Publications by authors named "Demaison L"

Previous studies in Western diet (WD)-fed male rats have highlighted a link between the stimulation of cardiac contractility, mitochondrial adaptations and a pro-inflammatory fatty acid profile of phospholipids in the heart. Our objectives were to determine (1) if WD-fed female Wistar rats and obese humans display a similar pro-inflammatory profile in their cardiac phospholipids and (2) if this lipid profile is associated with deleterious effects on the heart of the female rodents. Female Wistar rats were fed WD for 5 weeks or a laboratory chow as a control.

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The purpose of this study was to determine whether magnesium L-lactate is responsible for having a beneficial effect on the myocardium and the skeletal muscles and how this substrate acts at the molecular level. Twenty seven young male Wistar rats were supplied with a magnesium L-lactate (L) solution, a magnesium chloride (M) solution and/or water (W) as a vehicle for 10 weeks. The treated animals absorbed the L and M solutions as they wished since they also had free access to water.

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Obesity is a risk factor for the development of type 2 diabetes (T2D), which is associated with cardiovascular diseases [...

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It has been proven that dietary eicosapentaenoic acid (C20:5 n-3 or EPA) protects the heart against the deleterious effects of sepsis in female rats. We do not know if this is the case for male rodents. In this case, the efficiency of other n-3 polyunsaturated fatty acids (PUFAs) remains to be determined in both female and male rats.

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Evaluating the activity of cardiac mitochondria is probably the best way to estimate early cellular damage in chronic pathology. Early diagnosis allows rapid therapeutic intervention thus increasing patient survival rate in a number of diseases. However, data on human cardiac mitochondria are scarce in the international literature.

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Article Synopsis
  • Diabetes significantly increases the risk of heart failure, and both green tea extract (GTE) and eicosapentaenoic acid (EPA) may help mitigate these risks.
  • In a study with Wistar rats induced with diabetes, GTE alone showed benefits by reducing inflammation and improving lipid metabolism, while EPA posed a risk by causing rapid death in the animals unless paired with GTE.
  • The combination of EPA and GTE resulted in better coronary reactivity than GTE alone, highlighting the importance of combining antioxidants like GTE with EPA to protect cardiac function and enhance survival in diabetic conditions.
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Sepsis still causes death, often through cardiac failure and mitochondrial dysfunction. Dietary 3 polyunsaturated fatty acids are known to protect against cardiac dysfunction and sepsis lethality. This study set out to determine whether early low-severity sepsis alters the cardiac mitochondrial function in animals fed a Western-type diet and whether dietary eicosapentaenoic acid (EPA) administration protects the myocardium against the deleterious effects of sepsis and if so to seek possible mechanisms for its effects.

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Several meta-analyses describing the effect of n-3 polyunsaturated fatty acids on the survival rate of the victims of an acute coronary event do not clearly support a beneficial impact of these fatty acids. Yet, animal studies consistently show n-3 PUFA-induced protection against ischemia-reperfusion-induced myocardial injuries. The impact on reperfusion arrhythmias of these PUFAs is more controversial.

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Background: Better choices of dietary lipid sources and substitution of refined by fortified oils could reduce the intake of saturated fatty acids (FA) and increase the intake of omega 3 FA concomitantly to healthy bioactive compounds.

Methods: The development of obesity and metabolic disturbances was explored in rats fed during 11 weeks with a high fat diet (HFD) in which the amount of saturated and polyunsaturated FA was respectively reduced and increased, using rapeseed oil as lipid source. This oil was used in a refined form (R) or fortified (10 fold increase in concentration) with endogenous micronutrients (coenzyme Q10 + tocopherol only (RF) only and also with canolol (RFC)).

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Background: Obesity progressively leads to cardiac failure. Omega-3 polyunsaturated fatty acids (PUFA) have been shown to have cardio-protective effects in numerous pathological situations. It is not known whether rapeseed oil, which contains α-linolenic acid (ALA), has a similar protective effect.

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If it is sustained for several days, sepsis can trigger severe abnormalities of cardiac function which leads to death in 50% of cases. This probably occurs through activation of toll-like receptor-9 by bacterial lipopolysaccharides and overproduction of proinflammatory cytokines such as TNF- and IL-1 In contrast, early sepsis is characterized by the development of tachycardia. This study aimed at determining the early changes in the cardiac function during sepsis and at finding the mechanism responsible for the observed changes.

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Key Points: Older pregnant women have a greater risk of operative delivery, still birth and post-term induction. This suggests that maternal age can influence the timing of birth and processes of parturition. We have found that increasing maternal age in C57BL/6J mice is associated with prolongation of gestation and length of labour.

