Lymphocyte enzymatic antioxidant responses to oxidative stress following high-intensity interval exercise.

The purposes of this study were to 1) examine the immune and oxidative stress responses following high-intensity interval training (HIIT); 2) determine changes in antioxidant enzyme gene expression and enzyme activity in lymphocytes following HIIT; and 3) assess pre-HIIT, 3-h post-HIIT, and 24-h post-HIIT lymphocyte cell viability following hydrogen peroxide exposure in vitro. Eight recreationally active males completed three identical HIIT protocols. Blood samples were obtained at preexercise, immediately postexercise, 3 h postexercise, and 24 h postexercise. Total number of circulating leukocytes, lymphocytes, and neutrophils, as well as lymphocyte antioxidant enzyme activities, gene expression, cell viability (CV), and plasma thiobarbituric acid-reactive substance (TBARS) levels, were measured. Analytes were compared using a three (day) × four (time) ANOVA with repeated measures on both day and time. The a priori significance level for all analyses was P < 0.05. Significant increases in superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities were observed in lymphocytes following HIIT. No significant increases in lymphocyte SOD, CAT, or GPX gene expression were found. A significant increase in TBARS was found immediately post-HIIT on days 1 and 2. Lymphocyte CV in vitro significantly increased on days 2 and 3 compared with day 1. Additionally, there was a significant decrease in CV at 3 h compared with pre- and 24 h postexercise. These findings indicate lymphocytes respond to oxidative stress by increasing antioxidant enzyme activity. Additionally, HIIT causes oxidative stress but did not induce a significant postexercise lymphocytopenia. Analyses in vitro suggest that lymphocytes may become more resistant to subsequent episodes of oxidative stress. Furthermore, the analysis in vitro confirms that lymphocytes are more vulnerable to cytotoxic molecules during recovery from exercise.

Effect of free radical altered IgG on allergic inflammation.

The rheumatoid synovium is capable of producing large amounts of IgG which may become modified by the actions of free radicals. A rat model of synovitis was established and challenged with both normal and free radical altered IgG. IgG was prepared from homologous pooled serum by high performance liquid chromatography, and free radical damage was induced by 15 minutes ultraviolet (UV) irradiation. The results showed a worsening in gross assessments of inflammation, increases in biochemical indices of lipid peroxidation, and also a rise in the proportion of IgG which, on reisolation, showed the characteristic fluorescence associated with free radical damage. This demonstrated how the presence of free radical altered IgG might convert an inflammatory insult to a more persistent stimulus, and the capacity of an environment subjected to continuing antigenic stimulation to induce further free radical damage to IgG.

[Changes of locomotor activities, lipid peroxide levels and their related enzyme activities in rat loaded with swimming exercise (author's transl)].

The changes of locomotor activities in rat loaded with swimming exercise were recorded by our newly devised apparatus. In addition, changes of lipid peroxide levels and their related enzyme activities in rat brain, liver as well as blood were studied. The results obtained were as follows: 1. The locomotor activities in rat recorded by the apparatus showed the same patterns as that reported by the other researchers. 2. After the loading of swimming, locomotor activities in rat during the dark period decreased significantly as compared to those of the control. 3. The levels of TBARS (thiobarbituric acid reactive substance), SOD (superoxide dismutase) and GSH-px (glutathione peroxidase) in rat liver elevated after the swimming exercise in the first group, which was sacrificed after loading with one treatment (about 5 hours) exercise of swimming. 4. The level of TBARS in rat brain elevated after the swimming exercise in the second group, which was sacrificed after loading with two treatment exercise of swimming. 5. The level of TBARS in plasma decreased, and GSH-px, GR (glutathione reductase) and catalase in red blood cells elevated in the third group, which was sacrificed after two-hour rest following the loading with two treatment exercise of swimming. It is indicated that our newly devised apparatus is useful for monitoring locomotor activities in rat, and that the fatigue in rat caused by swimming load can be shown in terms of changes in the above activities. The elevation of the level of TBARS during the swimming exercise observed in tissues of the brain and liver may suggest that the lipid peroxidation will reflect a certain state of fatigue in rat.