Endogenous adenosine improves work rate to oxygen consumption ratio in catecholamine stimulated isovolumic rat heart

1989 ◽  
Vol 413 (4) ◽  
pp. 354-358 ◽  
Author(s):  
John Headrick ◽  
Roger J. Willis
Keyword(s):  
Oxygen Consumption ◽  
Rat Heart ◽  
Work Rate ◽  
Consumption Ratio ◽  
Endogenous Adenosine

Myocardial oxygen consumption of blood-perfused, isolated, supported, rat heart

1970 ◽  
Vol 219 (3) ◽  
pp. 604-612 ◽  
Author(s):  
WJ Gamble ◽  
PA Conn ◽  
AE Kumar ◽  
R Plenge ◽  
RG Monroe
Keyword(s):  
Oxygen Consumption ◽  
Rat Heart ◽  
Myocardial Oxygen Consumption

Abstract 104: Effects of Pinacidil and Ca 2 + on Sodium-loaded Rat Heart Mitochondria

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sergey M Korotkov ◽  
Vladimir P Nesterov ◽  
Irina V Brailovskaya ◽  
Larisa V Emelyanova ◽  
Svetlana A Konovalova ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Rat Heart ◽  
Mitochondrial Membrane ◽  
Mitochondrial Permeability Transition ◽  
Ischemia Reperfusion ◽  
Potassium Acetate ◽  
Heart Mitochondria ◽  
Inner Mitochondrial Membrane ◽  
Rat Heart Mitochondria ◽  
Acetate Medium

Deterioration of the contractile parameters of the heart muscle caused by ischemia and followed reperfusion is known as the main postoperative complication which is related to Ca 2+ and Na + overload in cardiomyocytes and mitochondria. Pinacidil reduced the overload in ischemia/reperfusion experiments. The mechanism of this phenomenon is still not clear. We hypothesized that increased ion permeability of the inner mitochondrial membrane (IMM) followed drop of electrochemical potential (ΔΨ mito ) can reduce the calcium. The aim of the study was to elucidate the effect of pinacidil (100 μM) and Ca 2+ (100 μM ) on swelling, oxygen consumption and ΔΨ mito of isolated sodium-loaded rat heart mitochondria (RHM(Na)) energized glutamate and malate. Pinacidil significantly enchanced the permeability of IMM to protons in ammonium nitrate medium. Also increased swelling of RHM(Na) energized with substrates in potassium acetate medium revealed that pinacidil increased potassium transport into matrix. Pinacidil stimulated oxygen consumption of RHM(Na) in State 4 and detained Ca 2+ -induced dissipation of ΔΨ mito . Under condition of Ca 2+ and Na + overload simulating ischemia/reperfusion, RHM(Na) oxygen consumption was not affected with pinacidil in State 3 and in the presence of 2,4-dinitrophenol. Cyclosporin A and ADP, the inhibitors of mitochondrial permeability transition pore (MPTP), markedly decreased Ca 2+ - induced swelling of RHM(Na) in nitrate ammonium or potassium acetate medium in the presence of pinacidil. Carboxyatractyloside, an inhibitor of cytosolic side-specific adenine nucleotide translocase, eliminated a pinacidil-stimulated oxygen consumption of succinate-energized RHMNa in State 4 regardless of the presence of Ca 2+ . Pinacidil was also concluded to accelerat potassium flux into energized RHM(Na) and promot MPTP opening in the low conduction state. Based on our data we suggested that the effect of pharmacological preconditioning induced by pinacidil could be due to it’s direct effect on mitochondria which is connected with above stimulation of the potassium permeability of the inner mitochondrial membrane and following reduce of the ΔΨ mito that thus prevent calcium overload of cardiomyocytes after ischemia/reperfusion in turn.

Malonate and fluoride effects on metabolism and contraction of electrically stimulated heart strips

1961 ◽  
Vol 200 (4) ◽  
pp. 727-731 ◽  
Author(s):  
Leslie I. Rice ◽  
David A. Berman
Keyword(s):  
Oxygen Consumption ◽  
Glucose Metabolism ◽  
Rat Heart ◽  
Contractile Activity ◽  
Simultaneous Recording ◽  
Force Of Contraction ◽  
Enzyme Systems ◽  
Pyruvate Oxidation ◽  
Oxidation Of Glucose ◽  
Stimulation Of

The effect of malonate and fluoride on the oxidation of C14-labeled substrates by electrically stimulated rat heart strips was investigated in an apparatus which permitted simultaneous recording of oxygen consumption and contractile activity. Malonate stimulated the force of contraction when glucose was the substrate, but not in the presence of pyruvate. Malonate had no significant effect on the rate of oxidation of glucose-1-C14, glucose-6-C14 or pyruvate-2-C14, indicating that its effect on contraction was not related to a) stimulation of glucose metabolism, b) inhibition of the Kreb's cycle, or c) stimulation of the phosphogluconate pathway. Malonate-2-C14 was oxidized by the ventricle strips, and the possibility exists that utilization of malonate as a substrate may account, at least in part, for its stimulation of contraction. The stimulation of contraction by fluoride was accompanied by significant alterations in metabolism. The oxidation of glucose and acetate was inhibited, whereas pyruvate oxidation was stimulated; these findings were interpreted in terms of known actions of fluoride on enzyme systems.

Oxygen consumption of cycle ergometry is nonlinearly related to work rate and pedal rate

1997 ◽  
Vol 29 (6) ◽  
pp. 775-780 ◽  
Author(s):  
BEN R. LONDEREE ◽  
JULIA MOFFITT-GERSTENBERGER ◽  
JAMES A. PADFIELD ◽  
DIANE LOTTMANN
Keyword(s):  
Oxygen Consumption ◽  
Cycle Ergometry ◽  
Work Rate ◽  
Pedal Rate

Sulfur Dioxide-Oxygen Consumption Ratio Reveals Differences in Bottled Wine Oxidation

2016 ◽  
Vol 67 (4) ◽  
pp. 449-459 ◽  
Author(s):  
A. L. Waterhouse ◽  
S. Frost ◽  
M. Ugliano ◽  
A. R. Cantu ◽  
B. L. Currie ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Sulfur Dioxide ◽  
Consumption Ratio ◽  
Wine Oxidation
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