Sarcolemmal and mitochondrial effects of a KATP opener, P-1075, in "polarized" and "depolarized" Langendorff-perfused rat hearts

Olga Jilkina, Bozena Kuzio, Gary J. Grover, Clifford Folmes, Hee Jeong Kong, Valery V. Kupriyanov

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

We investigated consequences of cardiac arrest on sarcolemmal and mitochondrial effects of ATP-sensitive potassium channel (KATP) opener, P-1075, in Langendorff-perfused rat hearts. Depolarised cardiac arrest (24.7 mM KCl) did not affect glibenclamide-sensitive twofold activation of rubidium efflux by P-1075 (5 μM) from rubidium-loaded hearts, but eliminated uncoupling produced by P-1075 in beating hearts: 40% depletion of phosphocreatine and ATP, 50% increase in oxygen consumption, and reduction of cytochrome c oxidase. Depolarized cardiac arrest by calcium channel blocker, verapamil (5 μM), also prevented uncoupling. Lack of P-1075 mitochondrial effects in depolarized hearts was not due to changes in phosphorylation potential, because 2,4-dintrophenol (10 μM) reversed the [PCr]/[Cr] increase and Pi decrease, characteristic of KCl-arrest, but did not restore uncoupling. In agreement with this conclusion, pyruvate (5 mM) increased [PCr]/[Cr] and decreased Pi, but did not prevent uncoupling in beating hearts. A decrease in mean [Ca2+] in KCl-arrested hearts could not account for lack of P-1075 mitochondrial effects, because calcium channel opener, S-(-)-Bay K8644 (50 nM), and beta-agonist, isoproterenol (0.5 μM), did not facilitate uncoupling. In contrast, in adenosine (1 mM) -arrested hearts (polarized arrest), P-1075 caused 40% phosphocreatine and ATP depletion. In isolated rat liver mitochondria, P-1075 (20 μM) decreased mitochondrial membrane potential (ΔΨ) by approximately 14 mV (demonstrated by redistribution of ΔΨ-sensitive dye, rhodamine 800) in a glibenclamide-sensitive manner. We concluded that cell membrane depolarization does not prevent activation of sarcolemmal KATP by P-1075, but it plays a role in mitochondrial uncoupling effects of P-1075.

Original languageEnglish (US)
Pages (from-to)39-50
Number of pages12
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1618
Issue number1
DOIs
StatePublished - Dec 3 2003
Externally publishedYes

Fingerprint

Rats
Heart Arrest
Rubidium
Phosphocreatine
Glyburide
Adenosine Triphosphate
Chemical activation
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
N-cyano-N'-(1,1-dimethylpropyl)-N''-(3-pyridinyl)guanidine
Isolated Heart Preparation
KATP Channels
Phosphorylation
Mitochondria
Liver Mitochondrion
Mitochondrial Membrane Potential
Depolarization
Calcium Channel Blockers
Electron Transport Complex IV
Calcium Channels
Cell membranes

Keywords

  • ATP-sensitive potassium channel
  • Cytochrome c oxidase
  • K opener
  • Oxidative phosphorylation
  • Oxygen consumption
  • P-1075
  • Rb/K efflux
  • Sarcolemmal polarization

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

Cite this

Sarcolemmal and mitochondrial effects of a KATP opener, P-1075, in "polarized" and "depolarized" Langendorff-perfused rat hearts. / Jilkina, Olga; Kuzio, Bozena; Grover, Gary J.; Folmes, Clifford; Kong, Hee Jeong; Kupriyanov, Valery V.

In: Biochimica et Biophysica Acta - Biomembranes, Vol. 1618, No. 1, 03.12.2003, p. 39-50.

