title: [Effect of changes in pH on intracellular Ca2+ and cell length of myocytes].
abstract: OBJECTIVE
  To examine the effects of pHi on [Ca2+]i, cell length and Ca2+ sensitivity of myofilaments in rat myocyte.
  
  
  METHODS
  We used microscopic spectral imaging approach to monitor simultaneously [Ca2+]i, pHi and cell length with fluorescent indicator indo-1 and SNARF-1 in isolated single rat myocyte.
  
  
  RESULTS
  Exposure of cell to 20 mmol/L Sodium Propionate induced an intracellular acidosis which increased slightly systolic and diastolic [Ca2+]i, decreased the cell shortening (CS) and Ca2+ sensitivity of myofilament (P < 0.01). Exposure of cell to 15 mmol/L NH4Cl induced an intracellular alkalosis which decreased systolic and diastolic [Ca2+]i, increased the cell shortening and Ca2+ sensitivity of myofilament (P < 0.01).
  
  
  CONCLUSIONS
  In the early time of acidosis, [Ca2+]i, as well as cell length increases respectively. While alkalosis, [Ca2+]i and cell length decreases respectively. The effect of acidosis and alkalosis on Ca2+ sensitivity presents non-linear relationship, i.e. the effect of acidosis on sensitivity, caused by pHi change, is less than that of alkalosis.
authors.affiliation: Department of Cardiovascular Medicine, First Affiliated Hospital of China Medical University, Shenyang 110001, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yue-Lan
authors.initials: YL
authors.lastname: Zhang
authors.forename: Jing-Quan
authors.initials: JQ
authors.lastname: Wang
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D048429:Cell Size; D006863:Hydrogen-Ion Concentration; D008297:Male; D009206:Myocardium / Q000166:cytology*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002118:Calcium