title: Relationship of abnormal intracellular calcium mobilisation to myocyte hypertrophy in human ventricular myocardium.
abstract: OBJECTIVE
  Calcium transients in muscles from patients with end stage heart failure consist of two components (L1 and L2) at physiological extracellular calcium concentrations ([Ca2+]o); the second component (L2) can appear in normal human myocardium at high [Ca2+]o. In muscles from end stage heart failure patients L2 is associated with significant hypertrophy. To expand these observations a group of muscles from control patients with mild hypertrophy but without overt heart disease was studied (n = 8), in which a second calcium transient component was present during high [Ca2+]o.
  
  
  METHODS
  Using the ratio of the two components of the calcium transient (L2/L1) seen in trabeculae from heart failure patients as a marker of intracellular calcium mobilisation, the hypothesis was tested that the extent of abnormality in transsarcolemmal calcium flux, and/or sarcoplasmic reticular calcium release and reuptake, correlates with the degree of hypertrophy present.
  
  
  RESULTS
  In contrast to non-hypertrophied myocardium, hypertrophied myocardium from patients without heart failure often showed an increase in the L2/L1 ratio at higher [Ca2+]o. Hypertrophied myocardium from patients with failure showed a progressive increase in the L2/L1 ratio, reflecting further impairment of calcium mobilisation. There was a positive correlation between the degree of hypertrophy and calcium mobilisation alterations that was enhanced by raised [Ca2+]o. Altered [Ca2+]i mobilisation may develop early in the course of hypertrophy, before the onset of clinical signs of cardiac dysfunction.
authors: Cardiovascular Disease Laboratory, Charles A Dana Research Institute, Beth Israel Hospital, Boston, MA 02215.
authors: J K
authors: JK
authors: Gwathmey
authors: L A
authors: LA
authors: Bentivegna
authors: B J
authors: BJ
authors: Ransil
authors: W
authors: W
authors: Grossman
authors: J P
authors: JP
authors: Morgan
mesh_terms: D000331:Aequorin; D002118:Calcium / Q000378:metabolism*; D006332:Cardiomegaly / Q000378:metabolism*; D006333:Heart Failure / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D009206:Myocardium / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000331:Aequorin; D002118:Calcium