Research output: Contribution to journalArticle

Jilkina, Olga ; Kuzio, Bozena ; Grover, Gary J. ; Folmes, Clifford ; Kong, Hee Jeong ; Kupriyanov, Valery V. / Sarcolemmal and mitochondrial effects of a KATP opener, P-1075, in "polarized" and "depolarized" Langendorff-perfused rat hearts. In: Biochimica et Biophysica Acta - Biomembranes. 2003 ; Vol. 1618, No. 1. pp. 39-50.
@article{3675ecb88595480cbbf2b6b366462b76,
title = "Sarcolemmal and mitochondrial effects of a KATP opener, P-1075, in {"}polarized{"} and {"}depolarized{"} Langendorff-perfused rat hearts",
abstract = "We investigated consequences of cardiac arrest on sarcolemmal and mitochondrial effects of ATP-sensitive potassium channel (KATP) opener, P-1075, in Langendorff-perfused rat hearts. Depolarised cardiac arrest (24.7 mM KCl) did not affect glibenclamide-sensitive twofold activation of rubidium efflux by P-1075 (5 μM) from rubidium-loaded hearts, but eliminated uncoupling produced by P-1075 in beating hearts: 40{\%} depletion of phosphocreatine and ATP, 50{\%} increase in oxygen consumption, and reduction of cytochrome c oxidase. Depolarized cardiac arrest by calcium channel blocker, verapamil (5 μM), also prevented uncoupling. Lack of P-1075 mitochondrial effects in depolarized hearts was not due to changes in phosphorylation potential, because 2,4-dintrophenol (10 μM) reversed the [PCr]/[Cr] increase and Pi decrease, characteristic of KCl-arrest, but did not restore uncoupling. In agreement with this conclusion, pyruvate (5 mM) increased [PCr]/[Cr] and decreased Pi, but did not prevent uncoupling in beating hearts. A decrease in mean [Ca2+] in KCl-arrested hearts could not account for lack of P-1075 mitochondrial effects, because calcium channel opener, S-(-)-Bay K8644 (50 nM), and beta-agonist, isoproterenol (0.5 μM), did not facilitate uncoupling. In contrast, in adenosine (1 mM) -arrested hearts (polarized arrest), P-1075 caused 40{\%} phosphocreatine and ATP depletion. In isolated rat liver mitochondria, P-1075 (20 μM) decreased mitochondrial membrane potential (ΔΨ) by approximately 14 mV (demonstrated by redistribution of ΔΨ-sensitive dye, rhodamine 800) in a glibenclamide-sensitive manner. We concluded that cell membrane depolarization does not prevent activation of sarcolemmal KATP by P-1075, but it plays a role in mitochondrial uncoupling effects of P-1075.",
keywords = "ATP-sensitive potassium channel, Cytochrome c oxidase, K opener, Oxidative phosphorylation, Oxygen consumption, P-1075, Rb/K efflux, Sarcolemmal polarization",
author = "Olga Jilkina and Bozena Kuzio and Grover, {Gary J.} and Clifford Folmes and Kong, {Hee Jeong} and Kupriyanov, {Valery V.}",
year = "2003",
month = "12",
day = "3",
doi = "10.1016/j.bbamem.2003.10.004",
language = "English (US)",
volume = "1618",
pages = "39--50",
journal = "Biochimica et Biophysica Acta - Biomembranes",
issn = "0005-2736",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Sarcolemmal and mitochondrial effects of a KATP opener, P-1075, in "polarized" and "depolarized" Langendorff-perfused rat hearts

AU - Jilkina, Olga

AU - Kuzio, Bozena

AU - Grover, Gary J.

AU - Folmes, Clifford

AU - Kong, Hee Jeong

AU - Kupriyanov, Valery V.

