Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung

Shigeru Watanabe; Kazumichi Matsushita; John B Stokes; Paul B McCray Jr

doi:10.1152/ajpgi.1998.275.6.G1227

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Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung

Journal article

Peer reviewed

Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung

Shigeru Watanabe, Kazumichi Matsushita, John B Stokes and Paul B McCray Jr

The American journal of physiology, Vol.275(6), p.G1227

12/1998

DOI: 10.1152/ajpgi.1998.275.6.G1227

PMID: 9843757

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Abstract

Na+ absorption via amiloride-sensitive Na+ channels is of critical importance in the transition between fetal and neonatal life in several tissues, including the colon, lung, and kidney. To characterize and contrast the mRNA expression of each of the three epithelial Na+ channel complex (ENaC) subunits, we conducted RNase protection assays (RPA) and in situ hybridization in colon and lung in fetal (17, 19, 20, and 21 days) and postnatal (1, 3, 9, 15, and 30 days) rats (r). In the colon the alpha-, beta-, and gamma-rENaC subunits showed quantitatively different but qualitatively similar expression. All three subunits gradually increased in abundance from fetal day 19 through day 30 of life. The amount of each subunit on day 30 was approximately three times the amount at day 1. In situ hybridization showed that each subunit was localized to the surface epithelial cells with minimal expression in the crypts. The lung showed a completely different pattern. In contrast to the colon, the total amount of alpha-rENaC mRNA (by RPA) in the lung increased dramatically from fetal day 19 to 21, whereas beta- and gamma-rENaC showed modest prenatal increases. The amounts of all three mRNAs fell after birth through day 9 (to about 75% of the day 1 value). On days 15 and 30 the amount of mRNA rose to approach the values on day 1. alpha-rENaC mRNA abundance always exceeded beta- and gamma-rENaC, and the quantitative expression was different for alpha- than for beta- and gamma-rENaC. In situ hybridization studies showed that all three subunits were expressed in epithelial cells of the bronchi, bronchioles, and alveoli and not in blood vessels. These studies show striking developmental heterogeneity in rENaC mRNA expression between lung and colon, probably reflecting different developmental regulatory mechanisms in these organs.

Colon - cytology

Animals, Newborn - metabolism

Epithelial Cells - metabolism

Fetus - metabolism

Colon - embryology

Gene Expression Regulation - physiology

Rats

Lung - cytology

RNA, Messenger - metabolism

Embryonic and Fetal Development - physiology

Fetus - physiology

Rats, Sprague-Dawley

Colon - metabolism

Fetus - cytology

Animals

In Situ Hybridization

Lung - embryology

Lung - metabolism

Sodium Channels - genetics

Details

Title: Subtitle: Developmental regulation of epithelial sodium channel subunit mRNA expression in rat colon and lung
Creators: Shigeru Watanabe - Department of Internal Medicine, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City, Iowa 52242, USA
Kazumichi Matsushita
John B Stokes
Paul B McCray Jr
Resource Type: Journal article
Publication Details: The American journal of physiology, Vol.275(6), p.G1227
DOI: 10.1152/ajpgi.1998.275.6.G1227
PMID: 9843757
NLM abbreviation: Am J Physiol
ISSN: 0002-9513
eISSN: 2163-5773
Publisher: American Physiological Society
Grant note: HL-02767 / NHLBI NIH HHS DK-52617 / NIDDK NIH HHS HL-55006 / NHLBI NIH HHS
Language: English
Date published: 12/1998
Academic Unit: Microbiology and Immunology; Pulmonary Medicine; Stead Family Department of Pediatrics; Internal Medicine
Record Identifier: 9984093316402771

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