scholarly journals Reactive nitrogen and oxygen species metabolism in rat heart mitochondria upon administration of NO donor in vivo

2012 ◽  
Vol 58 (2) ◽  
pp. 3-15 ◽  
Author(s):  
OV Akopova ◽  
◽  
IuP Korkach ◽  
AV Kotsiuruba ◽  
LI Kolchyns'ka ◽  
...  
Author(s):  
Olga V. Akopova ◽  
Yulia P. Korkach ◽  
Anatolii V. Kotsuruba ◽  
Lyudmila I. Kolchinskaya ◽  
Vadim F. Sagach

1976 ◽  
Vol 158 (2) ◽  
pp. 289-294 ◽  
Author(s):  
D R Parr ◽  
E J Harris

1. Very low concentrations of Pb2+ decrease the capacity of rat heart mitochondria, oxidizing pyruvate plus malate, to remove Ca2+ from the medium. 2. The primary effect is on the rate of Ca2+ sequestration; this is reflected in the overall extent of Ca2+ removal. 3. Pb2+ has at least two separate actions. Below about 0.5 nmol/mg of protein, it acts solely by competing with Ca2+ (Ki = 0.4 muM); above this concentration it also inhibits the production or use of respiratory energy, so that at 1 nmol of Pb2+/mg of protein, Ca2+ removal is almost completely abolished. 4. Pb2+ inhibits coupled and uncoupled respiratory O2 use by mitochondria oxidizing pyruvate plus malate, but at higher concentrations than those that affect Ca2+ removal; similar concentrations of Pb2+ inhibit pyruvate uptake, but not malate uptake, by the mitochondria. 5. Mg2+ only decreases Ca2+ removal by competition, and is a far-less effective competitor than Pb2+ (Ki = 0.15 mM). It is possible that the primary cause of the second effect of Pb2+ is displacement of membrane Mg2+. 6. The consequences of these results are discussed in terms of the possible involvement of heart mitochondria in excitation-contraction coupling, and the Pb2+ levels that might occur in heart tissue in vivo.


2001 ◽  
Vol 280 (3) ◽  
pp. H977-H983 ◽  
Author(s):  
Ernest A. Boehm ◽  
Barney E. Jones ◽  
George K. Radda ◽  
Richard L. Veech ◽  
Kieran Clarke

The physiological role of mitochondrial uncoupling proteins (UCPs) in heart and skeletal muscle is unknown, as is whether mitochondrial uncoupling of oxidative phosphorylation by fatty acids occurs in vivo. In this study, we found that UCP2 and UCP3 protein content, determined using Western blotting, was increased by 32 and 48%, respectively, in hyperthyroid rat heart mitochondria. Oligomycin-insensitive respiration rate, a measure of mitochondrial uncoupling, was increased in all mitochondria in the presence of palmitate: 36% in controls and 71 and 100% with 0.8 and 0.9 mM palmitate, respectively, in hyperthyroid rat heart mitochondria. In the isolated working heart, 0.4 mM palmitate significantly lowered cardiac output by 36% and cardiac efficiency by 38% in the hyperthyroid rat heart. Thus increased mitochondrial UCPs in the hyperthyroid rat heart were associated with increased uncoupling and decreased myocardial efficiency in the presence of palmitate. In conclusion, a physiological effect of UCPs on fatty acid oxidation has been found in heart at the mitochondrial and whole organ level.


1994 ◽  
Vol 47 (3) ◽  
pp. 549-553 ◽  
Author(s):  
Yu-Chiang Lo ◽  
Teng Che-Ming ◽  
Chen Chieh-Fu ◽  
Chen Chien-Chih ◽  
Hong Chuang-Ye

2007 ◽  
Vol 415 (1) ◽  
pp. 206-210 ◽  
Author(s):  
S. M. Korotkov ◽  
V. P. Nesterov ◽  
L. V. Emel’yanova ◽  
N. N. Ryabchikov

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Sergey M Korotkov ◽  
Vladimir P Nesterov ◽  
Irina V Brailovskaya ◽  
Larisa V Emelyanova ◽  
Svetlana A Konovalova ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document