A lethal protein toxin (toxin-PC) from the Indian catfish (Plotosus canius, Hamilton) venom.
Isolation and purification of a lethal protein toxin from the Indian catfish Plotosus canius, Hamilton, venom is described. The purification procedure involved ammonium sulfate precipitate of crude venom followed by DEAE-ion exchange chromatography. The purified toxin (toxin-PC) was homogeneous on one-dimensional PAGE and PAS-negative, and had a molecular weight 15 Kd. Toxin-PC was lethal (LD50 225 micrograms/kg, intravenous, in mice) and cardiotoxic, having neuromuscular blocking activity. Toxin-PC produced cardiac arrest on isolated toad and guinea pig hearts. Prior administration of atropine and propanolol failed to counteract toxin activity on isolated heart preparations. On isolated chick biventer cervicis, toxin-PC produced total blockage of electrically-induced twitch response without affecting carbachol- and acetylcholine-induced contraction. The tension developed by the muscle was Ca++ ion-dependent. Neuromuscular blocking time was reduced when K+ ion concentration was increased in the medium. Antiserum raised against toxin-PC failed to antagonize lethal activity of toxin-PC in mice. Toxin-PC probably represents a major toxic component of catfish venom (P. canius), and was responsible for the pathophysiological changes.
Auddy
B
B
Department of Physiology, University of Calcutta, India.
Muhuri
D C
DC
Alam
M I
MI
Gomes
A
A
D000645:Ammonium Sulfate / Q000737:chemistry; D000818:Animals; D001001:Anura; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002397:Catfishes; D002645:Chickens; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005397:Fish Venoms / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D006168:Guinea Pigs; D006323:Heart Arrest / Q000139:chemically induced; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009466:Neuromuscular Blocking Agents / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D010791:Phrenic Nerve / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D011433:Propranolol / Q000008:administration & dosage / Q000494:pharmacology; D013194:Staining and Labeling
D005397:Fish Venoms; D009466:Neuromuscular Blocking Agents; D001285:Atropine; D011433:Propranolol; D011188:Potassium; D000645:Ammonium Sulfate; D002118:Calcium