Aging-related ionic remodeling of L-type voltage dependent calcium channel in left atria of canine
10.3760/cma.j.issn.0253-3758.2012.04.015
- VernacularTitle:增龄引起犬心房L型电压依赖型钙通道离子重构的分子机制
- Author:
Xian-Hui ZHOU
1
;
Jian ZHANG
;
Tian-Yi GAN
;
Guo-Jun XU
;
Bao-Peng TANG
Author Information
1. 新疆医科大学第一附属医院
- Keywords:
Atrial fibrillation;
Age factors;
Calcium channel,L-type
- From:
Chinese Journal of Cardiology
2012;40(4):332-337
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate aging-related ionic remodeling of L-type voltage dependent calcium channel (LVDCC) in left atria of canine.Methods Seven adult (2.0-2.5 years ) and 10 aged (＞8 years) dogs were used.The current of LVDCC was recorded by patch clamp technique in the whole cell mode.The action potential duration (APD90),amplitude of action potential plateau (APA),ICa-L peak current density of LVDCC were recorded. The mRNA and protein expressions of αlc subunit (CaV1.2),sarcoplasmic reticulum Ca2+-ATPase ( SECRA2 ),Calpain-Ⅰ,ryanodine receptor ( RYR2 ) were detected by quantiative RT-PCR and Western blot,respectively.Results ICa-L peak current density [(-8.11 ± 0.54)pA/pF vs.(14.04 ±0.82)pA/pF,P＜0.05 ] was significantly reduced and action potential duration to 90％ repolarization ( APD90 ) significantly prolonged [ (340.5 ± 10.1 ) ms vs.( 320.0 ± 7.9 ) ms,P＜ 0.05 ]in aged group than in adult group. The mRNA gene expression level of CaV1.2 was significantly lower (0.90 ±0.35 vs.2.38 ± 0.40,P＜0.05) while mRNA expression of RYR2 was significantly higher (4.39±4.68 vs.1.49 ± 1.69,P＜0.05) in the aged dogs than in the adult dogs.mRNA expression of SECRA2 and Calpain-Ⅰ was similar between the two groups.Similarly,the protein expression level of CaV1.2 was significantly lower (0.13 ± 0.10 vs.0.29 ± 0.12,P＜0.05) while the protein expression level of RYR2 was significantly higher (0.18 ±0.21 vs.0.08 ±0.36,P＜0.05) in the aged dogs than in the adult dogs. Again, protein expression of SECRA2, PLN1 and Calpain-Ⅰ was similar between the two groups.Conclusion These data suggest that aging could induce mRNA and protein expression changes of CaV1.2 and RYR2 of LVDCC which might serve as the molecular basis of ICa-L remodeling in aged dogs and might be linked to the increased likelihood of developing atrial fibrillation (AF) in aged dogs.
