Figure 3.

Basal and regulated COX-1 expression in the cerebral vasculature. Bright-field images of COX-1-immunoreactive labeling of vessels from control (saline-injected) and IL-1- or LPS-challenged rats (both at 2 μg/kg, i.v.) that are otherwise untreated (top row) or in ones pretreated with intracerebroventricular clodronate liposome (Clod-Lips) injection to deplete PVCs (bottom). Under basal conditions, small circular profiles (red arrowheads) are associated with the vessel; the adjoining parenchyma contains more strongly labeled glial-like cells/processes (blue arrowheads). Enhanced COX-1-immunoreactive vascular labeling after IL-1 or LPS challenges takes two forms, one in which the circular (perinuclear-like) labeling seen under basal conditions is more intense and associated with punctate cytoplasmic labeling (red arrowheads and outlines) and the other comprising homogeneously stained round (nuclear-like) profiles (green arrows). In liposome-pretreated rats, cells displaying perinuclear plus cytoplasmic labeling (presumed PVCs) are not seen, whereas labeling of the other cell type (presumed endothelia) is enhanced. Scale bar, 25 μm.