Rabbit antivenom efficacy against myotoxic and neurotoxic activities of Bothrops jararacussu venom and bothropstoxin-I

Abstract

Bothrops jararacussu venom and its major toxin bothropstoxin-I (BthTX-I) possess myotoxic and neurotoxic properties. The efficacy of a rabbit antivenom raised against B. jararacussu venom in the neutralization of physiological, biochemical, and morphological changes induced by the venom and its major toxin BthTX-I was studied in mouse isolated phrenic nerve-diaphragm (PND) and extensor digitorum longus (EDL) preparations. The times required for 50% neuromuscular blockade in PND and EDL preparations for venom were 70+11.5 (S.E.M., n=5) min and 58+8 (n=16) (50 m g/mL), and for BthTX-I 31+6 (n=3) min and 30+3 (n=5) min (20 m g/mL), respectively. After 120 min incubation, creatine kinase (CK) concentrations in solution containing the EDL preparations were 3464+346 U/L after exposure to venom (50 m g/mL, n=5) and 3422+135 U/L to BthTX-I (20m g/mL, n=4), respectively. Rabbit antivenom dose-dependently neutralized venom and toxin-induced neuromuscular blockade in both preparations and effectively prevented venom and toxin-induced CK release from EDL. Histological analysis showed that rabbit antivenom neutralized morphological damage caused by B. jararacussu venom and BthTX-I in EDL preparations. These results indicate that rabbit antivenom effectively neutralized the biological activities of B. jararacussu venom and BthTX-I.