Effect of exercise on sarcoplasmic reticulum Ca transport in muscle of mouse lines long-term selected for different Performance traits

Mouse lines used were long-term selected for high (DU-hTP) or low treadmill Performance (DU-ITP), or high locomotor open field activity (DU-hOF). The control line DU-Ks was maintained unselected. For each line 30 mice were used at 42 days of age. All lines were split into three groups: the first group was investigated without running exercise, the second had to run 500 m, and the third had to run until exhaustion on the treadmill. Compared to mice without running, in exhausted mice the maximal rate of SR Ca uptake of the m. rectus femoris decreases were only found in the mouse lines DU-ITP, and DU-hOF (28.5 %, and 36.3 %, respectively; p<0.05). The effect ofthe 500 m run was significant (p<0.05) in DU-hTP, but not in the other lines. An effect of exhausting exercise on Ca* ATPase was detected only in DU-hOF with increased values after the exhaustive run. The hypothesis, that exercise induced alterations in Ca* transport in muscle of mice selected for high activity (DU-hOF) or high running Performance (DU-hTP) are attenuated compared to mice which were not selected (DU-Ks) or selected for low Performance (DU-ITP), could not be verified.