Immunofluorescence microscopy showed a significant reduced fluorescent staining for caspase 3 in smooth muscle from blood vessels. Lung tissue sections from guinea pig were incubated with rabbit polyclonal anti-caspase 3 antibody, followed by FITC-labeled goat anti-rabbit IgG. Nuclei were counterstained with DAPI and they are shown in blue. Caspase 3 positive (apoptotic) cells are uniformly distributed in bronchi either in samples from model asthma or control (upper panels observed by 40x magnification) as well as in blood vessel from control (medium panel, 20x magnification). In contrast, a significant decrease of apoptotic cells in blood vessel smooth muscle cells is observed in asthma model. Representative images of at least two independent experiments. * corresponds to smooth muscle bands in bronchi and lung vessels.