Cellular and Molecular Bases of the Initiation of Fever
Figure 4
Identification of the Pulmonary and Hepatic Cells Producing PGE2 at the Onset of LPS Fever in Rats
Immunolocalization of COX-2 in the lung and liver and identification of the cell types expressing this enzyme. Top row: tissue localization of COX-2 (green immunofluorescence) in the lung and liver of rats at 40 min after i.v. injection of saline or at the onset of the first febrile phase (i.e., 40 min after i.v. injection of LPS, 10 μg/kg) at thermoneutrality. Next rows: dual localization of LPS-induced COX-2–immunoreactivity (green; left column) with either the macrophage marker ED2 or the endothelial cell marker RECA1 (red; middle column) in the lung and liver at the onset of the first febrile phase. Doubly labeled cells appear yellow in the merged confocal images (right column). White arrows and black arrowheads mark examples of doubly and singly (COX-2 only) labeled cells, respectively. Scale bars represent 40 μm.