title: Energy metabolism of skeletal muscle biopsies stimulated anaerobically without load in vitro.
abstract: This study was made to test the validity of a simple biopsy technique for assessing the metabolic capacity of skeletal muscle. The biopsy is stimulated under mineral oil without attachment, i.e., without load or tension, then freeze-clamped and assayed for ATP, phosphocreatine, glucose 6-phosphate, and lactate. The mineral oil creates a closed anaerobic system. Background studies demonstrated in the absence of a load, metabolic changes with stimulation were little affected by cutting the fibers to obtain the biopsy; and high-energy phosphate (approximately P) consumption during a brief tetanus was not much lower than that for an isometric tetanus. Individual fast-twitch oxidative-glycolytic (IIA) and fast-twitch glycolytic (IIB) fibers obtained from the freeze-clamped biopsy showed distinct differences in approximately P consumption and metabolic changes. The results indicate that this technique could be useful for studies of normal and pathological human muscle.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000693:Anaerobiosis; D000818:Animals; D001706:Biopsy; D004558:Electric Stimulation; D004734:Energy Metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction; D009132:Muscles / Q000378:metabolism*; D010725:Phosphocreatine / Q000378:metabolism; D010732:Phosphofructokinase-1 / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D005958:Glucosephosphates; D007773:Lactates; D010725:Phosphocreatine; D019344:Lactic Acid; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D010732:Phosphofructokinase-1