Lipocortin-1 immunoreactivity in the normal human central nervous system and lesions with astrocytosis

The authors have examined the cellular distribution of lipocortin-1 (L-1) in the normal and diseased central nervous system (CNS) using the peroxidase-antiperoxidase (PAP) technique with a polyclonal antibody specific for L-1. L-1 immunoreactivity was evaluated in the frontal cortex, parahippocampal gyrus/lateral ventricle, cerebellum, medulla, and spinal cord from 27 normal human fetuses, neonates, and adults without neurologic disease and in these same regions and representative lesions from 35 patients with diseases producing varying degrees of astrocytosis, including intraparenchymal hemorrhage; embolic, thrombotic, or traumatic infarctions; and Alzheimer's disease (AD). L-1 immunoreactivity was identified in ependymocytes, choroid plexus epithelia, and scattered subependymal astrocytes throughout the ventricular system from 15 weeks gestation through 82 years of age in both normal and diseased CNSs. L-1 immunoreactivity was also detected in reactive astrocytes and many macrophages surrounding each infarction regardless of site or pathogenesis and in scattered reactive astrocytes in people with AD or SDAT. The limited distribution of L-1 in CNS is consistent with the low amounts of L-1 found in brain and suggests that L-1 may participate in the normal function of ependymocytes and the pathophysiology of reactive astrocytosis.