Hydrogen peroxide decelerates recovery of action potential after high-frequency fatigue in skeletal muscle.
Effects of reactive oxygen species (ROS), especially hydrogen peroxide (H(2)O(2)), on recovery of action potential by resting for 30 min after high-frequency fatigue were studied using frog skeletal muscle fibers. After stimulation at a frequency of 50 HZ for 2 min, the action potential amplitude was decreased by 14.5 mV from controls, and resting membrane was depolarized by 15.4 mV. Action potential duration was also prolonged by high-frequency stimulation (1.5 ms in controls to 2.6 ms). The high-frequency stimulation used here caused no muscle damage. The action potential was partially improved after a 30-min rest. Addition of catalase at 500 units/ml or H(2)O(2) at 0.5 mM to sartorius muscle did not alter any of the parameters of the action potential after high-frequency stimulation. Treatment with catalase accelerated post-fatigue recovery of the action potential. Application of H(2)O(2) delayed post-fatigue recovery of resting and action potentials. When added to detubulated toe muscle fibers, catalase no longer improved the attenuation of action potential induced by high-frequency stimulation, even after a 30-min rest. These findings suggest that removal of H(2)O(2) from transverse tubules is effective for post-fatigue recovery of action potential in skeletal muscle.
Oba
T
T
Department of Physiology, Nagoya City University Medical School, Mizuho-ku, Nagoya 467, Japan. tooba@med.nagoya-cu.ac.jp
Ishikawa
T
T
Takaishi
T
T
Aoki
T
T
Yamaguchi
M
M
D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008854:Microscopy, Electron; D018763:Muscle Fatigue / Q000502:physiology*; D009132:Muscles / Q000378:metabolism* / Q000502:physiology* / Q000648:ultrastructure; D011892:Rana catesbeiana; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide