Geographic variations and neurotoxic activity of the crotoxin from South American rattlesnake venoms: Crotalus durissus terrificus, Crotalus durissus collilineatus, Crotalus durissus ruruima, and Crotalus durissus cumanensis sub-species.

Diz Filho, E.B.S., Ponce-Soto, L.A., Fagundes F.H.R., Bonfim, V.L., Damico, D.C.S., and Marangoni. S.

Department of Biochemistry Institute of Biology UNICAMP – BRAZIL. 

The crotoxin complex purification, from the venom of the South American rattlesnake subspecies Crotalus durissus terrificus, Crotalus durissus collilineatus, Crotalus durissus ruruima and Crotalusdurissus cumanensis (Kentucky Reptile Zoo Natural Bridge State Park, Slade, Kentucky, USA), was performed on HPLC system using molecular exclusion column Protein Pack 300SW (Waters). To evaluate the neurotoxic activity of purified crotoxin from each subspecie, we used chicken biventer cervicis muscle-nerve preparation as originally described by Ginsborg and Waniney (1960). Control preparation was stable in the absence of crotoxin. The addition of ACh(60 and 120 mM) or KCl (13.4 mM) before and after crotoxin was done through indirect stimulae. It was observed that blockage of the toxin in the twich response was dose-dependent (10 and 20 mg/mL).The analysis was determined for each venom. The 50% paralysis time for 10 and 20mg/mL were 28 to 37 min and 20 to 35 min, respectively, for a 120 min assay (n=5). The non-reduction to the ACh contracture in the dose of 10 and 20 mg/mL showed a presynaptic neurotoxic action like b-neurotoxins described in the literature.

Financial Support: CAPES A and FAPESP.

Correspondence to: bridiz@hotmail.com