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The aim of this study was to characterize the early alterations of the liver mitochondrial function in ZDF (fa/fa) rats that develop diabetes compared to that of their lean counterparts ZDF (fa/+). Liver mitochondrial function was examined in 11- and 14-week-old ZDF (fa/fa) and ZDF lean (fa/+) rats. Oxygen consumption, H2O2 release, calcium retention capacity (CRC), membrane potential, membrane fluidity, and fatty acid composition were analyzed.

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Abdominal obesity increases the incidence of cardiac events but reduces mortality when one of these events occurs. The phenomenon called obesity paradox might be related to myocardial energetics. This study was aimed at determining whether long-term abdominal adiposity alters cardiac energy function.

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This study was aimed at characterizing the functional progression of the endothelial (ECs) and smooth muscle cells (SMCs) of the coronary microvasculature between youth and old age, as well as at determining the mechanisms of the observed changes on the basis of the glucose tolerance, mitochondrial energy metabolism, and oxidative stress. Male rats were divided into four age groups (3, 6, 11, and 17 months for the young (Y), young adult (YA), middle-aged (MA), and old (O) animals). The cardiac mechanical function, endothelial-dependent dilatation (EDD) and endothelial-independent dilatation (EID) of the coronary microvasculature were determined in a Langendorff preparation.

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Background: Saturated fatty acid-rich high fat (HF) diets trigger abdominal adiposity, insulin resistance, type 2 diabetes and cardiac dysfunction. This study was aimed at evaluating the effects of nascent obesity on the cardiac function of animals fed a high-fat diet and at analyzing the mechanisms by which these alterations occurred at the level of coronary reserve.

Materials And Methods: Rats were fed a control (C) or a HF diet containing high proportions of saturated fatty acids for 3 months.

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Background: There has been accumulating evidence associating diabetes mellitus and cardiovascular dysfunctions. However, most of the studies are focused on the late stages of diabetes and on the function of large arteries. This study aimed at characterizing the effects of the early phase of diabetes mellitus on the cardiac and vascular function with focus on the intact coronary microvasculature and the oxidative stress involved.

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This study aimed at determining whether glucose-insulin-potassium (GIK) solutions modify the NADH/NAD(+) ratio during postischemic reperfusion and whether their cardioprotective effect can be attributed to this change in part through reduction of the mitochondrial reactive oxygen species (ROS) production. The hearts of 72 rats were perfused with a buffer containing glucose (5.5 mM) and hexanoate (0.

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The aim of this study was to evaluate the involvement of mitochondria in the mechanism of the anti-arrhythmic lidocaine. Rats were fed with a diet containing either n-6 polyunsaturated fatty acids (PUFAs, SSO group) or an equimolecular mixture of n-3 and n-6 PUFAs (FO group) for 8 weeks. The hearts were perfused according to the working mode using a medium with or without lidocaine 5 μm.

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Cariporide, an Na/H exchanger inhibitor, is a drug with cardioprotective properties. However, chronic treatment with cariporide may modify the protein phenotype of the cardiomyocytes. Disruption of the equilibrium between a cariporide-modified phenotype and the supply of cariporide could be deleterious.

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Aging compromises restoration of the cardiac mechanical function during reperfusion. We hypothesized that this was due to an ampler release of mitochondrial reactive oxygen species (ROS). This study aimed at characterising ex vivo the mitochondrial ROS release during reperfusion in isolated perfused hearts of middle-aged rats.

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Hyperglycemia encountered during diabetes triggers abnormalities of vascular function associated with cell acidosis and calcium overload. The purpose of this study was to determine, whether Na+/H+ exchanger (NHE-1) inhibition by cariporide protects coronary cells against the deleterious effect of hyperglycemia in the rat. In vivo hyperglycemia was triggered by streptozotocin injection.

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Aging triggers several abnormalities in muscle glycolytic fibers including increased proteolysis, reactive oxygen species (ROS) production and apoptosis. Since the mitochondria are the main site of substrate oxidation, ROS production and programmed cell death, we tried to know whether the cellular disorders encountered in sarcopenia are due to abnormal mitochondrial functioning. Gastrocnemius mitochondria were extracted from adult (6 months) and aged (21 months) male Wistar rats.

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A novel i.v. lipid preparation (MCT:FO) containing 80% medium chain-triacylglycerols and 20% fish oil was recently developed to rapidly replenish cell membrane phospholipids with omega 3 (n-3) polyunsaturated fatty acids (PUFA).

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