Background: Preconditioning to ischemia is a phenomenon whereby a brief episode of sublethal ischemia and other nonlethal stressors produce protection against a subsequent detrimental ischemic insult. As mitochondrial dysfunction is related to necrotic and apoptotic neuronal death after cerebral ischemia, the authors examined if ischemic preconditioning is capable of inducing mitochondrial tolerance.
Methods: Forebrain ischemia was induced by bilateral common carotid artery occlusion with simultaneous hypotension for 8 min in Wistar rats (275-300 g). A 3-min ischemic episode performed 48 h before the 8-min ischemia was used for preconditioning. The extents of hippocampal CA1 neuronal damage were evaluated 7 days after reperfusion by neuro-specific nuclear protein immunostaining. Brain mitochondria were isolated 48 h after animals were subjected to the sham operation or the 3-min conditioning ischemia. Loss of cytochrome c from mitochondria after cerebral ischemia in vivo and after exposure of brain mitochondria to calcium in vitro was used as an indication of mitochondrial dysfunction.
Results: Results showed that ischemic preconditioning induced by a 3-min ischemic episode dramatically reduced the loss of hippocampal CA1 neurons resulting from a subsequent 8-min ischemia 7 days after reperfusion, and this protection was associated with a preservation of mitochondrial cytochrome c as examined after early reperfusion. Exposure of isolated brain mitochondria to calcium produced a dose-dependent increase in cytochrome c release either at 30 degrees C or at 37 degrees C. Compared with those animals receiving only sham operation, cytochrome c release caused by 100 microm calcium was significantly reduced in conditioned animals.
Conclusion: Regarding the importance of mitochondrial dysfunction in mediating ischemic neuronal death, the above results indicate that mitochondria may serve as end-effecting organelles to ischemic preconditioning.
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http://dx.doi.org/10.1097/00000542-200210000-00022 | DOI Listing |
Med Gas Res
June 2025
Department of Hyperbaric Oxygen, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
Common cardiovascular surgeries include coronary artery bypass grafting, cardiac valve replacement, radiofrequency ablation, and cardiac intervention surgery. Multiple postoperative complications, such as hypoxic encephalopathy, air embolism, retained intracardiac air, cognitive dysfunction and major adverse cardiovascular events, including heart failure, ischemic stroke, and myocardial infarction, may occur after these cardiovascular surgeries. Hyperbaric oxygen can be used in preconditioning to lower the morbidity of adverse complications.
View Article and Find Full Text PDFFree Radic Biol Med
January 2025
Department of Anesthesiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi People's Hospital, Wuxi Medical Center, Nanjing Medical University, Wuxi, Jiangsu, 214023, China. Electronic address:
Remote ischemic preconditioning (RIPC) induces the expression of unidentified protective cytokines that mitigate lung ischemia-reperfusion injury (LIRI). This study hypothesizes that MOTS-c, a mitokine with potent protective effects against mitochondrial damage, contributes to RIPC-mediated protection by alleviating endothelial barrier dysfunction. In human lung transplantation patients, serum levels of MOTS-c significantly decreased following IR injury but were markedly increased when RIPC was performed prior to transplantation.
View Article and Find Full Text PDFBrain Res
January 2025
The Second Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 15000, China. Electronic address:
Objectives: Exercise as a non-pharmacological intervention can exert beneficial effects directly through exosomes crossing the blood-brain barrier and reduce apoptosis after cerebral ischaemia/reperfusion injury (CI/RI). miRNA-124 (miR-124) is present in exosomes and plays an important role in regulating cerebral neurological activity; however, the mechanism of the relationship between exercise and the activity of exosomes and apoptosis after CI/RI remains unclear. Therefore, the present study investigated the effects of exercise preconditioning on cerebral ischemia/reperfusion injury from the perspective of exosomal miR-124 and apoptosis.
View Article and Find Full Text PDFEur J Appl Physiol
January 2025
Beijing Sport University, No. 48 Xinxi Road, Haidian District, Beijing, 100084, China.
J Appl Physiol (1985)
January 2025
Department of Kinesiology, Health Promotion and Recreation, University of North Texas, Denton, Texas, USA.
Remote Ischemic Preconditioning (RIPC) is a therapy characterized by repeated bouts of limb ischemia and reperfusion. RIPC protects against ischemia-reperfusion injury (IRI), and preclinical studies suggest that this is mediated through release of endogenous opioids. We aimed to interrogate the role of endogenous opioids in RIPC-signaling in humans, using an arm model of IRI.
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