Male and Female Rats Have Different Physiological Response to High-Fat High-Sucrose Diet but Similar Myocardial Sensitivity to Ischemia-Reperfusion Injury.

Prediabetes is a strong predictor of type 2 diabetes and its associated cardiovascular complications, but few studies explore sexual dimorphism in this context. Here, we aim to determine whether sex influences physiological response to high-fat high-sucrose diet (HFS) and myocardial tolerance to ischemia-reperfusion injury. Male and female Wistar rats were subjected to standard (CTRL) or HFS diet for 5 months.

Sex Differences of the Diabetic Heart.

Type 2 diabetes is a chronic disease associated with micro- and macro-vascular complications, including myocardial ischemia, and also with a specific and intrinsic cardiac dysfunction called diabetic cardiomyopathy (DCM). Both clinical and animal studies demonstrate significant sex differences in prevalence, pathophysiology, and outcomes of cardiovascular diseases (CVDs), including those associated with diabetes. The increased risk of CVDs with diabetes is higher in women compared to men with 50% higher risk of coronary artery diseases and increased mortality when exposed to acute myocardial infarction.

Cardiac remodeling and higher sensitivity to ischemia-reperfusion injury in female rats submitted to high-fat high-sucrose diet: An in vivo/ex vivo longitudinal follow-up.

Prediabetes is an important risk factor for Type 2 diabetes and cardiovascular complications, such as myocardial infarction. However, few studies explore female sex in this context. Here, we aim to investigate the effects of high-fat high-sucrose diet on cardiac parameters and sensitivity to ischemia-reperfusion injury of female Wistar rats.

Protective Effect of Resveratrol against Ischemia-Reperfusion Injury via Enhanced High Energy Compounds and eNOS-SIRT1 Expression in Type 2 Diabetic Female Rat Heart.

Type 2 diabetic women have a high risk of mortality via myocardial infarction even with anti-diabetic treatments. Resveratrol (RSV) is a natural polyphenol, well-known for its antioxidant property, which has also shown interesting positive effects on mitochondrial function. Therefore, we aim to investigate the potential protective effect of 1 mg/kg/day of RSV on high energy compounds, during myocardial ischemia-reperfusion in type 2 diabetic female Goto-Kakizaki (GK) rats.

Sex-Mediated Response to the Beta-Blocker Landiolol in Sepsis: An Experimental, Randomized Study.

Objectives: To investigate any gender effect of the beta-1 adrenergic blocker, landiolol, on cardiac performance and energy metabolism in septic rats, and to explore the expression of genes and proteins involved in this process.

Design: Randomized animal study.

Setting: University research laboratory.

Exercise training impacts exercise tolerance and bioenergetics in gastrocnemius muscle of non-obese type-2 diabetic Goto-Kakizaki rat in vivo.

The functional and bioenergetics impact of regular physical activity upon type-2 diabetic skeletal muscle independently of confounding factors of overweight remains undocumented. Here, gastrocnemius muscle energy fluxes, mitochondrial capacity and mechanical performance were assessed noninvasively and longitudinally in non-obese diabetic Goto-Kakizaki rats using magnetic resonance (MR) imaging and dynamic 31-phosphorus MR spectroscopy (P-MRS) throughout a 6-min fatiguing bout of exercise performed before, in the middle (4-week) and at the end of an 8-week training protocol consisting in 60-min daily run on a treadmill. The training protocol reduced plasmatic insulin level (-61%) whereas blood glucose and non-esterified fatty acids levels remained unaffected, thereby indicating an improvement of insulin sensitivity.

Reduced up-regulation of the nitric oxide pathway and impaired endothelial and smooth muscle functions in the female type 2 diabetic goto-kakizaki rat heart.

Background: Type 2 diabetes is associated with greater relative risk of cardiovascular diseases in women than in men, which is not well understood. Consequently, we have investigated if male and female displayed differences in cardiac function, energy metabolism, and endothelial function which could contribute to increased cardiovascular complications in type 2 diabetic female.

Methods: Male and female Control and type 2 diabetic Goto-Kakizaki (GK) isolated rat hearts were perfused during 28 min with a physiological buffer before freeze-clamping for biochemical assays.

Insulin Resistance Is Not Associated with an Impaired Mitochondrial Function in Contracting Gastrocnemius Muscle of Goto-Kakizaki Diabetic Rats In Vivo.

Insulin resistance, altered lipid metabolism and mitochondrial dysfunction in skeletal muscle would play a major role in type 2 diabetes mellitus (T2DM) development, but the causal relationships between these events remain conflicting. To clarify this issue, gastrocnemius muscle function and energetics were investigated throughout a multidisciplinary approach combining in vivo and in vitro measurements in Goto-Kakizaki (GK) rats, a non-obese T2DM model developing peripheral insulin resistant without abnormal level of plasma non-esterified fatty acids (NEFA). Wistar rats were used as controls.

Effect of isoproterenol on myocardial perfusion, function, energy metabolism and nitric oxide pathway in the rat heart - a longitudinal MR study.

