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[The abnormal calcium re-uptake from sarcoplasmic reticulum and influencing factors in failed rabbits.] [Article in Chinese]

Wang Lei, ZHANG Shi-Jie, Li Li, Lan Chao, Zhang Rui, LIU Zhi-Hua

Department of Emergency, the First Affiliated Hospital of Zhengzhou University, Zhengzhou,450052, China； Department of Clinical Laboratory, the First Affiliated Hospital of Zhengzhou University, Zhengzhou,450052, China； Department of Cardiology, the First Affiliated Hospital of Soochow University, Suzhou, 215006, China

Abstract

The aim of the present study was to investigate the abnormal calcium re-uptake function of myocardium sarcoplasmic reticulum (SR) in rabbits with heart failure, as well as potential mechanisms. Heart failure model was established in rabbits through aortic insufficiency and constriction of abdominal aorta. The SR Ca²⁺ re-uptake function was measured with a calcium imaging device. The activity of myocardium SR calcium adenodine triphosphatase 2a (SERCA2a) was measured by inorganic phosphate. The protein expressions of SERCA2a, CaMKII, PKA, PP1α, phospholamban (PLB), PLB-Ser¹⁶ and PLB-Thr¹⁷ were evaluated by Western blot. The activities of PKA and CaMKII were detected by γ-³²P substrate incorporation. The results showed that, compared with the sham operation group, the heart failure group exhibited reduced Ca²⁺ re-uptake amount (P < 0.01) and the expression and activity of SERCA2a (P < 0.05 or P < 0.01), decreased expression of PLB and its phosphorylation status in sites of Ser¹⁶ and Thr¹⁷ (P < 0.05), increased expressions and activities of PKA and CaMKII (P < 0.05 or P < 0.01), and increased expression of PP1α (P < 0.05). These results suggest that the abnormal Ca²⁺ re-uptake function in heart failure is related with reduced expression and activities of SERCA2a, as well as reduced expression of PLB and its phosphorylation status. Both PLB-Ser¹⁶ and -Thr¹⁷ may be involved in the regulation of myocardium SR calcium pump activity in heart failure.

Key words: Heart failure; calcium re-uptake; sarcoplasmic reticulum; phospholamban

Received: 2014-01-01　　Accepted: 2014-04-03

Corresponding author: 张世杰　　E-mail: zsj03@zzu.edu.cn

Citing This Article：

Wang Lei, ZHANG Shi-Jie, Li Li, Lan Chao, Zhang Rui, LIU Zhi-Hua. [The abnormal calcium re-uptake from sarcoplasmic reticulum and influencing factors in failed rabbits.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (4): 483-488 (in Chinese with English abstract).