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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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-cell function ( Davies et al. 2018 , Diabetes Canada Clinical Practice Guidelines Expert Committee et al. 2018 ). Furthermore, people with early-stage T2D often have undiagnosed and asymptomatic diastolic dysfunction, a key feature of diabetic
Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA
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The level of the obese gene product leptin is often positively correlated with body weight, supporting the notion that hyperleptinemia contributes to obesity-associated cardiac dysfunction. However, a link between leptin levels and cardiac function has not been elucidated. This study was designed to examine the role of leptin deficiency (resulting from a point mutation of the leptin gene) in cardiomyocyte contractile function. Mechanical properties and intracellular Ca2 + transients were evaluated in ventricular myocytes from lean control and leptin-deficient ob/ob obese mice at 12 weeks of age. Cardiac ultrastructure was evaluated using transmission electron microscopy. ob/ob mice were overtly obese, hyperinsulinemic, hypertriglycemic, hypoleptinemic and euglycemic. Ultrastructural examination revealed swelling and disorganization of cristae in mitochondria from ob/ob mouse ventricular tissues. Cardiomyocytes from ob/ob mice displayed reduced expression of the leptin receptor Ob-R, larger cross-sectional area, decreased peak shortening and maximal velocity of shortening/relengthening, and prolonged relengthening but not shortening duration compared with lean counterparts. Consistent with mechanical characteristics, myocytes from ob/ob mice displayed reduced intracellular Ca2 + release upon electrical stimulus associated with a slowed intracellular Ca2 + decay rate. Interestingly, the contractile aberrations seen in ob/ob myocytes were significantly improved by in vitro leptin incubation. Contractile dysfunction was not seen in age- and gender-matched high fat-induced obese mice. These results suggested that leptin deficiency contributes to cardiac contractile dysfunction characterized by both systolic and diastolic dysfunction, impaired intracellular Ca2 + hemostasis and ultrastructural derangement in ventricular myocytes.
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in the form of both diastolic and systolic dysfunction and of structural abnormalities ( Marwick 2006 ). In asymptomatic diabetic patients, diastolic dysfunction appears to be, in fact, very common ( Zabalgoitia et al . 2001 ). Since hypertension is
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Introduction Glucose toxicity contributes to development of diabetic cardiomyopathy characterized by systolic and diastolic dysfunctions independent of coronary macro- and micro-vascular diseases ( Galderisi et al. 1991 , Ren et
Hudson Institute of Medical Research, Clayton, Australia
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the MR are markedly affected by sex hormones. The cardiac tissue RAAS, aldosterone/MR activation and circulating RAAS all contribute to the onset of diastolic dysfunction, which is more common in older women as a result of hypertension and lower E2
Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
Cardiovascular Research Institute, University of Alberta, Edmonton, Alberta, Canada
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studies. Intriguingly, using a mouse model in which myocardial glucose oxidation is abolished due to cardiac-specific deletion of PDH ( Gopal et al. 2018 ), treatment with liraglutide can no longer alleviate diastolic dysfunction when these animals are
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that is arbitrarily defined as 1. Data are shown as mean± s.d. * P <0.05 versus normal rat. Discussion Diabetic cardiomyopathy is characterized by both systolic and diastolic dysfunction ( Galderisi 2006 ). In this current study, we established type 1
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diastolic dysfunction ( Jia et al. 2015 , 2016 , Rickard et al. 2014 ) Pulmonary HTN Unclear Pulmonary vascular remodeling and increase right ventricular systolic pressure ( Maron et al. 2013 , Preston et al. 2013 ) Cerebral
Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Monash Medical Centre, Clayton, Victoria, Australia
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Department of Molecular and Translational Research, Monash University, Melbourne, Victoria, Australia
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responses were similarly assessed following 16 weeks of a high-fat diet by another group who demonstrated that EC-MR play a key role in the activation of cardiac inflammatory and pro-fibrotic responses leading to cardiac diastolic dysfunction and aortic
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showing an association between low plasma adiponectin and a worsened diastolic dysfunction ( Negi et al . 2012 ). The results obtained about −d P /d t max and those regarding myocardial oxygen metabolism are of particular relevance and strengthen the