A lethal cardiotoxic protein isolated from Bidder's organ of common Indian toad, Bufo melanostictus Schneider.
A lethal cardiotoxic (BO-CT; Bidder's organ cardiotoxin) protein was purified from the Bidder's organ of the common Indian toad B. melanostictus by gel filtration on Sephadex G-200. The homogeneity of cardiotoxin was tested by gel electrophoresis. The molecular weight of lethal BO-CT was 62 KDa and was devoid of glycoprotein. LD50 of the BO-CT was 50 micrograms/20 g (i.v.) in male albino mice. On isolated heart and auricle BO-CT initially increased the rate and amplitude of contraction and finally produced irreversible blockade of contraction. BO-CT induced auricular blockade, was not influenced by verapamil, propranolol and atropine. On isolated chick biventer cervicis preparation BO-CT produced irreversible blockade of electrically induced twitch response followed by contracture. This action was not antagonized by 4-aminopyridine and neostigmine. BO-CT induced contracture on chick biventer cervicis was increased by Ca2+, decreased by Na+ and abolished by K+. Cardiotoxic and neuromuscular activity of BO-CT was heat stable and abolished by proteolytic enzyme.
Gomes
A
A
Department of Physiology, University of Calcutta, India.
Alam
M I
MI
Muhuri
D C
DC
Auddy
B
B
Dasgupta
S C
SC
D000818:Animals; D002025:Bufonidae / Q000378:metabolism*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006460:Hemolysin Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects
D006460:Hemolysin Proteins