Neuromuscular effects of venoms and crotoxin-like proteins from Crotalus durissus ruruima and Crotalus durissus cumanensis

• Neurotoxicity and myotoxicity of Viperidae venoms were compared in vitro.
• Crotalus durissus ruruima venom presented only neurotoxic activity.
• Crotalus durissus cumanensis venom presented neurotoxic and myotoxic activities.
• C. durissus cumanensis venom is more potent than C. durissus ruruima.
• Crotoxins found in both venoms were the main cause of their neurotoxicity.

A myographic study was performed to compare the neuromuscular effects of venoms and crotoxin-like proteins from Crotalus durissus ruruima and Crotalus durissus cumanensis in mice phrenic-diaphragm preparation. It was concluded that both venoms present neurotoxic activity as a consequence of their crotoxin content. Furthermore, crotoxin from C.d. cumanensis is more potent than that from C.d. ruruima venom. At the concentration range in which both venoms express neurotoxic activity, only C.d. cumanensis venom also manifest a direct myotoxic effect that probably involves the synergic participation of other components than crotoxin.