Tissue Changes in Glutathione Metabolism and Lipid Peroxidation Induced by Swimming are Partially Prevented by Melatonin

Authors

  • Masayuki Mara,

    1. Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio Texas 78284-7762, U.S.A.
    2. Department of Anatomy, St. Marianna University School of Medicine, 2-16-1 Sugao Miyamaeku, Kawasaki 216, Japan
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  • Mitsushi Abe,

    1. Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio Texas 78284-7762, U.S.A.
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  • Takuro Suzuki,

    1. Department of Anatomy, St. Marianna University School of Medicine, 2-16-1 Sugao Miyamaeku, Kawasaki 216, Japan
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  • Russel J. Reiter

    1. Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio Texas 78284-7762, U.S.A.
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Author for correspondence: Russel J. Reiter, Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78240-7762, U.S.A. (fax +1 (210) 567-6849).

Abstract

Abstract: The present study used male Sprague-Dawley rats to investigate changes in glutathione [reduced (GSH) and oxidized GSH (GSSG)], lipid peroxidation (as indicated by tissue levels of malonaldehyde and 4-hydroxyalkenals), and the activity of the antioxidant enzyme glutathione peroxidase after a bout of swimming (30 min.) with or without melatonin (N-acetyl-5-methoxytryptamine) treatment. In muscle, the concentration of GSH and the GSH/GSSG ratio were decreased following 30 min. of swimming; these changes are indicative of enhanced oxidative stress. Pretreatment with melatonin prevented these effects. In liver, swimming increased significantly both GSH and GSSG, and decreased the GSH/GSSG ratio. When animals were treated with melatonin, concentrations of GSH and GSSG were also increased after swimming; however, the reduction in the GSH/GSSG ratio was prevented by melatonin. Brain GSH/GSSG ratio was not affected by exercise or by melatonin. Swimming enhanced the levels of lipid peroxidation products is muscle; this was prevented in animals treated with melatonin. Glutathione peroxidase activity was significantly elevated after swimming in both liver and brain with the change not being influenced by concurrent melatonin treatment. It is concluded that swimming imposes an oxidative stress on liver and skeletal muscle and the results show that melatonin confers partial protection against oxidative toxicity, especially in muscle.

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