Effect of 17β-estradiol on mRNA expression of large-conductance, voltage-dependent, and calcium-activated potassium channel α and β subunits in guinea pig

Khalid Jamali, Barry R. Naylor, Martin Kelly, Oline Ronnekleiv

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Large-conductance, voltage- and calcium-activated potassium (MaxiK) channels play a key role in cell excitability. MaxiK channels are composed of a pore-forming α-subunit and a regulatory β-subunit, of which four (β1-4) genes have been identified. Previous findings suggested that MaxiK channel activity is regulated by estradiol. However, the underlying mechanisms have remained incompletely documented. Therefore, we used reverse transcriptase polymerase chain reaction to clone four cDNA fragments that were specific to the guinea pig α, β1, β2, and β4 genes. Using a sensitive ribonuclease protection assay, we found that the α and β4 mRNAs were the most abundant mRNAs in the brain and pituitary, whereas in the aorta, the α-subunit was coexpressed with the β1-subunit. Moreover, there was a significant upregulation of the α- but not the β1-subunit mRNA and the α-subunit protein in the aorta of the estrogenvs oil-treated ovariectomized animals. In specific brain areas including preoptic area, ventral hypothalamus, hippocampus, and amygdala, and in the pituitary, neither the α- nor β4-subunit mRNAs were affected by estrogen. These findings suggest that estrogen may not affect the mRNA expression of MaxiK channels in the brain and pituitary. However, estrogen causes increased expression of MaxiK α in the aorta, which may explain some of the cardioprotective effects of estrogen in women.

Original languageEnglish (US)
Pages (from-to)227-237
Number of pages11
JournalEndocrine
Volume20
Issue number3
DOIs
StatePublished - Apr 2003

Fingerprint

Calcium-Activated Potassium Channels
Large-Conductance Calcium-Activated Potassium Channels
Estradiol
Guinea Pigs
Estrogens
Messenger RNA
Aorta
Brain
Preoptic Area
Protein Subunits
Ribonucleases
Amygdala
Reverse Transcriptase Polymerase Chain Reaction
Genes
Hypothalamus
Hippocampus
Oils
Up-Regulation
Complementary DNA
Clone Cells

Keywords

  • Aorta
  • Brain
  • Estradiol effects
  • MaxiK channel subunits
  • mRNA expression

ASJC Scopus subject areas

  • Endocrinology

Cite this

@article{49d4f6dfbca146019fdd3521b29eb9f1,
title = "Effect of 17β-estradiol on mRNA expression of large-conductance, voltage-dependent, and calcium-activated potassium channel α and β subunits in guinea pig",
abstract = "Large-conductance, voltage- and calcium-activated potassium (MaxiK) channels play a key role in cell excitability. MaxiK channels are composed of a pore-forming α-subunit and a regulatory β-subunit, of which four (β1-4) genes have been identified. Previous findings suggested that MaxiK channel activity is regulated by estradiol. However, the underlying mechanisms have remained incompletely documented. Therefore, we used reverse transcriptase polymerase chain reaction to clone four cDNA fragments that were specific to the guinea pig α, β1, β2, and β4 genes. Using a sensitive ribonuclease protection assay, we found that the α and β4 mRNAs were the most abundant mRNAs in the brain and pituitary, whereas in the aorta, the α-subunit was coexpressed with the β1-subunit. Moreover, there was a significant upregulation of the α- but not the β1-subunit mRNA and the α-subunit protein in the aorta of the estrogenvs oil-treated ovariectomized animals. In specific brain areas including preoptic area, ventral hypothalamus, hippocampus, and amygdala, and in the pituitary, neither the α- nor β4-subunit mRNAs were affected by estrogen. These findings suggest that estrogen may not affect the mRNA expression of MaxiK channels in the brain and pituitary. However, estrogen causes increased expression of MaxiK α in the aorta, which may explain some of the cardioprotective effects of estrogen in women.",
keywords = "Aorta, Brain, Estradiol effects, MaxiK channel subunits, mRNA expression",
author = "Khalid Jamali and Naylor, {Barry R.} and Martin Kelly and Oline Ronnekleiv",
year = "2003",
month = "4",
doi = "10.1385/ENDO:20:3:227",
language = "English (US)",
volume = "20",
pages = "227--237",
journal = "Endocrine",
issn = "1355-008X",
publisher = "Humana Press",
number = "3",

