In vitro toxic effects of puff adder (Bitis arietans) venom, and their neutralization by antivenom.
This study investigated the in vitro toxic effects of Bitis arietans venom and the ability of antivenom produced by the South African Institute of Medical Research (SAIMR) to neutralize these effects. The venom (50 µg/mL) reduced nerve-mediated twitches of the chick biventer muscle to 19% ± 2% of initial magnitude (n = 4) within 2 h. This inhibitory effect of the venom was significantly attenuated by prior incubation of tissues with SAIMR antivenom (0.864 µg/µL; 67% ± 4%; P < 0.05; n = 3-5, unpaired t-test). Addition of antivenom at t50 failed to prevent further inhibition or reverse the inhibition of twitches and responses to agonists. The myotoxic action of the venom (50 µg/mL) was evidenced by a decrease in direct twitches (30% ± 6% of the initial twitch magnitude) and increase in baseline tension (by 0.7 ± 0.3 g within 3 h) of the chick biventer. Antivenom failed to block these effects. Antivenom however prevented the venom induced cytotoxic effects on L6 skeletal muscle cells. Venom induced a marginal but significant reduction in plasma clotting times at concentrations above 7.8 µg/100 µL of plasma, indicating poor procoagulant effects. In addition, the results of western immunoblotting indicate strong immunoreactivity with venom proteins, thus warranting further detailed studies on the neutralization of the effects of individual venom toxins by antivenom.
Department of Pharmacology, Monash University, Building 13E, Wellington Road, Clayton, Vic 3800, Australia. steven.fernandez@bakeridi.edu.au.
Steven
S
Fernandez
Department of Pharmacology, Monash University, Building 13E, Wellington Road, Clayton, Vic 3800, Australia. Wayne.Hodgson@monash.edu.
Wayne
W
Hodgson
Department of Pharmacology, Phramongkutklao College of Medicine, Bangkok 10400, Thailand. jenjuth@yahoo.com.
Janeyuth
J
Chaisakul
Department of Pharmacology, Monash University, Building 13E, Wellington Road, Clayton, Vic 3800, Australia. Rachelle.Kornhauser@monash.edu.
Rachelle
R
Kornhauser
Department of Pharmacology, Monash University, Building 13E, Wellington Road, Clayton, Vic 3800, Australia. nickikonstas@hotmail.com.
Nicki
N
Konstantakopoulos
Department of Biochemistry & Molecular Biology, Monash University, Building 77, Wellington Road, Clayton, Vic 3800, Australia. Ian.Smith@monash.edu.
Alexander Ian
AI
Smith
Department of Biochemistry & Molecular Biology, Monash University, Building 77, Wellington Road, Clayton, Vic 3800, Australia. Sanjaya.Kuruppu@monash.edu.
Sanjaya
S
Kuruppu
D000818:Animals; D000997:Antivenins / Q000494:pharmacology*; D015153:Blotting, Western; D002460:Cell Line; D002645:Chickens; D015180:Electrophoresis, Gel, Two-Dimensional; D066298:In Vitro Techniques; D051381:Rats; D014757:Viper Venoms / Q000037:antagonists & inhibitors / Q000633:toxicity*; D017819:Viperidae
D000997:Antivenins; D014757:Viper Venoms