Immunohistochemical Localization of Plasminogen Activator Inhibitor-1 in Rat and Human Brain Tissues

We investigated immunohistochemically the localization of type 1 plasminogen activator inhibitor (PAI-1) in rat and human brain tissues. In rat, neurons and astrocytes were stained positively for PAI-1 after colchicine treatment. In post-mortem human brain, neurons were stained for PAI-1 but the number of positive neurons varied greatly from case to case. PAI-1 positive astrocytes occurred in the white matter lesions of some patients. In Alzheimer's disease, weak PAI-1 labeling was seen in association with senile plaques and ghost tangles. The present results support a notion that PAI-1 and its target proteases such as plasminogen activators and thrombin are involved in a variety of physiological and pathological processes in brain.