|
|
||||||||
Department of Cellular and Molecular Physiology, Penn State College of Medicine, Pennsylvania State University, Hershey, Pennsylvania 17033
We used 2,3-butanedione monoxime (BDM) to suppress work by the perfused rat heart and to investigate the effects of calcium on NADH production and tissue energetics. Hearts were perfused with buffer containing BDM and elevated perfusate calcium to maintain the rates of cardiac work and oxygen consumption at levels similar to those of control perfused hearts. BDM plus calcium hearts displayed higher levels of NADH surface fluorescence, indicating calcium activation of mitochondrial dehydrogenases. These hearts, however, displayed 20% lower phosphocreatine levels. BDM suppressed the rates of state 3 respiration of isolated mitochondria. Uncoupled respiration was suppressed to a lesser degree, and the state 4 respiration rates were not affected. Double-inhibitor experiments with liver mitochondria using BDM and carboxyatractyloside (CAT) were used to identify the site of inhibition. BDM at low levels (0-5 mM) suppressed respiration. In the presence of CAT at levels that inhibit respiration by 60%, low levels of BDM were without effect. Because these effects were not additive, BDM does not inhibit adenine nucleotide transport. This was supported by an assay of adenine nucleotide transport in liver mitochondria. BDM did not inhibit ATP hydrolysis by submitochondrial particles but strongly suppressed reversed electron transport from succinate to NAD+. Oxidation of NADH by submitochondrial particles was inhibited by BDM but oxidation of succinate was not. We conclude that BDM inhibits electron transport at site 1.
adenine nucleotide translocase; heart; mitochondria; F0F1-adenosinetriphosphatase; fluorescence; reduced nicotinamide adenine dinucleotide; calcium; bioenergetics; site 1
This article has been cited by other articles:
![]() |
O. Eerbeek, E. G. Mik, C. J. Zuurbier, M. v. t Loo, C. Donkersloot, and C. Ince Ratiometric intracellular calcium imaging in the isolated beating rat heart using indo-1 fluorescence J Appl Physiol, December 1, 2004; 97(6): 2042 - 2050. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. K. S. Camara, Q. Chen, S. S. Rhodes, M. L. Riess, and D. F. Stowe Negative inotropic drugs alter indexes of cytosolic [Ca2+]-left ventricular pressure relationships after ischemia Am J Physiol Heart Circ Physiol, August 1, 2004; 287(2): H667 - H680. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. K. S. Camara, M. L. Riess, L. G. Kevin, E. Novalija, and D. F. Stowe Hypothermia augments reactive oxygen species detected in the guinea pig isolated perfused heart Am J Physiol Heart Circ Physiol, April 1, 2004; 286(4): H1289 - H1299. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |