title: The effect of different alkali metal ions on the release of muscle potassium during glycerol treatment.
abstract: Frog sartorius muscles were pretreated in 11.6 M (87%) ion-free glycerol. Then half of them were put in 5.8 M glycerol solutions containing 55 mM LiCl, NaCl, RbCl or CsCl and their pairs in ion-free 5.8 M glycerol solutions at 1:40 Vol. muscle:Vol. solution ratio. The release of potassium during exposure to the 5.8 M glycerol solution was significantly faster in the presence of Li or Na, but significantly slower in the presence of Rb than in the ion-free circumstance. The effect of Rb can be related to a cooperative phenomenon that implies existence of a structured phase of K-protein complexes. Some postulates of Ling's association-induction hypothesis are used for interpretation of two phases and their phase transitions in this type of bound-K structure in muscle. The phase transitions in this system could have an important role in the fast processes of excitation in muscle.
mesh_terms: D000818:Animals; D001001:Anura; D002414:Cations, Monovalent; D005990:Glycerol / Q000494:pharmacology*; D008094:Lithium / Q000494:pharmacology; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000378:metabolism*; D012413:Rubidium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology
chemical_list: D002414:Cations, Monovalent; D008094:Lithium; D012964:Sodium; D012413:Rubidium; D005990:Glycerol; D011188:Potassium