Expression and distribution of voltage-gated ion channels in ferret sinoatrial node

Mulugu V. Brahmajothi, Michael J. Morales, Donald L. Campbell, Charles Jr Steenbergen, Harold C. Strauss

Research output: Contribution to journalArticle

Abstract

Spontaneous diastolic depolarization in the sinoatrial (SA) node enables it to serve as pacemaker of the heart. The variable cell morphology within the SA node predicts that ion channel expression would be heterogeneous and different from that in the atrium. To evaluate ion channel heterogeneity within the SA node, we used fluorescent in situ hybridization to examine ion channel expression in the ferret SA node region and atrial appendage. SA nodal cells were distinguished from surrounding cardiac myocytes by expression of the slow (SA node) and cardiac (surrounding tissue) forms of troponin I. Nerve cells in the sections were identified by detection of GAP-43 and cytoskeletal middle neurofilament. Transcript expression was characterized for the 4 hyperpolarization-activated cation channels, 6 voltage-gated Na+ channels, 3 voltage-gated Ca2+ channels, 24 voltage-gated K + channel α-subunits, and 3 ancillary subunits. To ensure that transcript expression was representative of protein expression, immunofluorescence was used to verify localization patterns of voltage-dependent K+ channels. Colocalizations were performed to observe any preferential patterns. Some overlapping and nonoverlapping binding patterns were observed. Measurement of different cation channel transcripts showed heterogeneous expression with many different patterns of expression, attesting to the complexity of electrical activity in the SA node. This study provides insight into the possible role ion channel heterogeneity plays in SA node pacemaker activity.

Original languageEnglish (US)
Pages (from-to)131-140
Number of pages10
JournalPhysiological Genomics
Volume42 A
Issue number2
DOIs
StatePublished - Sep 2010

Fingerprint

Ferrets
Sinoatrial Node
Ion Channels
Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels
GAP-43 Protein
Voltage-Gated Potassium Channels
Atrial Appendage
Troponin I
Intermediate Filaments
Fluorescence In Situ Hybridization
Cardiac Myocytes
Fluorescent Antibody Technique
Cations
Neurons

Keywords

  • Cyclic nucleotide gated cation channels
  • Gene expression
  • L-type calcium channels
  • Potassium channels
  • Sodium channels
  • T-type calcium channels
  • Voltage-gated calcium channels

ASJC Scopus subject areas

  • Physiology
  • Genetics

Cite this

Expression and distribution of voltage-gated ion channels in ferret sinoatrial node. / Brahmajothi, Mulugu V.; Morales, Michael J.; Campbell, Donald L.; Steenbergen, Charles Jr; Strauss, Harold C.

In: Physiological Genomics, Vol. 42 A, No. 2, 09.2010, p. 131-140.

Research output: Contribution to journalArticle

Brahmajothi, Mulugu V. ; Morales, Michael J. ; Campbell, Donald L. ; Steenbergen, Charles Jr ; Strauss, Harold C. / Expression and distribution of voltage-gated ion channels in ferret sinoatrial node. In: Physiological Genomics. 2010 ; Vol. 42 A, No. 2. pp. 131-140.
@article{844aef47602648529ce23ddc9f7e460a,
title = "Expression and distribution of voltage-gated ion channels in ferret sinoatrial node",
abstract = "Spontaneous diastolic depolarization in the sinoatrial (SA) node enables it to serve as pacemaker of the heart. The variable cell morphology within the SA node predicts that ion channel expression would be heterogeneous and different from that in the atrium. To evaluate ion channel heterogeneity within the SA node, we used fluorescent in situ hybridization to examine ion channel expression in the ferret SA node region and atrial appendage. SA nodal cells were distinguished from surrounding cardiac myocytes by expression of the slow (SA node) and cardiac (surrounding tissue) forms of troponin I. Nerve cells in the sections were identified by detection of GAP-43 and cytoskeletal middle neurofilament. Transcript expression was characterized for the 4 hyperpolarization-activated cation channels, 6 voltage-gated Na+ channels, 3 voltage-gated Ca2+ channels, 24 voltage-gated K + channel α-subunits, and 3 ancillary subunits. To ensure that transcript expression was representative of protein expression, immunofluorescence was used to verify localization patterns of voltage-dependent K+ channels. Colocalizations were performed to observe any preferential patterns. Some overlapping and nonoverlapping binding patterns were observed. Measurement of different cation channel transcripts showed heterogeneous expression with many different patterns of expression, attesting to the complexity of electrical activity in the SA node. This study provides insight into the possible role ion channel heterogeneity plays in SA node pacemaker activity.",
keywords = "Cyclic nucleotide gated cation channels, Gene expression, L-type calcium channels, Potassium channels, Sodium channels, T-type calcium channels, Voltage-gated calcium channels",
author = "Brahmajothi, {Mulugu V.} and Morales, {Michael J.} and Campbell, {Donald L.} and Steenbergen, {Charles Jr} and Strauss, {Harold C.}",
year = "2010",
month = "9",
doi = "10.1152/physiolgenomics.00049.2010",
language = "English (US)",
volume = "42 A",
pages = "131--140",
journal = "Physiological Genomics",
issn = "1094-8341",
publisher = "American Physiological Society",
number = "2",

