title: [Abnormal abundances of calcium cycling regulatory proteins in rabbit myocytes with heart failure].
abstract: OBJECTIVE
  To investigate the abnormal abundances of calcium regulatory proteins in rabbit myocytes with failing hearts.
  
  
  METHODS
  Sixteen rabbits were divided into two groups: 8 rabbits with heart failure induced by volume plus pressure overload and 8 sham-operated animals. The hemodynamic parameters and cardiac structure and function were detected via catheterization and echocardiography respectively. L-type calcium channel (LTCC), Ryanodine receptor 2 (RyR2), Sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a), and Na(+)-Ca(2+) exchanger (NCX) protein abundances were determined by Western blot analysis.
  
  
  RESULTS
  The ratio of left ventricular mass to body weight, heart rate and left ventricular end diastolic pressure in heart failure rabbits were significantly increased compared with sham-operated rabbits (P < 0.01), but their left ventricular shorten fraction [(21.3 +/- 4.00)% vs. (36.5 +/- 1.36)%] and ejection fraction (0.45 +/- 0.07 vs. 0.70 +/- 0.02) were decreased (P < 0.01). In heart failure rabbits, the abundances of LTCC and RyR2 were significantly decreased (R(LTCC/actin): 0.287 +/- 0.029 vs. 0.624 +/- 0.009; R(RyR2/actin): 0.106 +/- 0.001 vs. 0.203 +/- 0.011; P < 0.01), whereas the expressions of SERCA2a and NCX were markedly increased (R(NCX/actin): 0.497 +/- 0.015 vs. 0.221 +/- 0.014; R(SERCA2a/actin): 0.611 +/- 0.036 vs. 0.433 +/- 0.008; P < 0.01).
  
  
  CONCLUSIONS
  Reductions of LTCC and RyR2 might contribute to risk factors of systolic dysfunction in failing hearts. In early stage of heart failure, upregulated SERCA2a and NCX protein levels may be helpful for maintaining cardiac performance.
authors.affiliation: Department of Cardiology, First Affiliated Hospital of Suzhou University, Suzhou 215006, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Zou
authors.forename: Zhi-hua
authors.initials: ZH
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.forename: Li-yan
authors.initials: LY
authors.lastname: Miao
authors.forename: Mei-ying
authors.initials: MY
authors.lastname: Qian
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Jian-ping
authors.initials: JP
authors.lastname: Song
authors.forename: Xiang-jun
authors.initials: XJ
authors.lastname: Yang
authors.forename: Ting-bo
authors.initials: TB
authors.lastname: Jiang
authors.forename: Wen-ping
authors.initials: WP
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000096:biosynthesis*; D005260:Female; D006333:Heart Failure / Q000378:metabolism*; D008297:Male; D011817:Rabbits; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000737:chemistry; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium