Antiapoptotic Effects of Aspirin on CA1 Pyramidal Neurons in Adult Rats

  Background and Objective: As one of the widely used drugs, aspirin (acetyl-salicylic acid, ASA) plays an important role in stroke treatment and prevention. In a previous study, we demonstrated ASA injection at 30 min after ischemia onset is neuroprotective. To determine whether the neurons protected by ASA had a normal ultrastructure, hippocampal CA1 pyramidal neurons were examined by Transmission Electron Microscope (TEM). Material and Methods: Adult male wistar rats were divided into three different groups (6 animals/group): Sham-operated, control (48 MCAO+vehicle) and aspirin (48 MCAO + ASA).  ASA (30 mg/kg) was injected 30 min after ischemia onset. The animals were killed 2 days after ischemia induction and their brain removed, processed, and examined under a TEM. Results: Apoptotic changes were observed in rats not treated with ASA. In contrast, pyramidal neuron ultrastructure appeared normal in rats that exhibited neuroprotection (defined at the light microscope level) by ASA when studied two days after ischemia. Conclusion: We conclude that administration of ASA after permanent focal cerebral ischemia remains a considerable therapeutic strategy.