐ or high‐fat diet (10% or 45% of kcal from fat, respectively) with adequate (6 mg/kg) or marginally deficient (1.5 mg/kg) copper content for 12 weeks. Contractile function was determined with an IonOptix system including peak shortening (PS), time‐to‐PS, time‐to‐90% relengthening, maximal velocity of shortening/relengthening, and intracellular Ca2+ ([Ca2+]I) rise and decay. Results: Neither dietary treatment affected blood pressure or glucose levels, although the high‐fat diet elicited obesity and glucose intolerance. Both diets depressed PS, maximal velocity of shortening/relengthening, and intracellular Ca2+ ([Ca2+]I) rise and prolonged time‐to‐90% relengthening and Ca2+ decay without an additive effect between the two. Ca2+ sensitivity, apoptosis, lipid peroxidation, nitrosative damage, tissue ceramide, and triglyceride levels were unaffected by either diet or in combination. Phospholamban (PLB) but not sarco(endo)plasmic reticulum Ca2+‐ATPase was increased by both diets. Endothelial NO synthase was depressed with concurrent treatments. The electron transport chain was unaffected, although mitochondrial aconitase activity was inhibited by the high‐fat diet. Discussion: These data suggest that high‐fat and marginally copper deficient diets impaired cardiomyocyte contractile function and [Ca2+]i homeostasis, possibly through a similar mechanism, without obvious lipotoxicity, nitrosative damage, and apoptosis.

show abstract

Basal and Ethanol-Induced Cardiac Contractile Response in Lean and Obese Zucker Rat Hearts

Cited by 4 publications

References 23 publications

Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

Angiotensin‐Converting Enzyme Inhibition Reduces Lipid Deposits in Myocardium and Improves Left Ventricular Function of Obese Zucker Rats

Dietary Interaction of High Fat and Marginal Copper Deficiency on Cardiac Contractile Function

Contact Info

Product

Resources

About