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

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.

Protective effect of melatonin on lipid peroxidation in various tissues of diabetic rats subjected to an acute swimming exercise

“…This result indicates that melatonin administration signifi cantly increased GSH levels in an acute swimming exercise. The fact that melatonin administration to rats subjected to a half-hour acute swimming exercise was shown to increase levels of GSH in various tissues, in comparison to the exercise group, which was not administered melatonin (27), is consistent with high GSH levels we found in our study.…”

Acute Exercise Increases Plasma Total Antioxidant Status and Antioxidant Enzyme Activities in Untrained Men

“…This suggests that senescence entails a decrease in the antioxidant defence system [43]. Hara et al [44] found an elevation of GPx activity in liver and muscle after a swimming test.…”

The protective effects of beta-carotene against ischemia/reperfusion injury in rat ovarian tissue

“…Tissue samples were centrifuged with Yellow Line DI 18 basic. The homogenates were centrifuged at 15,000 rpm for 15 min at +4 • C. Supernatants were collected and frozen at −80 • C until time of assay (Hara et al, 1996).…”