Abstract
The venoms of some Bothrops species produce neuromuscular blockade in avian and mammalian nerve–muscle preparations in vitro. In this study, we compared the neuromuscular activities (myotoxicity and neurotoxicity) of venoms from several Brazilian species of Bothrops ( B. jararaca, B. jararacussu, B. moojeni, B. erythromelas and B. neuwiedi) in chick isolated biventer cervicis muscle preparations and examined their neutralization by commercial antivenom. All of the venoms (50–200 μg/ml, n=3–7 each) induced long-lasting, concentration-dependent muscle contracture and twitch–tension blockade, and also inhibited the muscle responses to acetylcholine and KCl. Preincubation of the venoms (200 μg/ml) with bothropic antivenom (0.2 ml) for 30 min at 37 °C prevented the twitch–tension blockade to different extents, with the protection varying from 0.5% ( B. neuwiedi) to 88% ( B. moojeni). Complete protection against the neuromuscular action of B. neuwiedi venom was observed only with a mixture of bothropic and crotalic antivenoms. The venoms caused either high ( B. jararacussu, B. neuwiedi and B. moojeni) or low ( B. jararaca and B. erythromelas) creatine kinase release. Morphologically, myonecrosis was greatest with B. jararacussu venom (98–100% of fibers damaged) and least with B. jararaca venom (74% damage). The extent of neutralization by bothropic antivenom was B. jararaca (93%)> B. erythromelas (65.8%)> B. moojeni (30.7%)> B. neuwiedi (20%)> B. jararacussu (no neutralization). Despite this variation in neutralization, enzyme-linked immunosorbent assays indicated similar immunoreactivities for the venoms, although immunoblots revealed quantitative variations in the bands detected. These results show that Bothrops venoms produce varying degrees of neuromuscular blockade in chick nerve–muscle preparations. The variable protection by antivenom against neuromuscular activity indicates that the components responsible for the neuromuscular action may differ among the venoms.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
