Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle

G. J. Christ, W. Zhao, N. Day, S. Richards, S. Lee, M. Valcic, L. Salkoff, A. Melman

Research output: Contribution to journalArticle

Abstract

The KCa channel is an important modulator of corporal smooth muscle tone and erectile capacity. In this regard, intracavemous injection of the hSlo KCa cDNA in a rat model produced a significant increase in nerve-stimulated intracavernous pressure responses, compared to control animals. The goal of the present studies was to further assess the characteristics of the KCa channel in human corporal smooth muscle. Northern blots revealed similar levels of the hSlo KCa cDNA on frozen tissue and cultured cells derived from human corpora. Steady-state and kinetic studies were conducted on corporal tissue strips precontracted with phenylephrine (PE) or endothelin-1 (ET-1) (to ∼75% of maximum) in the absence and presence of the following KCa channel blockers; 1 mM tetraethylammonium or 1 μM carybdotoxin. Both K channel blockers produced roughly 20-30% increases in the magnitude of the PE- & ET-1-induced contractile response, while also halving the time required to acheive 1/2 maximal PE, but not ET-1 response (p<0.05). Elisa assays on CAT transfected smooth muscle cells documented that 4 hours of lipofectamine transfection resulted in optimal CAT gene expression. Ca2+ imaging experiments conducted on fura-2 loaded smooth muscle cells transfected under identical experimental conditions with hSlo cDNA revealed that both resting and ET-1-induced intracellular calcium levels were significantly lower in the transiently transfected cell population (p<0.05). This provides further evidence for the potential utility of intracavernous gene therapy in the treatment of erectile dysfunction.

Original languageEnglish (US)
JournalFASEB Journal
Volume11
Issue number3
StatePublished - 1997
Externally publishedYes

Fingerprint

endothelins
Potassium Channels
potassium channels
Endothelin-1
smooth muscle
phenylephrine
Smooth Muscle
Muscle
Phenylephrine
Cells
Complementary DNA
myocytes
Smooth Muscle Myocytes
Tissue
calcium
Gene therapy
Tetraethylammonium
gene therapy
Fura-2
Erectile Dysfunction

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Cell Biology

Cite this

Christ, G. J., Zhao, W., Day, N., Richards, S., Lee, S., Valcic, M., ... Melman, A. (1997). Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle. FASEB Journal, 11(3).

Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle. / Christ, G. J.; Zhao, W.; Day, N.; Richards, S.; Lee, S.; Valcic, M.; Salkoff, L.; Melman, A.

In: FASEB Journal, Vol. 11, No. 3, 1997.

Research output: Contribution to journalArticle

Christ, GJ, Zhao, W, Day, N, Richards, S, Lee, S, Valcic, M, Salkoff, L & Melman, A 1997, 'Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle', FASEB Journal, vol. 11, no. 3.
Christ, G. J. ; Zhao, W. ; Day, N. ; Richards, S. ; Lee, S. ; Valcic, M. ; Salkoff, L. ; Melman, A. / Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle. In: FASEB Journal. 1997 ; Vol. 11, No. 3.
@article{17bd4f7d6d3345719beb525a8b3e9d79,
title = "Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle",
abstract = "The KCa channel is an important modulator of corporal smooth muscle tone and erectile capacity. In this regard, intracavemous injection of the hSlo KCa cDNA in a rat model produced a significant increase in nerve-stimulated intracavernous pressure responses, compared to control animals. The goal of the present studies was to further assess the characteristics of the KCa channel in human corporal smooth muscle. Northern blots revealed similar levels of the hSlo KCa cDNA on frozen tissue and cultured cells derived from human corpora. Steady-state and kinetic studies were conducted on corporal tissue strips precontracted with phenylephrine (PE) or endothelin-1 (ET-1) (to ∼75{\%} of maximum) in the absence and presence of the following KCa channel blockers; 1 mM tetraethylammonium or 1 μM carybdotoxin. Both K channel blockers produced roughly 20-30{\%} increases in the magnitude of the PE- & ET-1-induced contractile response, while also halving the time required to acheive 1/2 maximal PE, but not ET-1 response (p<0.05). Elisa assays on CAT transfected smooth muscle cells documented that 4 hours of lipofectamine transfection resulted in optimal CAT gene expression. Ca2+ imaging experiments conducted on fura-2 loaded smooth muscle cells transfected under identical experimental conditions with hSlo cDNA revealed that both resting and ET-1-induced intracellular calcium levels were significantly lower in the transiently transfected cell population (p<0.05). This provides further evidence for the potential utility of intracavernous gene therapy in the treatment of erectile dysfunction.",
author = "Christ, {G. J.} and W. Zhao and N. Day and S. Richards and S. Lee and M. Valcic and L. Salkoff and A. Melman",
year = "1997",
language = "English (US)",
volume = "11",
journal = "FASEB Journal",
issn = "0892-6638",
publisher = "FASEB",
number = "3",

