title: A lethal cardiotoxic protein isolated from Bidder's organ of common Indian toad, Bufo melanostictus Schneider.
abstract: 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.
authors.affiliation: Department of Physiology, University of Calcutta, India.
authors.forename: A
authors.initials: A
authors.lastname: Gomes
authors.forename: M I
authors.initials: MI
authors.lastname: Alam
authors.forename: D C
authors.initials: DC
authors.lastname: Muhuri
authors.forename: B
authors.initials: B
authors.lastname: Auddy
authors.forename: S C
authors.initials: SC
authors.lastname: Dasgupta
mesh_terms: 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
chemical_list: D006460:Hemolysin Proteins