Continuous angiotensin-(1-7) infusion improves myocardial calcium transient and calcium transient alternans in ischemia-induced cardiac dysfunction rats.
The aim of this study was to evaluate the impact of Ang-(1-7) on calcium transient (CaT) in cardiomyocytes during the pathogenesis of heart failure. Cardiac dysfunction was induced by ligation of left anterior descending coronary artery in adult SD rats. Randomly selected rats were ligated and continuously infused with Ang-(1-7) [HF + Ang-(1-7) group] or saline (HF + saline group) via osmotic minipumps. After 28 days, hemodynamic parameters, the CaT, and the heart rate threshold of CaT alternans (CaT-Alt) were measured. Continuous Ang-(1-7) treatment could attenuate the impairment of cardiac function following LAD ligation. The amplitudes (F/F0) and 50%/90% recovery time of CaT were significantly different among HF + saline, HF + Ang-(1-7) and Sham-operated group. Compared to the Sham-operated group, the HF + saline group showed decreased CaT amplitude, and a prolonged 50%/90% CaT recovery time; Ang-(1-7) significantly improved these abnormalities. Compared with Sham-operated group, heart rate thresholds of CaT-Alt significantly reduced in HF + saline group, and Ang-(1-7) partly restored it. These findings indicate that Ang-(1-7) attenuates the CaT disturbance and increases the heart rate threshold of CaT-Alt during the pathogenesis of ischemic heart failure.
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China; Department of Cardiology, the Third People's Hospital of Chengdu, Sichuan 610031, PR China.
Duan
D
Luo
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China.
Xiaodong
X
Zhuang
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China.
Chufan
C
Luo
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China.
Ming
M
Long
Department of Cardiology, Guangdong Cardiovascular Institute, 96 Dongchuan RD, Guangzhou, Guangdong 510080, PR China.
Chunyu
C
Deng
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China.
Xinxue
X
Liao
Department of Cardiology, the First Affiliated Hospital of Sun Yat-sen University, 58 Zhangshan 2nd RD, Guangzhou, Guangdong 510080, PR China. Electronic address: zhxd2@mail2.sysu.edu.cn.
Lichun
L
Wang
D000803:Angiotensin I / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000502:physiology; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism*; D010446:Peptide Fragments / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D020746:Calcium Channels, L-Type; D010446:Peptide Fragments; D000803:Angiotensin I; C118790:angiotensin I (1-7); D002118:Calcium
Alternans; Angiotensin-(1–7); Calcium transient; Heart failure