Figure 5.

Resorcinol-based CB2R agonist inhibits leukocyte adhesion in ascending postcapillary venules. A, Representative images of 3D reconstructions of z stacks taken by multicolor two-photon intravital microscopy using animals with the indicted experimental conditions. The intraparenchymal microvasculature of the brain cortex (down to 800 μm below the cortex surface) was outlined by intravenous injection of 70 kDa FITC-conjugated dextrans (green). Leukocytes were fluorescently labeled by intravenous injection of rhodamine 6G (red). Leukocyte adhesion events were identified in ascending postcapillary venules ranging from 20 to 30 μm in diameter. In untreated control animals, only moving leukocytes were apparent (streaking cells; asterisks). Animals where LPS (6 mg/kg) was administered showed significant leukocyte adhesion (arrows). Insets, Maximum projection composites providing a top view of the z stack. Scale bars: 40 μm. B, The results of particle counting, providing a measure of the number of attached leukocytes per vessel surface area (assuming cylindrical dimensions and using 100 μm of vessel length). The results are shown as the mean adhesion ± SEM (n = 3). *p < 0.001 [difference between the groups compared (bracket)].