title: The effects of detergent on the contractility and ultrastructure of frog skeletal muscle.
abstract: The contractility of detergent-treated frog skeletal muscle and its ultrastructure were studied. Triton X-100 and Brij-58 were used as nonionic surface active substances. The concentrations of the detergent solutions were adjusted so that the trains of the twitch tensions would continue for about 10 min. The duration of the twitch tensions was about 10 min when the muscles were soaked in 0.1 mM (0.006%) Triton or in 2.5 mM (0.280%) Brij solution. The twitch tensions did not recover upon returning the muscles to the normal Ringer solution after treatment of the detergents. Rapid cooling of muscle that had been soaked in a 1.0 mM caffeine Ringer solution for 10 min provoked a marked contracture (RCC) in 0.1-0.2 mM Triton-treated preparation. No such contracture was obtained in 1.0-2.5 mM Brij-treated preparation. In ultrastructural findings of the Triton-treated muscle, some structural changes were observed in the transverse tubule and the junctional gap, but not in the terminal cisternae. Brij-treated muscle showed damage of each of these membranes, including the terminal cisternae. These findings suggest that the two detergents have different surface activities on the internal membrane system of the skeletal muscle. The biological activities of the membrane remained even after the treatment of Triton with a suitable concentration.
mesh_terms: D000818:Animals; D002592:Cetomacrogol / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology*; D007365:Intercellular Junctions / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000648:ultrastructure; D008854:Microscopy, Electron; D009119:Muscle Contraction / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure*; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011898:Ranidae; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure; D012996:Solutions; D013501:Surface-Active Agents / Q000494:pharmacology*
chemical_list: D003902:Detergents; D012996:Solutions; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D017830:Octoxynol; D002592:Cetomacrogol