1. Oxidative stress and mitochondrial dysfunction contributes to postoperative cognitive dysfunction in elderly rats
- Author
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Felipe Dal-Pizzol, Ana Olívia Martins Laurentino, Khiany Mathias, Aloir Neri de Oliveira Junior, Jucélia Jeremias Fortunato, Maria Eduarda Fileti, Gislaine T. Rezin, Naiana da Rosa, Tatiana Barichello, Amanda Della Giustina, Ana Beatriz Costa, Bianca Xavier de Farias, Mariana Pereira de Souza Goldim, Fabricia Petronilho, and Martins Back Netto
- Subjects
Male ,medicine.medical_specialty ,Immunology ,Prefrontal Cortex ,Hippocampus ,Hippocampal formation ,medicine.disease_cause ,Antioxidants ,Lipid peroxidation ,03 medical and health sciences ,Behavioral Neuroscience ,chemistry.chemical_compound ,Cognition ,Postoperative Complications ,0302 clinical medicine ,030202 anesthesiology ,Internal medicine ,medicine ,Animals ,Cognitive Dysfunction ,Rats, Wistar ,Prefrontal cortex ,Memory Disorders ,biology ,Superoxide Dismutase ,Endocrine and Autonomic Systems ,business.industry ,Brain-Derived Neurotrophic Factor ,Age Factors ,Brain ,medicine.disease ,Mitochondria ,Rats ,Disease Models, Animal ,Oxidative Stress ,Mitochondrial respiratory chain ,Endocrinology ,chemistry ,biology.protein ,Creatine kinase ,Lipid Peroxidation ,Cognition Disorders ,business ,Postoperative cognitive dysfunction ,030217 neurology & neurosurgery ,Oxidative stress - Abstract
Postoperative cognitive dysfunction (POCD) is defined by cognitive impairment determined by neuropsychological tests from before to after surgery. Several mechanisms have been proposed in this bidirectional communication between the immune system and the brain after surgery. We aimed at understanding the mechanisms underlying POCD elderly rats in an experimental tibial fracture model. Elderly male Wistar rats were subjected to tibial fracture (TF) model. Control (sham) and fracture (TF) groups were followed to determine nitrite/nitrate concentration; oxidative damage to lipids and proteins; the activity of antioxidant enzymes (superoxide dismutase-SOD and catalase-CAT), mitochondrial respiratory chain enzymes, and creatine kinase (CK); and BDNF levels in the hippocampus and prefrontal cortex (at 24 h and at seven days) and cognitive function through habituation to the open field task and novel object recognition task (only at seven days). TF group presented increased concentration of nitrite/nitrate, hippocampal lipid peroxidation at seven days, protein oxidative damage in the prefrontal cortex and hippocampus at 24 h, decreased antioxidant activity in both structures on the first postoperative day and compromised function of the mitochondrial respiratory chain complexes as well as the CK enzyme. In addition, the levels of BDNF were reduced and memory function was impaired in the TF group. In conclusion, elderly rats submitted to an experimental model of tibial fracture displayed memory impairment accompanied by an increase in oxidative stress, mitochondrial dysfunction and reduced neurotrophin level.
- Published
- 2018