Myocardial sarcoplasmic reticulum Ca2+ ATPase function is increased by aerobic interval training.
OBJECTIVE
Reduced activity of the sarcoplasmic reticulum Ca ATPase-2a (SERCA-2a) contributes to myocardial dysfunction. Exercise training improves myocardial Ca-handling, but SERCA-2a function is uncertain. We assessed SERCA-2a activity after exercise training.


METHODS
SERCA-2a function was assessed by sarcoplasmic reticulum Ca uptake in cardiomyocytes with other Ca uptake mechanisms blocked, in mice after aerobic interval training versus sedentary controls.


RESULTS
We established protocols to assess SERCA-2a function, and show that aerobic interval training increases the maximal rate of Ca uptake by 30%. This is at least partly explained by reduced phospholamban-to-SERCA-2a ratio.


CONCLUSIONS
Aerobic interval training improves myocardial SERCA-2a performance, explaining at least partly why myocardial Ca-handling improves after exercise training.
Kemi
Ole Johan
OJ
Institute of Biomedical and Life Sciences, University of Glasgow, UK. o.kemi@bio.gla.ac.uk
Ceci
Marcello
M
Condorelli
Gianluigi
G
Smith
Godfrey L
GL
Wisloff
Ulrik
U
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes; D016257:Fura-2; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D032383:Myocytes, Cardiac / Q000201:enzymology*; D005082:Physical Exertion / Q000502:physiology*; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism*; D015854:Up-Regulation; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D005456:Fluorescent Dyes; D016257:Fura-2; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban; C506947:Atp2a2 protein, mouse