Open AccessExercise with food withdrawal at thermoneutrality impacts fuel use, the microbiome, AMPK phosphorylation, muscle fibers, and thyroid hormone levels in rats
Author(s) -
Giacco Antonia,
delli Paoli Giuseppe,
Simiele Roberta,
Caterino Marianna,
Ruoppolo Margherita,
Bloch Wilhelm,
Kraaij Robert,
Uitterlinden André G.,
Santillo Alessandra,
Senese Rosalba,
Cioffi Federica,
Silvestri Elena,
Iervolino Stefania,
Lombardi Assunta,
Moreno Maria,
Goglia Fernando,
Lanni Antonia,
Lange Pieter
Publication year - 2020
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.14354
Subject(s) - endocrinology , medicine , ketone bodies , lipogenesis , hormone , thyroid , lipid metabolism , metabolism , gluconeogenesis , ampk , biology , chemistry , phosphorylation , biochemistry , protein kinase a
Exercise under fasting conditions induces a switch to lipid metabolism, eliciting beneficial metabolic effects. Knowledge of signaling responses underlying metabolic adjustments in such conditions may help to identify therapeutic strategies. Therefore, we studied the effect of mild exercise on rats submitted to food withdrawal at thermoneutrality (28°C) for 3 days. Animals were housed at thermoneutrality rather than the standard housing temperature (22°C) to avoid beta‐adrenergic signaling responses that themselves affect metabolism and well‐being. Quantitative analysis of multi‐organ mRNA levels, myofibers, and serum metabolites shows that this protocol (a) boosts fat oxidation in muscle and liver, (b) reduces lipogenesis and increases gluconeogenesis in liver, (c) increases serum acylcarnitines (especially C 4 OH) and ketone bodies and the use of the latter as fuel in muscle, (d) increases Type I myofibers, and (e) is associated with an increased thyroid hormone uptake and metabolism in muscle. In addition, stool microbiome DNA analysis revealed that food withdrawal dramatically alters the presence of bacterial genera associated with ketone metabolism. Taken together, this protocol induces a drastic switch toward increased lipid and ketone metabolism compared to exercise or food withdrawal alone, which may prove beneficial and may involve local thyroid hormones, which may be regarded as exercise mimetics.