Aging-related ionic remodeling of L-type voltage dependent calcium channel in left atria of canine / 中华心血管病杂志
Chinese Journal of Cardiology
;
(12): 332-337, 2012.
Article
in Chinese
| WPRIM
| ID: wpr-275048
ABSTRACT
<p><b>OBJECTIVE</b>To investigate aging-related ionic remodeling of L-type voltage dependent calcium channel (LVDCC) in left atria of canine.</p><p><b>METHODS</b>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 (APD(90)), amplitude of action potential plateau (APA), I(Ca-L) peak current density of LVDCC were recorded. The mRNA and protein expressions of α1c subunit (Ca(V1.2)), sarcoplasmic reticulum Ca(2+)-ATPase (SECRA(2)), Calpain-I, ryanodine receptor (RYR(2)) were detected by quantitative RT-PCR and Western blot, respectively.</p><p><b>RESULTS</b>I(Ca-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 (APD(90)) 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 Ca(V1.2) was significantly lower (0.90 ± 0.35 vs. 2.38 ± 0.40, P < 0.05) while mRNA expression of RYR(2) 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 SECRA(2) and Calpain-I was similar between the two groups. Similarly, the protein expression level of Ca(V1.2) was significantly lower (0.13 ± 0.10 vs. 0.29 ± 0.12, P < 0.05) while the protein expression level of RYR(2) 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 SECRA(2), PLN(1) and Calpain-I was similar between the two groups.</p><p><b>CONCLUSION</b>These data suggest that aging could induce mRNA and protein expression changes of Ca(V1.2) and RYR(2) of LVDCC which might serve as the molecular basis of I(Ca-L) remodeling in aged dogs and might be linked to the increased likelihood of developing atrial fibrillation (AF) in aged dogs.</p>
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Atrial Fibrillation
/
Action Potentials
/
Age Factors
/
Patch-Clamp Techniques
/
Ryanodine Receptor Calcium Release Channel
/
Calcium Channels, L-Type
/
Myocytes, Cardiac
/
Sarcoplasmic Reticulum Calcium-Transporting ATPases
/
Heart Atria
/
Metabolism
Limits:
Animals
Language:
Chinese
Journal:
Chinese Journal of Cardiology
Year:
2012
Type:
Article
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