Chinese Journal of Tissue Engineering Research ›› 2012, Vol. 16 ›› Issue (42): 7901-7908.doi: 10.3969/j.issn.2095-4344.2012.42.022

Previous Articles     Next Articles

Changes of action potential and L-type calcium channel of left atrial myocytes in the aging-associated rats

Gan Tian-yi1, Xu Guo-jun1, Zhou Xian-hui1, Tang Bao-peng1, Guo Xia2, Li Yao-dong1, Jiang Tao3, Zhang Jian1, Li Fa-peng1   

  1. 1Department of Cardiology, 3Medical Research Center, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China; 2Key Laboratory of Endemic Disease, Xinjiang Medical University, Urumqi 830000, Xinjiang Uygur Autonomous Region, China
  • Received:2012-08-01 Revised:2012-08-27 Online:2012-10-14 Published:2012-10-14
  • Contact: Tang Bao-peng, Doctor, Chief physician, Professor, Doctoral supervisor, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China tangbaopeng@hotmail.com
  • About author:Gan Tian-yi, Doctor, Attending physician, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Urumqi 830054, Xinjiang Uygur Autonomous Region, China taog666@sina.com.cn

PDF

583

Abstract:

BACKGROUND: Aging is the independent risk factor of atrial fibrillation. The aging-associated changes of electrophysiological properties of atrial myocytes may play an important role in the mechanisms of atrial fibrillation.
OBJECTIVE: To investigate the aging-associated changes of action potential and L-type calcium channel of left atrial myocytes.
METHODS: Seventeen canines were allocated to two groups, including seven adult canines and 10 old canines. The left atrial myocytes were separated from the adult and old canines by collagenase-Ⅱ. We used whole-cell patch-clamp to record action potential and L-type calcium current in left atrial myocytes of adult and older canines. The α1c subunit mRNA and protein expression of L-type calcium channel were assessed by real-time quantitative PCR and Western blotting respectively.
RESULTS AND CONCLUSION: Compared with the adult canines, the amplitude of left atrial myocytes action potential plateau in old canines was significantly decreased (P < 0.05), and the action potential duration was significantly prolonged (P < 0.05), while there was no significant difference of the maximum diastolic potential and action potential amplitude (P > 0.05); the L-type calcium channel current density of the left atrial myocytes in the old canines was lower than that in the adult canines (P < 0.05), while there was no significant difference of the current kinetic parameters of L-type calcium channel between old and adult canines (P > 0.05); compared with the adult canines, the α1c subunit mRNA and protein expression of L-type calcium channel in the old canines was significantly decreased (P < 0.05). There are different aging-associated cell electrophysiological changes in the left atrial myocytes.

CLC Number: