The effect of exercise training on IL 6 levels during exhaustion and recovery period in rats

The purpose of this study is to investigate the possible role of moderate and streneous swimming training on plasma, brain and cerebrospinal fluid IL 6 levels during recovery from exhaustive exercise in rats. Ninety male Wistar rats were divided into three groups: Sedantery control (C), moderate trained (MT) and streneous trained (ST) groups. MT rats were applied swimming exercise one hour/day and 5 days/week for 8 weeks. ST group was trained by swimming with a progressive exercise programme. Animals in ST group began swimming at 1 h/day, swimming duration was progressively increased 30 min/wk, reached 2.5 h/day by week 4 and stayed constant for additional 4 weeks. Afterwards, all animals were applied acute exhaustive swimming exercise and measured endurance capacity. After acute bouts of exhaustive exercise, all animals were divided into 3 groups, in 10 animals each, and decapitated immediately, 24 and 48 hours after exhaustion to obtain tissue samples. Muscle citrate synthase activity, plasma and cerebrospinal fluid IL 6 and cerebral cortex IL 6 levels were determined. Data analyzed using one way ANOVA and expressed as ±SD, statistical significance was considered at the p<0.05 level. The endurance capacity and skeletal muscle citrate synthase activity of the three groups were found higher in MT and ST groups compared with the C group. Although plasma and brain IL 6 levels were found unaltered among all groups and different time measurements, cerebrospinal IL 6 concentration was found to be increased 24 hours after exhaustive exercise session of ST group.We concluded that exercise training intensity is an important factor determining cerebrospinal IL 6 concentration after exhaustive exercise. ?Keywords: Training intensity, IL 6, exercise, rats