EFFECTS OF NEUROMUSCULAR BLOCKING AGENTS ON THE DIFFERENTIATION OF NERVE-MUSCLE CONNECTIONS IN SLOW AND FAST CHICK MUSCLES.

The effects of neuromuscular blocking drugs on the development of slow and fast muscle fibres and their neuromuscular junctions was studied in chick embryos. Treatment of embryos with the depolarizing neuromuscular blocking agent suxamethonium affected the development of muscle fibres of the slow anterior latissimus dorsi (ALD) muscle more than that of muscle fibres of the posterior latissimus dorsi (PLD). The differentiation of the presynaptic elements of the neuromuscular junction was delayed and this was particularly obvious in PLD.