title: Acetylcholine receptors at neuromuscular synapses: phylogenetic differences detected by snake alpha-neurotoxins.
abstract: Phylogenetic differences in acetylcholine receptors from skeletal neuromuscular synapses of various species of snakes and lizards have been investigated, using the snake venom alpha-neurotoxins alpha-atratoxin (cobrotoxin) and alpha-bungarotoxin. The acetylcholine receptors of the phylogenetically primitive lizards, like those from all other vertebrates previously tested, are blocked by these alpha-neurotoxins. In contrast, receptors from snakes and advanced lizards are insensitive to one or both of the toxins. It is suggested that toxin-resistant acetylcholine receptors appeared early in the evolution of Squamata and preceded the appearance of alpha-neurotoxins.
mesh_terms: D000818:Animals; D001001:Anura; D002038:Bungarotoxins / Q000494:pharmacology; D008116:Lizards; D009469:Neuromuscular Junction / Q000502:physiology*; D010802:Phylogeny; D011894:Rana pipiens; D011950:Receptors, Cholinergic; D012910:Snake Venoms / Q000494:pharmacology*; D012911:Snakes; D013045:Species Specificity; D013569:Synapses / Q000502:physiology*
chemical_list: D002038:Bungarotoxins; D011950:Receptors, Cholinergic; D012910:Snake Venoms