Hyperpolarized [1- C]pyruvate combined with the hyperinsulinaemic euglycaemic and hypoglycaemic clamp technique in skeletal muscle in a large animal model.

New Findings: What is the central question of this study? Is it possible to combine the hyperpolarized magnetic resonance technique and the hyperinsulinaemic clamp method in order to evaluate skeletal muscle metabolism in a large animal model? What is the main finding and its importance? The logistical set-up is possible, and we found substantial increments in glucose infusion rates representing skeletal muscle glucose uptake but no differences in ratios of [1- C]lactate to [1- C]pyruvate, [1- C]alanine to [1- C]pyruvate, and C-bicarbonate to [1- C]pyruvate, implying that the hyperpolarization technique might not be optimal for detecting effects of insulin in skeletal muscle of anaesthetized animals, which is of significance for future studies.

Abstract: In skeletal muscle, glucose metabolism is tightly regulated by the reciprocal relationship between insulin and adrenaline, with pyruvate being at the intersection of both pathways. Hyperpolarized magnetic resonance (hMR) is a new approach to gain insights into these pathways, and human trials involving hMR and skeletal muscle metabolism are imminent.

Remodeling after myocardial infarction and effects of heart failure treatment investigated by hyperpolarized [1- C]pyruvate magnetic resonance spectroscopy.

Purpose: Hyperpolarized [1- C]pyruvate MRS can measure cardiac metabolism in vivo. We investigated whether [1- C]pyruvate MRS could predict left ventricular remodeling following myocardial infarction (MI), long-term left ventricular effects of heart failure medication, and could identify responders to treatment.

Methods: Thirty-five rats were scanned with hyperpolarized [1- C]pyruvate MRS 3 days after MI or sham surgery.

Autologous cartilage and fibrin sealant may be superior to conventional fat grafting in preventing physeal bone bridge formation - a pilot study in porcines.

Purpose: The article compares physeal recovery after insertion of autologous cartilage and a conventional fat graft in a standardized porcine physeal gap model. Presence of a bone bridge was the primary outcome.

Methods: Ten porcines in two groups of five were included in a paired design.

Sex Differences in Kidney Function and Metabolism Assessed Using Hyperpolarized [1-C]Pyruvate Interleaved Spectroscopy and Nonspecific Imaging.

Metabolic sex differences have recently been shown to be particularly important in tailoring treatment strategies. Sex has a major effect on fat turnover rates and plasma lipid delivery in the body. Differences in kidney structure and transporters between male and female animals have been found.

Redundancy in regulation of lipid accumulation in skeletal muscle during prolonged fasting in obese men.

Fasting in human subjects shifts skeletal muscle metabolism toward lipid utilization and accumulation, including intramyocellular lipid (IMCL) deposition. Growth hormone (GH) secretion amplifies during fasting and promotes lipolysis and lipid oxidation, but it is unknown to which degree lipid deposition and metabolism in skeletal muscle during fasting depends on GH action. To test this, we studied nine obese but otherwise healthy men thrice: (a) in the postabsorptive state ("CTRL"), (b) during 72-hr fasting ("FAST"), and (c) during 72-hr fasting and treatment with a GH antagonist (GHA) ("FAST + GHA").