Intermediate filament proteins in developing human arteries

The distribution of intermediate filament proteins in adult human blood ves sels and in human fetal elastic arteries is relatively well-known. However, the distribution of these proteins in the course from neonate to adult has not been established. In this investigation, human postnatal arteries were studied with immunohistochemistry, using antibodies targeted on the interm ediate filament proteins desmin, vimentin and cytokeratins 8, 18 and 19. Vi mentin was present in most smooth muscle cells in all vessels and at all ag es. The proportions of desmin-expressing cells increased in the elastic art eries during the first year of life and was higher in the pulmonary trunk t han in the aorta. In the muscular arteries, the proportion of desmin-labell ed cells increased in the coronary and the deep femoral arteries, but remai ned constant in the renal and the cerebral arteries. Cytokeratins were dete cted in the pulmonary trunk earlier than in the aorta. Cytokeratins were pr esent throughout the wall of the ductus arteriosus, but desmin was present only in some cells. Thus, there are postnatal changes in the distribution o f intermediate filament proteins in the elastic arteries and in some muscul ar arteries, whereas the intermediate filament pattern remains unchanged in other muscular arteries.