[Effects of valsartan on myocardial calcium/calmodulin-dependent protein kinase-II expression and activity in a rabbit model of heart failure].

Abstract

OBJECTIVE:

To investigate the effects of valsartan on myocardial expression and activity of calcium/calmodulin-dependent protein kinase-II (CaMK II) in a rabbit model of heart failure.

METHODS:

Rabbits were divided into sham-operated group, heart failure group (volume overload by aortic valve destruction induced aortic insufficiency plus pressure overload induced by abdominal aortic banding) and heart failure plus valsartan (20 mg x kg(-1) x d(-1), n = 9 each). Seven weeks later, echocardiography and hemodynamic examinations were performed and myocardial CaMK II expression and activity were detected by Western blot and CaMK II activity assay kit, respectively.

RESULTS:

Compared with the sham operated rabbits, left ventricular mass index [LVMI (3.61 +/- 0.09) g/kg vs. (1.32 +/- 0.06) g/kg, P<0.05] and end-diastolic pressure [LVEDP (23.00 +/- 2.37) mm Hg (1 mm Hg = 0.133 kPa) vs. (-1.50 +/- 0.5) mm Hg, P<0.05] were significantly increased while left ventricular shortening fractions [LVFS (17.38 +/- 3.13)% vs. (37.83 +/- 3.58)%, P<0.05] and ejection fraction [LVEF (38.50 +/- 6.07)% vs. (71.92 +/- 4. 56)%, P<0.05] were significantly decreased (all P<0.05) in heart failure rabbits, these changes could be significantly attenuated by valsartan treatment: LVMI [(2.07 +/- 0.14) g/kg vs. (3.61 +/- 0.09) g/kg, P<0.05], LVEDP [(2.17 +/- 0.72) mm Hg vs. (23.00 +/- 2.37) mm Hg, P<0.05], LVFS [(33.83 +/- 2.85)% vs. (17.38 +/- 3.13)%, P<0.05] and LVEF [(64.45 +/- 3.66)% vs. (38.50 +/- 6.07)%, P<0.05]. CaMK II expression (1.45 +/- 0.13 vs 0.89 +/- 0.05, 1.13 +/- 0.12, P<0.05) and activity [(3.54 +/- 0.17) pmol x min(-1) x microg(-1) vs. (2.18 +/- 0.13) pmol x min(-1) x microg(-1), (2.79 +/- 0.14) pmol x min(-1) x microg(-1), P<0.05] in heart failure rabbits were significantly increased than those sham operated rabbits which could be significantly attenuated by valsartan treatment.

CONCLUSION:

Valsartan improved cardiac function in heart failure rabbits probably via downregulating myocardial CaMK II expression and activity.

• Authors: Fu-zheng Qu, Zhi-hua Liu, Bin Jiang, Cao Zou, Hong-xia Li, Lian-hua Han, Wen-ping Jiang
• Journal: Zhonghua xin xue guan bing za zhi (Zhonghua Xin Xue Guan Bing Za Zhi) Vol. 37 Issue 6 Pg. 501-4 (Jun 2009) ISSN: 0253-3758 [Print] China
• PMID: 19927629 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Angiotensin II Type 1 Receptor Blockers
• Tetrazoles
• Valsartan
• Calcium-Calmodulin-Dependent Protein Kinase Type 2
• Valine
• Calcium

Topics

• Angiotensin II Type 1 Receptor Blockers (therapeutic use)
• Animals
• Calcium (metabolism)
• Calcium-Calmodulin-Dependent Protein Kinase Type 2 (metabolism)
• Disease Models, Animal
• Female
• Heart Failure (drug therapy, metabolism)
• Male
• Myocardium (metabolism)
• Rabbits
• Tetrazoles (therapeutic use)
• Valine (analogs & derivatives, therapeutic use)
• Valsartan