}

TY - JOUR

T1 - Expression and distribution of voltage-gated ion channels in ferret sinoatrial node

AU - Brahmajothi, Mulugu V.

AU - Morales, Michael J.

AU - Campbell, Donald L.

AU - Steenbergen, Charles Jr

AU - Strauss, Harold C.

PY - 2010/9

Y1 - 2010/9

N2 - Spontaneous diastolic depolarization in the sinoatrial (SA) node enables it to serve as pacemaker of the heart. The variable cell morphology within the SA node predicts that ion channel expression would be heterogeneous and different from that in the atrium. To evaluate ion channel heterogeneity within the SA node, we used fluorescent in situ hybridization to examine ion channel expression in the ferret SA node region and atrial appendage. SA nodal cells were distinguished from surrounding cardiac myocytes by expression of the slow (SA node) and cardiac (surrounding tissue) forms of troponin I. Nerve cells in the sections were identified by detection of GAP-43 and cytoskeletal middle neurofilament. Transcript expression was characterized for the 4 hyperpolarization-activated cation channels, 6 voltage-gated Na+ channels, 3 voltage-gated Ca2+ channels, 24 voltage-gated K + channel α-subunits, and 3 ancillary subunits. To ensure that transcript expression was representative of protein expression, immunofluorescence was used to verify localization patterns of voltage-dependent K+ channels. Colocalizations were performed to observe any preferential patterns. Some overlapping and nonoverlapping binding patterns were observed. Measurement of different cation channel transcripts showed heterogeneous expression with many different patterns of expression, attesting to the complexity of electrical activity in the SA node. This study provides insight into the possible role ion channel heterogeneity plays in SA node pacemaker activity.

AB - Spontaneous diastolic depolarization in the sinoatrial (SA) node enables it to serve as pacemaker of the heart. The variable cell morphology within the SA node predicts that ion channel expression would be heterogeneous and different from that in the atrium. To evaluate ion channel heterogeneity within the SA node, we used fluorescent in situ hybridization to examine ion channel expression in the ferret SA node region and atrial appendage. SA nodal cells were distinguished from surrounding cardiac myocytes by expression of the slow (SA node) and cardiac (surrounding tissue) forms of troponin I. Nerve cells in the sections were identified by detection of GAP-43 and cytoskeletal middle neurofilament. Transcript expression was characterized for the 4 hyperpolarization-activated cation channels, 6 voltage-gated Na+ channels, 3 voltage-gated Ca2+ channels, 24 voltage-gated K + channel α-subunits, and 3 ancillary subunits. To ensure that transcript expression was representative of protein expression, immunofluorescence was used to verify localization patterns of voltage-dependent K+ channels. Colocalizations were performed to observe any preferential patterns. Some overlapping and nonoverlapping binding patterns were observed. Measurement of different cation channel transcripts showed heterogeneous expression with many different patterns of expression, attesting to the complexity of electrical activity in the SA node. This study provides insight into the possible role ion channel heterogeneity plays in SA node pacemaker activity.

KW - Cyclic nucleotide gated cation channels

KW - Gene expression

KW - L-type calcium channels

KW - Potassium channels

KW - Sodium channels

KW - T-type calcium channels

KW - Voltage-gated calcium channels

UR - http://www.scopus.com/inward/record.url?scp=77958074655&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77958074655&partnerID=8YFLogxK

U2 - 10.1152/physiolgenomics.00049.2010

DO - 10.1152/physiolgenomics.00049.2010

M3 - Article

VL - 42 A

SP - 131

EP - 140

JO - Physiological Genomics

JF - Physiological Genomics

SN - 1094-8341

IS - 2

ER -