COMPARATIVE STUDY OF VENOM OF Philodryas olfersii AND Philodryas patagoniensis (SERPENTES: COLUBRIDAE)

ROCHA, M.M.T.(1), ACOSTA DE PÉREZ, O.(2), FURTADO, M.F.D.(1)

(1)Laboratório de Herpetologia, Instituto Butantan, São Paulo, Brazil, (2)Facultad Ciências Veterinárias, Universidad Nacional Del Nordeste, Argentina.

Nowadays 65% of the existing snakes belong to Colubridae family.  Some, but not all, present complex glands denominated Duvernoy’s glands, considered to be homologous to the glands of proteroglyphous and solenoglyphous snakes, which produce toxic secretion or “venom”.  This group of snakes has been reported to cause human fatal accidents. The genus Philodryas has restrict distribution to South America, with 15 species, with only P. olfersii receiving attention in regard to the elucidation of its venom composition. A comparative study was performed on the pharmacology, biochemistry and pathology of venoms of P. olfersii and P. patagoniensis. The venoms induced lethal, hemorrhagic, myotoxic, no coagulant and desfibrinating effects, showing also proteolytic activity. The results showed that the P.olfersii venom has protein level of approximately 1mg/mg venom, while the P. patagoniensis venom presented 645mg/mg venom. The protein electrophoretic profile presents similar mobilities with components predominantly under 67kDa, with P. olfersii venom presenting greater number of bands.  The profile of glycoproteins is very similar to that of proteins, showing that the majority of the components of these venoms are glycoproteins. The proteolytic activity is high, with values above 200U/mg in both venoms. The hemorrhagic activity ensues rapidly, with DMH of 23ug at 4 hours in P. olfersii, and 27g at 2 hours in P. patagoniensis. P.olfersii presents DL50 of 58.85 g/mouse and P. patagoniensis, 62.43 g/mouse. Histologically after inoculation of 50mg/venom i.m., the hemorrhage sets up 15 min in both species. In 30min P. olfersii venom caused myonecrosis and inflammatory infiltrate, whereas in P. patagoniensis they arise in 60min. Venoms of both species presented the same activities, with variations in intensity and mainly in kinetics of action.

CORRESPONDENCE TO:

M.F.D. FURTADO, Laboratório de Herpetologia, Instituto Butantan, São Paulo, 05503-900, SP, Brazil, Email: fatimabut@lycos.com