The effects of the subcutaneous injection of the crude venom of the Australian common brown snake, Pseudonaja textilis on the skeletal neuromuscular system.
1 The effects of the crude venom of the Australian common brown snake on the mammalian neuromuscular system have been investigated. 2 The venom was injected subcutaneously into the dorso-lateral aspect of one hind limb of the rat. The limb was paralyzed within 90 min and remained paralysed for 2 to 3 days. 3 The exposed muscles failed to respond to indirect excitation, and individual fibres were not depolarized at the nerve-muscle junction by exposure to carbachol. 4 The wet weight, histological appearance, resting potential and input resistance of the muscle fibres and their ability to generate directly elicited action potentials were unaffected by exposure to the venom. 5 Administration of venom to isolated preparations caused a reduction in the amplitude of miniature endplate potentials, with no change in frequency. The quantal content of evoked endplate potentials was unchanged. 6 It was concluded that the crude venom was largely devoid of presynaptic activity and myotoxicity, and that its primary site of neurotoxicity was directed to the postsynaptic membrane.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001315:Australia; D002217:Carbachol / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D007279:Injections, Subcutaneous; D009045:Motor Endplate / Q000187:drug effects; D009132:Muscles / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D012910:Snake Venoms / Q000633:toxicity*; D013779:Tetrodotoxin / Q000633:toxicity
D012910:Snake Venoms; D013779:Tetrodotoxin; D002217:Carbachol