Acetylcholine activates two types of ion channels in sarcolemma from adult muscular dystrophic (mdx) mice.

Dissociated interosseus muscle fibres of wildtype and mdx mice were investigated to characterize acetylcholine (ACh) receptors with the single channel recording patch-clamp technique. On the muscle fibres of mdx mutants, two types of nicotinic acetylcholine receptor (nAChR) channels were found. One channel (29 pS, mean open time 2.1 ms) resembles channels on denervated and embryonic muscle and was not found on wildtype muscle where exclusively a 48 pS channel (mean open time 1.3 ms) was seen.