[Reactions between 3H-monoacetylcobratoxin and membrane preparations from denervated muscles and caudate nuclei]

3H-monoacetyl derivative of the major neurotoxin of venom obtained from Naja naja oxiana was used as a marker of the nicotinic cholinoreceptor (N-ChR). It was shown that binding of neurotoxin with the membranes of bovine caudate nuclei unlike binding with the membranes of the rabbit gastrocnemius muscles is less strong and cannot be blocked completely with high concentrations of neurotoxin and d-tubocurarine. Serum of the rabbits immmunized with the protein preparation isolated from the membranes of caudate nuclei inhibited the binding of the marker by the membranes of caudate nuclei to a greater measure than by muscle membranes. It is concluded that the marker in question can be used for detecting N-ChR in caudate nuclei and that this cholinoreceptor differs from that of muscles.