The effect of tetrodotoxin on mammalian sarcolemmal proteins and glycoproteins.

This study evaluates the relative contributions of neural impulse activity and neurotrophic (non-impulse) factors by comparing the effects of denervation and the blockage of neural impulse activity on various biochemical parameters of mixed muscle sarcolemma. Muscle paralysis was induced by repeated injection of Tetrodotoxin (TTx) to the sciatic nerve. After seven days of inactivity the isolated sarcolemma was analyzed for protein and glycoprotein composition, Na+/K+ ATPase activity, Concanavalin A binding to intact sarcolemma and to carbohydrate components separated in SDS-polyacrylamide gels and sialyl and galactosyl transferase activity. The results have shown that following muscle inactivity all of the parameters except glycosyl transferases changed in a similar manner but to a lesser degree than denervation. It is concluded that trophic factors in addition to neural impulse activity play a role in the regulation of a number of surface membrane properties.