title: Ammonium Chloride Ingestion Attenuates Exercise-Induced mRNA Levels in Human Muscle.
abstract: Minimizing the decrease in intracellular pH during high-intensity exercise training promotes greater improvements in mitochondrial respiration. This raises the intriguing hypothesis that pH may affect the exercise-induced transcription of genes that regulate mitochondrial biogenesis. Eight males performed 10x2-min cycle intervals at 80% VO2speak intensity on two occasions separated by ~2 weeks. Participants ingested either ammonium chloride (ACID) or calcium carbonate (PLA) the day before and on the day of the exercise trial in a randomized, counterbalanced order, using a crossover design. Biopsies were taken from the vastus lateralis muscle before and after exercise. The mRNA level of peroxisome proliferator-activated receptor co-activator 1α (PGC-1α), citrate synthase, cytochome c and FOXO1 was elevated at rest following ACID (P<0.05). During the PLA condition, the mRNA content of mitochondrial- and glucose-regulating proteins was elevated immediately following exercise (P<0.05). In the early phase (0-2 h) of post-exercise recovery during ACID, PGC-1α, citrate synthase, cytochome C, FOXO1, GLUT4, and HKII mRNA levels were not different from resting levels (P>0.05); the difference in PGC-1α mRNA content 2 h post-exercise between ACID and PLA was not significant (P = 0.08). Thus, metabolic acidosis abolished the early post-exercise increase of PGC-1α mRNA and the mRNA of downstream mitochondrial and glucose-regulating proteins. These findings indicate that metabolic acidosis may affect mitochondrial biogenesis, with divergent responses in resting and post-exercise skeletal muscle.
authors.affiliation: Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand.|School of Sport and Exercise, Massey University, Palmerston North, New Zealand.
authors.forename: Johann
authors.initials: J
authors.lastname: Edge
authors.affiliation: School of Sport and Exercise, Massey University, Palmerston North, New Zealand.
authors.forename: Toby
authors.initials: T
authors.lastname: Mündel
authors.affiliation: Centre of Inflammation and Metabolism (CIM), Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Henriette
authors.initials: H
authors.lastname: Pilegaard
authors.affiliation: Centre of Inflammation and Metabolism (CIM), Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Emma
authors.initials: E
authors.lastname: Hawke
authors.affiliation: Department of Renal Medicine, Wellington Hospital, Newtown, New Zealand.
authors.forename: Murray
authors.initials: M
authors.lastname: Leikis
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lopez-Villalobos
authors.affiliation: Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
authors.forename: Rodrigo S F
authors.initials: RS
authors.lastname: Oliveira
authors.affiliation: Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Bishop
mesh_terms: D000328:Adult; D000643:Ammonium Chloride / Q000494:pharmacology*; D002119:Calcium Carbonate / Q000494:pharmacology*; D002950:Citrate (si)-Synthase / Q000235:genetics / Q000378:metabolism; D018592:Cross-Over Studies; D045304:Cytochromes c / Q000235:genetics / Q000378:metabolism; D004311:Double-Blind Method; D015444:Exercise; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D055815:Young Adult
chemical_list: C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D051275:Glucose Transporter Type 4; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger; D014157:Transcription Factors; D000643:Ammonium Chloride; D045304:Cytochromes c; D002950:Citrate (si)-Synthase; D002119:Calcium Carbonate