scholarly journals Treatment of Rats With Hypolipidemic Compound Pirinixic Acid Protects Their Hearts Against Ischemic Injury: Are Mitochondrial KATP Channels and Reactive Oxygen Species Involved?

2013 ◽  
pp. 577-584 ◽  
Author(s):  
M. NEMČEKOVÁ ◽  
S. ČARNICKÁ ◽  
M. FERKO ◽  
M. MURÁRIKOVÁ ◽  
V. LEDVÉNYIOVÁ ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Rat Heart ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Katp Channels ◽  
Ros Generation ◽  
Peroxisome Proliferator ◽  
Oxygen Species ◽  
Protective Effects ◽  
Mitochondrial Katp Channels

Hypolipidemic compound pirinixic acid (WY-14643, WY) is known to exert pleiotropic (other than primary) effects, such as activation of peroxisome proliferator-activated receptors (PPAR-α), transcription factors regulating different cardiac functions. Their role in ischemia-reperfusion (I/R) injury and cardioprotection is less clear, although protective effects of PPAR agonists have been documented. This study was designed to explore the effects of WY on the I/R injury in the rat heart and potential mechanisms involved, including mitochondrial KATP channels (mitoKATP) opening and production of reactive oxygen species (ROS). Langendorff-perfused hearts of rats intragastrally treated with WY (3 mg/kg/day) for 5 days and of control animals were subjected to 30-min global ischemia and 2-h reperfusion with or without 15-min perfusion with mitoKATP blocker 5-hydroxydecanoate (5-HD) prior to I/R. Evaluation of the infarct size (IS, TTC staining) served as the main end-point of protection. Lipid peroxidation (a marker of ROS production) was determined by measurement of myocardial concentration of conjugated dienes (CD), whereas protein expression of endothelial NO synthase was analysed by Western blotting. A 2-fold increase in the cardiac protein levels of eNOS after treatment with WY was accompanied by lower post-I/R levels of CD compared with those in the hearts of untreated controls, although WY itself enhanced ROS generation prior to ischemia. IS was reduced by 47 % in the hearts of WY-treated rats (P<0.05), and this effect was reversed by 5-HD. Results suggest that PPAR-α activation may confer protection against lethal I/R injury in the rat heart that involves up-regulation of eNOS, mitoKATP opening and reduced oxidative stress during I/R.

scholarly journals Protection against ischemia-induced ventricular arrhythmias and myocardial dysfunction conferred by preconditioning in the rat heart: involvement of mitochondrial KATP channels and reactive oxygen species

2009 ◽  
pp. 9-19 ◽  
Author(s):  
J Matejíková ◽  
J Kucharská ◽  
M Pintérová ◽  
D Pancza ◽  
T Ravingerová
Keyword(s):  
Reactive Oxygen Species ◽  
Rat Heart ◽  
Ventricular Arrhythmias ◽  
Myocardial Dysfunction ◽  
Reactive Oxygen ◽  
Katp Channels ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Mitochondrial Katp Channels

Ischemic preconditioning (I-PC) induced by brief episodes of ischemia and reperfusion (I/R) protects the heart against sustained I/R. Although activation of mitochondrial KATP channels (mitoKATP) interacting with reactive oxygen species (ROS) has been proposed as a key event in this process, their role in the antiarrhythmic effect is not clear. This study was designed: 1) to investigate the involvement of mito KATP opening in the effect of I-PC (1 cycle of I/R, 5 min each) on ventricular arrhythmias during test ischemia (TI, 30-min LAD coronary artery occlusion) in Langendorff-perfused rat hearts and subsequent postischemic contractile dysfunction, and 2) to characterize potential mechanisms of protection conferred by I-PC and pharmacological PC induced by mito KATP opener diazoxide (DZX), with particular regards to the modulation of ROS generation. Lipid peroxidation (an indicator of increased ROS production) was determined by measurement of myocardial concentration of conjugated dienes (CD) and thiobarbituric acid reactive substances (TBARS) in nonischemic controls, non-preconditioned and preconditioned hearts exposed to TI, I-PC alone, as well as after pretreatment with DZX, mito KATP blocker 5-hydroxydecanoate (5-HD) and antioxidant N-acetylcysteine (NAC). Total number of ventricular premature beats (VPB) that occurred in the control hearts (518±71) was significantly (P<0.05) reduced by I-PC (195±40), NAC (290±56) and DZX (168±22). I-PC and NAC suppressed an increase in CD and TBARS caused by ischemia indicating lower production of ROS. On the other hand, I-PC and DZX themselves moderately enhanced ROS generation, prior to TI. Bracketing of I-PC with 5-HD suppressed both, ROS production during PC and its cardioprotective effect. In conclusion, potential mechanisms of protection conferred by mito KATP opening in the rat heart might involve a temporal increase in ROS production in the preconditioning phase triggering changes in the pro/antioxidant balance in the myocardium and attenuating ROS production during subsequent prolonged ischemia.

