title: The effects of black widow spider venom on the innervation of muscles paralysed by botulinum toxin.
abstract: Botulinum toxin (BoTx) was injected into the muscles of one leg in mice causing local paralysis. Black widow spider venom (b.w.s.v.) was then injected into the paralysed muscles 3 or 15 d later. In both groups b.w.s.v. destroyed the nerve terminals poisoned by BoTx. In the 15 d group axonal sprouts, which had former due to the block of neuromuscular transmission by BoTx, were also destroyed. Within a few days the motor nerve terminal regenerated and the muscles recovered from paralysis at a faster rate than after BoTx alone. Recovery seemed to begin earlier in muscles where axonal sprouting was already advanced when b.w.s.v. was injected. The normal pattern of innervation was re-established in both groups, which was in marked contrast with muscles after BoTx alone where numerous sprouts and many ectopic end-plates had formed.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001180:Arthropod Venoms / Q000494:pharmacology*; D001740:Black Widow Spider; D001905:Botulinum Toxins / Q000494:pharmacology*; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D008297:Male; D051379:Mice; D008854:Microscopy, Electron; D009045:Motor Endplate / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects* / Q000294:innervation; D009416:Nerve Regeneration / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*; D013111:Spider Venoms / Q000494:pharmacology*; D013112:Spiders; D013569:Synapses / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D001180:Arthropod Venoms; D013111:Spider Venoms; D001905:Botulinum Toxins; D000109:Acetylcholine