Diazacholesterol Myotonia: Accumulation of Desmosterol and Increased Adenosine Triphosphatase Activity of Sarcolemma

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Science  02 Mar 1973:
Vol. 179, Issue 4076, pp. 910-912
DOI: 10.1126/science.179.4076.910


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 Ca2+-stimulated adenosine triphosphatases of the sarcolemma are increased, but not the Mg2+-stimulated adenosine triphosphatase. The altered sterol composition of the sarcolemma may cause this type of myotonia by decreasing the chloride conductance of the membrane.