title: Isolation of a toxin from jellyfish Acromitus rabanchatu and its effect on skeletal muscle.
abstract: A toxin (T-Ar) from the crude extract of jellyfish Acromitus rabanchatu was purified by (NH4)2SO4 fractionation followed by ion-exchange chromatography on DEAE-cellulose column. The mol. wt of T-Ar was found to be about 182,000. T-Ar reversibly blocked the twitch response of rat diaphragm muscle stimulated either indirectly or directly. It also reversibly blocked the twitch responses of chick biventer-cervicis muscle preparations. T-Ar failed to alter the contractures of the denervated rat diaphragm muscle preparation induced by acetylcholine, potassium chloride and caffeine. Similarly, acetylcholine and carbachol-induced contractures on chick biventer-cervicis muscle preparation were not influenced by T-Ar. The T-Ar-induced blockade of twitch responses of rat phrenic nerve-diaphragm was enhanced in high Na+ or low Ca2+ medium, and reduced in low Na+ or high Ca(2+)-containing medium. The results suggest that the toxin (T-Ar) possesses a direct paralysing effect on the muscle membrane.
authors.affiliation: Department of Pharmaceutical Technology, Jadavpur University, Calcutta, India.
authors.forename: T K
authors.initials: TK
authors.lastname: Ghosh
authors.forename: A
authors.initials: A
authors.lastname: Gomes
authors.forename: A K
authors.initials: AK
authors.lastname: Chaudhuri
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000645:Ammonium Sulfate; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002645:Chickens; D002848:Chromatography, DEAE-Cellulose; D003064:Cnidarian Venoms / Q000302:isolation & purification* / Q000633:toxicity; D003964:Diaphragm / Q000187:drug effects / Q000294:innervation; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects* / Q000294:innervation; D010791:Phrenic Nerve / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D037401:Scyphozoa / Q000737:chemistry*; D012964:Sodium / Q000378:metabolism
chemical_list: D003064:Cnidarian Venoms; D002110:Caffeine; D011189:Potassium Chloride; D012964:Sodium; D000109:Acetylcholine; D000645:Ammonium Sulfate; D002118:Calcium