ABSTRACT
Brain hemorrhage includes subarachnoid and intracerebral hemorrhage. The aim of surgically produced brain hemorrhage in animals is to model the neurobiological effects of brain hemorrhage in humans. Acute ischemic brain injury and reduced cerebral blood flow (CBF) after subarachnoid hemorrhage (SAH) are the most important factors leading to a poor outcome after hemorrhage. The damage from SAH is similar to other brain injuries leading to secondary injuries that disturb intracranial dynamics, including increased intracranial pressure, decreased CBF, and disordered cerebral metabolism. The technique of injecting collagenase into the brain to produce intracerebral hemorrhage model is based on the function of the matrix metalloproteinases (MMPs) family. Collagenase occurs in an inactive form in cells; brain injury induces collagenase release and activation, which leads to digestion of the extracellular matrix. The microglia, astrocytes, and endothelial cells in the brain can secrete MMPs and serine proteases.
