Estratégias de neuroproteção em diferentes modelos de acidente vascular encefálico: avaliação do dano neuromotor e estresse oxidativo estriatal

Abstract

The stroke is one of the leading causes of death and disability worldwide, and is divided into two subtypes: ischemic, caused by a decreased on blood flow; and hemorrhagic, characterized by leakage of blood in brain tissue. Considering the high mortality rate and severity of post stroke sequelae, it is extremely important to search for therapeutic targets aimed at reducing the consequences caused by ischemic and hemorrhagic frames. Thus, this study investigated the neuroprotective effects of physical exercise (8 weeks prior to injury) in an ischemic stroke modle (by bilateral occlusion of the common carotid arteries) and the neuroprotective effects of apocynin (after the injury - 2, 6 and 24 hours - at a dose 0.5 mg/kg) in a hemorrhagic stroke model (by collagenase infusion into the striatum) in Wistar rats. Open Field (OF), Rotarod (RR) and Neurologic Disabilities Scale (NDS) were used to evaluate the motor function of the animals. To the striatal redox balance evaluation we assessed the presence of ROS, TBARS (reactive species to thiobarbituric acid) and total antioxidant capacity (FRAP). Our results showed that physical exercise is a partially effective strategy to protect against ischemic stroke. However, apocynin was not an effective neuroprotective strategy in a experimental model of hemorrhagic stroke. These results show the possibility of using exercise as a neuroprotective strategy. The apocynin need to be better studied in cases of hemorrhagic stroke, whereas the investigation of its mechanism, dosages and times of administration.