IMMUNOHISTOCHEMICAL LOCALIZATION OF MACROPHAGE-MIGRATION INHIBITORY FACTOR (MIF) IN TANYCYTES, SUBCOMMISSURAL ORGAN AND CHOROID-PLEXUS IN THE RAT-BRAIN

We investigated the immunohistochemical localization of the macrophage migration inhibitory factor (MIF) in the rat brain. in addition to ep ithelial ependymal cells lining the ventricular wall, tanycytes in the basomedial hypothalamus were heavily immunostained. The immunoreactiv e processes of tanycytes made contacts to sinusoidal capillaries and r eached the pial surface forming an immune-positive structure at the fl oor of the hypothalamus. Other immunoreactive cells contained the subc ommissural organ in the roof of the third ventricle and the epithelial lamina of the choroid plexus. The localization of MIF in cells which have contact with cerebrospinal fluid and blood vessels suggests that MIF might play a role as a humoral factor in the brain.