An immunofluorescent analysis of lectin binding to normal and regenerating skeletal muscle of rat.

Ten different fluorescein-conjugated lectins of various known sugar specificities were used to study cell surface glycoconjugates of normal and regenerating rat skeletal muscle. In normal muscle, Canavalia ensiformis agglutinin, Triticum vulgaris agglutinin (wheat germ agglutinin, WGA), Ricinus communis agglutinin-I, and Maclura pomifera agglutinin bound strongly to the endomysial region of the myofibers. No binding was observed in the cytoplasm of the myofibers. Other lectins (Dolichos biflorus agglutinin, Griffonia simplifolia agglutinin I and II, Ulex europaeus agglutinin, Arachis hypogaea agglutinin, Glycine max agglutinin) bound very poorly or not at all in the normal muscle. Skeletal muscle degeneration and regeneration was induced by autotransplantation of the extensor digitorum longus muscle. In the transplanted muscles, the endomysial lectin binding of the degenerating myofibers became weak and lacked continuity, indicating a breakdown of the endomysium. Of all the lectins tested, only WGA revealed intense binding in the myogenic zone of regenerating muscle. As the regeneration progressed, this WGA binding became restricted to the new endomysium. In completely regenerated muscle, binding of all lectins was similar to that seen in normal muscle. The specific binding of WGA to the myogenic zone may be important in identifying factors or glycoconjugates, which constitute a favorable environment for skeletal muscle regeneration.