Quantitative Analysis of the Expression and Distribution of Calcium Channel α 1 Subunit mRNA in the Atria and Ventricles of the Rat Heart

doi:10.1006/jmcc.2001.1534

Journal of Molecular and Cellular Cardiology

Volume 34, Issue 5, May 2002, Pages 519-532

https://doi.org/10.1006/jmcc.2001.1534 Get rights and content

Abstract

Two distinct calcium currents are present in mammalian cardiac myocytes. Utilizing quantitative RT-PCR methods, we have analysed the expression patterns and abundance of four calcium channel α 1 subunit mRNAs in different regions of the rat heart and compared them to the known density of calcium currents recorded from rat atria. Our results show that Ca_V1.2 is the most abundant of the four α 1 subunit transcripts in the rat heart. The Ca_V1.2 message is more abundant in ventricle than in atria and does not vary in expression as a function of developmental age. Ca_V2.3, Ca_V3.1 and Ca_V3.2 mRNAs are 10–100 times less abundant than Ca_V1.2. Interestingly, Ca_V2.3, Ca_V3.1 and Ca_V3.2 are expressed in both atria and ventricle. The abundance of atrial Ca_V3.1 mRNA does not change significantly during development and remains high in older animals. In contrast, levels of atrial Ca_V3.2 mRNA are high in embryonic tissue and at 3- and 4-weeks postnatal but become undetectable at 5 weeks. Expression of atrial Ca_V2.3 mRNA is highest at 4-weeks postnatal and then declines gradually. We have previously documented that the LVA calcium current density is highest within 4–5 weeks after birth and then declines gradually reaching less than 30% of its maximal value at 12–14 weeks. The complex relationship between atrial LVA current density and the abundance of Ca_V2.3, Ca_V3.1 and Ca_V3.2 mRNA suggests that their contribution to the cardiac LVA current may vary as a function of postnatal age.

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^f1: Please address all correspondence to: Janice Larsen, PhD, University of Illinois, Molecular & Integrative Physiology, 407 South Goodwin Avenue, 524 Burrill Hall, MC-114, Urbana, IL 61801, USA. Tel: 217-244-2940; Fax: 217-333-1133; E-mail: [email protected]

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Regular ArticlesQuantitative Analysis of the Expression and Distribution of Calcium Channel α 1 Subunit mRNA in the Atria and Ventricles of the Rat Heart

Abstract

FEBS Lett

J Biol Chem

J Mol Cell Cardiol

FEBS Lett

J Biol Chem

Increase in T-type calcium current in atrial myocytes from adult rats with growth hormone-secreting tumors

Proc Natl Acad Sci USA

T-type calcium currents in rat cardiomyocytes during postnatal development: contribution to hormone secretion

Am J Physiol Heart Circl Physiol

Contribution of two types of calcium currents to the pacemaker potentials of rabbit sino-atrial node cells

J Physiol (Lond)

Primary structure and functional expression of the cardiac dihydropyridine-sensitive calcium channel

Nature

Structure and function of voltage-gated ion channels

Annu Rev Biochem

Immunodetection of alpha1E voltage-gated Ca(2+) channel in chromogranin-positive muscle cells of rat heart, and in distal tubules of human kidney

J Histchem Cytochem

Reexpression of T-type Ca2+ channel gene and current in post-infarction remodeled rat left ventricle

Cardiovasc Res

Cloning and characterization of alpha1H from human heart, a member of the T-type Ca2+ channel gene family

Circ Res

Structure and functional characterization of a novel human low-voltage activated calcium channel

J Neurochem

Antisense oligonucleotides against rat brain alpha1E DNA and its atrial homologue decrease T-type calcium current in atrial myocytes

Proc Natl Acad Sci USA

Identification of the calcium channel a1E (CaV2.3) isoform expressed in atrial myocytes

Biochim Biophys Acta

Molecular characterization of a neuronal low voltage-activated, T-type, calcium channel

Nature

Structure and functional expression of a member of the low voltage-activated calcium channel family

Science

Antisense oligonucleotides against alpha1E reduce R-type calcium currents in cerebellar granule cells

Proc Natl Acad Sci USA

Regular Articles
Quantitative Analysis of the Expression and Distribution of Calcium Channel α 1 Subunit mRNA in the Atria and Ventricles of the Rat Heart

Identification of the calcium channel a1E (Ca_V2.3) isoform expressed in atrial myocytes