title: Plasma membranes of muscle in experimental myotonia in rats.
abstract: Determinations of protein and phospholipid composition, as well as enzymatic activity, were carried out in plasma membranes isolated from the muscle of rats, after different periods of 20,25-diazacholesterol administration. A decrease in the level of phospholipids, and in the total amount of plasma membrane proteins, connected with a relative reduction in the amount of protein of a molecular weight of 100000 daltons, was found. The activity of (Na+ + K+)-ATP-ase gradually decreased while a reverse tendency was observed in the case of 5'-nucleotidase. Changes in ATP-ase and phospholipids appeared even prior to electrophysiologically recorded signs of the myotonia. The mechanism of these changes and their possible role in myotonia are discussed.
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D001372:Aza Compounds; D002784:Cholesterol / Q000031:analogs & derivatives; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D009222:Myotonia / Q000139:chemically induced / Q000378:metabolism*; D009708:Nucleotidases / Q000032:analysis; D010743:Phospholipids / Q000032:analysis; D051381:Rats; D012508:Sarcolemma / Q000032:analysis*
chemical_list: D001372:Aza Compounds; D008565:Membrane Proteins; D010743:Phospholipids; D002784:Cholesterol; D009708:Nucleotidases; D000251:Adenosine Triphosphatases