Figure 1.

Reduced expression of the dystroglycan complex in dystrophic heart membranes. Shown are immunoblots of normal (lane 1), 15-week-old mdx (lane 2), and 15-week-old mdx-3cv (lane 3) cardiac muscle membranes, labelled with antibodies to the Dp427 isoform of dystrophin (a), α-dystroglycan (α-DG) (b), β-dystroglycan (β-DG) (c), laminin (LAM) (d), the α-subunit of the Na⁺/K⁺-ATPase (NKA) (e), the α₂-subunit of the dihydropyridine receptor (α₂-DHPR) (f), the RyR2 isoform of the ryanodine receptor Ca²⁺ release channel (g), and the slow/cardiac SERCA2 isoform of the sarcoplasmic reticulum Ca²⁺-ATPase (h). Dystrophin-deficient cardiac microsomes clearly exhibit a drastic reduction in both dystroglycans.