}

TY - JOUR

T1 - Expression and significance of the maxi-K (KCa) potassium channel subtype in human corporal smooth muscle

AU - Christ, G. J.

AU - Zhao, W.

AU - Day, N.

AU - Richards, S.

AU - Lee, S.

AU - Valcic, M.

AU - Salkoff, L.

AU - Melman, A.

PY - 1997

Y1 - 1997

N2 - The KCa channel is an important modulator of corporal smooth muscle tone and erectile capacity. In this regard, intracavemous injection of the hSlo KCa cDNA in a rat model produced a significant increase in nerve-stimulated intracavernous pressure responses, compared to control animals. The goal of the present studies was to further assess the characteristics of the KCa channel in human corporal smooth muscle. Northern blots revealed similar levels of the hSlo KCa cDNA on frozen tissue and cultured cells derived from human corpora. Steady-state and kinetic studies were conducted on corporal tissue strips precontracted with phenylephrine (PE) or endothelin-1 (ET-1) (to ∼75% of maximum) in the absence and presence of the following KCa channel blockers; 1 mM tetraethylammonium or 1 μM carybdotoxin. Both K channel blockers produced roughly 20-30% increases in the magnitude of the PE- & ET-1-induced contractile response, while also halving the time required to acheive 1/2 maximal PE, but not ET-1 response (p<0.05). Elisa assays on CAT transfected smooth muscle cells documented that 4 hours of lipofectamine transfection resulted in optimal CAT gene expression. Ca2+ imaging experiments conducted on fura-2 loaded smooth muscle cells transfected under identical experimental conditions with hSlo cDNA revealed that both resting and ET-1-induced intracellular calcium levels were significantly lower in the transiently transfected cell population (p<0.05). This provides further evidence for the potential utility of intracavernous gene therapy in the treatment of erectile dysfunction.

AB - The KCa channel is an important modulator of corporal smooth muscle tone and erectile capacity. In this regard, intracavemous injection of the hSlo KCa cDNA in a rat model produced a significant increase in nerve-stimulated intracavernous pressure responses, compared to control animals. The goal of the present studies was to further assess the characteristics of the KCa channel in human corporal smooth muscle. Northern blots revealed similar levels of the hSlo KCa cDNA on frozen tissue and cultured cells derived from human corpora. Steady-state and kinetic studies were conducted on corporal tissue strips precontracted with phenylephrine (PE) or endothelin-1 (ET-1) (to ∼75% of maximum) in the absence and presence of the following KCa channel blockers; 1 mM tetraethylammonium or 1 μM carybdotoxin. Both K channel blockers produced roughly 20-30% increases in the magnitude of the PE- & ET-1-induced contractile response, while also halving the time required to acheive 1/2 maximal PE, but not ET-1 response (p<0.05). Elisa assays on CAT transfected smooth muscle cells documented that 4 hours of lipofectamine transfection resulted in optimal CAT gene expression. Ca2+ imaging experiments conducted on fura-2 loaded smooth muscle cells transfected under identical experimental conditions with hSlo cDNA revealed that both resting and ET-1-induced intracellular calcium levels were significantly lower in the transiently transfected cell population (p<0.05). This provides further evidence for the potential utility of intracavernous gene therapy in the treatment of erectile dysfunction.

UR - http://www.scopus.com/inward/record.url?scp=33750183092&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33750183092&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33750183092

VL - 11

JO - FASEB Journal

JF - FASEB Journal

SN - 0892-6638

IS - 3

ER -