The stress-related changes in the cerebral blood flow in newborn rats with intracranial hemorrhage: metabolic and endothelial mechanisms

Neonatal brain hemorrhages is a major problem of future generation’s health due to the high rate of cognitive disability of newborns after vascular catastrophes in the brain. Despite the public health impact of neonatal brain hemorrhages, the mechanisms underlying in these pathological processes remain unknown. Here, using a model of sound-stress-induced brain hemorrhages (per diapedesis, no per rhexis) in newborn rats and optical methods, we found that brain hemorrhages in newborn rats are accompanied by the increase in perfusion of brain tissues, which closely associated with reducing of cerebral oxygenation and increasing of nitric oxide production in both the brain tissues and blood. We assume that nitric oxide contributes the dilation of cerebral vessels during hypoxia and the increasing of cerebral blood flow in newborn rats with brain hemorrhages. Hypoxic-hyperperfusion during stress-related hemorrhages in newborn animals can be an important protective mechanism against anoxia and critical changes in cerebral hemodynamics.