Experssion of cholesteryl ester transfer protein in rabbits with cardiac hypertrophy

  AIM  To investigate the expression of cholesteryl ester transfer protein (CETP) in isoproterenol induced cardiac hypertrophy in rabbits.

  METHODS  Twelve male New Zealand rabbits were randomly divided into a model group (n=6) and a control group (n=6). Cardiac hypertrophy was induced in the model group by daily isoproterenol administration 15 mg/(kg·d) for 14 days, while the control group was treated similarly with saline. At the end of the experimental period, samples of serum, heart and lungs were collected. Cardiac hypertrophy was quantified by the ratios of heart weight to body weight (HW/BW), the ratios of left ventricle weight to body weight (LVW/BW), the ratios of right ventricle weight to body weight (RVW/BW) and the expressions of fetal genes including ANP and β-MHC. The ratio of lung weight to body weight (LW/BW) was also detected. The morphological changes in the left ventricle tissue were observed by HE staining and the contents of serum TG, TC, LDL-C and HDL-C were detected. CETP in left ventricle was further observed by fluorescence quantitative PCR, Western blot and enzyme linked immunosorbent assay, respectively.

  RESULTS  Isoproterenol 15 mg/(kg·d) treatment for 14 days induced cardiac hypertrophy as evidenced by the increases of HW/BW and LVW/BW, the enlargement of myocardial cells with widened interstitium, as well as the up-regulations of the hypertrophy-related fetal gene expressions (P<0.05). An increasing tendency of RVW/BW and LW/BW was observed in the model group in comparison with that in the control group. Compared with those in the control group, the content of serum TG was significantly increased (P<0.05) and the contents of serum TC and LDL-C showed an increasing tendency, whereas the content of serum HDL-C showed a decreasing trend. Further research found that isoproterenol significantly induced the up-regulations of CETP mRNA level and CETP protein expression as well as the increase of CETP content in left ventricle (P<0.05).

  CONCLUSION  CETP expression is up-regulated in isoproterenol induced cardiac hypertrophy in rabbits. But whether it is involved in cardiac hypertrophy remains to be futher studied. This study may provide an ideal animal model fo the follow-up study of the relationship between CETP and cardiac hypertrophy.