Vitronectin (serum spreading factor): its localisation in normal and fibrotic tissue

The distribution of vitronectin and fibronectin in normal and fibrotic tissue was directly compared using indirect immunofluorescence. Both glycoproteins were ubiquitiously localised to loose connective tissue. Vitronectin, unlike fibronectin, was not detected in basement membranes, in normal renal glomeruli, or around smooth muscle cells of both musculares mucosae and propria of the gastrointestinal tract. The presence of vitronectin could not be shown in washed permeabilised platelets. Vitronectin was very much increased in reactive and fibrotic tissue, as was fibronectin. This was observed in lymph nodes affected by both nodular sclerosing Hodgkin's disease and by metastatic carcinoma as well as in myelofibrotic bone marrow and sclerotic glomeruli. These findings suggest that vitronectin may have an important role in the processes of inflammation and repair.