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The effects of Anemonia sulcata toxin II on vertebrate skeletal muscle
Author(s) -
Harris John B.,
Pollard Sandra,
Tesseraux Irene
Publication year - 1985
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1985.tb09459.x
Subject(s) - extensor digitorum longus muscle , skeletal muscle , depolarization , stimulation , extensor digitorum muscle , anatomy , soleus muscle , extensor muscle , toxin , chemistry , medicine , biology , tetrodotoxin , endocrinology , biochemistry
1 Some effects of the sea anemone toxin, ATX‐II, on vertebrate skeletal muscle have been described. 2 At a concentration of 1 × 10 −7 ‐ 1 × 10 −6 M, ATX‐II caused a sodium‐dependent depolarizaton of the muscle fibres of the rat soleus and extensor digitorum longus, of the mouse soleus and extensor digitorum longus and of the chicken posterior latissimus dorsi. The muscle fibres of the frog sartorius were insensitive to the toxin. 3 Action potentials generated by direct stimulation were prolonged by ATX‐II, but the degree of prolongation was variable. Chicken posterior latissimus dorsi muscle fibres were most sensitive in this regard, and mouse extensor digitorum longus were least sensitive. 4 Both denervated and immature muscle fibres were more sensitive to ATX‐II than mature innervated muscle fibres. The sensitivity to ATX‐II declined rapidly as muscle fibres matured. 5 In some muscles, the prolongation of the action potential was enhanced by repetitive stimulation, but not by the passive depolarization or hyperpolarization of the muscle fibres. 6 The actions of ATX‐II could be reversed by washing in all but the innervated soleus of the mature rat.