The effect of acute alloxan diabetes on the sensitivity of the rat skeletal neuromuscular junction to drugs.

Preparations from alloxan diabetic rats showed a reduced sensitivity to the neuromuscular blocking action of (+)-tubocurarine but no alteration in sensitivity to the depolarizing neuromuscular blocking drug decamethonium. Physostigmine was less effective in augmenting twitch height in preparations from alloxan diabetic rats and such preparations had a significantly lowered total cholinesterase activity compared with control preparations. An additional observation was a reduction in the effectiveness of the pre-junctionally active agent beta-bungarotoxin in producing neuromuscular blockade in physostigmine-treated preparations from alloxan diabetic rats. All the changes produced by alloxan administration were prevented by treatment with insulin.