Lectin receptors in the cockroach neuromuscular system. II. Effects of denervation on muscle lectin receptors.

The binding of fluorescent derivatives of plant lectins to the 6 coxal depressor muscles in the leg of the cockroach was examined at 1, 2, 3 and 5 weeks after denervation. Histochemical analysis of the binding of the lectins to frozen sections of the muscles demonstrated that all detectable binding was to the surfaces of the muscle fibers. In addition, within one week of denervation those muscles which in the innervated state have different amounts of D-galactose and/or alpha-N-acetylgalactosamine on their surfaces, now all have identical amounts of these carbohydrates. Biochemical analysis of concanavalin A and wheat germ agglutinin glycoprotein receptors by sodium dodecylsulphate polyacrylamide gel electrophoresis indicated that approximately 17% of all the receptors detected altered their relative levels in denervated muscles. These changes were observed in those receptors that were present in equal amounts in each of the muscles as well as in those receptors that were distributed among the 6 muscles in a manner that correlated with innervation by an identified motor neuron. However, in spite of these changes that reduced the biochemical differences in the denervated CDMs it was still possible to distinguish among the 6 muscles by the nature of the Con A and WGA glycoprotein receptors. Denervated muscles still present biochemically different cell surfaces to regenerating motor neurons.