Anesthetic Preconditioning Improves Adenosine Triphosphate Synthesis and Reduces Reactive Oxygen Species Formation in Mitochondria after Ischemia by a Redox Dependent Mechanism

2003 ◽  
Vol 98 (5) ◽  
pp. 1155-1163 ◽  
Author(s):  
Enis Novalija ◽  
Leo G. Kevin ◽  
Janis T. Eells ◽  
Michele M. Henry ◽  
David F. Stowe
Keyword(s):  
Reactive Oxygen Species ◽  
Cardiac Function ◽  
Adenosine Triphosphate ◽  
Reactive Oxygen ◽  
Atp Synthesis ◽  
Ros Generation ◽  
Oxygen Species ◽  
Protective Effects ◽  
Anesthetic Preconditioning ◽  
Species Formation

Background Mitochondrial changes that characterize the heart after anesthetic preconditioning (APC) or the mechanisms by which mitochondrial triggering factors lead to protection are unknown. This study hypothesized that generation of reactive oxygen species (ROS) during APC is required to initiate the mitochondrial protective effects, and that APC leads to improved mitochondrial electron transport chain function and cardiac function during reperfusion. Methods Isolated guinea pig hearts were subject to 30 min ischemia and 120 min reperfusion. Prior to ischemia hearts were either untreated (I/R), or treated with sevoflurane (APC), in the presence or absence of the ROS scavenger tiron (TIR), or the superoxide dismutase mimetic MnTBAP (TBAP). Intracellular ROS were measured by spectrofluorometry using the fluorescent probe dihydroethidium (DHE). In another series of experiments, using the same protocol, hearts were reperfused for only 5 min and removed for measurement of adenosine triphosphate (ATP) synthesis by luciferin-luciferase luminometry and ROS generation by dichlorohydro-fluorescein (DCF) fluorescence in isolated mitochondria. Results The APC improved cardiac function and reduced infarction. Tiron or MnTBAP abrogated the protection afforded by APC. Mitochondrial ATP synthesis was decreased by 70 +/- 3% after IR alone, by only 7 +/- 3% after APC, by 69 +/- 2% after APC+TIR, and by 71 +/- 3% after APC + TBAP. Mitochondrial ROS formation (DCF) increased by 48 +/- 3% after IR alone, by 0 +/- 2% after APC, by 43 +/- 4% after APC + TIR, and by 46 +/- 3% after APC + TBAP. ROS generation (DHE) was increased in I/R group at 5 and 120 min reperfusion. This was attenuated by APC but this protective effect was abrogated in APC + TIR and APC + TBAP groups. Conclusions The results indicate that ROS are central both in triggering and mediating APC, and that the mitochondrion is the target for these changes.

Mitochondrial KATP channels-derived reactive oxygen species activate pro-survival pathway in pravastatin-induced cardioprotection

APOPTOSIS ◽  
2010 ◽  
Vol 15 (6) ◽  
pp. 669-678 ◽  
Author(s):  
Luong Cong Thuc ◽  
Yasushi Teshima ◽  
Naohiko Takahashi ◽  
Yasuko Nagano-Torigoe ◽  
Kaori Ezaki ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Katp Channels ◽  
Oxygen Species ◽  
Survival Pathway ◽  
Mitochondrial Katp Channels

scholarly journals TRPC1 Deficiency Exacerbates Cerebral Ischemia/Reperfusion-Induced Neurological Injury by Potentiating Nox4-Derived Reactive Oxygen Species Generation

2018 ◽  
Vol 51 (4) ◽  
pp. 1723-1738 ◽  
Author(s):  
Ning Xu ◽  
Hao Meng ◽  
Tianyi Liu ◽  
Yingli Feng ◽  
Yuan Qi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Nadph Oxidase ◽  
Severity Score ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Neurological Injury ◽  
Ros Generation ◽  
Oxygen Species ◽  
Neurological Severity Score

Background/Aims: Transient receptor potential cation channel 1 (TRPC1)-mediated the calcium (Ca2+) influx plays an important role in several brain disorders. However, the function of TRPC1 in ischemia/reperfusion (I/R)-induced neurological injury is unclear. Methods: Wild-type or TRPC1 knockout mice underwent middle cerebral artery occlusion for 90 min followed by 24 h of reperfusion. In an in vitro study, neuronal cells were treated with oxygen–glucose deprivation and reoxygenation (OGD/R) to mimic I/R. The intracellular Ca2+ concentration [Ca2+]i was measured by Fura 2-AM under a microscope. Cerebral infarct volume was measured by triphenyltetrazolium chloride staining. Neurological function was examined by neurological severity score, Morris water maze test, rotarod test and string test. Oxidative parameters were detected by malondialdehyde, glutathione peroxidase, and superoxide dismutase commercially available kits. The protein expression levels of TRPC1, Nox4, p22phox, p47phox, and p67phox were analyzed by western blotting. Results: Brain tissues from cerebral I/R mice showed decreased TRPC1 expression. Similarly, TRPC1 expression was reduced in HT22 cells upon exposure to OGD/R treatment, followed by decreased Ca2+ influx. However, TRPC1 overexpression reversed the OGD/R-induced decrease in [Ca2+]i. TRPC1 knockout significantly exacerbated I/R-induced brain infarction, edema, neurological severity score, memory impairment, neurological deficits, and oxidative stress. In contrast, TRPC1 upregulation inhibited the increase in reactive oxygen species (ROS) generation induced by OGD/R. Analysis of key subunits of the Nox family and mitochondrial ROS revealed that the effects of TRPC1 downregulation on oxidative stress were associated with activation of Nox4-containing NADPH oxidase. TRPC1 interacted with Nox4 and facilitated Nox4 protein degradation under OGD/R conditions. In addition, TRPC1 inhibition potentiated the OGD/R-induced translocation of p47phox and p67phox as well as the interaction between Nox4 and p47phox or p67phox, whereas TRPC1 overexpression had the opposite effects. Conclusion: TRPC1 deficiency potentiates ROS generation via Nox4-containing NADPH oxidase, which exacerbates cerebral I/R injury. TRPC1 may be a promising molecular target for the treatment of stroke.

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