title: [Effect of ouabain on intracellular Ca(2+) concentration in rat vascular smooth muscle cells in vitro].
abstract: OBJECTIVE
  To explore the effect of ouabain on intracellular Ca(2+) concentration ([Ca(2+)]i) in thoracic aorta vascular smooth muscle cells (VSMCs) in vitro.
  
  
  METHODS
  Primary SD rat thoracic aorta VSMCs were cultured by tissue adherent method and identified by immunochemistry. The binding ability between ouabain and VSMCs was detected by autoradiography, and fluo 3-AM (a Ca(2+) fluorescent probe) was employed to investigate whether ouabain affected VSMCs within a short period of time. The effect of a truncated fragment of the sodium pump α2 subunit was assayed in antagonizing the effect of ouabain on [Ca(2+)]i in the VSMCs.
  
  
  RESULTS
  Within the concentration range of 0.1-100 nmol/L, ouabain was found to dose-dependently bind to the VSMCs. Different concentrations of ouabain (0-3200 nmol/L) caused a transient, dose-dependent increase in [Ca(2+)]i in the VSMCs, which was antagonized by the application of the truncated fragment of sodium pump α2 subunit.
  
  
  CONCLUSIONS
  Elevations in [Ca(2+)]i in the VSMCs can be the cytological basis of high ouabain-induced hypertension. The truncated fragment of the sodium pump α2 subunit can antagonize ouabain-induced increase of [Ca(2+)]i in the VSMCs, which provides a clue for understanding the pathogenesis of and devising a therapeutic strategy for high ouabain-induced hypertension.
authors.affiliation: Department of Cardiology, Second Affiliated Hospital of Xian Jiaotong Uniersity College of Medicine, Xi'an 710004, China.E-mail: zhangmingjuan@mail.xjtu.edu.cn.
authors.forename: Mingjuan
authors.initials: M
authors.lastname: Zhang
authors.forename: Meicheng
authors.initials: M
authors.lastname: Zhang
authors.forename: Chaoying
authors.initials: C
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Canzhan
authors.initials: C
authors.lastname: Zhu
authors.forename: Zongming
authors.initials: Z
authors.lastname: Duan
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000254:Sodium-Potassium-Exchanging ATPase
chemical_list: D010042:Ouabain; C498532:Atp1a2 protein, rat; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium