scholarly journals Methylene blue improves mitochondrial respiration and decreases oxidative stress in a substrate-dependent manner in diabetic rat hearts

2017 ◽  
Vol 95 (11) ◽  
pp. 1376-1382 ◽  
Author(s):  
Oana M. Duicu ◽  
Andreea Privistirescu ◽  
Adrian Wolf ◽  
Alexandra Petruş ◽  
Maria D. Dănilă ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Mitochondrial Respiration ◽  
Respiratory Function ◽  
Complex I ◽  
Acute Administration ◽  
Dependent Manner ◽  
Retention Capacity ◽  
Calcium Retention ◽  
Rat Hearts ◽  
Calcium Retention Capacity

Diabetic cardiomyopathy has been systematically associated with compromised mitochondrial energetics and increased generation of reactive oxygen species (ROS) that underlie its progression to heart failure. Methylene blue is a redox drug with reported protective effects mainly on brain mitochondria. The purpose of the present study was to characterize the effects of acute administration of methylene blue on mitochondrial respiration, H2O2 production, and calcium sensitivity in rat heart mitochondria isolated from healthy and 2 months (streptozotocin-induced) diabetic rats. Mitochondrial respiratory function was assessed by high-resolution respirometry. H2O2 production and calcium retention capacity were measured spectrofluorimetrically. The addition of methylene blue (0.1 μmol·L−1) elicited an increase in oxygen consumption of mitochondria energized with complex I and II substrates in both normal and diseased mitochondria. Interestingly, methylene blue elicited a significant increase in H2O2 release in the presence of complex I substrates (glutamate and malate), but had an opposite effect in mitochondria energized with complex II substrate (succinate). No changes in the calcium retention capacity of healthy or diabetic mitochondria were found in the presence of methylene blue. In conclusion, in cardiac mitochondria isolated from diabetic and nondiabetic rat hearts, methylene blue improved respiratory function and elicited a dichotomic, substrate-dependent effect on ROS production.

scholarly journals Effects of aging on mitochondrial hydrogen peroxide emission and calcium retention capacity in rat heart

2018 ◽  
Vol 14 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Mi-Hyun No ◽  
Jun-Won Heo ◽  
Su-Zi Yoo ◽  
Han-Sam Jo ◽  
Dong-Ho Park ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Rat Heart ◽  
Retention Capacity ◽  
Calcium Retention ◽  
Effects Of Aging ◽  
Calcium Retention Capacity

scholarly journals Chloride channel blocker IAA-94 increases myocardial infarction by reducing calcium retention capacity of the cardiac mitochondria

Life Sciences ◽  
2019 ◽  
Vol 235 ◽  
pp. 116841 ◽  
Author(s):  
Devasena Ponnalagu ◽  
Ahmed Tafsirul Hussain ◽  
Rushi Thanawala ◽  
Jahnavi Meka ◽  
Piotr Bednarczyk ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Chloride Channel ◽  
Channel Blocker ◽  
Cardiac Mitochondria ◽  
Retention Capacity ◽  
Calcium Retention ◽  
Chloride Channel Blocker ◽  
Calcium Retention Capacity

scholarly journals Opposing effects of nitric oxide and prostaglandin inhibition on muscle mitochondrial V̇o2 during exercise

2012 ◽  
Vol 303 (1) ◽  
pp. R94-R100 ◽  
Author(s):  
Robert Boushel ◽  
Teresa Fuentes ◽  
Ylva Hellsten ◽  
Bengt Saltin
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Ex Vivo ◽  
Knee Extension ◽  
Physiological Effect ◽  
Dependent Manner ◽  
Concentration Dependent Manner

