Effects of disuse on the function of fragmented sarcoplasmic reticulum of rabbit M. gastrocnemius.
A preparation method has been described to obtain a relatively pure and functionally intact fragmented sarcoplasmic reticulum (SR) vesicles fraction from normal and atrophied muscles. Purified SR preparations from rabbit gastrocnemius muscle atrophied by disuse showed similar protein composition (gel electrophoresis; Laemmli 1970) and similar vanadate induced crystallization (Dux and Martonosi 1983) properties of Ca2+-ATPase as those of control preparations. In the early period of atrophy (1-2 weeks) both the Ca2+-ATPase activity and Ca2+ uptake showed a 2-3-fold increase (from 3.42 +/- 0.24 to 7.34 +/- 0.25 mumol Pi X mg-1 prot X min-1 and from 1.26 +/- 0.10 to 3.36 +/- 0.22 mumol/l Ca2+ X min-1 X mg-1 prot. respectively).
D000818:Animals; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000302:isolation & purification / Q000378:metabolism; D002458:Cell Fractionation; D003460:Crystallization; D066298:In Vitro Techniques; D008297:Male; D009133:Muscular Atrophy / Q000378:metabolism*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013997:Time Factors
D000252:Calcium-Transporting ATPases; D002118:Calcium