title: Diazacholesterol myotonia: accumulation of desmosterol and increased adenosine triphosphatase activity of sarcolemma.
abstract: Myotonia induced in rats by 20,25-diazacholesterol is accompanied by accumulation of desmosterol in serum, fragmented sarcoplasmic reticulum, and sarcolemma. Activities of (Na(+),K(+))- and Ca(2+)-stimulated adenosine triphosphatases of the sarcolemma are increased, but not the Mg(2+)-stimulated adenosine triphosphatase. The altered sterol composition of the sarcolemma may cause this type of myotonia by decreasing the chloride conductance of the membrane.
mesh_terms: D000251:Adenosine Triphosphatases / Q000032:analysis*; D000818:Animals; D001372:Aza Compounds; D002784:Cholesterol; D003897:Desmosterol / Q000097:blood; D005260:Female; D009132:Muscles / Q000473:pathology; D009222:Myotonia / Q000097:blood / Q000139:chemically induced* / Q000201:enzymology / Q000473:pathology; D051381:Rats; D012508:Sarcolemma / Q000201:enzymology*; D012519:Sarcoplasmic Reticulum; D013261:Sterols / Q000097:blood*
chemical_list: D001372:Aza Compounds; D013261:Sterols; D003897:Desmosterol; D002784:Cholesterol; D000251:Adenosine Triphosphatases