Binding of Ricinus communis I lectin to the muscle cell plasma membrane in diseased muscle.

Using an electron histochemical technique, we have observed the binding of a D-galactose-specific lectin to the muscle cell plasma membrane in muscle biopsies taken from patients with various neuromuscular disorders. In spinal muscular atrophy, the only neurogenic disease studied, the plasma membrane stained as in normal muscle. However, in the myopathies Becker and limb-girdle muscular dystrophy and in the polymyositis there was a reduction in both the occurrence and the intensity of staining of the plasma membrane. Reduced lectin binding by the plasma membrane probably reflects secondary changes in the composition of glycoproteins and/or glycolipids in the membrane and seems to be common to all these myopathies to varying degrees.