The chronic administration of the β-adrenoreceptor agonist isoproterenol (IsoP) is used in animals to study the mechanisms of cardiac hypertrophy and failure associated with a sustained increase in circulating catecholamines. Time-dependent changes in myocardial blood flow (MBF), morphological and functional parameters were assessed in rats in vivo using multimodal cardiac MRI. Energy metabolism, oxidative stress and the nitric oxide (NO) pathway were evaluated in isolated perfused rat hearts following 7 days of treatment.

Upregulation of eNOS and unchanged energy metabolism in increased susceptibility of the aging type 2 diabetic GK rat heart to ischemic injury.

We investigated the tolerance of the insulin-resistant diabetic heart to ischemic injury in the male Goto-Kakizaki (GK) rat, a model of type 2 diabetes. Changes in energy metabolism, nitric oxide (NO) pathway, and cardiac function were assessed in the presence of physiological substrates. Age-matched control Wistar (n = 19) and GK (n = 18) isolated rat hearts were perfused with 0.

Limitation of myocardial and endothelial injury of the rat heart graft after preservation with Centre de Résonance Magnétique Biologique et Médicale (CRMB) solution.

Myocardial injury caused by prolonged storage compromises post-transplantation contractile performance and induces endothelial injury. The aim of this study was to compare a solution developed in our laboratory [Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution] with a widely used solution (Celsior, Genzyme, Saint Germain en Laye, France). Metabolic and contractile parameters as well as indexes of endothelial injury were measured in a heterotopic rat heart transplantation model with a 3-h ischaemia and a 1-h reperfusion.

Defective myocardial blood flow and altered function of the left ventricle in type 2 diabetic rats: a noninvasive in vivo study using perfusion and cine magnetic resonance imaging.

Objective: In type 2 diabetes mellitus, cardiovascular complications are related to microvascular abnormalities. In this work, we aimed at characterizing in vivo myocardial blood flow and left ventricular function of the Goto-Kakizaki (GK) rat as a nonobese model of type 2 diabetes.

Materials And Methods: We performed arterial spin labeling magnetic resonance imaging (MRI) for myocardial blood flow quantification and cine MRI for functional evaluation in free-breathing isoflurane-anesthetized animals.

Gender differences in hypertrophy, insulin resistance and ischemic injury in the aging type 2 diabetic rat heart.

Aging and diabetes in women increase their susceptibility to myocardial ischemic injury, but the cellular mechanisms involved are not understood. Consequently, we studied the influence of gender on cardiac insulin resistance and ischemic injury in the aging of Goto-Kakizaki (GK) rat, a model of type 2 diabetes. Male and female GK rats had heart/body weight ratios 29% (P < 0.

Initial steps of insulin signaling and glucose transport are defective in the type 2 diabetic rat heart.

Objective: Whole body insulin resistance and diabetes are risk factors for cardiovascular diseases, yet little is known about insulin resistance in the diabetic heart. The aim of this work was to define the insulin response in hearts of the Goto-Kakizaki (GK) rat, a polygenic model of spontaneous type 2 diabetes.

Methods: We measured D[2-3H]glucose uptake before and after insulin stimulation, plus initial steps of the insulin signaling pathway after insulin infusion via the caudal vena cava in hearts from the male Wistar and spontaneously diabetic GK rats.

High-resolution myocardial perfusion mapping in small animals in vivo by spin-labeling gradient-echo imaging.

An ECG and respiration-gated spin-labeling gradient-echo imaging technique is proposed for the quantitative and completely noninvasive measurement and mapping of myocardial perfusion in small animals in vivo. In contrast to snapshot FLASH imaging, the spatial resolution of the perfusion maps is not limited by the heart rate. A significant improvement in image quality is achieved by synchronizing the inversion pulse to the respiration movements of the animals, thereby allowing for spontaneous respiration.

NOS substrate during cardioplegic arrest and cold storage decreases stunning after heart transplantation in a rat model.

Background: In this study, we evaluated how adding L-arginine to Centre de Résonance Magnétique Biologique et Médicale (CRMBM) solution affected myocardial performance during post-ischemic in vivo reperfusion.

Methods: Experiments were conducted using a modified Lewis-Lewis heterotopic heart transplantation model, with a total ischemic time of 3 hours followed by 1 or 24 hours of blood reperfusion. Heart grafts were arrested using intra-aortic injection of CRMBM solution, either supplemented or not supplemented with 2 mmol/liter L-arginine (n = 12 in each group).

Thiazolidinedione treatment normalizes insulin resistance and ischemic injury in the zucker Fatty rat heart.

Obesity is associated with risk factors for cardiovascular disease, including insulin resistance, and can lead to cardiac hypertrophy and congestive heart failure. Here, we used the insulin-sensitizing agent rosiglitazone to investigate the cellular mechanisms linking insulin resistance in the obese Zucker rat heart with increased susceptibility to ischemic injury. Rats were treated for 7 or 14 days with 3 mg/kg per os rosiglitazone.