Effect of exercise on sarcoplasmic reticulum Ca2+ 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 us ed at 42 days of age. All lines were split into three groups: the first gro up 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 mic e without running, in exhausted mice the maximal rate of SR Ca2+ uptake of the m. rectus femoris decreases were only found in the mouse lines DU-ITP, and DU-hOF (28.5%, and 35.3%, respectively; p<0.05). The effect of the 500 m run was significant (p<0.05) in DU-hTP, but not in the other lines. An ef fect of exhausting exercise on Ca2+ ATPase was detected only in DU-hOF with increased values after the exhaustive run. The hypothesis, that exercise i nduced alterations in Ca2+ transport in muscle of mice selected for high ac tivity (DU-hOF) or high running performance (DU-hTP) are attenuated compare d to mice which were not selected (DU-Ks) or selected for low performance ( DU-ITP), could not be verified.