title: Neuromuscular action of venom from the South American colubrid snake Philodryas patagoniensis.
abstract: Snakes of the opisthoglyphous genus Philodryas are widespread in South America and cause most bites by colubrids in this region. In this study, we examined the neurotoxic and myotoxic effects of venom from Philodryas patagoniensis in biventer cervicis and phrenic nerve-diaphragm preparations and we compared the biochemical activities of venoms from P. patagoniensis and Philodryas olfersii. Philodryas patagoniensis venom (40 microg/mL) had no effect on mouse phrenic nerve-diaphragm preparations but caused time-dependent neuromuscular blockade of chick biventer cervicis preparations. This blockade was not reversed by washing. The highest concentration of venom tested (40 microg/mL) significantly reduced (p<0.05) the contractures to exogenous acetylcholine (55 microM and 110 microM) and K(+) (13.4 mM) after 120 min; lower concentrations of venom had no consistent or significant effect on these responses. Venom caused a concentration- and time-dependent release of creatine kinase (CK) from biventer cervicis preparations. Histological analysis showed contracted muscle fibers at low venom concentrations and myonecrosis at high concentrations. Philodryas venoms had low esterase and phospholipase A(2) but high proteolytic activities compared to the pitviper Bothrops jararaca. SDS-PAGE showed that the Philodryas venoms had similar electrophoretic profiles, with most proteins having a molecular mass of 25-80 kDa. Both of the Philodryas venoms cross-reacted with bothropic antivenom in ELISA, indicating the presence of proteins immunologically related to Bothrops venoms. RP-HPLC of P. patagoniensis venom yielded four major peaks, each of which contained several proteins, as shown by SDS-PAGE. These results indicate that P. patagoniensis venom has neurotoxic and myotoxic components that may contribute to the effects of envenoming by this species.
authors.affiliation: Serpentário do Centro de Estudos da Natureza, Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba , São José dos Campos, 12244-000, SP, Brazil.
authors.forename: Roberta S
authors.initials: RS
authors.lastname: Carreiro da Costa
authors.forename: Luiz
authors.initials: L
authors.lastname: Prudêncio
authors.forename: Erika Fonseca
authors.initials: EF
authors.lastname: Ferrari
authors.forename: Gustavo H M F
authors.initials: GH
authors.lastname: Souza
authors.forename: Sueli Moreira
authors.initials: SM
authors.lastname: de Mello
authors.forename: Antonio Carlos Guimarães
authors.initials: AC
authors.lastname: Prianti Júnior
authors.forename: Wellington
authors.initials: W
authors.lastname: Ribeiro
authors.forename: Stella Regina
authors.initials: SR
authors.lastname: Zamunér
authors.forename: Stephen
authors.initials: S
authors.lastname: Hyslop
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Cogo
mesh_terms: D000818:Animals; D000997:Antivenins / Q000378:metabolism; D017837:Bothrops; D002645:Chickens; D002851:Chromatography, High Pressure Liquid; D017812:Colubridae / Q000378:metabolism*; D003429:Cross Reactions; D003435:Crotalid Venoms / Q000378:metabolism; D003964:Diaphragm / Q000187:drug effects / Q000294:innervation; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004950:Esterases / Q000032:analysis; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009119:Muscle Contraction / Q000187:drug effects*; D009336:Necrosis; D009466:Neuromuscular Blocking Agents / Q000378:metabolism / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000473:pathology; D010447:Peptide Hydrolases / Q000032:analysis; D054467:Phospholipases A2 / Q000032:analysis; D010791:Phrenic Nerve / Q000187:drug effects; D012910:Snake Venoms / Q000201:enzymology / Q000378:metabolism / Q000494:pharmacology*; D013020:South America; D013997:Time Factors
chemical_list: D000997:Antivenins; D003435:Crotalid Venoms; D009466:Neuromuscular Blocking Agents; D012910:Snake Venoms; D004950:Esterases; D054467:Phospholipases A2; D010447:Peptide Hydrolases