ConA and WGA receptors in rat skeletal muscles. Changes in density, distribution and composition following denervation.

The differential binding of fluorescein-labeled ConA, WGA and UEA to cryostatic sections of control and of 8 days denervated muscles is described. Receptor sites for ConA and WGA appear to be very abundant in skeletal muscles and their abundance seems to increase following denervation. In contrast, concentration of receptor sites for UEA is below the sensitivity of the method. Differences in the distribution of the binding sites for ConA and WGA, apparent in untreated sections, were further analysed following predigestions by collagenase, hyaluronidase or neuraminidase. The most important difference among lectins appeared to be the preferential binding of ConA to the surface of muscle fibres and of WGA to connective tissue. By comparing results in control and denervated muscles a clear change of the effects of neuraminidase on WGA binding was evident following denervation. The binding of fluorescein-labeled ConA and WGA to untreated and to predigested cryostatic sections of skeletal muscle is a sensitive and simple histochemical method which can disclose precocious changes in composition of glycoconjugates following denervation and, what might be useful, in other experimental or pathological conditions.