Membrane potential, Ca2+ influx, and Ca2+ release in single vascular muscle cells

Kent Hermsmeyer, Michael Sturek

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Isolated single vascular muscle cells from azygous vein of rats were used to make measurements of intracellular Ca2+ release, using a differential interference contrast 2 wavelength system and the Ca2+ indicator arsenazo III (Az III). Ca2+ release in spontaneously contracting isolated single muscle cells was extremely nonuniform, giving Ca2+ signals in some areas that were at least five times as great as those in others. Some areas of the cell showed virtually no detectable increase in Ca2+ activity during contraction, and these differences in Ca2+ activity corresponded with differences in contractile filament movement within the cell. The possibility that the nonuniformity of the Ca2+ signals was due to localization of Az III, which had been introduced by liposomes, was excluded because optical density at the 580 nm isosbestic point in any 5-20 μm2 area varied by not >50% from the average Az III concentration. In contrast, when isolated single vascular muscle cells were stimulated with electric current pulses, Ca2+ release and contraction were uniformly synchronized throughout the cell. Our data suggest that the uptake and removal process by intracellular transport is the major determinant of intracellular Ca2+ activity in azygous venous vascular muscle cells.

Original languageEnglish (US)
Pages (from-to)S38-S41
JournalJournal of Cardiovascular Pharmacology
Volume8
StatePublished - 1986
Externally publishedYes

Fingerprint

Membrane Potentials
Muscle Cells
Blood Vessels
Arsenazo III
Liposomes
Cell Movement
Veins

Keywords

  • Calcium sequestration
  • E-C couplin
  • Excitation

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Pharmacology

Cite this

Membrane potential, Ca2+ influx, and Ca2+ release in single vascular muscle cells. / Hermsmeyer, Kent; Sturek, Michael.

In: Journal of Cardiovascular Pharmacology, Vol. 8, 1986, p. S38-S41.

Research output: Contribution to journalArticle

@article{5e32b14f666a4b599b67944f12f4da08,
title = "Membrane potential, Ca2+ influx, and Ca2+ release in single vascular muscle cells",
abstract = "Isolated single vascular muscle cells from azygous vein of rats were used to make measurements of intracellular Ca2+ release, using a differential interference contrast 2 wavelength system and the Ca2+ indicator arsenazo III (Az III). Ca2+ release in spontaneously contracting isolated single muscle cells was extremely nonuniform, giving Ca2+ signals in some areas that were at least five times as great as those in others. Some areas of the cell showed virtually no detectable increase in Ca2+ activity during contraction, and these differences in Ca2+ activity corresponded with differences in contractile filament movement within the cell. The possibility that the nonuniformity of the Ca2+ signals was due to localization of Az III, which had been introduced by liposomes, was excluded because optical density at the 580 nm isosbestic point in any 5-20 μm2 area varied by not >50{\%} from the average Az III concentration. In contrast, when isolated single vascular muscle cells were stimulated with electric current pulses, Ca2+ release and contraction were uniformly synchronized throughout the cell. Our data suggest that the uptake and removal process by intracellular transport is the major determinant of intracellular Ca2+ activity in azygous venous vascular muscle cells.",
keywords = "Calcium sequestration, E-C couplin, Excitation",
author = "Kent Hermsmeyer and Michael Sturek",
year = "1986",
language = "English (US)",
volume = "8",
pages = "S38--S41",
journal = "Journal of Cardiovascular Pharmacology",
issn = "0160-2446",
publisher = "Lippincott Williams and Wilkins",

}

TY - JOUR

T1 - Membrane potential, Ca2+ influx, and Ca2+ release in single vascular muscle cells

AU - Hermsmeyer, Kent

AU - Sturek, Michael

PY - 1986

Y1 - 1986

N2 - Isolated single vascular muscle cells from azygous vein of rats were used to make measurements of intracellular Ca2+ release, using a differential interference contrast 2 wavelength system and the Ca2+ indicator arsenazo III (Az III). Ca2+ release in spontaneously contracting isolated single muscle cells was extremely nonuniform, giving Ca2+ signals in some areas that were at least five times as great as those in others. Some areas of the cell showed virtually no detectable increase in Ca2+ activity during contraction, and these differences in Ca2+ activity corresponded with differences in contractile filament movement within the cell. The possibility that the nonuniformity of the Ca2+ signals was due to localization of Az III, which had been introduced by liposomes, was excluded because optical density at the 580 nm isosbestic point in any 5-20 μm2 area varied by not >50% from the average Az III concentration. In contrast, when isolated single vascular muscle cells were stimulated with electric current pulses, Ca2+ release and contraction were uniformly synchronized throughout the cell. Our data suggest that the uptake and removal process by intracellular transport is the major determinant of intracellular Ca2+ activity in azygous venous vascular muscle cells.

AB - Isolated single vascular muscle cells from azygous vein of rats were used to make measurements of intracellular Ca2+ release, using a differential interference contrast 2 wavelength system and the Ca2+ indicator arsenazo III (Az III). Ca2+ release in spontaneously contracting isolated single muscle cells was extremely nonuniform, giving Ca2+ signals in some areas that were at least five times as great as those in others. Some areas of the cell showed virtually no detectable increase in Ca2+ activity during contraction, and these differences in Ca2+ activity corresponded with differences in contractile filament movement within the cell. The possibility that the nonuniformity of the Ca2+ signals was due to localization of Az III, which had been introduced by liposomes, was excluded because optical density at the 580 nm isosbestic point in any 5-20 μm2 area varied by not >50% from the average Az III concentration. In contrast, when isolated single vascular muscle cells were stimulated with electric current pulses, Ca2+ release and contraction were uniformly synchronized throughout the cell. Our data suggest that the uptake and removal process by intracellular transport is the major determinant of intracellular Ca2+ activity in azygous venous vascular muscle cells.

KW - Calcium sequestration

KW - E-C couplin

KW - Excitation

UR - http://www.scopus.com/inward/record.url?scp=0023036139&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023036139&partnerID=8YFLogxK

M3 - Article

VL - 8

SP - S38-S41

JO - Journal of Cardiovascular Pharmacology

JF - Journal of Cardiovascular Pharmacology

SN - 0160-2446

ER -