Age-related responses of brain mitochondria to ischaemic stroke

Introduction: The increased risk of ischaemic stroke is related to aging. Previously we reported that ischemia inhibits mitochondrial respiration, but ischemia- induced MPTP does not cause the release of cytochrome c. The inhibition of MPTP formation just partly protected against necrosis. Methods: In this study, we evaluated 90 min. ischemia-effect on mitochondrial respiration and, calcium retention capacity (CRC) in the 7 days, 2-3, 10 and 24 month rats cerebellum characterised as neurons rich region and cerebral cortex as astrocytes rich region. Results: We found that ischaemia caused persistent inhibition of respiration of mitochondria isolated from cortex at all ages of animals. However, CRC of cortical mitochondria was decreased after ischaemia only 2-24 months rats, whereas neonatal mitochondrial CRC has no statistically significant difference from control. Ischaemia induced inhibition of cerebellar mitochondrial respiration at the age of 7 days, 2-3 and 24 months, whereas CRC after ischaemia decreased only in mitochondria from cerebellum of 10-24 months rats. Conclusion: Altogether data suggest that ischaemia induced injuries to mitochondria are related with age of the animal and region of the brain. . [...].