Figure 7. SUNCR1 global knockout blocks the effect of succinate on muscle fiber switch in vivo .

Male C57BL/6J or SUNCR1 KO mice were fed with chow diet supplemented with 0 or 1% SUC for 6 weeks.

• A–G
  (A, B) The O₂ consumption (VO₂), (C, D) RER, (E) muscle grip strength, (F) four‐limb handing time, and (G) low‐speed running time.
• H–J
  The enzymes activity of (H) HK, (I) LDH, and (J) SDH in gastrocnemius.
• K, L
  Immunoblots and quantification of MyHC I, MyHC IIb, NFAT, and PGC‐1α protein in gastrocnemius.
• M, N
  Representative images and quantification of laminin (green), or MyHC I and MyHC IIb (red) immunofluorescent staining in gastrocnemius muscle (n = 3). Scale bar in (M) represents 100 μm.

Data information: Results are presented as mean ± SEM (n = 5–6). *P ≤ 0.05 and **P ≤ 0.01 by non‐paired Student's t‐test.