title: Acute exercise increases brain region-specific expression of MCT1, MCT2, MCT4, GLUT1, and COX IV proteins.
abstract: The brain is capable of oxidizing lactate and ketone bodies through monocarboxylate transporters (MCTs). We examined the protein expression of MCT1, MCT2, MCT4, glucose transporter 1 (GLUT1), and cytochrome-c oxidase subunit IV (COX IV) in the rat brain within 24 h after a single exercise session. Brain samples were obtained from sedentary controls and treadmill-exercised rats (20 m/min, 8% grade). Acute exercise resulted in an increase in lactate in the cortex, hippocampus, and hypothalamus, but not the brainstem, and an increase in β-hydroxybutyrate in the cortex alone. After a 2-h exercise session MCT1 increased in the cortex and hippocampus 5 h postexercise, and the effect lasted in the cortex for 24 h postexercise. MCT2 increased in the cortex and hypothalamus 5-24 h postexercise, whereas MCT2 increased in the hippocampus immediately after exercise, and remained elevated for 10 h postexercise. Regional upregulation of MCT2 after exercise was associated with increases in brain-derived neurotrophic factor and tyrosine-related kinase B proteins, but not insulin-like growth factor 1. MCT4 increased 5-10 h postexercise only in the hypothalamus, and was associated with increased hypoxia-inducible factor-1α expression. However, none of the MCT isoforms in the brainstem was affected by exercise. Whereas GLUT 1 in the cortex increased only at 18 h postexercise, COX IV in the hippocampus increased 10 h after exercise and remained elevated for 24 h postexercise. These results suggest that acute prolonged exercise induces the brain region-specific upregulation of MCT1, MCT2, MCT4, GLUT1, and COX IV proteins.
authors.affiliation: Laboratory of Exercise Physiology and Biochemistry, Graduate School of Sport and Exercise Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Takimoto
authors.forename: Taku
authors.initials: T
authors.lastname: Hamada
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D003576:Electron Transport Complex IV / Q000096:biosynthesis*; D005786:Gene Expression Regulation; D051272:Glucose Transporter Type 1 / Q000096:biosynthesis*; D008297:Male; D027501:Monocarboxylic Acid Transporters / Q000096:biosynthesis*; D009124:Muscle Proteins / Q000096:biosynthesis*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D027981:Symporters / Q000096:biosynthesis*; D013997:Time Factors; D000099233:Monocarboxylate Transport Protein 1
chemical_list: D003576:Electron Transport Complex IV; D051272:Glucose Transporter Type 1; D027501:Monocarboxylic Acid Transporters; D009124:Muscle Proteins; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1; C516342:Slc16a3 protein, rat; C091633:Slc16a7 protein, rat; C495679:Slc2a1 protein, rat
keywords: MCT substrate; brain; exercise; transporter