摘要:SummaryThe DBA/2J (D2)mdxmouse is a more severe model of Duchenne muscular dystrophy when compared to the traditional C57BL/10 (C57)mdxmouse. Here, we questioned whether sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) function would differ in muscles from young D2 and C57mdxmice. Both D2 and C57mdxmice exhibited signs of impaired Ca2+uptake in the gastrocnemius, diaphragm, and left ventricle; however, the level of impairment was more severe in D2mdxmice. Reductions in maximal SERCA activity were also more prominent in the D2mdxgastrocnemius and diaphragm when compared to those from C57mdxmice; however, there were no differences detected in the left ventricle. Across all muscles, D2mdxmice had the highest levels of oxidative stress as indicated by protein nitrosylation and/or nitration. In conclusion, our study shows that SERCA function is more impaired in young D2mdxmice compared with age-matched C57mdxmice.Graphical abstractDisplay OmittedHighlights•Ca2+uptake is severely impaired in muscles from young DBA/2J (D2)mdxmice•Maximal SERCA activity is lowered to a greater degree in muscles from D2mdxmice•Muscles from young D2mdxmice have higher levels of oxidative/nitrosative stress•Worsened SERCA function may contribute to worsened muscle pathology in D2mdxmicePathophysiology; Cell biology