PY - 2003/12/3

Y1 - 2003/12/3

N2 - We investigated consequences of cardiac arrest on sarcolemmal and mitochondrial effects of ATP-sensitive potassium channel (KATP) opener, P-1075, in Langendorff-perfused rat hearts. Depolarised cardiac arrest (24.7 mM KCl) did not affect glibenclamide-sensitive twofold activation of rubidium efflux by P-1075 (5 μM) from rubidium-loaded hearts, but eliminated uncoupling produced by P-1075 in beating hearts: 40% depletion of phosphocreatine and ATP, 50% increase in oxygen consumption, and reduction of cytochrome c oxidase. Depolarized cardiac arrest by calcium channel blocker, verapamil (5 μM), also prevented uncoupling. Lack of P-1075 mitochondrial effects in depolarized hearts was not due to changes in phosphorylation potential, because 2,4-dintrophenol (10 μM) reversed the [PCr]/[Cr] increase and Pi decrease, characteristic of KCl-arrest, but did not restore uncoupling. In agreement with this conclusion, pyruvate (5 mM) increased [PCr]/[Cr] and decreased Pi, but did not prevent uncoupling in beating hearts. A decrease in mean [Ca2+] in KCl-arrested hearts could not account for lack of P-1075 mitochondrial effects, because calcium channel opener, S-(-)-Bay K8644 (50 nM), and beta-agonist, isoproterenol (0.5 μM), did not facilitate uncoupling. In contrast, in adenosine (1 mM) -arrested hearts (polarized arrest), P-1075 caused 40% phosphocreatine and ATP depletion. In isolated rat liver mitochondria, P-1075 (20 μM) decreased mitochondrial membrane potential (ΔΨ) by approximately 14 mV (demonstrated by redistribution of ΔΨ-sensitive dye, rhodamine 800) in a glibenclamide-sensitive manner. We concluded that cell membrane depolarization does not prevent activation of sarcolemmal KATP by P-1075, but it plays a role in mitochondrial uncoupling effects of P-1075.

AB - We investigated consequences of cardiac arrest on sarcolemmal and mitochondrial effects of ATP-sensitive potassium channel (KATP) opener, P-1075, in Langendorff-perfused rat hearts. Depolarised cardiac arrest (24.7 mM KCl) did not affect glibenclamide-sensitive twofold activation of rubidium efflux by P-1075 (5 μM) from rubidium-loaded hearts, but eliminated uncoupling produced by P-1075 in beating hearts: 40% depletion of phosphocreatine and ATP, 50% increase in oxygen consumption, and reduction of cytochrome c oxidase. Depolarized cardiac arrest by calcium channel blocker, verapamil (5 μM), also prevented uncoupling. Lack of P-1075 mitochondrial effects in depolarized hearts was not due to changes in phosphorylation potential, because 2,4-dintrophenol (10 μM) reversed the [PCr]/[Cr] increase and Pi decrease, characteristic of KCl-arrest, but did not restore uncoupling. In agreement with this conclusion, pyruvate (5 mM) increased [PCr]/[Cr] and decreased Pi, but did not prevent uncoupling in beating hearts. A decrease in mean [Ca2+] in KCl-arrested hearts could not account for lack of P-1075 mitochondrial effects, because calcium channel opener, S-(-)-Bay K8644 (50 nM), and beta-agonist, isoproterenol (0.5 μM), did not facilitate uncoupling. In contrast, in adenosine (1 mM) -arrested hearts (polarized arrest), P-1075 caused 40% phosphocreatine and ATP depletion. In isolated rat liver mitochondria, P-1075 (20 μM) decreased mitochondrial membrane potential (ΔΨ) by approximately 14 mV (demonstrated by redistribution of ΔΨ-sensitive dye, rhodamine 800) in a glibenclamide-sensitive manner. We concluded that cell membrane depolarization does not prevent activation of sarcolemmal KATP by P-1075, but it plays a role in mitochondrial uncoupling effects of P-1075.

KW - ATP-sensitive potassium channel

KW - Cytochrome c oxidase

KW - K opener

KW - Oxidative phosphorylation

KW - Oxygen consumption

KW - P-1075

KW - Rb/K efflux

KW - Sarcolemmal polarization

UR - http://www.scopus.com/inward/record.url?scp=0345276641&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0345276641&partnerID=8YFLogxK

U2 - 10.1016/j.bbamem.2003.10.004

DO - 10.1016/j.bbamem.2003.10.004

M3 - Article

VL - 1618

SP - 39

EP - 50

JO - Biochimica et Biophysica Acta - Biomembranes

JF - Biochimica et Biophysica Acta - Biomembranes

SN - 0005-2736

IS - 1

ER -