Changes of rat’s brain vesseles after air shock wave exposure

Abstract

Mild blast-induced traumatic brain injury is common among the military, resulting in cognitive impairment, reduced socialization, which leads to disability and, as a result, a deterioration in the quality of life. It is considered that blood-brain barrier disruption and microvascular dysfunction are the key to this type of injury. The purpose of study was to study changes in brain vessels after air shock wave exposure. The study was carried out on 48 mature male Wistar rats, which were randomly divided into 2 groups: an experimental group, in which animals were subjected to inhalation anesthesia using halothane and exposed to a shock wave with an overpressure of 26.4±3.6 kPa, and a Sham group. After simulation of injury on days 1st, 3rd, 7th, 14th, and 21st, the rats were euthanized and the brain was removed and after all subjected to standard histological procedures and stained with hematoxylin and eosin. For immunohistochemical studies, as primary antibodies were used eNOS. The finished preparations were examined by light microscopy and photographed. Disorders of the cerebral vessels in experimental rats were detected from day 1st of the posttraumatic period. It was found that the blast wave led to vascular rupture, as well as increased vascular permeability with diapedesis of red blood cells and cerebral edema for up to 21st days. Focal violations of the vascular wall integrity in cortical and hippocampal hemocapillaries, venular link of the submembrane vessels; changes in the morphology of the metabolic vessels endothelium; uneven blood filling of the brain vessels were of major importance. These changes indicate that increased eNOS expression leads to dilation of cerebral vessels, which is a compensatory mechanism in response to injury to improve cerebral blood circulation. However, eNOS is not involved in vasodilation, which we observed up to 21st day post-trauma.