Nitric oxide (NO) and prostaglandins (PG) together play a role in regulating blood flow during exercise. NO also regulates mitochondrial oxygen consumption through competitive binding to cytochrome- c oxidase. Indomethacin uncouples and inhibits the electron transport chain in a concentration-dependent manner, and thus, inhibition of NO and PG synthesis may regulate both muscle oxygen delivery and utilization. The purpose of this study was to examine the independent and combined effects of NO and PG synthesis blockade (l-NMMA and indomethacin, respectively) on mitochondrial respiration in human muscle following knee extension exercise (KEE). Specifically, this study examined the physiological effect of NO, and the pharmacological effect of indomethacin, on muscle mitochondrial function. Consistent with their mechanism of action, we hypothesized that inhibition of nitric oxide synthase (NOS) and PG synthesis would have opposite effects on muscle mitochondrial respiration. Mitochondrial respiration was measured ex vivo by high-resolution respirometry in saponin-permeabilized fibers following 6 min KEE in control (CON; n = 8), arterial infusion of NG-monomethyl-l-arginine (l-NMMA; n = 4) and Indo ( n = 4) followed by combined inhibition of NOS and PG synthesis (l-NMMA + Indo, n = 8). ADP-stimulated state 3 respiration (OXPHOS) with substrates for complex I (glutamate, malate) was reduced 50% by Indo. State 3 O2 flux with complex I and II substrates was reduced less with both Indo (20%) and l-NMMA + Indo (15%) compared with CON. The results indicate that indomethacin reduces state 3 mitochondrial respiration primarily at complex I of the respiratory chain, while blockade of NOS by l-NMMA counteracts the inhibition by Indo. This effect on muscle mitochondria, in concert with a reduction of blood flow accounts for in vivo changes in muscle O2 consumption during combined blockade of NOS and PG synthesis.

scholarly journals The Effect of Mitochondrial Complex I-Linked Respiration by Isoflurane Is Independent of Mitochondrial Nitric Oxide Production

2018 ◽  
Vol 8 (2) ◽  
pp. 113-122 ◽  
Author(s):  
Fuqi Xu ◽  
Shigang Qiao ◽  
Hua Li ◽  
Yanjun Deng ◽  
Chen Wang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mitochondrial Respiration ◽  
Complex I ◽  
Adenosine Diphosphate ◽  
Sprague Dawley ◽  
No Donor ◽  
Anesthetic Preconditioning ◽  
Rat Hearts ◽  
Nos Inhibitor

Background: Anesthetic preconditioning (APC) of the myocardium is mediated in part by reversible alteration of mitochondrial function. Nitric oxide (NO) inhibits mitochondrial respiration and may mediate APC-induced cardioprotection. In this study, the effects of isoflurane on different states of mitochondrial respiration during the oxidation of complex I-linked substrates and the role of NO were investigated. Methods: Mitochondria were isolated from Sprague-Dawley rat hearts. Respiration rates were measured polarographically at 28ºC with a computer-controlled Clark-type O2 electrode in the mitochondria (0.5 mg/mL) with complex I substrates glutamate/malate (5 mM). Isoflurane (0.25 mM) was administered before or after adenosine diphosphate (ADP)-initiated state 3 respiration. The NO synthase (NOS) inhibitor L-N5-(1-iminoethyl)-ornithine (L-NIO, 10 μM) and the NO donor S-nitroso-N-acetylpenicillamine (SNAP, 1 μM) were added before or after the addition of ADP. Results: Isoflurane administered in state 2 increased state 2 respiration and decreased state 3 respiration. This attenuation of state 3 respiration by isoflurane was similar when it was given during state 3. L-NIO did not alter mitochondrial respiration or the effect of isoflurane. SNAP only, added in state 3, decreased state 3 respiration and enhanced the isoflurane-induced attenuation of state 3 respiration. Conclusion: Isoflurane has clearly distinguishable effects on different states of mitochondrial respiration during the oxidation of complex I substrates. The uncoupling effect during state 2 respiration and the attenuation of state 3 respiration may contribute to the mechanism of APC-induced cardioprotection. These effects of isoflurane do not depend on endogenous mitochondrial NO, as the NOS inhibitor L-NIO did not alter the effects of isoflurane on mitochondrial respiration.

