The Effects of Caffeine on Metabolomic Responses to Muscle Contraction in Rat Skeletal Muscle

• Published in: Nutrients 2019-08, Vol.11 (8), p.1819
• Main Authors: Tsuda, Satoshi, Hayashi, Tatsuya, Egawa, Tatsuro
• Format: Article
• Language: English
• Subjects: Animals; Caffeine; Caffeine - pharmacology; Carnitine; Data analysis; Dehydrogenase; Electric Stimulation; Environmental studies; Enzymatic activity; Enzyme activity; ergogenic effect; exercise; Glucose; Glycerol; Glycerol-3-phosphate; Glycolysis; Kinases; Laboratory animals; Lactic acid; Male; Mass spectrometry; Metabolic activation; Metabolic disorders; Metabolic rate; Metabolism; Metabolites; metabolome; Metabolomics; Muscle contraction; Muscle Contraction - drug effects; Muscle Contraction - physiology; Muscle, Skeletal - drug effects; Muscle, Skeletal - metabolism; Muscles; Muscular function; Musculoskeletal system; Oxidation; Potassium; Principal components analysis; Rats; Rats, Sprague-Dawley; Scientific imaging; Skeletal muscle; Succinate dehydrogenase; Succinic acid; Tricarboxylic acid cycle
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu11081819

Exercise has beneficial effects on our health by stimulating metabolic activation of skeletal muscle contraction. Caffeine is a powerful metabolic stimulant in the skeletal muscle that has ergogenic effects, including enhanced muscle power output and endurance capacity. In the present study, we aim to characterize the metabolic signatures of contracting muscles with or without caffeine stimulation using liquid chromatography-mass spectrometry and capillary electrophoresis coupled to mass spectrometry. Isolated rat epitrochlearis muscle was incubated in the presence or absence or of 3 mM caffeine for 30 min. Electrical stimulation (ES) was used to induce tetanic contractions during the final 10 min of incubation. Principal component analysis and hierarchical clustering analysis detected 184 distinct metabolites across three experimental groups-basal, ES, and ES with caffeine (ES + C). Significance Analysis of Microarray identified a total of 50 metabolites with significant changes in expression, and 23 metabolites significantly changed between the ES and ES + C groups. Changes were observed in metabolite levels of various metabolic pathways, including the pentose phosphate, nucleotide synthesis, β-oxidation, tricarboxylic acid cycle, and amino acid metabolism. In particular, D-ribose 5-phosphate, IMP, O-acetylcarnitine, butyrylcarnitine, L-leucine, L-valine, and L-aspartate levels were higher in the ES + C group than in the ES group. These metabolic alterations induced by caffeine suggest that caffeine accelerates contraction-induced metabolic activations, thereby contributing to muscle endurance performance and exercise benefits to our health.