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INFLUENCE OF SKF‐525A CONGENERS, STROPHANTHIDIN AND TISSUE‐CULTURE MEDIA ON DESENSITIZATION IN FROG SKELETAL MUSCLE
Author(s) -
TERRAR D.A.
Publication year - 1974
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.1476-5381.1974.tb09656.x
Subject(s) - carbachol , desensitization (medicine) , depolarization , chemistry , biophysics , skeletal muscle , membrane potential , repolarization , muscle contraction , grenouille , medicine , endocrinology , pharmacology , biology , electrophysiology , biochemistry , salientia , receptor , xenopus , gene
1 Microelectrodes have been used to follow changes in membrane potential at end‐plate regions of frog skeletal muscle fibres exposed to carbachol; the depolarizing drug was applied to narrow strips of muscle in a rapidly flowing solution containing relatively impermeant anions rather than chloride. 2 During prolonged applications of carbachol (10 to 20 μ m ), the depolarization caused by the drug showed a gradual decline which was attributed to desensitization. 3 Desensitization was little if at all affected by supplementing the external solution with factors present in tissue‐culture media, or by treating the muscle with strophanthidin (25 μ m ). 4 The rate of repolarization in the presence of carbachol (10 to 20 μ m ) was greatly increased by the SKF‐525A congeners pipenzolate bromide (10 μ m ) and adiphenine hydrochloride (1 μ m ). The desensitization‐enhancing action of these compounds is discussed.