}

TY - JOUR

T1 - Effect of 17β-estradiol on mRNA expression of large-conductance, voltage-dependent, and calcium-activated potassium channel α and β subunits in guinea pig

AU - Jamali, Khalid

AU - Naylor, Barry R.

AU - Kelly, Martin

AU - Ronnekleiv, Oline

PY - 2003/4

Y1 - 2003/4

N2 - Large-conductance, voltage- and calcium-activated potassium (MaxiK) channels play a key role in cell excitability. MaxiK channels are composed of a pore-forming α-subunit and a regulatory β-subunit, of which four (β1-4) genes have been identified. Previous findings suggested that MaxiK channel activity is regulated by estradiol. However, the underlying mechanisms have remained incompletely documented. Therefore, we used reverse transcriptase polymerase chain reaction to clone four cDNA fragments that were specific to the guinea pig α, β1, β2, and β4 genes. Using a sensitive ribonuclease protection assay, we found that the α and β4 mRNAs were the most abundant mRNAs in the brain and pituitary, whereas in the aorta, the α-subunit was coexpressed with the β1-subunit. Moreover, there was a significant upregulation of the α- but not the β1-subunit mRNA and the α-subunit protein in the aorta of the estrogenvs oil-treated ovariectomized animals. In specific brain areas including preoptic area, ventral hypothalamus, hippocampus, and amygdala, and in the pituitary, neither the α- nor β4-subunit mRNAs were affected by estrogen. These findings suggest that estrogen may not affect the mRNA expression of MaxiK channels in the brain and pituitary. However, estrogen causes increased expression of MaxiK α in the aorta, which may explain some of the cardioprotective effects of estrogen in women.

AB - Large-conductance, voltage- and calcium-activated potassium (MaxiK) channels play a key role in cell excitability. MaxiK channels are composed of a pore-forming α-subunit and a regulatory β-subunit, of which four (β1-4) genes have been identified. Previous findings suggested that MaxiK channel activity is regulated by estradiol. However, the underlying mechanisms have remained incompletely documented. Therefore, we used reverse transcriptase polymerase chain reaction to clone four cDNA fragments that were specific to the guinea pig α, β1, β2, and β4 genes. Using a sensitive ribonuclease protection assay, we found that the α and β4 mRNAs were the most abundant mRNAs in the brain and pituitary, whereas in the aorta, the α-subunit was coexpressed with the β1-subunit. Moreover, there was a significant upregulation of the α- but not the β1-subunit mRNA and the α-subunit protein in the aorta of the estrogenvs oil-treated ovariectomized animals. In specific brain areas including preoptic area, ventral hypothalamus, hippocampus, and amygdala, and in the pituitary, neither the α- nor β4-subunit mRNAs were affected by estrogen. These findings suggest that estrogen may not affect the mRNA expression of MaxiK channels in the brain and pituitary. However, estrogen causes increased expression of MaxiK α in the aorta, which may explain some of the cardioprotective effects of estrogen in women.

KW - Aorta

KW - Brain

KW - Estradiol effects

KW - MaxiK channel subunits

KW - mRNA expression

UR - http://www.scopus.com/inward/record.url?scp=0038064494&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0038064494&partnerID=8YFLogxK

U2 - 10.1385/ENDO:20:3:227

DO - 10.1385/ENDO:20:3:227

M3 - Article

C2 - 12721501

AN - SCOPUS:0038064494

VL - 20

SP - 227

EP - 237

JO - Endocrine

JF - Endocrine

SN - 1355-008X

IS - 3

ER -