Figure 1.

COX-1 antibody validation. Top, Western blots of brain extracts from rats (left) and mice (right) probed with a monoclonal antibody against COX-1 protein. Hypothalamic extracts from rats killed 2 h after intravenous injection of saline (Sal) or LPS (2 μg/kg, i.v.) show a single major band migrating at ∼70 kDa, corresponding to the molecular weight of COX-1 monomer. Cortical (left two bands) and hypothalamic (right) extracts from wild-type (wt) mice also display a single band at 70 kDa that is not detected in COX-1 knock-out mice (KO). Both blots were reprobed with β-actin (bottom) to provide a loading control. Bottom, Bright-field micrographs showing COX-1-IR (top row) and COX-2-IR (bottom row) in wild-type mice (wt; left) and COX-1-deficient mice (COX-1^−/−; right) killed 3 h after LPS injection (100 μg/kg, i.p.). Wild-type mice display COX-1-IR in vascular and parenchymal cells, whereas no labeling is observed in knock-out mice. Both genotypes display qualitatively similar labeling for COX-2 in vascular cells only. These findings indicate that the COX-1 antiserum does not cross-react with the structurally related COX-2 enzyme. Scale bar, (bottom 4 panels) 50 μm.