On the nature and action of coelenterate toxins
Welsh, J.H. (1955). On the nature and action of coelenterate toxins, in: Papers in Marine Biology and Oceanography. Dedicated to Henry Bryant Bigelow, By His Former Students and Associates on the occasion of The Twenty-fifth Anniversary of the Founding of The Woods Hole Oceanographic Institution 1955. Deep-Sea Research (1953), 3(Supplement): pp. 287-297
In: (1955). Papers in Marine Biology and Oceanography. Dedicated to Henry Bryant Bigelow, By His Former Students and Associates on the occasion of The Twenty-fifth Anniversary of the Founding of The Woods Hole Oceanographic Institution 1955. Deep-Sea Research (1953), 3(Supplement). Pergamon Press: London & New York. 498 pp., meer
In: Deep-Sea Research (1953). Pergamon: Oxford; New York. ISSN 0146-6291; e-ISSN 1878-2485, meer
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| Abstract |
Tetramethylammonium, known to occur in sea anemones, has been thought to be one or constituents of coelenterate nematocyst toxins. To test this suggestion it was first shown that the tendency to drop legs, or autotomize, in the fiddler crab Uca mordax, was reduced by previous injection of extracts of tentacles of two species of anemones and of Physalia, the Portuguese-man-of-war. It was then found that injected tetramethylammonium chloride or acetylcholine had similar actions to those of the extracts. Further experiments of a comparable nature were done at another location, using as a test animal the shore crab, Hemigrapsus nudus. Extracts of tentacles of Metridium when injected into H. nudus, produced spontaneous autotomy of walking legs and chelae, followed by a degree of paralysis dependent upon the dose. After the injection of tetramethylammonium chloride into H. nudus there were no spontaneous autotomies, but there was a type of paralysis similar to that produced by tentacle extracts. Tetraethylammonium chloride, and a related compound called Banthine, were highly effective in blocking the autotomy-inducing and paralyzing actions of Metridium tentacle extracts. This is added evidence that a quaternary ammonium base similar to tetramethylammonium occurs in coelenterate tentacle extracts. When Metridium and Cyanea tentacle extracts were tested on an isolated mollusc heart, evidence for the presence of an excitor amine was obtained. It appeared not to be histamine. Later experiments strongly suggested that the material with the marked action on the molluscan heart was 5-hydroxytryptamine, a known histamine-releaser and potent pain producer. Through the use of paper chromatography further evidence has been obtained for the presence of 5-hydroxytryptamine in extracts of tentacles of Metridium and Physolia. This approach has also shown the presence of two or more quaternary ammonium bases, one of which has been tentatively identified as urocanylcholine, also known as murexine. The pain producing factor in coelenterate tentacle extracts is probably 5-hydroxytryptaminc: while paralysis could be due to two or more related quaternary ammonium bases such as tetramethylammonium and urocanylcholine. |
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