J. Venom. Anim. Toxins incl. Trop. Dis.

Vol.9, No.2, p.370, 2003.

Poster - ISSN 1678-9199.

 

Unusual neurotoxic effect chicken biventer cervicis preparation of the PLA2 (F6) of crotoxin isolated from Crotalusdurissus collilineatus venom

 

Ponce-Soto, L.A.(1), Toyama, M.H.(2), Rodrigues-Simioni, L. (3), Novello, J.C.(1), Marangoni, S.(1)

 

(1)Departments of Biochemistry, (2)Physiology and Biophysics, I.B, (3)Farmacology Faculty of Medical Sciences, State University of Campinas (UNICAMP) Campinas, Brasil.

 

Objectives: To evaluate the activity unusual neurotoxic of a PLA2 (F6) of crotoxin isolated from C. d. collilineatus purified in a system of HPLC-RP, Using preparations of muscle biventer cervicis from chicken, through the technical conventional myographic (Fisiografo Gould RS 3400), in vat of 5 mL content nutritive solution of Krebs, at 37șC. A preparations were subjected to one constant tension of 0.5 g and stimulated using a bipolar electrodes and pulses supremaximals of 0.1 Hz of frequency and 0.2 ms duration from a Stimulator Grass S48.

Methods and Results:The PLA2 (F6) was purified by using HPLC-RP. Experiments controls were carried out besides the treated ones with two concentrations: 10 and 20 mg/mL. The addition of ACh (60 and 120 mM) or KCl (13.4 mM) before and after the addition of the PLA2 (F6) in preparations stimulated indirectly, I cause contract. It was observed that the PLA2 (F6) blocks the contractile response in dose-dependent manner (10 and 20 mg/mL) was determined for each. The 50% paralysis times was 42 ±4, and 30 ±1, (n=3) respective after 120 min observation. The PLA2 (F6) inhibited the twitch-tension of the contractile response irreversible in to the direct stimulus and it was able to reduce the contract induced by the ACh (10 mg/mL) 17 ±16.66% and (20 mg/mL) 24 ±14.52 % (n=3). The reduction of the answer to KCl (13.4mM) it was of 16 ±8.02%.

Conclusion The PLA2 (F6) from C. d. collilineatus blocked the twitch-tension induced in the muscle biventer cervicis of chicken in a dose-time-dependent way, suggest that the neurotoxic action of crotoxin is strongly influenced by PLA2 (F6).

 

Financial supported by: FAPESP

 

CORRESPONDENCE TO:

Luis Alberto Ponce-Soto, Avenida Santa Isabel, 1125 Bloco B-2, Campinas, SP, CEP: 13084-970, Brasil, Email: pelao01@hotmail.com