Intracellular sodium elevation reprograms cardiac metabolism.

Intracellular Na elevation in the heart is a hallmark of pathologies where both acute and chronic metabolic remodelling occurs. Here, we assess whether acute (75 μM ouabain 100 nM blebbistatin) or chronic myocardial Na load (PLM mouse) are causally linked to metabolic remodelling and whether the failing heart shares a common Na-mediated metabolic 'fingerprint'. Control (PLM), transgenic (PLM), ouabain-treated and hypertrophied Langendorff-perfused mouse hearts are studied by Na, P, C NMR followed by H-NMR metabolomic profiling.

Is there a causal link between intracellular Na elevation and metabolic remodelling in cardiac hypertrophy?

Alterations in excitation-contraction coupling and elevated intracellular sodium (Na) are hallmarks of pathological cardiac remodelling that underline contractile dysfunction. In addition, changes in cardiac metabolism are observed in cardiac hypertrophy and heart failure (HF) that lead to a mismatch in ATP supply and demand, contributing to poor prognosis. A link between Na and altered metabolism has been proposed but is not well understood.

Identification of Flavin-Containing Monooxygenase 5 (FMO5) as a Regulator of Glucose Homeostasis and a Potential Sensor of Gut Bacteria.

We have previously identified flavin-containing monooxygenase 5 (FMO5) as a regulator of metabolic aging. The aim of the present study was to investigate the role of FMO5 in glucose homeostasis and the impact of diet and gut flora on the phenotype of mice in which the gene has been disrupted ( mice). In comparison with wild-type (WT) counterparts, mice are resistant to age-related changes in glucose homeostasis and maintain the higher glucose tolerance and insulin sensitivity characteristic of young animals.

Proteomic and metabolomic changes driven by elevating myocardial creatine suggest novel metabolic feedback mechanisms.

Mice over-expressing the creatine transporter have elevated myocardial creatine levels [Cr] and are protected against ischaemia/reperfusion injury via improved energy reserve. However, mice with very high [Cr] develop cardiac hypertrophy and dysfunction. To investigate these contrasting effects, we applied a non-biased hypothesis-generating approach to quantify global protein and metabolite changes in the LV of mice stratified for [Cr] levels: wildtype, moderately elevated, and high [Cr] (65-85; 100-135; 160-250 nmol/mg protein, respectively).

Contractile function assessment by intraventricular balloon alters the ability of regional ischaemia to evoke ventricular fibrillation.

Background And Purpose: In drug research using the rat Langendorff heart preparation, it is possible to study left ventricular (LV) contractility using an intraventricular balloon (IVB), and arrhythmogenesis during coronary ligation-induced regional ischaemia. Assessing both concurrently would halve animal requirements. We aimed to test the validity of this approach.