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Phosphate And Acidosis Act Synergistically To Depress Peak Power In Rat Muscle Fibers, Cassandra R. Nelson, Edward P. Debold, Robert H. Fitts

Biomedical Sciences Faculty Research and Publications

Skeletal muscle fatigue is characterized by the buildup of H⁺ and inorganic phosphate (P_i), metabolites that are thought to cause fatigue by inhibiting muscle force, velocity, and power. While the individual effects of elevated H⁺ or P_i have been well characterized, the effects of simultaneously elevating the ions, as occurs during fatigue in vivo, are still poorly understood. To address this, we exposed slow and fast rat skinned muscle fibers to fatiguing levels of H⁺ (pH 6.2) and P_i (30 mM) and determined the effects on contractile properties. At 30°C, elevated P_{i …}