scholarly journals Modification of calcium retention capacity of rat liver mitochondria by phosphate and tert-butyl hydroperoxide

2019 ◽  
pp. 59-65 ◽  
Author(s):  
R. Endlicher ◽  
Z. Drahota ◽  
Z. Červinková
Keyword(s):  
Rat Liver ◽  
Cyclosporine A ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Retention Capacity ◽  
Butyl Hydroperoxide ◽  
Calcium Retention ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide ◽  
Calcium Retention Capacity

By determining the calcium retention capacity (CRC) of rat liver mitochondria, we confirmed and extended previous observations describing the activation of mitochondrial swelling by phosphate and tert-butyl hydroperoxide (t-BHP). Using CRC measurements, we showed that both phosphate and t-BHP decrease the extent of calcium accumulation required for the full mitochondrial permeability transition pore (MPTP) opening to 35 % of control values and to only 15 % when both phosphate and t-BHP are present in the medium. When changes in fluorescence were evaluated at higher resolution, we observed that in the presence of cyclosporine A fluorescence values return after each Ca(2+) addition to basal values obtained before the Ca(2+) addition. This indicates that the MPTP remains closed. However, in the absence of cyclosporine A, the basal fluorescence after each Ca(2+) addition continuously increased. This increase was potentiated both by phosphate and t-BHP until the moment when the concentration of intramitochondrial calcium required for the full opening of the MPTP was reached. We conclude that in the absence of cyclosporine A, the MPTP is slowly opened after each Ca(2+) addition and that this rate of opening can be modified by various factors such as the composition of the media and the experimental protocol used.

scholarly journals Low-intensity treadmill exercise protects cognitive impairment by enhancing cerebellar mitochondrial calcium retention capacity in a rat model of chronic cerebral hypoperfusion

2021 ◽  
Vol 17 (5) ◽  
pp. 324-330
Author(s):  
Jae-Min Lee ◽  
Jongmin Park ◽  
Joo-Hee Lee ◽  
Hyo-Bum Kwak ◽  
Mi-Hyun No ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Treadmill Exercise ◽  
Neuroprotective Effect ◽  
Cerebral Hypoperfusion ◽  
Mitochondrial Calcium ◽  
Retention Capacity ◽  
Calcium Retention ◽  
Cerebellar Purkinje Cells ◽  
The Brain ◽  
Calcium Retention Capacity

Chronic cerebral hypoperfusion (CCH) is caused by reduced blood flow to the brain representing gradually cognitive impairment. CCH induces mitochondrial dysfunction and neuronal cell death in the brain. Exercise is known to have a neuroprotective effect on brain damage and cognitive dysfunction. This study aimed to clarify the neuroprotective effect of low-intensity treadmill exercise (LITE) by enhancing cerebellar mitochondrial calcium retention capacity in an animal model of CCH. Wistar rats were divided into the sham group, the bilateral common carotid arteries occlusion (BCCAO) group, and the BCCAO and treadmill exercise (BCCAO+Ex) group. BCCAO+Ex group engaged the LITE on a treadmill for 30 min once a day for 8 weeks before the BCCAO surgery to investigate the protective effect of LITE on cognitive impairment. CCH induced by BCCAO resulted in mitochondrial dysfunction in the cerebellum, including impaired calcium homeostasis. CCH also decreased cerebellar Purkinje cells including of calbindin D28k and parvalbumin, resulting in cognitive impairment. The impairment of mitochondrial function, loss of cerebellar Purkinje cells, and cognitive dysfunction ameliorated by exercise. The present study showed that LITE hindered the deficit of spatial working memory and loss of Purkinje cell in the cerebellum induced by CCH. We confirmed that the protective effect of LITE on Purkinje cell by enhanced the mitochondrial calcium retention capacity. We suggest that LITE may protect against cognitive impairment, and further studies are needed to develop the intervention for patients who suffered from CCH.

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