Browsing by Author "Remani, K"

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    Metabolic Modulation by Medium-Chain Triglycerides Reduces Oxidative Stress and Ameliorates CD36-Mediated Cardiac Remodeling in Spontaneously Hypertensive Rat in the Initial and Established Stages of Hypertrophy
    (J Cardiac failure, 2017-03) Ismael, S; Lakshmi, S; Remani, K; Nair, RR
    Background: Left ventricular hypertrophy (LVH) is characterized by a decrease in oxidation of longchain fatty acids, possibly mediated by reduced expression of the cell-surface protein cluster of differentiation 36 (CD36). Spontaneously hypertensive rats (SHRs) were therefore supplemented with medium-chain triglycerides (MCT), a substrate that bypasses CD36, based on the assumption that the metabolic modulation will ameliorate ventricular remodeling. Methods: The diet of 2-month-old and 6-month-old SHRs was supplemented with 5% MCT (Tricaprylin), for 4 months. Metabolic modulation was assessed by mRNA expression of peroxisome proliferator– activated receptor α and medium-chain acyl-CoA dehydrogenase. Blood pressure was measured noninvasively. LVH was assessed with the use of hypertrophy index, cardiomyocyte cross-sectional area, mRNA expression of B-type natriuretic peptide, cardiac fibrosis, and calcineurin-A levels. Oxidative stress indicators (cardiac malondialdehyde, protein carbonyl, and 3-nitrotyrosine levels), myocardial energy level (ATP, phosphocreatine), and lipid profile were determined. Results: Supplementation of MCT stimulated fatty acid oxidation in animals of both age groups, reduced hypertrophy and oxidative stress along with the maintenance of energy level. Blood pressure, body weight, and lipid profile were unaffected by the treatment. Conclusions: The results indicate that modulation of myocardial fatty acid metabolism by MCT prevents progressive cardiac remodeling in SHRs, possibly by maintenance of energy level and decrease in oxidative stress. (J Cardiac Fail 2017;23:240–251)
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    Negative inotropic response to cerium in ventricular papillary muscle is mediated by reactive oxygen species
    (BIOLOGICAL TRACE ELEMENT RESEARCH, 2003)
    This study was performed with the objective of assessing the mechanical response of the myocardium. to different levels of cerium and delineation of the mechanism underlying the mediation of the functional changes. Rat ventricular papillary muscle was used as the experimental model. Isolated papillary muscles were exposed to different concentrations of CeCl3 and the force of contraction was measured using a force transducer. Experiments have revealed that the negative inotropic response to CeCl3 was proportional to its concentration. The inotropic changes were found to be completely reversible at concentrations less than or equal to 5 muW, and partially reversible at higher concentrations. Neutralization of cerium-induced inotropic changes by the superoxide anion scavenger superoxide dismutase (SOD) at concentrations less than or equal to 5 muW indicates that the mechanical changes are mediated by reactive oxygen species. At higher concentrations of Ce3+, SOD partially reversed the contractile changes. The beneficial effect of SOD was seen only if the muscles were pretreated with the scavenger prior to the addition of cerium chloride.