title: [Changes of sarco(endo)plasmic reticulum Ca2+-Mg2+-ATPase activity of cultured myoblast induced by cyclic stretch].
abstract: OBJECTIVE
  To evaluate the effect of stretch on sarco(endo)plasmic reticulum Ca2+-Mg2+ ATPases activity and mRNA level and study the remodeling reaction of muscle in a variety of mechanical environments.
  
  
  METHODS
  Myoblast from maxillofacial skeletal muscle of one-week-old male Sprague-Dawley rat was cultured and stretched cyclicly using a four-point bend device. Inorganic Phosphorus test was used to compare the activity of Ca2+-Mg2+ ATPases of myoblast before and after stretch. RT-PCR was also used to observe the Ca2+-Mg2+ ATPases mRNA level.
  
  
  RESULTS
  The activity of Ca2+-Mg2+ ATPases of myoblast down regulated significantly in 4 hours. During the period of 8 hours to 24 hours, up-regulation followed then returned to control level at the 48 hour point. RT-PCR showed that Ca2+-Mg2+ ATPases mRNA level were elevated by stretch, particularly at 2 hour and 48 hour point.
  
  
  CONCLUSIONS
  The results suggested a transcriptional control of Ca2+-Mg2+ ATPases activity was involved in the muscle remodeling process induced by stretch.
authors.affiliation: Dept. of Orthodontics, Beijing Stomatology Hospital, Beijing 100050, China.
authors.forename: Xiao-xia
authors.initials: XX
authors.lastname: Che
authors.forename: Hong
authors.initials: H
authors.lastname: Zeng
authors.forename: Song-jiao
authors.initials: SJ
authors.lastname: Luo
mesh_terms: D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D008297:Male; D032446:Myoblasts / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*
chemical_list: D017301:Ca(2+) Mg(2+)-ATPase